User:Born2flie/Cessna CH-1

Main article: Cessna CH-1

CH-1 Skyhook
CH-1B designated YH-41
Role	Light helicopter
Manufacturer	Cessna
Designer	Richard Ten Eyck
First flight	July 1953
Introduction	1956
Status	Out of production

The Cessna CH-1 is the only helicopter ever built by the Cessna Aircraft Company. The single, twin-bladed main rotor helicopter used a front-mounted reciprocating engine which gave the aircraft a stable center-of-gravity (CG). Its semi-monocoque airframe greatly resembles its light airplane siblings built by Cessna. The helicopter was named Skyhook for the civil market, similar to the marketing names used in the Cessna single engine airplane line, such as Skyhawk, Skylane and Skywagon. The CH-1's military designation for the United States Army was the YH-41 Seneca. The Skyhook would achieve several helicopter "firsts" and set a world record, but ultimately, it would never be a commercial or military success.

Development

Cessna Aircraft Company acquired the Seibel Helicopter Company (pronounced "See-bull") of Wichita, Kansas on 14 January 1952 through a stock swap with Seibel investors. All equipment from the Seibel Helicopter Company, including the Seibel S-4B, was moved to Cessna's Pawnee Plant in Wichita and work began on the CH-1 design during the summer of 1952. Charles Seibel, who became the new Helicopter Division's chief designer as part of the acquisition, believed that the S-4B with a Cessna body would make an excellent helicopter. Cessna pilots test flew Seibel's S-4B for several months to familiarize the engineers with helicopters, and then it was scrapped.

A quarter-size wind tunnel model of the CH-1 was created and tests were conducted at Wichita State University. The first full-size machine did not have an enclosed fuselage or cowling, nor a horizontal stabilizer. This test bed skeleton (referred to by the company as CH1-1) first hovered in July 1953, eventually making test flights as high as 10,000 feet. The actual prototype CH-1 was built based on modifications made to the test bed aircraft and this second ship made its first flight in 1954, at the Prospect plant.

On 9 June 1955, the CH-1 receieved CAA type-certificate 3H10. Originally certified as a two-place helicopter, stability problems at higher gross weights required additional engineering solutions. A larger, free-floating horizontal stabilizer was introduced. During forward flight, the stabilizer pivoted to a variable mechanical stop, which was linked to the fore and aft cyclic control, thereby altering the stabilizer angle of incidence during flight. Reworking the stabilizer permitted the addition of a second row of seating, and the four-place ship, designated the CH-1A, was certificated on 28 February 1956.

CH-1B

In December 1955, Cessna was awaiting a contract to produce a limited number of CH-1s for evaluation by the Army. In preparation for the contract, Cessna began modifying the CH-1A with an upgraded engine and other aerodynamic and structural changes in the possibility of eliciting a production contract. In spring 1956, the Army awarded Cessna with a US$1.1 million contract for 10 test aircraft, designated as the YH-41 Seneca. For marketing purposes, the CH-1A prototype (N5156) was painted in an olive drab Army scheme.

Design

The CH-1 external design was created by Richard Ten Eyck, an industrial designer for Cessna. It was a low profile streamlined aircraft-style body, featuring the engine in front and cabin seating behind the powerplant. The forward engine location provided "ease of access,...efficient cooling, and frees the center of gravity behind the cockpit for use in disposable load," but also presented a problem for how to vent the exhaust which would prove to be a problem throughout the aircraft's life. Additionally, the tail boom size, resulting from the airplane-style fuselage, created aerodynamic problems in hover and forward flight that would have to be solved by later aerodynamic structural changes.

Engine

The prototype CH-1 had a turbocharged Continental FSO-470 engine rated at 260 h.p. at 3200 rpm. The turbocharger and cooling fans were driven by belts. Cessna had a long relationship with Continental who provided engines for their light airplanes, but the use of the Continental engine in a helicopter was considered as much of a test as Cessna's foray into the helicopter market itself, especially in a time when most other light helicopter manufacturers were using Lycoming engines.

Operational history

The CH-1 established many firsts. The CH-1A was the first helicopter to land on Pikes Peak, at an altitude of 14,110 feet on 15 September 1955, it had a higher cruise speed than comparable machines, and a CH-1B, modified with a FSO-526-2X engine, set an official FAI world altitude record for helicopters of 29,777 feet on December 27, 1957. The previous record had been set by a turbine powered Aérospatiale Alouette II and was later broken by another Alouette II, but the record set by the CH-1B remains the highest altitude ever achieved by a piston-powered helicopter. The CH-1C was the first helicopter to receive IFR certification by the FAA.

On 26 December 1962, Cessna decided to entirely eliminate its helicopter program. Among the various reasons cited are continuing design problems, loss of military sales, poor timing for introduction into the market marked by a lack of sales, and competition from turbine-powered models all contributed to a perception that the CH-1 was a poor fit to the Cessna line of aircraft. In January 1963, Dwane Wallace, chairman of the Board, made the announcement. Cessna bought back all of the existing CH-1 aircraft. In 1989, Cessna cancelled the FAA Type Certificate, 3H10.

Variants

CH1-1

test bed machine which did not have a skin, for initial hover and flight testing.

CH-1

The prototype CH-1 was powered by a Continental FSO-470 engine with a 2-place cabin.

CH-1A

Four-seat version of the CH-1 created by solving stability problems presented by the tail boom.

CH-1B

1955 changes to secure an Army contract. Continental FSO-526 engine (derated to 270 hp) with a gear driven supercharger and a horizontal, gear driven cooling fan. An automatic collective pitch reducer lowered the collective pitch in the event of an engine failure.

YH-41A

Two CH-1Bs purchased by the United States Army for evaluation against possible future production contract.

CH-1C

UH-41A

15 CH-1C aircraft purchased by the United States Government for its Military Assistance Program (MAP) to foreign countries.

CH-4

Cessna's entry for the U.S. Army's Light Observation Helicopter program, it was a CH-1C powered by an Allison Model 250 engine mounted behind the rear passenger seat.

CH-1D

CH-1C modified with Continental's "Whirlaway" engine.

Operators

Ecuador

four UH-41A

Iran

five UH-41A, replaced by Bell 205 and Bell 206 aircraft.

United States

• United States Army: 10 YH-41As for evaluation.

Survivors

Approximately 50 machines were built before Cessna ended their venture into helicopters. Most of the aircraft built were bought back and scrapped by Cessna, and the type certificate was revoked, presumably to remove any liability to Cessna for continued operation of any copies they could not retrieve. However, the Army Aviation Museum at Fort Rucker, Alabama has a YH-41A Seneca prototype (serial number 56-4244) as a part of its collection, although it is not currently on display.

Specifications (CH-1C)

Data from {CollectAir.com}

General characteristics

• Crew: One or two pilots
• Capacity: four, including crew
• Length: 42 ft 6 in (12.95 m)
• Height: 8 ft 5 in (2.6 m)
• Empty weight: 2,080 lb (940 kg)
• Gross weight: 3,100 lb (1,400 kg)
• Powerplant: 1 × Continental FSO-526 6-cylinder, supercharged, flat engine , 270 hp (200 kW)
• Main rotor diameter: 35 ft 0 in (11 m)
• Main rotor area: 962 sq ft (89.4 m²)

Further reading

• Lambermont, Paul Marcel. Helicopters and autogyros of the world. London: Cassell, 1958. OCLC 1247556

Related content

Related development

• Seibel S-4

Source Text

The Beginning

Charles Seibel was the Cessna helicopter program. A dynamic engineer, with a 1943 Masters Degree (Engineering - Helicopter Theory) from California Institute of Technology, part genius and part clown, with a very affable nature, but demanding, and with seemingly unbounded energy and enthusiasm for rotary-wing development, Seibel's ideas were meticulously translated into drawings and metal by the small Cessna staff. He encouraged original thinking by his engineers and prodded engineering minds to explore new avenues. Let's take a look at how Seibel (pronounced "See-bull") became part of the Cessna team.

A young engineer at the Gardenville, New York (a suburb of Buffalo) factory (a rented shop) of the early Bell helicopter, having been hired in June 1943 by Bob Stanley, Chief Test Pilot, Siebel decided to design his own, simplified and inexpensive helicopter. Living in Kenmore, N.Y., near fellow Bell employee Dick Ledwin, they began building the S-3 helicopter in the attic of the duplex building where Charlie lived. In 1945, the helicopter group moved to the Niagara Falls plant where work was commencing on the Model 42 helicopter. Note: During this period at the Niagara Falls facility, Bell was working on the XS-1; beginning with the mockup in April, 1945, the first XS-1 was rolled our near the end of December, 1945; without engine, this ship was first destined for glide tests. A Renton B-29, 45-21800, was modified to accept the XS-1 which made the first flight on January 25, 1946.

Charlie decided to leave Bell in the fall of 1946, departing the winters of upstate New York for the Mid-West, he moved with his wife Thelma and young son David, to Wichita, Kansas where he had graduated from high school, took a job as an aerodynamicist with Boeing on the XL-15 and continued work on his own S-3 design, building the innovative light helicopter in his basement with his friend "Red" Lubben who departed Bell to join with Charlie. Dick Ledwin, still in New York, machined parts for the S-3 from drawings sent east by Seibel.

Boeing L-15 Scout, Model 451.

In 1943 Seibel had made preliminary designs and patented (March 1944) his first design, the S-1, which was a twin tilt rotor that looks amazingly like the current Bell VS-22(!) - the idea preceeded his Bell employment so the patent was his. The next Seibel design, the S-2, was a co-axial design study that he shelved. He launched his first helicopter, the S-3, at Wilson Field in September 1947 for its first hovering lift-off. This design had been tested in model form, as shown below in a 1947 photo. The tethered scale model approach had previously been successfully used by the brilliant designer of the Bell Model 30 helicopter (pictured above and the genesis of the Model 47), mathematician Arthur M. Young, and Seibel obviously followed this example of a man whom he highly respected. Seibel had extensive experience at Bell operating a control-line helicopter model during testing. (The use of control-line or tethered helicopter models was more widespread than just Bell or Seibel. The used of tethered scale models for full-scale aviation research was used by many researchers, not only in the past, but currently as well. The well known Igor Benson, later of autogiro fame, worked as the Chief of Research at Kaman Aircraft Corp. in the early 1950s concurrent with Charles Seibel's helicopter efforts in Wichita. Under Benson's direction, as many as twenty models were tested, powered by compressed air, electric motor, and gas engines; a tip jet "microlaboratory" Kaman K-6 model was featured in the May 1952 issue of Air Trails magazine.)

The S-3 incorporated the Seibel-designed simplified control system wherein a moveable cabin section shifted in response to "cyclic" stick inputs thereby shifting the center of gravity and causing the machine to respond accordingly. This machine, NX735B, is pictured below as it appeared in a magazine fold-out from the May 1948 issue of Air Trails Pictorial (the Boeing L-15 appears on the other side of this foldout - this issue has one of the best articles, entitled "Basement Helicopter", appearing in any magazine of the era on the Seibel design and his efforts) and on the cover of the American Helicopter issue for December 1948 which shows the S-3 with cyclic control being flown by test pilot Johnny Gibbs. Charlie flew this machine in hover for about 8 hours without having any previous flight experience prior to obtaining the services of qualified pilots. The book, "Borne on the South Wind", by Rowe and Miner, 1994, has a few paragraphs on Seibel and the Cessna helicopter.

The October 1948 issue of MECHANIX ILLUSTRATED featured Seibel's helicopter on the front cover with the caption, "Builds Helicopter From Truck Parts - See Page 64."

Two pages of pictures and some text were devoted to the project. The entire text is reproduced here: "He Built a Helicopter in His Cellar. When Charles Seibel of Wichita, Kansas, broached his idea for a new-type helicopter to an aircraft company, they laughed at him - said construction alone would take a quarter of a million bucks.

"So he retired to his own cellar and started building. At the end of seven months he had an egg beater which flew easily and was cheap to operate and maintain. And it cost him less than $5,000.

"Seibel used Ford truck gears and clutches, odd pieces of sheet metal, aluminum tubing, wood and wiring picked up at war surplus stockpiles.

"When testing day came, he had no test-pilot so he flew it himself - successfully! And he had never flown a plane before in his life!"

CAPTIONS: "Seibel first built this model to prove his ideas. Test flight: Seibel squeezed his 6-foot frame into his helicopter. Flew it himself while family watched. Cellar Factory: In this basement workshop Seibel built his "impossible" helicopter. It was made in 3 parts so it could be removed from the cellar without having to be disassembled. To start the 65-hp Franklin engine, below, he spins it with a cord like an outboard motor (see photo above that went with this caption). Control: In his unique system the fuselage splits and moves backward or forward, changing the center of gravity of the ship and causing it to climb, lower left, or glide, lower right." Some good publicity at about the time Charlie was courting investors!

The moveable c.g. concept was subsequently abandoned on the S-3 (insufficient control and the potential for roll-over on hard landing) and a more conventional cyclic control system was installed for continued testing and promotional flying. The Seibel Helicopter Company was formed with investors from the local oil industry in 1948. Quiting his job with Boeing to work full-time on helicopter projects, the Seibel S-4, a 2-place ship, was a follow-on development utilizing a similar control system as the later S-3 and incorporated Seibel's rotor system using stacked, stainless steel "L" shaped blade attachments which carried all rotor loads and flexed for control input thereby eliminating blade pitch bearings. Also, the ship used a supercritical tail rotor shaft and simplified ring and pinion transmission. The S-4 first flew in early January 1949 with a heavy schedule of test flying for test pilot Johnny Gibbs who had a helicopter background doing crop dusting. The S-3 was still being used as a promotional demonstrator until early 1949 and it was dismantled, having accumulated 100 hours - three "pilots" had flown the S-3, only one of whom was licensed as a rotary wing pilot. The Seibel Helicopter Company moved from their Wilson Field facility to a North Broadway building (5613 No. Broadway) in the fall of 1949 and made application for a type certificate, only the 5th company in the U.S. to do so. Dick Ledwin departed Bell and joined Seibel.

Certification tests were completed in March 1950; the flight test engineer from the C.A.A. on this project was San Hinton who later became part of the Cessna program. The S-4 received C.A.A. Type Certification on April 23,1950 during a celebration of the big event at the Wichita Municipal Airport - attending the ceremony was Dwane Wallace, Al Mooney, Earl Shaffer (Boeing) and Walter Beech - and the S-4 was demonstrated on a very, but typical, windy day. A larger engine, a Lycoming O-290B of 125 h.p., was subsequently installed and certificated as the S-4A with Hal Hermes as the C.A.A. test pilot. The S-4A won a contract with the Army for an evaluation quantity of two ships as the YH-24.

The first, 51-5112, was delivered in April 1951 to Fort Bragg, N.C.; the second YH-24, 51-5113 to Wright Field. The YH-24 failed to win Army approval and the two ships were later scrapped by Cessna in 1952. The single control YH-24 couldn't be used for training, so that deficiency prompted Seibel to design a new version, the S-4B in only two months. The Seibel S-4B embodied a side-by-side arrangement with skid gear and was fitted with a larger engine, the Franklin 6A4-165-B3 of 165 h.p. The S-4B was a rather basic helicopter layout with an undistinguished appearance yet it embodied the important design basics of rotor, drive system and control that would become incorporated in the Cessna CH-1 in the future. During the summer of 1951, Jack Zimmerman (who had been flying helicopters in Alaska) was hired at Seibel Helicopters as test pilot - he would become the Chief Test Pilot for the Cessna program. The S-4B was demonstrated at Fort Sill, Oklahoma after being completed in only two months and it received a glowing report from that Army Air Training Department in October 1951. Nevertheless, lack of capital prevented the Seibel Helicopter Company from pursuing further Army business, by this time having moved again to 3400 North Broadway adjacent to grain elevators!. The S-4B was never certificated and remained in the experimental category.

Looking ahead to possible future military programs, Dwane Wallace, president of the Cessna Aircraft Company, was attracted by Seibel's local Wichita efforts and was instrumental in effecting a stock swap with the Seibel investors in the Seibel Helicopter Company by January 14, 1952. The Wichita Eagle newspaper carried a headline that day, "Cessna Moves to Take Over Seibel Helicopter Production." in March, 1952 all equipment, including the S-4B, were moved to the Pawnee Plant of Cessna. Personnel were hired or transferred from other departments and work began on the CH-1 design during the summer of 1952. The Seibel S-4B, N5154, was flown for several months to familiarize Cessna with helicopters, and then scrapped. Seibel believed that the S-4B with some Cessna aluminum wrapped around it would have made an excellent and inexpensive trainer for the Army. This would not happen.

THE CH-1

The artist's drawing shown above was the origin of the CH-1 design; it was drawn by an industrial designer, Richard Ten Eyck, who consulted on most aircraft designs for Cessna. It has obvious airplane characteristics: engine in front, streamlined body, cabin seating behind the powerplant, low profile, and, in general, a sleek, non-helicopter appearance. I do not know exactly how much input Seibel had in this external design configuration but it was jelled between April and Summer 1952 from initial sketches (showing military markings!) which were for a slightly smaller cabin - possibly made by Seibel. Ten Eyck reconfigured the fuselage to the final shape. He also later helped shape the master plaster mold for the fuselage and cowling. Unlike so many projects, the actual prototype CH-1 looked almost identical to this drawing. The forward engine location had some advantages such as maintenance accessibility, cabin visibility and c.g. control (permitted occupants to be near c.g.) but it also presented a problem of what to do with the exhaust, a complication that plagued the ship throughout its brief life and spawned numerous "solutions", none of which were really successful. Also, the airplane-style fuselage, although nice looking, resulted in a tail boom volume that was much too large in hover flight and required aerodynamic solutions to overcome, particularly because of pitching moments in forward flight caused by the streamlined body.

A quarter-size wind tunnel model of the CH-1 was tested at Wichita State University. Drawings were being produced and metal being cut for static tests and a dynamic, flying test bed early in the program. I have the original memo which outlines the program and the schedule through February of 1953. This first machine did not have an enclosed fuselage or cowling - a true flying test bed. The memo, in part, states;

"The first helicopter CH1-1 is being built for the following purposes:

1. To serve as a mock-up for control systems, fuel systems, etc.

1. To place machinery (clutch, free wheeling unit, transmissions, and rotor systems) into operation at the earliest possible date in order to uncover mechanical deficiencies, design errors, etc.

1. To serve as a flying test bed to investigate hovering control and stability and other slow speed flight characteristics.

1. To serve as a flying test bed to investigate rotor system stresses and vibration characteristics.

1. To allow initiation of C.A.A. certification testing of the helicopter drive and rotor systems at the earliest possible date."

I came on this scene in 1952 at a time when an engineer was needed to assist project engineer, Sanford Hinton, with a U.S. Navy Office of Naval Research (ONR) helicopter research contract which had been obtained by Cessna; a system of rotor blade suction boundary layer control was to be designed and flight tested for effectiveness in delaying retreating blade stall on a Cessna CH-1 helicopter (which was only a paper helicopter at the time the contract was signed!). The announcement of this ONR contract was made in the August 22, 1952 issue of the Cessquire company magazine as presented below.

I tested two-dimensional oscillating blade sections, with varying degrees of BLC, in a four-foot wind tunnel at Wichita State University and did preliminary design work on a complete BLC system for the CH-1. I was taking a wind tunnel course at the university, using the same tunnel that I was designing a test installation for! Talk about on-the-job training. More on the BLC later in this article. The helicopter group was crammed in a second floor office at the rear corner of the main Pawnee production plant; we overlooked the small Cessna field, grass with a tiny runway aiming right at McConnell AFB, and B-47s from the AFB noisily whizzed by our windows on their take-offs from the field shared by Boeing and the Air Force. Just below the office, a tail rotor test rig whirred away night and day, the CH-1 was being constructed and the giant rivets for all the Cessna airplane wing struts were bucked right below us. In addition to the light single-engine airplane production line (Cessna had no twins in production at this time), giant tail assemblies for the B-47 were being built, along with sections for the T-33, F-94C and F-84F under subcontract by Cessna; a real Mutt and Jeff situation that I got to see on my passage each day as I walked the production line to our office. I witnessed an important event in Cessna history on January 3, 1953, a Saturday afternoon, as test pilot Hank Waring lifted the new prototype 310 off the AFB runway under a cheery winter sun for a 30 minute first flight. A little more than a year later I became a guest of the U.S. Army, still doing helicopter work. The helicopter development group moved to and became part of the Military Division (T-37s) at the west side Prospect Plant (Cessna was awarded the development contract for the Cessna Jet Trainer Model 318 in January, 1953) and the original division manager, Sherman Graves, was tragically killed in a freak Cessna 170 ground collision with a DC-3 in Richmond , Indiana in December 1952 and later, in the Spring, replaced by Jack Leonard who came from Goodyear.

The test bed skeleton of the CH-1 first hovered in July, 1953 (this test bed flew as high as 10,000 feet and later became the basis for the second prototype) and the prototype CH-1 was tested at the Prospect plant, N5156 (ship #2) making its first flight in 1954. Of interest, this first prototype did not have a horizontal stabilizer and flew extensively before one was added - no publicity photos were released of this initial version that I know of. Dick Ledwin (now deceased) was the shop manager and he and his crew worked magic when it came to building prototypes. I was in the Army at the time and took the photo below from an L-19 in August 1954 on a foray from Ft. Sill to Wichita. Shown on the tie-down test stand is N5156, still ten months from C.A.A. type certification - there is no horizontal tail on this ship.

The prototype CH-1 had a Continental FSO-470 engine rated at 260 h.p. at 3200 rpm equipped with a belt driven supercharger and belt driven cooling fans. It should be mentioned here that Cessna was using Continental engines exclusively at this time - the company would not even consider a flat Lycoming engine. An airplane with a Lycoming engine was always lurking in the experimental hangar reportedly just to keep Continental on their toes. The CH-1 was going to have a Continental engine no matter what else was available. The high rpm, big bore Continentals were unproven in production aircraft so we were a test bed.

Portion of Continental ad from December, 1954. Copy reads, in part, "New, modern helicopters are finding it increasingly beneficial to make use of the latest Continental developments for power production. Two examples of recently tested engined built around Continental power plants are shown. One - the Sikorsky XH-39 at left, above - employs the CAE Model 220 shaft turbine; the other - Cessna's CH-1 at right - uses CMC Model FSO470 piston engine. Both are unique. The CH-1 features simplified design, using one-third fewer gears. Location of engine in the nose makes for ease of access, promotes efficient cooling, and frees the center of gravity behind the cockpit for use in disposable load."

The engine exhaust exited under the helicopter with little noise attenuation. Project Engineer Bob Smith recalls the noisy exhaust on the early CH-1; "Jack (Zimmerman) complained about it right after the completed CH-1 started flying. Mel Vague and I went out to the tie-down area one afternoon to record sound readings and the temperature and humidity to correct the sound measurements. We didn't have hearing protection in those days. Jack was right! It felt like someone sticking needles in our ears! Anyway, the dB level corrected to 141; the temperature was 114 degrees F and the humidity was 3%. Good old Kansas summertime. This dB level was way above the Fletcher-Munson curve which showed the levels above which permanent hearing loss was probable. Right after that we started in earnest to design a muffler; I guess we never did get it right."

Cessna released a drawing in 1:20 scale of a 3-view of the CH-1, complete with sections, in about 1955. This drawing could be used to construct a scale model. The side view shown above is a part of this drawing - a little yellowed with age. The drawing measures 16" x 36".

CAA certification

The 3,000 lb. gross weight CH-1 received C.A.A. type certification, 3H10, on June 9, 1955; the new helicopter had the highest never-exceed-speed of any certificated helicopter, 122 mph (although at a reduced gross weight), and a maximum gross weight hover ceiling of 11,000 feet, exceptional numbers for the time. The CH-1 was certificated as a two-place helicopter; longitudinal stability problems at aft c.g. caused by the pitching moment of the streamlined fuselage required additional engineering and test work on the stabilizer system. The floating stabilizer stop was then linked to the longitudinal control and the CH-1 was then quickly certificated as a four-place and designated the CH-1A on February 28, 1956.

The ink wasn't dry on the type certificate before a record flight to Pike's Peak was made with the CH-1 and work began on the "B" model directed at even better performance with an improved engine with a military contract in mind. Continental couldn't attain sufficient belt life for the original engine and suggested a change to the FSO-526.

The following information is from the 1955 Cessna CH-1 brochure, shown above, in order to give an idea of the selling points being promoted. It wasn't intended that this basic CH-1 model would ever go into production, but this brochure certainly gives the impression: "Smart and trim, the CH-1, first Cessna helicopter, having advantages never before offered in a helicopter, employs a single lifting rotor and a single anti-torque tail rotor. Both fuselage and rotor blades are metal, combining high utility with minimum upkeep.

"Sturdy skid-type landing gear allows landings on all types of terrain. Snap-on wheel assemblies save ground handling time. The tail rotor is elevated to safeguard ground personnel and permit the CH-1 to operate in heavy brush.

"For easy installation and servicing the supercharged engine is mounted in the fuselage nose. This location also gives added cargo and passenger space in the fuselage around the main rotor shaft.

"Unusually smooth control operation is acheived through a simple, totally enclosed rotating control assembly and the aero-dynamically clean rotor assembly. A control boost system, supplied as standard equipment, eliminates cyclic feed-back to the pilot's control stick. The angle blade attaching member and spiral bevel transmission gears combine to give long operating life to the drive system."

Pike's Peak

On September 13, 1955, the CH-1, N5156, now certificated, landed, hovered and took off with two and three persons from Pike's Peak, Colorado, an elevation of 14,110 feet, the first helicopter ever to do so (the highest in North America). These flights were conducted with a representative from the U.S. Army to demonstrate the CH-1's amazing altitude performance capabilities, such performance totally lacking in the Army's fleet at the time and in civilian use by supercharged machines as well. The photos below were widely distrbuted by Cessna and the flights received good press. Cessna test pilot Jack Zimmerman (now deceased; Jack was a WWII helicopter pilot flying Sikorsky R-4s) was the pilot for these flights and flew off the Peak with Captain Knowles of Fort Carson and then with the commanding general of Fort Carson, Major General Van Houten. An altitude of 17,600 ft. was reached during these Colorado evaluation tests with Captain Knowles. Tests with Army personnel were conducted at Camp Hale, Colorado where Zimmerman and Captain Knowles made landings on Horn Silver Mountain (11.300 ft.), Ptarmigan Hill (12,154 ft.) and Sugar Loaf Peak (12,567 ft.). Bell Helicopter became aware of Cessna's program to land on Pike's Peak and made an attempt to beat the CH-1 with a Bell 47G-2; coming in second, Bell landed on the Peak later on that same day! Details of the helicopter landings on Pike's Peak appeared in the Denver Post evening edition that day.

Bronze relief plaque commemorating Pikes Peak landing. I took this poor photo at the Wichita Air Museum. There is supposed to be a plaque on Pikes Peak; does anyone know if this is true? The plaque inscription is as follows: "SEPTEMBER 15, 1955 PIKES PEAK 14,110 FT. CESSNA CH-1 HELICOPTER. First successful landing and take-off ever accomplished by any aircraft from this peak was on September 15, 1955. The aircraft was a Cessna CH-1 helicopter manufactured by the Cessna Aircraft Company, Wichita, Kansas."

This is the exact Bell 47G-2 that Hersey Young landed on Pike's Peak following the CH-1. Hersey picked up this G-2 at Bell on June 17, 1955 and participated in a dedication of Stapleton Field on June 19 with a demonstration carrying a passenger to 16.100 feet. The G-2 was powered by a non-supercharged Lycoming VO-435. Hersey is at the controls in this photo which was taken at Bell. This was only the second G-2 delivered, the first going to France on May 30. Jean Moine took that ship to a record in France by landing and taking off with a passenger from the 15,771-foot-summit of Mount Blanc in early June, 1955. Unfortunately there was no similar height available in the U.S. for demonstration!

CH-1B (YH-41 Seneca)

Work commenced on the CH-1B during 1955, really a design change aimed at the military, using a Continental FSO-526 engine (derated to 270 h.p.) with a gear driven supercharger and a newly designed horizontal, gear driven cooling fan. The Continental FSO-470 of the CH-1 proved to have unreliable belt life for the supercharger/fans and the FSO-526 was an option because the Cessna four-engine 620 used a similar engine. Other improvements were made to the "B" model as well, including a larger, constant chord moving stabilizer. The stabilizer free floated to a vertical position during hover and pivoted to a stop during forward flight; the stop was connected to the fore and aft cyclic control thereby altering the stabilizer incidence during flight. Also, an automatic collective pitch reducer lowered the collective pitch in the event of an engine failure. The rotor speed was increased by changing the transmission ring gear from 51 teeth to 49 (pinion gear had 6 teeth).

One incident with the CH-1 is a reminder of the amazing flying skill that test pilot Jack Zimmerman brought to the program. It was about this time that the CH-1 was to be flown to Muskegon, Michigan to the Continental factory for some engine tests (probably concerning the new FSO-526). Jack was the pilot and a Cessna salesman went along for experience (I believe it was Sid Shannon, Sales Manager). We always wore parachutes for flights above about 1,000 feet so both Jack and the salesman had chutes. The cyclic and collective controls went up through the rotor mast and connected to pitch arms which transferred movement to a bearing supported torque tube which went out to the rotor blade at the point the blade attached to the "L" shaped attachment angles. The prototype pitch arms were castings. Somewhere between Wichita and Michigan, while in cruise, cross country flight, the ship suddenly experienced a wild divergence of the rotor blades, a monumental out-of-track condition which threatened to shake the helicopter to pieces. Of course Jack had no idea whatsoever of what was happening; he only recognized that a some sort of major failure was occuring and that continued operation was out of the question before something came apart. He ordered the salesman to bail out, so the door was jettisoned and the passenger stepped out on the skid gear and hung on to the door frame but then just froze and refused to jump. Meanwhile Jack had reduced power and lowered collective and found a setting that reduced the vibration somewhat. Having no choice nor time to cajole a reluctant skydiver, Jack had the passenger return to the cabin and prodeeded to fly the helicopter to a landing in a field. A pitch horn had failed. The blade attach angles had forced the blade pitch to a "neutral" postion for that blade thereby allowing flight, albeit rather scary, without any control attachment for one of the two blades! Try that on any other helicopter flying at the time. Future pitch horns were made of forgings. No panic, just cool flying and doing what ever necessary by assessing the situation and taking corrective action - that was Jack Zimmerman.

Cessna was awarded an Army contract for $1.1 million to build ten ships, designated as the YH-41 Seneca, for military evaluation purposes, this contract being signed in the spring of 1956. The contract was actually for the CH-1A using the FSO-470 engine, however this engine had already been scrapped in favor of the FSO-526 so Cessna had to bite the bullet on the price and swallow the extra engineering costs associated with the CH-1B development which would become the YH-41.

The well used prototype, N5156, a CH-1A, was painted in an Army scheme and photos released showing this as the newly ordered Army YH-41 helicopter although it was really a "lipstick" job with the old engine. Pictures of N5156 in olive drab were used into1957 for advertising and promotional purposes linked to the military evaluation order.

By the end of 1955, the Cessna helicopter program had entered a transition from the preliminary design, prototype construction, test and certification phase to one of being integrated into the company as the beginning of the manufacturing phase thereby involving departments within Cessna that previously had no contact with the helicopter division. Charlie Seibel wrote a memo dated December 16, 1955 preparing the company for the manufacturing phase where he emphasized and explained the need for the strict tolerances and manufacturing techniques required for the helicopter's dynamic components. Metal fatigue considerations weren't of the prime importance on airplanes that the helicopter demanded. The cover memo for the report, "The State of the Helicopter," stated:"The Cessna Helicopter activities are now being integrated into the Pawnee Plant departments. Del Roskam and Chris Hesse have suggested that a discussion be prepared by the helicopter engineering department as an introduction to this new field. Accordingly, the attached report - "The State of the Helicopter" is submitted to you for your information.

"During the development period of the CH-1 helicopter, those of us in the Helicopter Division have been looking forward to this day when we start to build helicopters. We believe the sun is rising on a new business at Cessna. There will be many problems, and we are looking forward to working with you in solving these problems. Please feel free to visit with us at any time concerning our mutual interest, the Cessna CH-1 helicopter. (Signed) Charlie"

Putting the Army procurement contract in the proper chronological space, note that this December 1955 report, page 11, Section VIII, states: "The evaluation order of Cessna CH-1 helicopters is being purchased for one reason only. THESE HELICOPTERS ARE BEING PURCHASED TO EVALUATE THE AIRCRAFT, TO COMPARE OUR PRODUCT WITH OUR COMPETITORS LATEST PRODUCT, TO DETERMINE IF A PRODUCTION ORDER SHOULD BE MADE. Yes, these evaluation machines are sales tools for larger production. We can't wait to get QUALITY in the 100th helicopter produced. We must have quality in the first one, and in every one." Oddly, the actual Army contract for the YH-41 wasn't placed with Cessna until May, 1956, six months later.

This was a pretty tall order for Cessna where such techniques weren't necessary for the production of Skyhawks although the military production crews were well aware of material and tolerance controls as sub-contracted tail assemblies for the B-52 rolled off the line.

In May, 1955, Seibel addressed the American Helicopter Society in Washington, D.C., and stated that the CH-1 was, "the first helicopter I ever worked on where the performance exceeded my calculations." He was elected president of the society for the 1956-57 term. In conjunction with the AHS meeting, Newsweek magazine, May 2, 1955, ran an article on the CH-1; the article is reproduced below.

ONR BOUNDARY LAYER CONTROL PROJECT 1952-1955

1955

• August 1952, Cessna signs a contract with the United States Army Transportation Corps and United States Navy's Office of Naval Research (ONR). The contract involved flight tests of an active suction boundary layer control system for the main rotor, designed to delay the onset of retreating blade stall and allow faster speeds.
• 30 June 1955, first forward flight of BLC equipped CH-1 after wind tunnel tests throughout 1952-53 to find optimum airfoil configuration.

The rotor blade structural design and fatigue test was handled by the Prewitt Aircraft Company, Clifton Heights, PA, manufacturer of the Cessna blades. The photo below shows a test slotted blade section undergoing fatigue tests at Prewitt. The blades for the BLC program were specially constructed of an aluminum layered honeycomb sandwich (to replace the aluminum hat-sections and the .009 stainless steel skin) which was then bonded to the 4140 steel "D" tube spar to provide strength in the suction slot area and to provide a smooth air duct.

Richard H. "Dick" Prewitt had been the Chief Engineer at the Kellett Company and had designed the 1936 Army YG-1 Autogiro amongst other projects while working for Wallace Kellett. Army people called Prewitt "Daddy of this Whirligig." Prewitt eventually became a rotor blade manufacturer; the CH-1 blades were a brilliant design, incorporating a 4140 steel "D" spar with aluminum hat sections running aft to the trailing edge and then a thin stainless steel skin (excellent protection against corrosion and abrasion) was wrapped and bonded to form the exterior of the blade. Fatigue tests proved that the .009 skin would always show cracks before the load carrying "D" spar experienced any fatigue failure. Besides being an outstanding rotary wing engineer and pioneer in the field, Dick Prewitt was just a very nice guy and a real pleasure to work with.

Final results showed an increase of about 13% in speed by delaying the stall, from 118 mph to 133 mph. Tests were conducted at 10,000 feet where blade stall becomes a speed limiting factor in many cases - the CH-1 was one of the few helicopters at the time that could operate effectively at altitude for these test conditions. Even with its altitude capability, control and power limitations kept the speed increase to this number; estimates are that a 50 m.p.h. increase would have been possible.

CH-1 boundary layer control test helicopter in-flight with chase plane. 42 hours of flight time were accumulated and 34 flights actually had the BLC system operating. The system was not practical, however, in that the installed weight and horsepower required for the BLC system was entirely too much although no attempt was made to optimize inasmuch as the objectives of the contract were met.

YH-41 DELIVERIES AND EVALUATION

1957

• 5 July 1957, The CH-1B was certificated. The CH-1B was the basis for the YH-41. The CH-1B/YH-41 evaluation quantity of ten machines, serial numbers 56-4236 through 56-4245, later designated as NH-41A in 1962, was manufactured at Cessna
• September 1957, first YH-41, 56-4237, is delivered to Edwards Air Force Base for preliminary testing following acceptance flying by Lt. A.E. Lush. An "army" of government inspectors from the CAA, Army and Air Force decended upon Cessna prior to delivery; in addition, the Army and Air Force Contract Technical Compliance Inspection Board, consisting of about a half-dozen colonels, met at Cessna to study the YH-41 design.

The helicopter was shipped to Edwards onboard a C-130; the YH-41 "Seneca" was loaded intact into the "Hercules" at McConnell AFB.

1963 Lockheed-Georgia ad for the "Hercules", six years after the YH-41 loading event!

The rest of the YH-41s were delivered to the U.S. Army Aviation Center for extensive user testing; the Transportation Supply and Maintenance Command to determine logistical support needs, and the Army Aviation School at Fort Rucker (two ships) for trainer suitability and service testing by the Army's Test Board. All deliveries took place in 1957 and 1958. Six "Senecas" were assigned to the Army by the end of 1957, the balance in early 1958. Cessna built eleven CH-1B/YH-41 helicopters in total at the Pawnee plant, finishing production at the end of January, 1958. All jigs and fixtures were moved to the new Wallace plant along with helicopter engineering.

The Edwards AFB test ship, 4237, was used for altitude testing at sites near Bishop, California. The YH-41 met performance figures at test sites ranging to 9,500 feet (Coyote Flats) and was flown by Air Force pilots with data gathering and maintenance by Edwards personnel. In late September, 1958, 4237, flown by Maj. R.G. (Bob) Ferry, made a dramatic rescue near Mt. Whitney. A man injured in a fall from a horse was picked up at an altitude of 9,300 feet and Ferry made a vertical takeoff from a 30 degree slope between tall pines. A news article stated, "He (Maj. Ferry) said the rescue mission could not have been accomplished without the exceptional high altitude performance of the YH-41 which permitted a vertical takeoff and climb from the high elevation of the rescue area."

The Army evaluation tests did not result in any further military contracts. Undoubtedly, the Army would have been reluctant to add another helicopter manufacturer to its contractor lists at the time, even with the YH-41's obvious performance advantages. Some comments published have indicated that the Army experienced problems with maintainability and there is no question that the CH-1B/YH-41 had stability and control deficiencies (detailed in the military reports) which were addressed later on the production CH-1C.

The following extract from an appendix to the Army's official YH-41 report is from an article by Charles Siebel: "Captain R.G. Ferry (FTFOB) and Mr. V. K. Putnam (FTFEE) visited the Cessna Aircraft Company on 15-17 July 1958 to review progress on fixes being developed by this company for items deemed unsatisfactory on the YH-41 helicopter by Army and Air Force test agencies...

"Cessna personnel demonstrated fixes for every major problem area that has been found on the H-41....AFFTC personnel were highly impressed with this contractor's comprehensive and open-minded approach to the solution of these problems, and outstanding progress which has been made in a short period of time. This progress is commendable compared to past experience with other contractors in the rotory wing industry." The final military evaluation reports came out about two years later; by that time, turbine helicopters were on the horizon.

Some Army YH-41s were continued to be operated into the 1960s and some were either scrapped or repurchased by Cessna in the 1960s with the exception of 56-4244 which was retained as a museum piece. This machine is now in deep, dusty, poorly lighted storage at the U.S. Army Aviation Museum at Fort Rucker, Alabama. The picture below appeared by itself in the "Warbird Report" in the May 1979 issue of Air Classics. Note that this exhibit in the open changed drastically to dingy conditions at the museum by the time I took the pictures described in the next paragraph.

I took the two photos of 56-4244 below in 1996 (compare to 1979 picture above). I know that 4236 (used for the instrument certification program) and 4245 were at Cessna in 1961 (they're in my logbook) so perhaps they both were bailed back to Cessna at the time for some test programs. As I recall, they were returned to the factory on flatbed rail cars and the engine mounts had been broken by the "g" forces of humping. Several references cite that six Senecas were purchased by Cessna from the Army to be rebuilt as CH-1C commercial models. The disposition of Army Senecas which were continued to be flown by the Army, other than the museum example, is unknown; they were probably scrapped.

WORLD'S ALTITUDE RECORD

The high altitude capabilities of the CH-1 prompted Charlie Seibel, in 1957, to explore the possibility that a modified version of the ship could actually beat the existing absolute altitude record for helicopters. At that time, the three post-WWII record holders were turbine powered helicopters. First, the Sikorsky XH-39, using a Continental CAE Model 220 shaft turbine, flew to 24,500 feet in 1954, then the French Alouette II, piloted by Jean Boulet, with a record flight of 26,932 feet in June,1955 from the Buc airport which was soon beaten by a Sud-Aviation Djinn at 27,830 feet on March 22, 1957. Though not mentioned as a NAA record holder, a Piasecki YH-21 (reciprocating powered) went to a record altitude of 22,289 feet at the 1953 Dayton Air Show, piloted by USAF Captain Russell Dobyns, a remarkable feat.

The idea that Cessna could beat these turbine records with a reciprocating engine was audacious, but Seibel was convinced. At stake was the potential of a military contract and Cessna was going all out to gain approval for the new helicopter on the block.

The concept was to put a record winning ship in the air with an Army pilot at the controls for the record attempt and then promote the heck out of the achivement, touting it as an Army record in a Cessna helicopter. That is exactly what we did.

Work on the record machine began with my Test Proposal No. 18, "Altitude Record Attempt", issued on September 20, 1957, the same month that the first YH-41 was delivered to Edwards AFB. The introduction to this proposal read as follows: "An attempt is to be made to establish an altitude record with a specially equipped CH-1B helicopter. Major modifications to the aircraft in preparation for the record attempt will be:

"(1) Engine modifications to include higher supercharger blower ratio and installation of altitude magnetos and high tension leads.

"(2) Removal of all unnecessary equipment to reduce the empty weight of the helicopter."

The proposal also stated, "Two flights will be made. The first flight will be a preliminary attempt to determine if the altitude record can be broken. Data will be taken with a gun camera during this flight. If satisfactory results are obtained on the first flight an official record attempt will be made with the cooperation of the NAA."

This effort had been preceeded by a preliminary altitude flight on July 2, 1957 in N5157 (ship #3) which was not extensively modified but somewhat lightened by removal of seats, engine cowl, upholstery, L.H. controls etc. for a T.O. gross weight of 2421 lbs. which included a single pilot and 20 lb. of ballast. An altitude of 23,100 feet was attained with the standard engine; Jack Zimmerman was the test pilot. Extrapolating this test data for a further weight reduction and using a power chart for a higher blower gear ratio engine, it was concluded that a record could possibly be set thereby setting in motion the proposal of September 20th.

The helicopter was stripped of nearly everything that wasn't essential for flight or pilot safety. Some examples: Most of the electrical system, batteries, relays, generator etc. were replaced with two dry cells to operate instruments. The auxiliary fuel pump was eliminated. The starter relay, vibrator, and the starter itself were removed after starting. The entire landing gear was replaced with two small scuff tubes on belly. The exhaust system was removed and only short pipes remained. Doors were replaced with vinyl with a zipper emergency exit on rh side. The transmission oil cooler was removed. The engine fan was lightened with removal of the fan ring and dome. Engine filter, air box and CAH removed along with miscellaneous baffles etc. All this change required tail ballast which consisted of a lead weight mounted on a braced tail skid; the F-1 oxygen tank was also installed on the tail skid for ballast. The final configuration had to be flown off of a special dolly. Approximately 266 lbs were removed with about 27 lb. added including ballast. I was assisted on this project by two other flight test engineers, Frank Robinson (yes, the helicopter entrepreneur who now builds more nifty helicopters than the rest of the industry) and John Parks; we were all under the age of 27.

Ship #3 was prepared for an instrumented test flight on December 18, 1957 with Jack Zimmerman at the controls. The special Continental FSO-526-2X engine was installed and most weight control items removed with the exception of the landing gear which was retained for this flight. Fuel load was a full 59.2 gallons for a takeoff gross weight of 2408 lbs. Jack flew the prepared flight profile and reached an altitude of 26,860 feet with 42 gallons of fuel remaining in the tanks. It should be mentioned that the decision had been made to terminate the final altitude attempt with the Army pilot when the onboard fuel reached ten gallons. Prevailing winds caused the ship to head east and Jack landed in Augusta, Kansas, about 18 nautical miles. Following his return flight from Augusta, there were 32 gallons of fuel remaining. With this information, we were certain that the record could be broken and arrangements were made for an Army pilot and NAA certification of the record flights.

The altitude record flights were made on December 27, 1957. Captain James E, Bowman, U.S. Army Aviation Board, Fort Rucker, Alabama was the pilot for the record attempts; he was the evaluation pilot for the YH-41 at the Test Board. Two flights were made in order to qualify for two weight categories. The helicopter was weighed with the NAA representative in attendance, M.J. (Jerry) Gordon from Beech Aircraft, who witnessed the figures. The T.O. weight for Flight #1 was 2108.7 lbs which included a reduced fuel load and a recording barograph. This flight qualified for the 1,102-2,204 lbs category. A beautiful winter day between Christmas and New Year's; the record flight went off without incident. Captain Bowman flew the profile, narrowly squeezed in airspeed where the best rate of climb speed can also be limited by compressibility and retreating blade stall at the high angle of attack required. Reaching an indicated altitude of 30,355 feet, Bowman returned to the Wichita airport now known as Wichita Mid Continent. The photo below is one of the only existing photographs of this record breaking ship, taken as Captain Bowman returned from Flight #1 and landed on the dolly. Another photo showed it hovering several feet above the dolly.

This photograph was marked "Not for Release" and neither the public, the Army, nor the press was aware of what this modified ship looked like; Captain Bowman later had his picture taken for publicity with a standard YH-41 in the background giving the impression that the record flight was in that helicopter. This publication of this photo of N5157 is the first time to my knowledge that the photo has been shown outside of Cessna except for a video made by Charles Seibel in 1990 which shows a hovering scene as Bowman made his landing ( video available from the American Helicopter Society). A second record attempt was made with a takeoff gross weight of 2229.1 lbs. by adding about 20 gallons of fuel; this qualified for the 2,204-3,858 lb. category in which there was no previous record. Bowman reached an altitude of 28,200 feet on this flight. Of special interest is the fact that the CH-1 left a contrail! Caught in the edge of the jetstream, Bowman was carried east and had to land at El Dorado, about 31 nautical miles from takeoff. He caught the wrath of the airport manager as he landed on the tarmac and burned holes in the asphalt with the abbreviated straight exhaust pipes!

The press release on this record flight featured Bowman's picture with a YH-41 as shown here in a newspaper clipping. Captain Bowman was presented the Distinguished Flying Cross by General Maxwell Taylor in Washington, D.C. on January 2, 1958. The same day, Bowman appeared as a guest on the Arthur Godfrey show and gave an account of his altitude feat. If I remember correctly, Captain Bowman was seriously burned in in a crash of an Army L-23 in St. Louis some time later.

The final official NAA (acting as the U.S. representative for Federation Aeronautique Internationale) altitude figure was given to Cessna as 29,777 feet as measured by their sealed recording barograph, a device with a rotating drum, lamp blacked surface and a barograph needle scribing a mark. I did not agree with this lower figure inasmuch as we had established an altimeter error of less than 29 feet at the altitude and airspeed attained. As expected, our absolute world's altitude record was beaten the following year, again by a turbine powered Sud Aviation Alouette II flying from the French Air Force test center at Bretigny, near Paris; an altitude of 36,501 feet was reached. Turbine helicopters dominated the altitude records during the 1950s with the single exception of the Cessna. In December,1959, Capt. Walter J. Hodgson and Maj. William J. Davis USAF flew a standard Kaman H-43B with a Lycoming T-53-L-1B engine to an altitude of 30,100 feet at Bloomfield, Connecticut, an unofficial record for Class E-1-D Helicopter.

Records are only set to be beat. It's exciting to be able to do something "first" but the realization is that constant development results in "records" becoming commonplace as time goes by, so while no other helicopter/pilot had ever been to 30,000 feet when we set a record, the world of turbine helicopters changed everything. Standard military versions of working helicopters left the 30,000 foot mark far behind. In 1964, a group of pilots from the Army Test and Evaluation Command's Edwards AFB and the Fort Rucker Test Board set a new record for weights up to 9,921 lbs. in a Bell UH-1D Huey by reaching 35,150 feet.

THE CH-1C AND INSTRUMENT CERTIFICATION

The Helicopter Division began a concentrated effort in 1958 to further refine the CH-1 by addressing various flight stability and control deficiencies (from military evaluation), exhaust problems, a new tail rotor and raising the gross weight by 100 lbs. Additionally, the U.S. Navy and the U.S. Army were seeking a new helicopter instrument trainer and the CH-1 was, in our view, the perfect ship for the job, if and when we could engineer sufficient changes to meet instrument flight requirements. This ongoing department effort resulted in the Cessna CH-1C Skyhook which eventually became the civilian production version with initial deliveries in July 1961. An instrument variant of the CH-1C, equipped with additional stability devices, was licensed by the FAA for instrument flight, making it the very first helicopter to ever receive IFR certification and the only one, to this day, to be qualified for instrument flight without an autopilot installation or the need for electronic stabilization. The instrument program was aimed solely at a military contract as there was no real market for a light, civilian instrument rated helicopter. Unfortunately, the Navy elected to purchase the Bell HTL-7 (Bell 47K) for instrument training and took delivery of 18 ships in 1958. The Bell HUL-1 was already in Navy inventory. However, an Army need for instrument trainers was still in the works.

The CH-1B's poor lateral stability and unwanted roll inputs caused by the combination of power changes with the high tail rotor position was the prime deficiency to be taken aim at. Seibel and the design department under project engineers Mel Vague and Bob Smith, with design engineer Harold Bull and others, came up with a mechanical roll rate gyro which was driven off the main transmission; the nearly 4-lb., 10 in. single-axis gyro's inputs were fed into the lateral boost system through mixing linkage to effect significant damping of roll excursions.

To correct the tail rotor thrust rolling moment, a mechanical feedback from a cylinder sensing the pressure differential across the engine supercharger fed into the lateral boost valve through a mixing linkage; this lateral cyclic pitch input counteracted the rolling moment from the high tail rotor thrust line very effectively. Longitudinal stabilty was improved by use of a larger, 9-ft. span stabilizer which was free floating in hover to a vertical position caused by the downwash. The stabilizer was rotated about its pitch axis in response to forward speed by a ram air pressured bellows linked to the stabilizer torque tube (spar). At about 40-50 mph the stabilizer reached a stop which, in turn, was linked to the collective pitch. A drop in collective pitch, such as entry to autorotation or a change in power moved the stabilizer stop and permitted the stab to change incidence to achieve longitudinal trim. The ram air bellows damped the stabilizer response during the transistion stage.

CH-1C image from Cessna 16" x 20" color promotional litho - 1959.

The CH-1C received FAA Type Certificate approval on July 28, 1959, the "Airplane Flight Manual" being signed by FAA engineering test pilot Harold H. Hermes (1920-1989) from the Kansas City regional office. Hermes was a Wright Field Army Lieutenant in 1943 and was a pilot on the Army team that demonstrated landings and Takeoffs in a Sikorsky XR-4 off a deck platform in the open ocean on the freighter James Parker, a first. Hermes had been a helicopter student, along with Charles Lindbergh, of Charles Lester Morris who was Sikorsky's chief helicopter test pilot from 1941 to 1944. This helicopter was further modified with flight instrumentation sufficient for instrument flight although the helicopter was not certificated for actual instrument operation. The combination of dual instrumentation and the excellent handling qualities and stability made the CH-1C a delight to fly on instruments. This ship, N5159, was taken on a demonstration tour of eastern military installations (mostly Washington D.C. and Fort Rucker) in 1959 to show off the instrument capabilities to the military with an eye to the Army's instrument trainer needs. J.J. Pohlen from Cessna and a contract pilot, Hersey Young from Denver, flew the demonstration circuit. At this point the CH-1C was not FAA certificated yet for actual instrument operation. The booklet shown at left is from 1959 and was used during the tour. In it, the CH-1C is referred to as the "CH-1C Instrument Helicopter". The Cessna photo below, from 1959, of the helicopter in the clouds was to subtly infer instrument operation (and quite effectively). Army pilots were impressed with the CH-1C's instrument capability and were satisfied with it "as is".

This photo was featured in "The Aerospace Year Book 1960". In my opinion, this is the finest photo ever taken of the CH-1. Cessna used this photo in a full-page ad in the Dallas-based magazine, "Flight," in December, 1959.

As an aside, by March, 1959, in the six years since the Cessna 310 made that first flight on a cold winter day in January, the factory turned out 1,000 310s.

   The Cessna helicopter was featured on the cover of the "American Helicopter Society Newsletter" many times. This example is from December, 1960. A thorough nine-page article on the new CH-1C Skyhook was included in this issue; the article was written by Oliver Hopkins, Rotary Wing Specialist, who later died in a crash of a Skyhook while flying cross country on a demonstration tour - more info on this further below.

As 1960 approached, several projects were underway. An improved exhaust system was devised to prevent hot gases from burning grass and combustibles. No doubt that my hearing deficiencies today are the result of doing test work on that damn exhaust system! The decision to go into production hadn't been made yet and engineering was "cleaning up" the CH-1C to prepare for civilian sales. The potential of military buy of the CH-1C as an instrument trainer spurred action on that front in two directions. Although the basic CH-1C as certificated seemed to be an ideal instrument platform, the helicopter did not satisfy the FAA requirements for instrument flight. Since there were no regulations directly aimed at helicopter instrument certification (we were the first to ever apply), the FAA, in their usual wisdom, elected to apply airplane requirements with some special regulations thrown in. Therefore we had to meet dihedral stability criteria, stick force gradiant with airspeed criteria, etc.

We went to work and devised mechanical systems to satisfy the FAA regulations. Ram air sensors were used to drive bellows which fed the proper stick force gradiants for both longitudinal and lateral controls: the longitudinal bellows was equipped with a "g" valve which phased the input correctly. The lateral bellows (2) were fed by a vertical cylinder on top of the cabin which had ports located 90 degrees apart, sensing yaw differential pressure - the cylinder could be rotated for yaw trim. The lateral bellows were also fitted with a "g" valve (located in the aft portion of the tail cone) to provide proper phasing (bellow force input alone would be destabilizing). Fuselage strakes atop the cabin satisfied dihedral stabilty requirements. In all, the instrument version finally met all the FAA regulations by mechanical means alone, no black boxes, no electronic gadgets. The final product did not fly as nicely as the basic CH-1C! You could, however, fly the ship hands off indefinitely and regulations were met. After going many rounds with the FAA, the modified CH-1C ( a loaned YH-41 brought up to the "C" configuration, Army 64236) was finally approved for instrument flight (two pilots) by the FAA Kansas City Regional Office on July 7, 1960, the first helicopter to achieve this certification. The two photos below pertain to the IFR award. Note that this was the only CH-1C that was built to this configuration.

Caption from The Wichita Beacon, October 2, 1960: "Cessna Aircraft Co. and Federal Aviation Agency personnel who took part in certification of Cessna CH-1C as the first instrument flight approved helicopter are (left to right) Charles Seibel, Cessna helicopter chief engineer; Steve Remington, Cessna flight test engineer; Jack Zimmerman, chief test pilot for Cessna; Harvey Van Wyen, Kansas City FAA flight test engineer; Bob Faith, Washington, FAA flight test section; Hal Hermes, Kansas City FAA flight test section chief, and Clay Staples, of the Washington FAA flight test section."

Also in October, 1960, the CH-1C was "unveiled" with an official public introduction at the Municipal Airport and an announcement that the helicopter was to be put into production for civilian sales with the first deliveries scheduled in mid-1961. Cessna sales pilot J.J. Pohlen gave dignitaries and press people rides. By December, 1960, over 70 Skyhook demonstrations were given to various operators and government agencies. The Prospect Plant Department 146 commenced production of the Skyhook. The Skyhook was to be marketed through Cessna airplane dealers for sales and servicing, a rather ambitious undertaking as the helicopter was an unfamiliar product for most dealerships. Ships were being constructed in 1960 with serial number 15 on the line by October.

Meanwhile in 1960, military sales of the instrument CH-1C were being pursued. Ship N5159 (a standard CH-1C) was flown to the Patuxent River Naval Air Test Center in May, 1960. Test pilot Jack Zimmerman and I, and a Cessna Technician conducted a structural and aerodynamic demonstration of the CH-1C in accordance with an abbreviated form of SR-189, Section 6, to furnish only enough data for a basic flight envelope sufficient for a Navy evaluation of the ship. Patuxent engineers, including Richard Wernecke, installed instrumentation and witnessed the tests which included "g" maneuvers, static stability, height-velocity curve autorotation landings with a Fairchild photographic flight analyzer, a 7.0 fps hard landing measured with a Trodi, and many other maneuvers. It was concluded that the CH-1C met structural requirements for Navy testing of performance and stability.

Reference Cessna Report 1-941-144. Yet, the CH-1C lost out to the Bell HTL-7 for an 18 ship Navy buy for instrument trainers in 1960, even considering that the CH-1C was the only helicopter to have been FAA licensed for instrument flight - there was no way that the Bell Ranger could have met civil IFR requirements. This was standard practive however as military helicopter instrument training was all conducted in helicopters that couldn't meet civil standards as the CH-1C did.

CH-1C over Wichita in nearly the production paint scheme.

Other projects and CH-1C refinements were also being pursued in 1960. Design work on a new, fully coning tail rotor commenced; this improved tail rotor would be test flown the following year but, to my knowledge, was not incorporated on the production line machines. The Army RFP for the huge Light Observation Helicopter (LOH) program had many companies working feverishly on design proposals including Cessna. I was working hot and heavy on the "Performance Data Report", and other design features, for the Cessna CH-4 Design Proposal in the fall of 1960 and the full-scale mock-up was going together late in the year. The proposal had to be ready for submittal by January 16, 1961.

Consider this: by the end of this year, Cessna had been investing in the development of the CH-1 helicopter for eight and one-half years with very little return (delivery of ten ships to the Army and a small ONR contract). The company was betting on landing the LOH contract, a huge program, getting some military orders for a CH-1C instrument trainer, and getting a significant foothold in the civilian helicopter market with the Skyhook. This was the position of the Helicopter Division as the new year of 1961 dawned.

LOH

The CH-4 LOH proposal was submitted in full to the Army in January, 1961 to kick off the year. An award announcement was expected by May, 1961. Companies submitting proposals were Bell, Hiller, Boeing, Cessna, Gyrodyne, Kaiser, Kaman, McDonnell, Republic, Hughes, Lockheed and Sikorsky; a dozen contenders for two spots. The CH-4 mock-up is pictured below; the turbine engine compartment is located behind the rear seats.

Flight strain survey tests and performance tests on the new coning tail rotor took place during the first half of the year. Talk continued about Navy and Army interest in instrument trainers and the Navy indicated some interest in a turbine powered CH-1 using the Boeing engine.

Military contracts for Cessna helicopters were not to be in 1961. The LOH award went to Bell and Hiller in May, quite a blow to Cessna hopes for entry into large-scale military production. The Navy BuWeps were looking for an assault support helicopter for the Marines and the Army LOH designs did not satisfy their requirements, so bids for a for a new ASH helicopter were solicited from ten manufacturers, including Cessna, on October 16, 1961. Cessna, Gyrodyne and Doman did not respond. One item of LOH interest. The Hiller proposal for the LOH, as submitted to the Army, included a design philosophy report which outlined the Hiller design process for their proposal. A number of wind tunnel models of differing fuselage configurations were tested for drag. As part of the study, the report states, "...the Cessna YH-41 was studied as a representative high-speed helicopter. The models were built to gather wind tunnel data which could be compared with predicted performance figures..." The YH-41 wind tunnel model, as built and tested by Hiller, is pictured at left (from Hiller Engineering Report No. 60-101).

Production was in full swing at the Prospect plant on the Skyhook with an announced price of $79,960 and ships coming down the line in May, 1961. A fatal Skyhook accident took the life of Marketing Division pilot, Oliver Hopkins, near Midland, Texas in April. He was on a demonstration tour of the CH-1C. Hopkins was one of the airplane sales specialists who got a helicopter rating. I don't know what the final NTSB report found but, at the time, it was reported that an eyewitness, working on a powerline, saw the rotor chop off the tailboom. I assumed it was a power failure and the collective was not lowered in time to prevent rpm decay. The Cessna policy of not hiring helicopter pilots for sales work may have bitten them.

We had no serious accidents doing test work during the life of the program. One typical incident: Jack and I were doing a strain survey on the new coning tail rotor. Reversal maneuvers were required which entailed full travel tail rotor pedal reversals at the never-exceed-speed. Working up to it, we were trying the reversals with both left pedal first and with right pedal first. We managed to clobber the tailboom fin with a blade but everything stayed together so we flew back to the field, a flight of about ten minutes. Oddly, the same thing happened when I later worked at Hiller Helicopters as we struck the tail boom (and battery box) during left pedal first reversals at Vne on the UH-12L4, #2173, in 1964.

My recall is a bit sketchy, but around 1960-61 an Army YH-41 crashed in a steel yard in Albuquerque, New Mexico, killing the pilot and a female civilian who, most likely, was an unapproved passenger. I and a technician, Mel Osborne, drove all night in a VW to Albuquerque to investigate the wreckage. My brain must have fried in the 116 degree heat because I just can't remember much of it but I must have written a report. I received (7/03) comments from Bill Evans of Phoenix who remembers, as a young teenager, the Arizona Republic newspaper carried a front-page photo of the crashed YH-41 in an Albuquerque steelyard along with information that the Army pilot had met a flight attendant in a bar and decided to demonstrate the YH-41, crashing soon after takeoff.

The May, 1961 "Flying" magazine carried a significant pilot report on the Skyhook; this article was well timed to be just prior to first deliveries scheduled for June/July of the 1962 Skyhook. A CH-1C was featured at the Cessna Dealers All-Model Show at the famous Nut Tree Inn in June, 1961. Deliveries of new Skyhooks to dealers and distrubutors began in the fall of 1961.

The Helicopter Experimental Department 182, under Dick Ledwin, constructed a cut-away of the Skyhook for the training section ground school of the Marketing division in the summer of 1961. Dick is pictured below on the right as he shows the dynamic components and internal working parts of the CH-1C.

Cessna sold about fifteen (according to Charles Seibel in a 1991 video presentation) CH-1Cs to the U.S. Government, designated as UH-41As, under the U.S. Army Transportation Material Command, for use in the Military Assistance Program (MAP) or the Mutual Defense Assistance Pact (MDAP). Serial numbers were 62-5845/5848, 62-12350, 63-9793 and 63-8067/8071 (these s/n's add up to only 11so were there more?). Of interest, some of the MAP helicopters were delivered by Cessna in 1963 after the decision to scrap the commercial program was made. These ships went to Latin American or South American air forces and Iran and used primarily as high altitude rescue and casualty evacuation aircraft as pictured at left. No information seems to exist which documents the final disposal of these machines. Were they eventually returned to the U.S. Army for scrapping? - doubtful. Do some still exist? - perhaps. Any wrecks still in some overgown jungle hideaway? If you can shed any light on them please let me know. Reportedly, four Cessnas were delivered to Ecuadorian armed forces; who knows, maybe there is a Cessna helicopter hulk on some schoolyard playgound in Guayaquil or on some slope high in the Ecuadorean Andes! Some ships (three? - or more?) were operated in Iran as well. Bob Smith remembers spares manager Kenny Burris shipping a rotor blade to Iran in the early 1960s to replace a badly dented blade which had made contact with an unfortunate person's head. Ed MacKenzie recalls performing production test acceptance flights on two MDAP Skyhooks destined for Peru in 1962 - he also trained several Peruvian pilots. According to Seibel's 1991 video, some of the South American MAP ships were diverted to Iran.

Mr. Farzin Nadimi of Tehran, Iran has added (November 2003) some valuable information to the subject of Skyhooks in Iran. Mr. Nadimi is an aviation historian and has interest in the Cessna program. He writes, "Some time between 1962 or 1963 (Persian year of 1341), the Iranian Gendarmerie Aviation Unit received three Cessna UH-41A helicopters for observation, liason and utility purposes. Flying and maintenance crew were reportedly trained at the Lackland Army Aviation base (correct me if I'm wrong). Service of these helicopters were unique not only in Iran, but also the region. They were later replaced by Augusta-Bell 205 and 206 models, and no further information is available of their final fate." Mr. Nadimi has run across internet info which suggests that five ships, serial numbers 63-8067/8071, were destined for Iran under the MAP program but it is not confirmed. He has submitted two photos, shown below, of the Skyhook in Iranian service. It is interesting that the Skyhooks were replaced by Augusta-Bell turbine helicopters which would have been years after the Cessna buy-back of Skyhooks and the Army discarding the YH-41s - perhaps there is a junk CH-1 lurking somewhere in Iran serving as a chicken coop. Mr. Davood Moazami of Tehran, Iran, an aviation researcher, emailed information in December 2006 stating that there were five UH-41s delivered to Iran. He says that three helicopters crashed and two were retired because of low performance in Iran's mountains, but no dates were given.

The loss of the LOH competition and the obvious lack of any new and significant helicopter programs prompted me to start looking around for another job before the bottom fell out. The LOH was a magnet attraction so I applied to Bell and Hiller where I figured the light helicopter action would be the strongest. In August of 1961, I resigned from Cessna and moved to Palo Alto, California and joined the Flight Test Department of Hiller Helicopters.

1962 - THE LAST YEAR OF THE CESSNA HELICOPTER

Twenty-three civil CH-1Cs are reported to have been delivered (sold) by Cessna, most in 1962. Can anyone provide the exact number by serial numbers?

The Skyhook was presented at the 1962 Helicopter Association of America convention with two ships giving demonstrations.. The picture below, taken at the January, 1962 HAA, shows the Skyhook along with its major 1962 competition, the Hiller UH-12E4 and Bell J models.

Aviation photographer Chad Slattery kindly provided pictures of a 1962 Cessna 5" x 8" promotional postcard which is from the estate of Al Vopal who ran Custom Models in Macedonia, Ohio; Al made many models for Cessna but Chad can't recall seeing a Skyhook model. The back of the card has a rather flowery sales pitch for the Skyhook - I'm sure this text (see below) must have given a few helicopter operators a good laugh.

"The Skyhook is a perfect answer to man's ages old quest for taking the shortest distance between two points. In a Skyhook, you can gracefully climb up and over the congestion of the city or over bridgeless rivers with equally nimble ease. If you're involved in production, you can go from plant to plant...if you're in merchandising, you can go from store to store...and if you're in sales, you can literally go from door to door...and all directly...without wasting so much as a minute, a step or a penny in unnecessary travel time, effort or money!

"With the Skyhook you can lop hours of costly on-the-job commuting from your schedule. You can haul loads, survey building or development sites, link out-of-the-way facilities with the home office, or take advantage of your pick of a thousand other ingenious uses discovered by others. Or better still, invent a brand new application for the Skyhook, yourself.

"Start now. Plan to attend the special Skyhook showing as my personal guest. See the world's finest four-place, rotary-wing aircraft...the Cessna Skyhook for 1962. I'll be looking for you."

It has been reported that the Skyhook experienced numerous engine problems in actual service; the Continental FSO-526 at 3200 rpm apparently ate up cylinders, broke rods and a crankshaft failure was experienced - the 526 experienced fatigue failures from inertial loading at high rpm and low power, a common helicopter situation. The Skyhook was operated at the 1962 Seattle World's Fair by Seattle Helicopter Airways, Inc. as official transportation; the photo below is from a postcard. Incorporating five seats, it is reported that 10,000 passengers were carried during the fair by three operating Skyhooks. A helicopter charter poster from 1962 is also presented below.

A serious CH-1C accident happened in October 1962 in the Gulf of Mexico. A Skyhook on floats crashed into the Gulf with the loss of four lives. Only a few small parts and the floats were found and it was assumed that an engine failure resulted in a misjudged water autorotation landing attempt. November 2003: I've received a communication from James Brown of Lorain, Ohio who was three years-old when his father, Frank Gilbert Brown, was killed piloting this CH-1C in the Gulf. James would appreciate any information possible about this accident which is no longer carried in NTSB records.

New spray rig for Skyhook is shown in mid-1962. Permits normal coverage of 190 acres per hour in 70-foot swaths. Owned by Sky Hook Inc. of Durango, Colorado. Rig has 20-foot booms and two 45-gallong tanks.

Do you have information? There is a report that Alaska Coastal Airlines in Juneau, Alaska was considering a Skyhook (must have been 1962) - or perhaps bought one as a dealer - and the ship suffered an engine failure and plopped into the harbor and sank but the crew survived with no injuries. Is this true? Can you provide further info?

As 1962 was coming to an end, Cessna announced the new CH-1D model for 1963 which incorporated improvements; this new model was not available at the annual sales meeting in October. A new engine drive shaft to absorb torsional vibration, a rotor brake (we worked on that in 1961), an increase in gross weight to 3250 lbs., and a beefed up engine, the Whirlaway, which sported heavier connecting rods and bolts, heavier cylinder barrels, new supercharger clutch, new crankshaft damper weights, and double breaker mags.

Also incorporated in the CH-1D was an awful exhaust system which overcame the objections of the low, under fuselage exhaust stream. An exhaust pipe collected the gases in the collector/venturi box, was routed under the fuselage to the tail boom where it made a 45 degree angle change upwards, disappearing into the tail cone, and exiting above the tail cone (shown in the picture below). As I mentioned in the beginning of this article, the exhaust problem was never solved and this terrible arrangement only proves the point. This must be the reason for the gross weight increase! The "D" model received certification on December 24, 1962. With the "D" certification, there were six CH-1 models listed on the type certificate.

Cessna "Kinedyne" proposal. Following the unsuccessful 1961 bid for the LOH contract, the helicopter R&D efforts went into a replacement for the aging Army L-19 liason aircraft. A sort-of autogiro, the "Kinedyne", was proposed in 1962. This machine was turbine powered, had counter-rotating props for thrust and used a heavy, high inertia rotor which could be run-up for takeoff and would have adequate energy for near-hover landings. The trademark rotor system of the CH-1 was not evident as a completely different rotor was envisioned. Directional control in-flight was obtained by a rudder-like surface while directional control in the low-speed flight regime was gained by use of a torque control unit clutched to the main rotor. In hindsight, this proposed aircraft does not appear to be a very practical machine with far too many complexities for a two-place observation craft.

Don Burwell became a CH-1C flight instructor at Cessna in 1962. Don has kindly submitted the following comments concerning his brief employment with Cessna; I believe that he would have worked for the Sales Department as opposed to the Helicopter Division but I'm including the instructors in with Division personnel. Actually my use of "Division" is incorrect inasmuch as once production of the CH-1C started, the group became a "Department".

Don writes, " It is my understanding, the original Skyhook sales and training personnel were taken out of the ranks of the Cessna fixed wing division. Have no idea who trained them. This just did not work and some accidents occurred.

"A decision was made to search for someone who could revitalize the entire program. This resulted in the hiring of Ed MacKenzie. Ed was working for Southern Airways as a helicopter flight instructor and flight leader. Southern Airways had a civilian contract to teach Army personnel to fly helicopters at Camp Walter in Mineral Wells Texas. Ed's main duty at Cessna was chief helicopter instructor. Soon after, he was put into charges of sales and I was hired as the chief instructor. I was also a helicopter instructor at Camp Walters. Not sure how much flight time Ed had, but I had been flying helicopters in both the Navy and at Camp Walters for seven years and accumlictated over 8,000 hours. I am sure Ed had more than that.

Cessna received an FAA Approved Flight School Certificate in the spring of 1962; the school had been operating since August, 1961. The photo above shows The FAA General Aviation Operations Inspector, Theo Moore (R) presenting the Flight School Certificate to Dr. Robert McCormick, Cessna Director of Training and Edward MacKenzie, Head of Rotary Wing Flight Instruction. The school was part of the Cessna Marketing Division's training department and included both flight and maintenance training.

"Everything was put into place to make the Cessna helicopter program a success. It just did not happen before management pulled the plug. Sometimes I wonder if management even knew that Ed and I were there to reorganize the program.

"Ed was checked out by the test pilot and I was given a briefing and a one hour check ride by Ed before I felt comfortable with the Skyhook. My time was very short with Cessna, and once they dropped the program, they wanted to get rid of and erase an existence of the helicopter. All pictures and literature were ordered to be destroyed.

"Most of my time was spent demonstrating the Skyhook to potential buyers. As it turned out there was only one sales while I was there. I don't remember who the purchaser was, but they sent one of their employees to be trained. Using my experience and the flight training manual as a guide, the employee was able to solo without any difficulty. I would only guess that he was given about twenty hours of instruction. The cost was included in the total cost of the Skyhook. New owners were also given an extensive ground school training on the maintence of the Skyhook. Can't remeber the name of the ground school instructor, but he was also hired from Southern Airways.

"Ed remained with Cessna and became a very sucessful sales person before becoming a dealer for Cessna and then later for Beech aircraft."

Thanks Don for your insight to the sales effort at Cessna. Ed MacKenzie relates that he accumulated more than 500 flight hours in the Skyhook during his 15 months with the program and that he demonstrated the Skyhook from coast to coast. He experienced one flight incident which he describes as "unsettling"; lifting off to a hover, he lost hydraulic control boost, having to muscle the ship safely to the ground. A teardown inspection of the control system by Dick Ledwin and Charlie Seibel disclosed contamination in the hydraulic fluid. During our FAA flight tests on the CH-1, we had to demonstrate all flight maneuvers with the boost system turned off - loss of boost definitely resulted in high, but manageable, control forces.

West Coast Operations of the Cessna Skyhook. I recently had a conversation with Jack Coshow who now resides in Oregon. Jack was a P-38 pilot with the 95th Fighter Squadron of the famous 82nd Fighter Group of the 12th and 15th Air Force during World War II. Jack worked for United Airlines in quality control and was associated with a Cessna dealer, Sequoia Aviation, at San Carlos, California as a salesman in the early 1960s. Sequoia was owned by Lou Rohr and John Pritchard was sales manager.

Jack was with Sequoia - his first job in aircraft sales - when Cessna began delivering Skyhooks to dealers in the 1961-1962 era. Three Skyhooks were originally used as helicopter demonstrators on the West Coast. One at San Carlos, one at Van Nuys and one in Seattle. Sequoia Aviation was convinced that the Skyhook's superb altitude capability would result in sales in the Sierra; as far as Jack remembers, however, no Cessna helicopters found customers anywhere on the West Coast.

The Seattle World's Fair created a passenger market for the Seattle dealer and, as mentioned previously in this article, a brisk helicopter business was created giving passenger rides from the waterfront with a trip up around the needle. The Seattle Helicopter Airways operation was able to get FAA approval for a rear "bench-type" seat which then allowed four passengers to be carried in addition to the pilot - a real money maker. Long lines waiting for a ride convinced the dealer to get another Skyhook and apparently Cessna found another machine to provide the operation. Continued passenger interest resulted in the Seattle dealer contacting Sequoia Aviation and leasing Sequoia's Skyhook for a total of three working machines giving rides.

Previously unpublished photos (above and below) by Jim Larsen of the CH-1C of Seattle Helicopter Airways using the helipad at the Space Needle during the Seattle World's Fair.

About this time, a potential customer in the Reno area asked about the Skyhook so Sequoia made a deal to borrow the ship from Van Nuys in order to give a demonstration. Sequoia's chief helicopter pilot, Jack Loney, and Jack Coshow departed SFO on an early morning DC-6B to LAX with the intention of picking up the Skyhook and making it back to San Carlos that same day. Things went awry!

A nearly empty flight on the 4-engine Douglas so the stewardess invited the duo to sit up front in first class, a nice gesture. However, not so nice upon landing as the front tire blew and the business end of the airliner got shook pretty hard! Stuck on the runway, Jack and Jack didn't make it to the terminal to pick up their ride to Van Nuys on time. A phone call and wait eventually got them to Van Nuys where Loney inspected the Skyhook and determined that it was due a 25-hr. check. So they waited for the mechanics to finish off the check before getting ready to depart. Seeing that there was no way they could get back to San Carlos, they decided to RON at Oxnard; Loney called a motel on the field and made arrangements to set the helicopter down on their motel lawn.

Flying in to Oxnard, Loney wisely decided that the postage-stamp size lawn wasn't going to work as a landing site, so requested an air taxi to the local FBO. Hovering across the airport, the two Jacks saw a crowd and a red truck waiting for them on the ramp - such a reception! Turns out that at the 25-hr. inspection at Van Nuys, a mechanic failed to securely tighten an oil line and leaking oil was causing smoke to trail the Skyhook giving rise to a fire alarm by the observant tower operator. They made it back to San Carlos the next day - that helicopter wasn't sold and became one of the four on the West Coast that were bought back by Cessna in early 1963.

Jack Coshow fondly remembers the Cessna Skyhook and still has some memorabilia associated with the machine. He got about 5-hrs of dual and regrets never getting completely checked out in it.

More Sequoia/Skyhook connections: Richard A. "Dick" Bridgeford was the originator of the highly successful Bridgeford Flying Service at Lake Tahoe, Stockton and Napa airports; Dick has recently written of his aviation experiences in a published book, Living the High Life. He obtained a helicopter license as part of a Brantly Helicopter sales outlet deal. BFS was a Cessna dealer at Stockton and Dick flew with Sequoia's chief helicopter pilot, Jack Loney, in a Sequoia-owned CH-1C to Lake Tahoe to demonstrate the ship to Bill Ledbetter of the Harveys Resort Hotel; they flew to the hotel parking lot, demonstrated the helicopter, and flew back to Stockton. This would have been in 1962. Dick has provided me with the two photos shown below, taken at that time. Dick Bridgeford is the gentleman standing on the left.

Received the following comments from Bill Evans in February 2006: " I really enjoyed reading your web page about the Cessna Skyhook. Executive Aircraft which was a Cessna dealer in Kansas City, MO had a Cessna Skyhook. It was operated by a pilot by the name of Jerry Getz. He was probably one of the few operators with any degree of sucess with this helicopter. Later when Cessna recalled the remaining aircraft and bought them back he became a professional witness for Cessna in many of the lawsuits that came about. I did some flying with Jerry Getz in the early sixties and he had many good stories about flying the Skyhook."

The decision was made on December 26, 1962 to kill the Cessna helicopter program entirely. Accumulated problems, poor timing, looming turbine-powered competition, lack of sales, a poor fit in the Cessna company, loss of any potential military sales, or maybe conflicting attitudes in management - whatever the reasons, Dwane Wallace, chairman of the Board, made the announcement in January 1963. All existing civil CH-1s in the field were bought back by Cessna in order to eliminate any ongoing servicing support (and product liability!). The returned ships were scrapped along with unsold inventory (a Kansas correspondent wrote that when he was a very young lad, he remembers seeing Skyhooks piled in a Wichita wrecking yard. Now, if we could locate that yard, old records might exist indicating how many were scrapped). Subsequent information comes from Leon Bowman who worked at Cessna from 1964 to 1974 - he remembers seeing a CH-1 fuselage in a wrecking yard on Waterman Street between Broadway and the railroad tracks on the north side of the street. Does anyone else have a recollection of this salvage yard?

The end of the line for the Cessna helicopter - a rather ignominious way for a record setter to die. Cessna, however, did continue to deliver MAP helicopters to foreign countries into 1963 and I have no idea how these were supported. The high altitude (or hot weather) capability of the Cessna made the ship popular with MAP users and more could have been sold; also, the Army had a continuing interest in the CH-1C as an instrument trainer. It is estimated that a total of somewhere between 47 and 50 CH-1's of all models were constructed but the exact number is not known nor is it likely to be known - there were ships in construction at the time of the shutdown that would have received serial numbers. Charles Seibel is quoted as saying that there were "approximately fifty" built.

To add further to the saga of the CH-1's demise, Cessna cancelled the CH-1 FAA Type Certificate, 3H10, in 1989 thereby removing the Cessna Skyhook from all records.

Note: Charles Seibel and Sanford Hinton, prime movers of the helicopter division, are both deceased. Seibel had a large archive of photos and movies of the CH-1 project - the whereabouts unknown of the originals but Seibel made a video in 1991 using much of his material. Jack Leonard took a position as manager of a new eastern office in Washington for the Hughes Tool Company after leaving Cessna in early 1962 - he became responsible for coordination of the company's military programs in the eastern states.

CHARLES SEIBEL - Post Cessna. A little note of interest. Seibel went on to Bell Helicopter from Cessna and he developed the Huey Cobra in short order, a huge success for Bell at the time. Seibel was the Chief Experimental Project Engineer and was given the job in 1964 to investigate an improved version of the UH-1B in the weapons role. The prototype HueyCobra was started in early 1965 using many components from the UH-1C helicopter. Prototypes were flown with both retractable gear and skids during the development program. In February 2004, the new CEO of Bell, Mike "Red" Redenbaugh, had the following exchange in an interview with a Defence Helicopter magazine reporter who queried, "The thing about the Huey is they got it done in months (Vietnam), the attack one as well. Here we are on Year Fifteen, or something, on LHX-Comanche. Crazy stuff..." and Mr. Redenbaugh answered, "You hit an intriguing question and in fact just yesterday I asked them to go back and pull the supplementary data on all that. When you want to go down the road ahead, sometimes you ask the people coming back what they saw! There's a lot of history, a lot of passion to the Huey. I want to 'reach back' and see what they did." Well, "Red", Charles Seibel was the reason that the HueyCobra program was so successful so quickly as you will no doubt find out. The industry today needs people who know how to get things done but the existing corporate culture and military complexities stifle the "free enterprise" approach that was used by Seibel and many others such as the Lockheed "Skunk Works".