CESSNA SKYMASTER

The 'Cessna Skymaster' is a twin-engine civil utility aircraft built in a push-pull configuration. Instead of the engines being mounted on the wings, one is mounted on the nose and the other at the rear of the pod-style fuselage. The stabilizers are mounted on twin booms that extend from the wings. The rear engine is between the booms. The combination of a tractor and a pusher engine produces a unique sound.

Contents

Development

Design

Operational history

Variants

Cessna 327

Cessna 336

Cessna 337

Reims Cessna F337

Conroy Stolifter

Summit Sentry

Spectrum SA-550

Military Operators

Specifications (337D)

External links

Related content

Development

The first model of the Skymaster was the '336'. It had fixed landing gear and first flew in February 1961. It went into production in 1963 and 195 were produced to mid 1964.
In 1965 Cessna introduced the model '337 Super Skymaster'. This aircraft was larger, had more powerful engines, retractable landing gear and a dorsal air scoop for the rear engine (the "Super" was subsequently dropped from the name). In 1967 the turbocharged 'T337' was introduced and in 1972 the pressurized 'T337G' entered production. Cessna built 1,859 standard and turbocharged Skymasters and 332 T337Gs. In addition, they built 513 military O-2 versions.
Cessna production ended in 1982 but Skymaster production continued with Reims in France with the 'FTB337' STOL and the military 'FTMA ''Milirole'''. Reims produced a total of 94 Skymasters.
After a 20-year hiatus the centerline thrust, pod and twin-boom concept has been revived in the Adam A500.

Design

The Skymaster has different handling characteristics than a conventional twin-engine aircraft. Foremost is that it will not yaw into the dead engine if one engine quits. Consequently, it has no tendency to depart the runway if an engine fails on the takeoff roll. The adage, "dead foot, dead engine" -- used to remind a pilot which propeller to feather when an engine quits -- is useless with the Skymaster. When a Skymaster loses power, the pilot must use the instruments to determine which engine has failed. The Skymaster is also controllable at lower airspeeds than a comparable conventional twin. There is no minimum controllable speed advisory (Vmc) on the airspeed indicator. Nevertheless, the Skymaster requires a multi-engine-rated pilot, and must be trained to manage both engines.
One would think that with the Skymaster's superior single-engine handling it would have a lower accident rate than conventional twins. This turns out not to be true. The rear engine tends to overheat and quit while taxiing on very hot days. When this has happened, many pilots have inexplicably attempted take-off on the nose engine alone even though the single-engine take-off roll exceeded the runway length. The Skymaster also has a higher-than-average rate of accidents due to fuel mismanagement. This is puzzling since the fuel system is unremarkable.
The Skymaster produces a unique unmistakable sound. All rear-engined aircraft produce a characteristic sound as the propeller slices through turbulent air coming off the airframe. Since the Skymaster also has a nose engine, with a propeller that operates in undisturbed air, its sound is different from a pure pusher. This sound can be heard in the movie Bat
★ 21 where Danny Glover's character flies an O-2 Skymaster.

Operational history

The California Division of Forestry uses various models of the 337 Skymaster as spotter planes during firefighting operations.
In 1994 the Cuban exile group ''Hermanos al Rescate'' (Brothers to the Rescue) used Skymasters to drop life-saving supplies to rafters attempting to cross the Florida Straits to defect from Cuba. They were also used to violate Cuban airspace, flying over Cuba's capital, Havana, and dropping leaflets with anti-Castro propaganda. They chose Skymasters because they were easier to control at slow speeds than conventional twin-engine aircraft. One plane contacted the water (it is difficult to judge altitude over relatively calm water), damaging the landing gear doors and the nose propeller. Since the rear engine is mounted higher, it wasn't damaged and the aircraft was able to return to Florida to make a belly landing.
In 1996 two of the Brothers to the Rescue's Skymasters were shot down by the Cuban Air Force over international waters. One by a MiG-23 and another by a MiG-29.

Variants

Cessna 327

★ '327 Mini Skymaster' - reduced scale version of the 337, with cantilever wings (instead of the strut-braced configuration), one built. The cantilever wing was not stiff enough to prevent "boom bounce", a persistent up-down movement of the empennage after any disturbance due to turbulence or pilot input. This problem, together with an unacceptably high estimated cost of production, led to the factory decision to cancel further work on this program. Only known prototype was delivered to NASA to serve as a full blown model for wind tunnel testing.

Cessna 336

★ '336 Skymaster' - production version powered by two 195 hp Continental IO-360-A engines, 195 built.

Cessna 337

★ '337 Super Skymaster' - 336 with retractable undercarriage, re-designed nose cowling and new rear engine intake, and greater wing angle of incidence, powered by two 210hp Continental IO-360-C engines, 239 built.

★ '337A Super Skymaster' - 337 with minor detail changes, 255 built.

★ '337B Super Skymaster' - 337A with increased take-off gross weight, option belly cargo pack and optional turbocharged engines, 230 built.

★ '337C Super Skymaster' - 337B with a new instrument panel and increased take-off gross-weight, 223 built.

★ '337D Super Skymaster' - 337C with minor detail changes, 215 built.

★ '337E Super Skymaster' - 337D with cambered wingtips and minor changes, 100 built.

★ '337F Super Skymaster' - 337E with increased take-off gross weight, 114 built.

★ '337G Super Skymaster' - 337F with split airstair entry door, smaller rear side windows, improved flaps, larger fron propeller, powered by a Continental IO-360-G engine, 352 built.

★ 'T337G Super Skymaster' - 337G with presurised cabin and turbocharged engines, 292 built.

★ '337H Skymaster' - 337G with minor changes and optional turbocharged engines, 136 built.

★ 'P337H Pressurised Skymaster' - T337G with minor changes, 64 built.

★ '337M' - US military version, designated O-2 Skymaster in service, 513 built.

★ 'O-2A' - US military designation of the 337M Forward air control, observation aircraft for the US Air Force.

★ 'O-2B' : Psychological warfare version for the US Air Force (31 former civil aircraft not 337Ms).

★ 'O-2T' : Twin turboprop-powered version of the O-2.

★ 'O-TT' :

★ 'Sentry O2-337' : Military version.

★ 'Lynx' : Armed military version for the Rhodesian Air Force.

★ 'T337H-SP'

Reims Cessna F337

★ 'F337E Super Skymaster' - Reims-built 337E, 24 built.

★ 'F337F Super Skymaster' - Reims-built 337F, 31 built.

★ 'F337G Super Skymaster' - Reims-built 337G, 29 built.

★ 'FT337G Super Skymaster' - Reims-built T337G, 22 built.

★ 'F337H' - Reims-built 337H, one built.

★ 'FP337H Pressurised Skymaster' - Reims-built P337H, 1 built.

★ 'FTB337G Milirole' - Reims-built military F337G with Robertson STOL modifications and underwing hardpoints, 61 built.

★ 'Lynx' : Rhodesian designation for 21 FTB337Gs delivered to the Rhodesian Air Force.

Conroy Stolifter

One 337 radically modified by Conroy Aircraft as a STOL cargo plane. Front engine replaced with an Garrett AiResearch TPE-331 and rear engine with an extended cargo pod.
===AVE Mizar===
Flying car created by Advanced Vehicle Engineers by attaching the wings, tail, and rear engine of a Skymaster to a Ford Pinto outfitted with aircraft controls and instruments.

Summit Sentry

Summit Aviation built a militarized Skymaster as the 'O2-337' in 1980, and sold a few examples to the Haiti Air Corps and the Thai Navy

Spectrum SA-550

Spectrum Aircraft Corporation of Van Nuys, California made an extensive conversion of a Reims FTB337G in the mid 1980s - the 'Spectrum SA-550'. They removed the nose engine, lengthened the nose and replaced the rear engine with a turboprop. This aircraft (serial number 61) is currently registered to Basler Turbo Conversions of Oshkosh, Wisconsin.

Military Operators

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★ : Chilean Air Force

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★ : Portuguese Air Force (32 FTB-337G)
These aircraft were bought in 1973 by Portugal to replace its aging Dornier Do-27 that were being intensively used in the Portuguese Colonial War, but the first deliveries only arrived in December 1974 - after the end of the war. The last Skymaster in service with the Portuguese Air Force was retired in July 25, 2007.

★ : South African Air Force

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★ : Thai Air Force

★ : Togo Air Force

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★ (Rhodesia)

★ Tamil Eelam

Specifications (337D)

External links

★ The Unofficial Cessna Skymaster Web Site

★ Hermanos al Rescate

★ The Spectrum SA-550

★ Mitzar, Flying Pinto?

★ A Pinto for Icarus

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