Piper PA-30 Twin Comanche

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PA-30 Twin Comanche
Piper PA-30 Twin Comanche landing.jpg
1965 model Piper Turbo Twin Comanche with deicing boots installed
RoleCabin monoplane
ManufacturerPiper Aircraft
First flight3 May 1963[citation needed]
Number built2,142
 
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PA-30 Twin Comanche
Piper PA-30 Twin Comanche landing.jpg
1965 model Piper Turbo Twin Comanche with deicing boots installed
RoleCabin monoplane
ManufacturerPiper Aircraft
First flight3 May 1963[citation needed]
Number built2,142
Turbo PA-30 with tip tanks and vortex generators installed
PA-30 Twin Comanche with modified dorsal fin and modified air intake in nacelles
PA-30 Twin Comanche

The Piper PA-30 Twin Comanche is an American twin-engined cabin monoplane designed and built by Piper Aircraft. It was a twin-engined development of the PA-24 Comanche single-engined aircraft. A variant with counter-rotating propellers was designated the Piper PA-39 Twin Comanche C/R.

Development[edit]

The Twin Comanche was designed to replace the Piper Apache in the company's lineup of products. The Twin Comanche was developed from the single-engined Comanche by Ed Swearingen who at the time operated a facility that specialized in the modification of production aircraft. The normally aspirated aircraft was equipped with two 4-cylinder 160 hp (120 kW) Lycoming IO-320-B1A fuel injected engines, but 200 hp (150 kW) engines were available as a modification. A version with turbocharged engines for higher altitude flight was also developed, using IO-C1A engines of the same nominal power. All Twin Comanche engines have long times between overhaul (2000 hours for the B1A) and have developed a reputation for reliability. The PA-39 was a version with counter-rotating engines (to eliminate the critical engine) that replaced the PA-30 in the early 1970s. The Twin Comanche was produced on the same Lock Haven, Pennsylvania production line as its single-engined cousin; production ceased when the factory was flooded in 1972. Piper chose at that time to focus on its equally-popular Cherokee 140/180/235/Arrow line, manufactured in Florida, and its highly popular twin-engined Seneca, which is essentially a Twin Cherokee Six. The Piper PA-40 Arapaho had been scheduled to replace the PA-39 in the 1973-4 timeframe. Three were manufactured, and the aircraft was already fully certified when the decision was made not to proceed with the manufacture. One of the three Arapahos was destroyed in a flat spin accident in 1973; the test pilot (who was none other than future aviation entrepreneur Clay Lacy) successfully escaped. One was scrapped by Piper. One remains flightworthy as of this writing but is not currently being flown.

Design[edit]

The Twin Comanche is a low-wing cantilever monoplane with a retractable tricycle landing gear. The Twin Comanche is the most fuel-efficient aircraft in its class. With tip tanks, the aircraft holds 120 gallons (454 l) of fuel. Fuel burn at typical cruise settings is approximately 15.5 gph (58.7 lph) with a cruise speed of 165 kts. It easily climbs to 18,000' (5,500 m) when desired (24,000' - 7,300 m - if turbocharged). When compared with the Seminole (in reality a Twin Arrow), the Twin Comanche goes faster, carries more, burns less fuel, climbs more rapidly and ultimately higher, is quieter, and is more difficult for a novice to land. When compared to the Seneca, which is really quite a different aircraft, the more noticeable differences are in handling. Another contemporary competitor to the Twin Comanche was the Beechcraft Travel Air. A similar airplane in form and function was the Gulfstream American GA-7 Cougar, which went into production after the Twin Comanche's production run ended.

Operational history[edit]

An early high-ratio of training accidents on the original Twin Comanche was reduced by raising the minimum airspeed at which engine-out flights were conducted. In the 1960s, engine-out stalls were performed as part of multiengine training at low altitudes. This, combined with the Twin Comanche's ease of entry into a flat spin if an engine-out stall is taken too far, led to many early accidents. A revision of training procedures combined with revised placarded speed restrictions for single-engine operation as well as a service bulletin which added a rudder-aileron interconnect and leading edge stall strips resulted in a significant improvement in the accident rate.[citation needed]

Prince William of Gloucester bought a Twin Comanche and used it as his personal aircraft for several years in the 1960s. He flew it from the United Kingdom to Nigeria, where he held a diplomatic post; then later returned in it to the United Kingdom and flew it to Japan when he took up a diplomatic post in that country.[1]

A Twin Comanche was flown in the 1992 and 1994 French Arc en Ciel air races. It is the only US aircraft to have raced twice around the world. In the pilot-skilled races, 1992 pilot and Pioneer Hall of Fame enshrinee and 100 Aviation Hero for the First Century of Flight, Marion P. Jayne and her daughter Nancy Palozola placed second. In 1994 Jayne and her daughter, Patricia Jayne (Pat) Keefer won the FAI Gold Medal in what, so far, is the longest race in history at over 21,000 miles flown May 1–24, 1994. With FAA approval the twin carried a total of 252 gallons in 11 tanks and at maximum power went over 2,100 miles nonstop between Marrakech, Morocco and Istanbul, Turkey in 11:19 hours.[2]

Variants[edit]

Three versions of the PA30 were produced: the original, a B model, and a C model. The B and C models can carry six passengers and can be identified by the additional side windows. Factory turbocharged engines became available in 1965. Turbo models can be identified by the presence of vents on the nacelle sides. These use Rajay turbochargers with manual wastegates operated by twin knobs under the throttle quadrant. They are properly termed "turbonormalized" since the compression ratio and maximum manifold pressure remained unchanged. Pilots are required to use care to avoid overboosting at low altitudes, since no overboost popoff valves are used. Since there is no accompanying power increase, the B/C models simply give owners a fuel vs. passenger tradeoff. The two rearmost seats, occupying the baggage compartment, are quite small.

PA-30 Twin Comanche
Four-seat twin-engined cabin aircraft. PA-24 with engine removed and nose faired in and powered by two 160-hp (119-kW) Lycoming IO-320-B1A engines in wing-mounted nacelles. Optional turbos were Rayjay models as on later iterations, but kept the B1A version of the engines.[citation needed]
PA-30B Twin Comanche
PA-30 with a third cabin window on each side and an optional fifth or sixth seat.
PA-30B Turbo Twin Comanche
Turbonormalized version of the PA-30B Twin Comanche, powered by two Rayjay turbonormalized IO-320-C1A piston engines.
PA-30C Twin Comanche
Twin Comanche B with new instrument panel, switches, and other minor variations. Optional turbonormalized version.
PA-30-200 Twin Comanche B
Experimental PA-30 with two 200hp Lycoming engines, one only from Piper.
PA-39 Twin Comanche C/R
PA-30 with counter-rotating 160hp Lycoming IO-320-B1A engines and modified wing leading edges.
PA-39 Turbo Twin Comanche C/R
Turbocharged version of the PA-39 Twin Comanche C/R.
Piper PA-40 Arapaho
Developed and fully certified version of PA-39 with entirely different wing and extensive fuselage modifications. Three prototypes only.

Specifications (PA-39)[edit]

Data from The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985), 1985, Orbis Publishing, Page 2735

General characteristics

Performance

See also[edit]

Related development

References[edit]

Notes
Bibliography

External links[edit]

Media related to Piper PA-30 Twin Comanche at Wikimedia Commons