Blog on World of Civil Airplanes : PIPER PA-30/39 TWIN

PIPER PA-30/39 TWIN

Jagriti Srivastava

The Twin Comanche was a derivative of the single engine Comanche and was introduced in 1963 as a replacement for the Apache H. Little was done to the original Comanche fuselage when it was adapted for use in the Twin Comanche in order to simplify tooling and assembly operations. The PA-30 was offered in four models: Standard, Custom, Sportsman, and Turbo. The latter differed in engine power, and the rest contained different interior appointments, electronics, and instrumentation. Piper announced the end of PA-30 production in 1970 and introduced a new PA-39 line. The new Twin Comanche was fitted with counter-rotating props to simplify engine-out procedures. A starboard engine that was a mirror image of the port engine equalized the single-engine performance of both powerplants. Piper also claimed improved flight characteristics due to a balanced airflow over each wing.

DEVELOPMENT

The Twin Comanche was designed to replace the Piper Apache in the company's line up 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. 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

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).

VARIANTS

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.

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)

General characteristics

Capacity: four/six seat

Length: 25 ft 2 in (7.67 m)

Wingspan: 36 ft 9½ in (11.21 m)

Height: 8 ft 3 in (2.51 m)

Wing area: 178 ft2 (16.54 m2)

Empty weight: 2270 lb (1030 kg)

Gross weight: 3725 lb (1690 kg)

Powerplant: 2 × Avco Lycoming IO-320-B1A flat-four piston engine with counter-rotating propellers, 160 hp (119 kW) each each

Performance

Maximum speed: 205 mph (330 km/h)

Range: 1200 miles (1931 km)

Service ceiling: 20,000 ft (6095 m)

POWERPLANTS

PA-30-160 - Two 120kW (160hp) Lycoming IO-320-B1A fuel injected flat four piston engines driving two blade constant speed Hartzell propellers.

PA-39 - Two 120kW (160hp) counter rotating Lycoming L/IO-320-C1As.

PERFORMANCE

PA-30-160 - Max speed 330km/h (178kt), max cruising speed 312km/h (168kt), long range cruising speed 267km/h (144kt). Initial rate of climb 1460ft/min. Service ceiling 18,600ft. Max range with no reserves and standard fuel 1795km (970nm), or with tip tanks 2190km (1182nm).

PA-39 Turbo - Max speed 376km/h (203kt), max cruising speed 357km/h (193kt), economical cruising speed 327km/h (177kt). Initial rate of climb 1460ft/min. Service ceiling 25,000ft. Range at max cruising speed 2373km (1282nm), range at economical cruising speed 2582km (1395nm).

WEIGHTS

PA-30-160 - Empty 1002kg (2210lb), max takeoff 1633kg (3600lb), or 1690kg (3725lb) with tip tanks.

PA-39 Turbo - Empty 1097kg (2416lb), max ramp 1690kg (3725lb).

DIMENSIONS

Wing span 10.97m (36ft 0in) or 11.22m (36ft 10in) with tip tanks, length 7.67m (25ft 2in), height 2.49m (8ft 2in). Wing area 16.5m2 (178sq ft)

CAPACITY

Typical seating for four, including pilot in Twin Comanche. Up to six including pilot in Twin Comanche B.

PRODUCTION

Total Twin Comanche production was 2156, comprising 2001 PA-30s and 155 PA-39s.

Regards,