Blog on World of Civil Airplanes : Piper PA-34 Seneca is an American twin-engined light Aircraft,

The Piper PA-34 Seneca is an American twin-engined light Aircraft, produced by Piper Aircraft since 1971 and still in production in 2012.The Seneca is primarily used for personal and business flying

Country of origin

United States of America

History

The most successful six place light twin since its introduction, the Seneca is a twin engine development of the Cherokee Six.

Seneca development began when Piper flew a converted trimotor Cherokee Six, designated PA-32-3M, fitted with two additional 85kW (115hp) Lycomings O-235 on either wing. The subsequent twin engine prototype PA-34-180 Twin 6 first flew with two 135kW (180hp) Lycomings, while the definitive standard third Seneca prototype, the PA-34-200 Twin 6, first flew in October 1969 with fuel injected 150kW (200hp) IO-360s. Production deliveries of the initial PA-34-200 Seneca began in late 1971.

Handling and performance criticisms were addressed from the 1974 model year with the PA-34-200T Seneca II which introduced changes to the flight controls and, more importantly, two turbocharged Continental TSIO-360-Es. Piper originally planned that the follow-on PA-34-220T Seneca III would feature a T-tail, but these plans were dropped and the main changes introduced were counter rotating 165kW (220hp) TSIO-360s and a revised interior and instrument panel. Introduced in 1981, the Seneca III was replaced by New Piper's improved PA-34-220T Seneca IV in 1994 with aerodynamic refinements, axisymetric engine inlets and a revised interior.

The current PA-34-220T Seneca V was introduced in January 1997. It features intercooled turbocharged L/TSIO-360-RB engines which maintain rated power to 19,500ft, and seating for five, with a standard entertainment/executive workstation with extendable worktable and optional phone/fax. A sixth seat in place of the workstation is optional.

The Seneca was also built or assembled by other manufacturers, AICSA in Colombia, Chincul in Argentina (as the PA-A-34), Embraer in Brazil (as the EMB-810), and PZL-Mielec in Poland (as the M-20 Mewa, partly with PZL/Franklin engines).

Conversions are made by Seguin as the Princess, and by Robertson as the Super Seneca I and II.

Development

The Seneca was developed as a twin-engine version of the Piper Cherokee Six. The prototype was a Cherokee Six that had wing-mounted engines installed, retaining its nose engine. The prototype was flown as a tri-motor aircraft in the initial stages of the test-flying program.

PA-34-180 Twin Six

With the decision to abandon the three-engined design tested on the PA-32-3M the PA-34 was developed as a twin-engined design. The prototype PA-34-180 Twin Six, registered N3401K first flew on 25 April 1967. The prototype had two 180 hp (134 kW) Lycoming O-360 engines, a fixed nosewheel landing gear and a Cherokee Six vertical tail. The second prototype flew on 30 August 1968, still with the 180 hp (134 kW) Lycomings but had retractable landing gear and a taller vertical tail. During development flying the wingspan was increased by two feet. The third prototype was closer to the production standard and flew on 20 October 1969; it was fitted with 200 hp (149 kW) Lycoming IO-360-A1A engines.

PA-34-200 Seneca I

Certified on 7 May 1971 and introduced in late 1971 as a 1972 model, the PA-34-200 Seneca I, is powered by pair of Lycoming IO-360-C1E6 engines. The righthand engine is a Lycoming LIO-360-C1E6 engine variant, the "L" in its designation indicating that the crankshaft turns in the opposite direction, giving the Seneca I counter-rotating engines. The counter-rotating engines eliminate the critical engine limitations of other light twins and make the aircraft more controllable in the event of a shut down or failure of either engine. A total of 934 Seneca I models were built, including one prototype.

The early Seneca I models have a maximum gross weight of 4,000 lb (1,810 kg), while later serial numbers allowed a take-off weight of 4,200 lb (1,910 kg).

PA-34-200T Seneca II

Responding to complaints about the aircraft's handling qualities, Piper introduced the PA-34-200T Seneca II. The aircraft was certified on 18 July 1974 and introduced as a 1975 model.

The new model incorporated changes to the aircraft's control surfaces, including enlarged and balanced ailerons, the addition of a rudder anti-servo tab, and a stabilator bobweight.

The "T" in the new model designation reflected a change to turbocharged, six cylinder Continental TSIO-360E or EB engines for improved performance, particularly at higher altitudes. The Seneca II retained the counter-rotating engine arrangement of the earlier Seneca I.

The Seneca II also introduced optional "club seating" whereby the two center-row seats face rearwards and the two back seats face forward allowing more legroom in the passenger cabin. A total of 2,588 Seneca IIs were built.

Gross weights are 4,570 lb (2,070 kg) for takeoff and 4,342 lb (1,969 kg) for landing, with all weight in excess of 4,000 lb (1,800 kg) required to be fuel.

PA-34-220T Seneca III

In 1981, the PA-34-220T Seneca III was introduced, having completed certification on 17 December 1980.

The change in model designation reflected an engine upgrade. Continental TSIO-360-KB engines were used which produced 220 horsepower (165 kW), although only rated as such for five minutes and then dropping to 200 hp (149 kW)).

The horsepower increase, with the new engines' limit of 2800 rpm (up from 2575 rpm), combined for much improved climb and cruise performance. The new aircraft also incorporated a one piece windshield and a bare metal instrument panel instead of one covered with a removable plastic fascia; and some models have electrically-actuated flaps. More than 930 Seneca IIIs were built; the last 37 Seneca IIIs built had a 28-volt electrical system rather than the 14-volt system of previous aircraft.

The aircraft's gross weight was increased to 4,750 lb (2,155 kg) for takeoff and 4,513 lb (2,047 kg) for landing.

PA-34-220T Seneca IV

In 1994, the "New" Piper Aircraft company introduced the Seneca IV, having achieved certification on 17 November 1993. This model was similar to the Seneca III offering minor improvements, such as a streamlined engine cowl for increased cruise performance. It continued to use the counter-rotating Continental TSIO-360-KB engines and gross weights remained unchanged.A total of 71 Seneca IVs were built.

PA-34-220T Seneca V

Certified on 11 December 1996, the Seneca V was put into production as a 1997 model year. Again the cowls were redesigned for increased performance, several cockpit switches were relocated from the panel to the headliner, and an improved engine variant, the Continental TSIO-360-RB, fitted with an intercooler, was used.

The Seneca V's gross weights remain the same as the Seneca III and IV at 4,750 lb (2,155 kg) for takeoff and 4,513 lb (2,047 kg) for landing.

Embraer EMB-810 Seneca

From 1975 the Seneca was built under licence in Brazil by Embraer as the EMB-810. The PA-34-200T was produced as the EMB-810C Seneca (452 built) and the PA-34-220T as the EMB-810D (228 built).

Operators

Civil

The aircraft is popular with air charter companies and small feeder airlines, and is operated by private individuals and companies. One notable civil operator is the Costa Rican Air Surveillance Service.

Military

Brazil

Brazilian Air Force (EMB 810C Seneca)

Panama

Panamanian Public Forces

Serbia

Serbian Air Force

Accidents and incidents

On 17 February 1982 a Piper Seneca crashed near Hanover, Germany.[13] The only survivor was football manager Uli Hoeneß.

On 18 August 2012 a PA-34-200 Seneca crashed in the Philippines, killing Philippine Interior and Local Government Secretary Jesse Robredo.[14]

Specifications (PA-34-220T Seneca V)

General characteristics

Crew: One

Capacity: Five or six passengers

Length: 28 ft 7.44 in (8.72 m)

Wingspan: 38 ft 10.87 in (11.86 m)

Height: 9 ft 10.8 in (3.02 m)

Wing area: 208.7 ft² (19.39 m²)

Airfoil: laminar flow NACA 652-415

Empty weight: 3212 lb (1457 kg)

Loaded weight: 4773 lb (2165 kg)

Useful load: 993 lb (450 kg)

Max. takeoff weight: 4750 lb (2155 kg)

Powerplant: 2 × Continental TSIO-360RB and LTSIO-360RB 6-cylinder, air-cooled, horizontally-opposed piston engine, 220 hp (164 kW) each

Performance

Never exceed speed: 204 knots (378 km/h, 235 mph)

Maximum speed: 204 knots (378 km/h, 235 mph) at 23,000 ft (7,000 m)

Cruise speed: 188 knots (348 km/h, 216 mph) econ cruise at 25,000 ft (7,600 m)

Stall speed: 61 knots (113 km/h, 70 mph) wheels and flaps down

Range: 870 nmi (1611 km, 1000 mi) max fuel, econ cruise at 18,000 ft (5,500 m), no reserves

Service ceiling: 25,000 ft (7,620 m)

Rate of climb: 1550 ft/min (7.87 m/s)

Wing loading: 21.2 lb/ft² (104 kg/m²)

Power/mass: 0.1 hp/lb (164 W/kg)

Powerplants

PA-34-200 Seneca - Two 150kW (200hp) Lycoming IO-360-A1A fuel injected flat fours driving two blade c/s props.

PA-34-220T Seneca V - Two 165kW (220hp) Teledyne Continental L/TSIO-360-RB turbocharged, intercooled fuel injected counter rotating flat sixes driving two blade Hartzell or optional three blade McCauley c/s prop.

Performance

PA-34-200 Seneca - Max speed 314km/h (170kt), max cruising speed 300km/h (160kt), long range cruising speed 267km/h (144kt). Initial rate of climb 1360ft/min. Service ceiling 19,400ft. Max range with no reserves 1818km (982nm).

PA-34-220T Seneca V - Max speed 379km/h (205kt), max cruising speed at 10,000ft 341km/h (184kt), at 18,500ft 367km/h (198kt), normal cruising speed at 10,000ft 322km/h (174kt), at 16,500ft 352km/h (190kt). Initial rate of climb 1550ft/min. Max certificated altitude 25,000ft. Range at max range power with reserves at 10,000ft 1295km (700nm), at 18,500ft 1222km (660nm).

Weights

PA-34-200 Seneca - Empty 1190kg (2623lb), max takeoff 1905kg (4200lb).

PA-34-220T Seneca V - Empty equipped 1532kg (3377lb), max takeoff 2155kg (4750lb).

Dimensions

PA-34-200 Seneca - Wing span 11.85m (38ft 11in), length 8.69m (28ft 6in), height 3.02m (9ft 11in). Wing area 19.2m2 (206.5sq ft).

PA-34-220T Seneca V - Same except length 8.72m (28ft 8in). Wing area 19.4m2 (208.7sq ft).

Capacity

Seating for six in all but Seneca V which seats five or optionally six.

Production

Approximately 4750 Senecas built by Piper (incl approx 200 Vs), plus approx 20 Seneca IIs licence built in Poland by PZL-Mielec as the M-20 Mewa, and over 870 in Brazil by Embraer as the EMB-810.

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