TYPE: Six-seat utility twin.

PROGRAMME: Original PA-34 Seneca certified 7 May 1971 and announced 23 September 1971, having been preceded by prototypes of fixed-gear PA-34-180 Twin Six (flown 25 April 1967) and retractable gear version in following year; 149 kW (200 hp) engines; redesignated Seneca II with increased MTOW, certified 18 July 1974 and introduced for 1975; improved Seneca III with more powerful counter-rotating (C/R) engines certified 17 December 1980 and introduced 15 February 1981; Seneca IV with axisymmetric engine inlets, aerodynamic refinements and interior improvements and restyling certified 17 November 1993 and introduced in 1994. Seneca V with L/TSIO-360-RB engines unveiled 16 January 1997 (having been secretly certified on 11 December 1996); engines, equipped with intercoolers and density control system (automatic wastegate), maintain S/L rated power to 5,945 m (19,500 ft). Other new features include redesigned instrument panel with digital display monitoring panel (DDMP), overhead switch/dome light/speaker panel, entertainment/executive console with extendable work table and in-flight phone/fax option replacing the second row seat on the starboard side. Senecas have also been built in Brazil and Poland.

CUSTOMERS: Total of 28 Seneca IVs delivered in 1995, and 18 in 1996; 39 Seneca Vs delivered in 1997, 55 each in 1998 and 1999, 42 in 2000, 38 in 2001, 43 in 2002, and 22 in the first nine months of 2003. Widely used as twin-conversion trainer; recent customers include Sabena Airlines, which took delivery of two in 1999 for its training centre at Scottsdale, Arizona.
Production of the PA-34 series in the USA totals some 4,700; the prototype first flew on 30 August 1968.

COSTS: Standard equipped price US$624,800 (2003).

DESIGN FEATURES: Twin-engined version of Cherokee SIX/Saratoga. Low-mounted, constant-chord wings and tailplane; leading-edge gloves inboard of engines; constant-chord tailplane.
Wing section NACA 652-415; dihedral 7°; thickness/chord ratio 15 per cent; washout 0° 41'; twist 2° 41'.

FLYING CONTROLS: Manual. Frise ailerons, rudder and one-piece all-moving tailplane with combined anti-balance and trim tab; anti-servo tab in rudder; wide-span electrically operated slotted flaps. Control surface movements: ailerons +35/-20°; tailplane +12° 3'/-7° 30'; rudder ±35°. Maximum flap deflection 40°.

STRUCTURE: Conventional light alloy, with semi-monocoque fuselage; single-spar wings; glass fibre wingtips.

LANDING GEAR: Hydraulically retractable tricycle type. Main units retract inward, nose unit forward. Oleo-pneumatic shock-absorbers. Steerable nosewheel. Emergency free-fall extension system. Mainwheels and tyres size 6.00-6 (8 ply), pressure 3.79 bar (55 lb/sq in); nosewheel and tyre size 6.00-6 (6 ply), pressure 2.76 bar (40 lb/sq in). Nosewheel safety mirror. High-capacity disc brakes. Parking brake.

POWER PLANT: One 164 kW (220 hp) Teledyne Continental TSIO-360-RB (port) and one 164 kW (220 hp) LTSIO-360-RB (starboard) flat-six turbocharged counter-rotating engine, each driving a Hartzell BHC-C2YF-2/FC8459(B)-8R (port) or /FJC8459(B)-8R (starboard) two-blade, constant-speed, fully feathering metal propeller; McCauley 82NJA-6 and L82NJA-6 three-blade propellers optional, but mandatory when de-icing equipment installed. Propeller synchrophasers standard. Fuel in four tanks in wings, with a total capacity of 485 litres (128 US gallons; 107 Imp gallons), of which 462 litres (122 US gallons; 102 Imp gallons) are usable. Oil capacity 7.5 litres (2.0 US gallons; 1.7 Imp gallons). Glass fibre engine cowlings.

ACCOMMODATION: Enclosed cabin, seating five people on individual seats with 0.25 m (10 in) centre aisle; sixth seat (second row, starboard side) optional, replacing entertainment/executive console. Dual controls standard. Pilot's storm window. Two forward-hinged doors, one on starboard side at front, the other on port side at rear. Large utility door adjacent rear cabin door provides an extra-wide opening for loading bulky items. Passenger seats easily removable to provide different seating/baggage/cargo combinations. Space for 39 kg (85 lb) baggage at rear of cabin, and for 45 kg (100 lb) in nose compartment with external door on port side. Cabin heated and ventilated. Windscreen defrosters standard.

SYSTEMS: Electrohydraulic system for landing gear actuation. Electrical system powered by two 28 V 85 A alternators; 24 V 19 Ah battery. Optional pneumatic de-icing boots on wing, tailplane and fin leading-edges. Oxygen system optional.

AVIONICS: Comms: Dual Garmin GNS-430/530 com/nav/GS/GPS; GMA-340 audio panel with marker beacon receiver and intercom; GTX-327 transponder; ground clearance system; Telex 100T microphone and Airman 760 headset.
Radar: Provision in nose and on instrument panel for weather radar installation.
Flight: Dual Garmin GNS-430/530; Meggitt ST-361 ADI; ST-180 slaved HIS; dual GI-106A VOR/LOC/GS/GPS indicators; AR-850 altitude encoder; Meggitt System 55 dual-axis FCS.
Instrumentation: Piper true airspeed indicator, magnetic compass, sensitive altimeter, ADI, HIS, rate of turn indicator, rate of climb indicator, illuminated OAT gauge, digital ammeter, annunciator panel with push-to-test, recording tachometer, dual mainfold pressure gauges, three-way oil pressure, temperature and CHT gauge, dual fuel quantity gauges and vacuum gauge with warning indicator. Co-pilot's 75 mm (3 in) instrument and United 5035-P40 encoding altimeter panel optional.

EQUIPMENT: Standard equipment as listed for Saratoga II HP, plus emergency landing gear extension system, cabin dome light, pilot's storm window, sun visors with power setting table and checklist, chemical corrosion protection, flush fuel caps and nose gear safety mirror. Piper Aire air conditioning system, built-in oxygen system and foreign certification gross weight kit optional.