Piper PA-34 Seneca

Summary

Description

The Seneca was conceived as a twin-engined variant of the Piper Cherokee Six. Initial development involved a prototype Cherokee Six retrofitted with wing-mounted engines, which uniquely retained its nose engine, resulting in a tri-motor configuration for early test flights. With the decision to abandon the three-engined design tested on the PA-32-3M, the PA-34 was further developed as a twin-engined aircraft. The prototype PA-34-180 Twin Six, registered as N3401K, first flew on 25 April 1967. This prototype featured two 180 hp (134 kW) Lycoming O-360 engines, a fixed nosewheel landing gear, and a Cherokee Six vertical tail. A subsequent prototype flew on 30 August 1968, retaining the 180 hp (134 kW) Lycomings but incorporating retractable landing gear and a taller vertical tail. Further refinements included increasing the wingspan by two feet during development flying. The third prototype, closely aligned with the production standard, flew on 20 October 1969, equipped with 200 hp (149 kW) Lycoming IO-360-A1A engines. The PA-34-200 Seneca was certified on 7 May 1971 and introduced in late 1971 as a 1972 model.

The Piper PA-34 Seneca has undergone several design modifications throughout its production, each aimed at improving performance and handling. The initial PA-34-200 Seneca was equipped with counter-rotating Lycoming IO-360-C1E6 engines to eliminate critical engine limitations. Later, the PA-34-200T Seneca II featured turbocharged Continental TSIO-360E or EB engines, along with revised control surfaces, including enlarged ailerons, a rudder anti-servo tab, and a stabilator bobweight. The PA-34-220T Seneca III introduced Continental TSIO-360-KB engines, a one-piece windshield, and a bare metal instrument panel. Subsequent models like the Seneca IV and V incorporated streamlined engine cowls and improved engine variants such as the Continental TSIO-360-RB with an intercooler, while maintaining the same basic airframe and dimensions. The airfoil used is a laminar flow NACA 652-415.

The Piper PA-34 Seneca is not designed for military operations and lacks any dedicated armament systems. It is a civilian aircraft primarily intended for personal and business use, as well as flight training. As such, it does not feature hardpoints, bomb racks, or any provisions for carrying missiles, rockets, or gun pods, nor does it have an internal bay for ordnance. The design focuses on passenger and pilot comfort, flight characteristics, and payload in terms of passengers, baggage, and fuel. The maximum takeoff weight for the Seneca V is 4,750 lb (2,155 kg), and the standard useful load for the 2014 model is 1,331 lb (604 kg), reduced to approximately 1,134 lb (514 kg) when equipped with optional features such as air conditioning, deicing, and co-pilot instruments, all of which is dedicated to civilian use.

The Piper PA-34 Seneca has seen use in both civil and military roles across the globe. It is used by air charter companies, small feeder airlines, and private owners, finding utility in personal and business aviation as well as multi-engine flight training. The Brazilian Air Force employs the Embraer-built EMB-810C Seneca, designated as the U-7, for various roles. Military operators include the air forces of Belize, Colombia, Dominican Republic, Ecuador, Honduras, Peru, and Serbia, and it is also used by the armed forces and public protection units in Colombia and Panama, respectively.

Main variants:

• PA-34-200 Seneca: The initial production model, certified in 1971, is powered by counter-rotating Lycoming IO-360 engines to improve handling.

• PA-34-200T Seneca II: Introduced in 1975, this variant features turbocharged Continental TSIO-360 engines and modified control surfaces for enhanced performance and handling.

• PA-34-220T Seneca III: This 1981 upgrade includes Continental TSIO-360-KB engines producing 220 horsepower for improved climb and cruise performance, along with a one-piece windshield.

• PA-34-220T Seneca IV: Introduced in 1994 by the "New" Piper Aircraft company, this model is similar to the Seneca III but includes a streamlined engine cowl to increase cruise performance.

• PA-34-220T Seneca V: This 1997 model features redesigned cowls, relocated cockpit switches, and an improved Continental TSIO-360-RB engine variant with an intercooler for increased performance.

Technical specifications

Current operating countries

Country		Units
	Colombia	3
	Peru	2
	Dominican Republic	1
	Ecuador	1
	Honduras	1
	Panama	1

Numbers in parentheses, e.g. '(+5)', indicate units ordered but not yet delivered.

All operators

Brazil • Colombia • Dominican Republic • Ecuador • Honduras • Nicaragua • Pakistan • Panama • Peru