Twin Engine (19)
The Piper PA-23, named Apache and later Aztec, is a four-to-six-seat twin-engined light aircraft aimed at the general aviation market that also saw service with the United States Navy and other countries' military forces in small numbers.The Apache and its more powerful development the Aztec were manufactured from 1952-1981View items...
The Piper PA-31 Navajo is a family of cabin-class, twin-engine aircraft.PIPER NAVAJO VARIANTS PA-31 Navajo
Initial production version, also known unofficially as the PA-31-310.PA-31-300 Navajo
Variant of the Navajo with normally aspirated engines; 14 built.PA-31 Navajo B
Marketing name for 1971 improved variant with 310 hp (231 kW) Lycoming TIO-540-E turbocharged piston engines, new air conditioning and optional pilot access door and optional wide utility door.PA-31 Navajo C
Marketing name for 1974 improved variant with 310 hp (231 kW) Lycoming TIO-540-A2C engines and other minor improvements.PA-31P Pressurized Navajo
Pressurized version of the PA-31 Navajo, powered by two 425 hp (317 kW) Lycoming TIGO-541-E1A piston engines.PA-31-325 Navajo
Referred to as the Navajo “C/R” for counter-rotating. Variant of Navajo with counter-rotating propellers introduced with the PA-31-350 Chieftain. 325 hp (242 kW) Lycoming TIO-540 / LTIO-540 engines.PA-31-350 Chieftain
Stretched version of the Navajo with more powerful 350 hp (261 kW) engines that rotate in opposite directions (a Lycoming TIO-540 and a Lycoming LTIO-540) to eliminate critical engine issues.PA-31P-350 Mojave
Piston engine variant of the PA-31T1 Cheyenne I; 50 aircraft built.PA-31-350T1020
Also known as the T1020/T-1020; variant of the PA-31-350 Chieftain optimized for commuter airline use, with less baggage and fuel capacity and increased seating capacity (nine passengers). First flight Sept. 25, 1981; 21 built.PA-31T3
Also known as the T1040/T-1040; turboprop powered airliner with fuselage of the PA-31-350T1020, and wings, tail and Pratt & Whitney Canada PT6A-11 engines of PA-31T Cheyenne. First flight July 17, 1981; 24 built.PA-31-353
Experimental version of PA-31-350; two built.T1050
Unbuilt airliner variant with fuselage lengthened by 11 feet, 6 inches (3.51 m) compared to the PA-31-350.EMB 820C
Version of Chieftain built under license by Embraer in Brazil.Neiva Carajá
Turboprop conversion of EMB 820C, fitted with two Pratt & Whitney Canada PT6A-27 engines flat-rated to 550 shp. The Carajá’s MTOW of 8,003 pounds was 1,000 pounds more than that of the Chieftain.Colemill Panther
Re-engined Navajo with 350 hp (261 kW) Lycoming TIO-540-J2B engines, four-blade “Q-Tip” propellers and optional winglets. Conversion designed by Colemill Enterprises of Nashville, Tenn.View items...
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.View items...
In the years immediately after World War II, General Aviation was growing—but not very predictably. Manufacturers were constantly going from feast to famine, and several old, venerable airplane companies had gone broke when they found they couldn't survive the market fluctuations.
There was one emerging market, however, in which a few of the more far-seeing planemakers were interested—Business Aviation—bigger, faster, more sophisticated (and profitable) equipment that was flown for commerce instead of for enjoyment.
In 1967, Piper Aircraft began marketing a six- to eight-seat cabin-class twin known as the PA-31 Navajo. Several variants were produced, including a T1000 series aimed at the commuter airline marketplace.
Production of the Navajo ended in 1984 with 3,942 built. Piper had—and still has—the Seneca and Seminole light twins in the lineup, but its cabin-class aircraft offerings thereafter have been limited to single engine models.
May 2014- Last month, I discussed the history and maintenance of the PA-23 Apache. But as a longtime owner, I have some insights about flying and owning an Apache, too. This month I’ll focus on specific flying tips and the practical aspects of ownership of Piper’s original twin.
April 2014- The PA-23 Apache was Piper’s first twin engine aircraft. In 1952 Piper began construction and testing of a prototype, but the original design—with 125 hp engines, a twin tail arrangement and fabric covering—was unsuccessful.
The aircraft was tweaked and the new design included 150 hp Lycoming engines, retractable landing gear, constant speed full feathering Hartzell propellers, all metal construction and a more conventional single tail.
Now called the Apache, the 150 hp prototype flew in 1953. The design received its FAA type certificate on Jan. 29, 1954. There were 2,047 Apaches and 4,930 Aztec models produced from 1954 to 1982, including a few U.S. Navy models.
November 2005- In October of 1958, Piper proposed a twin-engine version of the successful Comanche single. This was not the PA-30 Twin Comanche, planning of which had begun two years earlier but development and production of which would be several years hence (thus the skip in numeric order).
Piper initially planned for the model to be developed in California by Bill Lear, and would furnish a PA-24 Comanche airframe and two 200 hp IO-360 engines. Whether this actually ever happened is not recorded, but in 1962 the PA-30 project was given to San Antonio designer Ed Swearingen.
November 2005- Our charter company operated a 1970 model PA-31-310 Navajo for several years. We purchased it out in California, took the insurance-required flight training and flew it home to Florida, making a stop in Vegas for the night, and another at the Grand Canyon, just to sightsee.
After the 15-hour ride home we thought we knew her pretty well. Six months later we had put about 75 hours on the old girl and had grown to know her even better.
July 2005- One time-tested way to create a light twin is to take a single, remove the engine, and replace it with two engines on the wings. Sometimes the engines are smaller than those on the single—as in Piper’s Twin Comanche. Sometimes the engines are as powerful as that on the single—as in the Beech Baron.
Piper took the first approach with the PA-34 Seneca: it’s basically a Saratoga airframe with the 300 hp single engine replaced by two 200 (later 220) hp wing engines. The result is one of the longest-running twins in General Aviation.
The original Seneca was introduced in 1972, and you can still buy a brand-new Seneca V from Piper today. The original PA-34-200 Seneca had some problems, notably a low single-engine service ceiling.
Piper had success with its twin-engine Seneca, but complaints of poor handling had plagued the early models and Piper had been on a quest for more power and better handling for the Seneca nearly from the outset.
To gain more power for the 4,200-pound (gross weight) Seneca, Piper engineers looked at the possibility of adding a supercharger. They tried out the 220 hp Franklin 6A-350-C1 as well as turbocharged engines from Lycoming and Continental. In tests the 200 hp turbocharged Continental L/TSIO-360-E performed well and was eventually chosen for the powerplant.
In-flight handling was improved by adding aerodynamically balanced ailerons, an anti-servo tab for increased rudder effectiveness and a redesigned stabilator, while ground handling received enhancements in the form of a reworked nosegear steering linkage. To keep things simple engineers chose a fixed wastegate.
If at first you don’t succeed, don’t “tri” again. But Piper’s trimotor testing wasn’t all for naught.
What do you do when you’ve completed initial testing of a new version of your wildly popular single-engine aircraft? If you’re Piper Aircraft in the 1960s, you slap a couple more engines on it and try it out as a trimotor.
That’s just what happened in 1964. Piper had completed initial tests on its PA-32-260 Cherokee Six and used that airframe to attach two more engines to the wings (in this case using the 115 hp Lycoming O-235) while retaining the 250 hp Lycoming O-540 of the “Six” for the center engine.