Piper Aerostar

The Piper Aerostar (formerly the Ted Smith Aerostar) is an American twin-engined propeller-driven executive or light transport aircraft, designed by Ted R. Smith. It was originally built by Ted Smith Aircraft Company, but the design was acquired in 1978 by the Piper Aircraft Corporation, which continued production of the aircraft as the PA-60.

Aerostar / Superstar / Sequoya
An Aerostar 600 in Red Deer, Alberta in 2000
Role	Light transport aircraft
National origin	United States
Manufacturer	Ted Smith Aircraft Company Piper Aircraft Corporation
Designer	Ted R. Smith
First flight	1967
Status	Active service
Produced	1967–1984
Number built	1,010

Development

The first Aerostar prototype, the Model 320, was built with two 160 hp (120 kW) Lycoming IO-320 engines and first flew in November 1966. The same aircraft was upgraded with a pair of 180 hp (130 kW) Lycoming IO-360 engines and a more streamlined vertical fin and renamed the Model 360; it was subsequently upgraded again with 200 hp (150 kW) IO-360s and renamed again as the Model 400. The aircraft finally entered production as the Aerostar 600 with two 290 hp (220 kW) Lycoming IO-540-K engines, first flown in December 1967. Also produced, and the base of most of the subsequent models, was a version with turbocharged engines, the Aerostar 601.

1974 saw the introduction of the successful 601P, which introduced cabin pressurization, allowing more convenient high-altitude operation; the designers were able to adapt the fuselage to pressurization without having to limit its service life. The 601P and the 601B, which was introduced in 1977, both feature improvements to the turbocharging system and a 2.5-foot (0.76 m) greater wingspan, increasing climb rates and making the engines more reliable and easier to operate.

The aircraft were originally built at Van Nuys, California, but in 1968 the company was bought by the American Cement Company. The acquisition was not a success, and in 1969 the company was sold again to Butler Aviation, owners of Mooney Airplane Company. The new company was renamed Aerostar Aircraft Corporation, and plans were made to move production to the Mooney plant at Kerrville, Texas, but this did not occur. In 1971, Smith attempted to purchase the rights and announced he would be building an all-new design that was better than the Aerostar, but negotiations broke down. In 1972, Ted Smith successfully bought back all the rights to the aircraft and began manufacturing Aerostars under the Ted R. Smith and Associates banner in Santa Maria, California, introducing the pressurized Aerostar 601P along with the Aerostar 700 Superstar. In 1976, the company name was changed to the Ted Smith Aerostar Corporation.

Smith died suddenly in 1976. In 1978, the Aerostar line was acquired by the Piper Aircraft Corporation, which continued to build two variants, the 600A and 601B, and then re-introduced the 601P. Piper continued using the basic Ted Smith model designation system but prefixed each model as the PA-60. Piper introduced the enhanced 602P, which was initially marketed as the Sequoya, and also put the 700 Superstar into production as the 700P. After discontinuing production of the non-pressurized models, Piper moved production to Vero Beach, Florida, building the last Aerostar there in 1984.

Smith conducted engineering studies for a jet-powered Aerostar, but these plans never came to fruition during the aircraft's production run.

Design

The Aerostar emerged as a mid-wing cantilever monoplane powered by two wing-mounted piston engines, with a tricycle landing gear. It is designed to seat six, and is distinguished from light twins of similar size and weight by its high wing loading, careful attention to fine aerodynamic details, a mid wing, and in early models, the absence of cowl flaps; Smith was adamant that they were not needed because of the refined cooling system design. Despite this, the later 700P used cowl flaps because engine cooling of earlier models proved marginal if the system is not maintained rigorously.

The engines of early 601s are turbonormalized—they retain the higher compression ratio typical of a non-turbocharged engine, and the turbo system is designed to primarily to compensate for increasing altitude by providing more boost pressure as the outside air pressure declines. Later models featured a redesigned turbo system intended to increase reliability and be more forgiving of improper operation by the pilot. Unusual Aerostar design features include electrically operated remote fuel valves, which avert the need to run fuel lines into the cockpit; electrically operated nosewheel steering; and unusually thick and stiff wing skins, which—together with the high wing loading—give the Aerostar an unusually smooth ride in turbulence.

Some disadvantages of the aircraft compared to its competitors are the absence of a nose baggage locker, and a cabin that can only be accessed through a single door next to the pilot's seat.

Aerostar model numbers nominally refer to the total installed engine horsepower, but some model numbers vary from the precise total, particularly the later models.

Operational history

During the time of production, the Aerostar held the speed record for fastest twin piston general aviation aircraft, capable of cruise speeds from 220 knots (410 km/h; 250 mph) for the earliest 600 models to 261 knots (483 km/h; 300 mph) for the later 700 models. Light construction, low drag, and powerful engines contribute to fast climb rates, while allowing high operating altitudes and class-leading fuel efficiency. The Aerostar has a reputation for high maintenance requirements due to a cooling system design that is intolerant of poor maintenance, and a turbo system that is sensitive to exhaust system problems.

Most Aerostars have a fuselage fuel tank and individual fuel tanks in each wing, which are designed to feed into a common chamber near the fuselage tank; the common chamber in turn feeds the engines, while a network of fuel valves allow fuel to be rerouted. The aircraft's relative lack of wing dihedral gives the wing tanks a well-documented tendency to feed unevenly when operated in this manner, causing a fuel imbalance as flight progresses. Pilots have found that this problem can be mitigated by using the valves to route fuel from one wing tank to the opposite engine, bypassing the common chamber; however, the wing tanks are prone to unporting (sucking air into the fuel lines as fuel sloshes away from the pickup in a mostly empty tank), causing engines to lose power or stop running due to fuel starvation. A 1984 airworthiness directive required owners to install more accurate fuel gauges for the wing tanks to mitigate this problem.

Although nominally a six-seat aircraft, owners often remove center-row seats because most Aerostars have inadequate payload to simultaneously carry six people, their baggage, and a large fuel load, and most passengers prefer the quieter third-row seats, which are difficult to access with both second-row seats in place.

The Aerostar type certificate and manufacturing documentation were sold in 1991 to former Ted Smith Aerostar Corporation employees Jim Christy and Steve Speer, who operate Aerostar Aircraft Corporation, providing maintenance and support of the aircraft and continued research and development. In 2006, Speer restarted design studies for a jet-powered Aerostar, and in 2010, Aerostar Aircraft first flew the Aerostar Jet, a 601P refitted with a pair of wing-mounted 1,460 lbf (6.5 kN) Pratt & Whitney CW615F engines, providing an estimated maximum cruise speed of 355 knots (657 km/h; 409 mph). In 2014, Aerostar Aircraft said it was investigating production of the aircraft.

Variants

Model 320

First prototype, powered by two 160 hp (120 kW) Lycoming IO-320 engines

Model 360

Modification of first prototype with two 180 hp (130 kW) Lycoming IO-360 engines and a redesigned empennage

Model 400

Modification of first prototype with two 200 hp (150 kW) IO-360 engines; type certified, but did not enter production

Model 500/500P

Projected versions with 250 hp (190 kW) fuel injected engines, to be non-pressurized and pressurized respectively; none built

600 (later PA-60-600)

Initial production model with two 290 hp (220 kW) Lycoming IO-540-K engines, 282 produced under four different company names

600A

Model 600 with some minor detail changes

600E

Designation used for aircraft sold in Europe

601 (later PA-60-601)

This aircraft still holds the land closed speed record for a production piston twin

Model 600 with 290 hp turbocharged Lycoming TIO-540 engines, 117 built

601B

Model 601 with increased wingspan and improved turbo system, 44 built

601P (later PA-60-601P)

Pressurized version of 601 with increased gross weight, increased wingspan and improved turbo system, 492 built

602P Sequoya (later PA-60-602P)

Piper-developed version of 601P with 290 hp Lycoming TIO-540-AA1A5 engines, 124 built

620

The prototype pressurized Aerostar with 310 hp (230 kW) TIO-540 engines, one built (at Van Nuys in mid-1969)

700 Superstar

Prototype of stretched fuselage variant with two IO-540M engines, one built

700P (later PA-60-700P)

602P with counter-rotating 350 hp (260 kW) Lycoming TIO-540-U2A engines, 26 built

702P

New modification of 700P with a reinforced nose gear allowing for higher takeoff weight

800

601P with stretched fuselage, enlarged tail and two 400 hp (300 kW) Lycoming engines, one built

Speedstar 850

A modification to replace the twin piston engines with a single nose mounted turboprop

Aerostar Jet

601P with two 1,460 lbf (6.5 kN) Pratt & Whitney CW615F engines; one converted from a 601P

• 
  Ted Smith-built Aerostar 601 in 1971
• 
  Piper PA-60-600 Aerostar, built in 1977
• 
  A Piper Sequoia 602P at Paris Air Show Le Bourget in 1981
• 
  An experimental turbine powered Aerostar FJ-80 in 2011
• 
  1980 Aerostar 601P
• 
  Speedstar 850
• 
  Aerostar 600

Accidents and incidents

• On January 4, 1995, an Aerostar 601P, N720EM, piloted by Eduardo Mata, former conductor of the Dallas Symphony Orchestra, crashed into a ravine and exploded after an engine failure during climbout from Cuernavaca Airport en route to Dallas, killing Mata and his single passenger. Investigators were unable to determine the cause of the engine failure.

Specifications (700P)

Data from Jane's Civil and Military Aircraft Upgrades 1994–95

General characteristics

• Crew: 1
• Capacity: 5 passengers
• Length: 34 ft 9.75 in (10.61 m)
• Wingspan: 36 ft 8 in (11.18 m)
• Height: 12 ft 1 in (3.68 m)
• Wing area: 178.2 sq ft (16.56 m²)
• Empty weight: 4,275 lb (1,939 kg)
• Gross weight: 6,315 lb (2,864 kg)
• Powerplant: 2 × Avco Lycoming TIO-540-U2A flat six counter-rotating piston , 350 hp (261 kW) each

Performance

• Maximum speed: 306 mph (492 km/h, 266 kn)
• Cruise speed: 242 mph (390 km/h, 210 kn)
• Range: 1,024 mi (1,648 km, 890 nmi)
• Service ceiling: 25,000 ft (7,620 m)
• Rate of climb: 1,840 ft/min (9.4 m/s)

References

Bibliography

• The Illustrated Encyclopedia of Aircraft (Part Work 1982–1985), 1985, Orbis Publishing
• Michell, Simon. Jane's Civil and Military Aircraft Upgrades 1994–95. Coulsdon, UK: Jane's Information Group, 1994. ISBN 0-7106-1208-7.
• Simpson, R.W. Airlife's General Aviation, 1991, Airlife Publishing, ISBN 1-85310-194-X
• Taylor, John W. R. Jane's All The World's Aircraft 1967–68. London: Sampson Low, Marston & Company, 1967.

External links

• Aerostar Aircraft Corporation
• Media related to Piper Aerostar at Wikimedia Commons