General information about the Mooney M20
The Mooney M20 is a family of piston-powered, four-seat, propeller-driven, general aviation aircraft, all featuring low wings and tricycle gear, manufactured by the Mooney International Corporation.
The M20 was the 20th design from Al Mooney, and his most successful. The series has been produced in many variations over the last 60 years, from the wooden-wing M20 and M20A models of 1955, to the M20V Acclaim Ultra that debuted in 2016. More than 11,000 aircraft in total have been produced.
In November 2008, the company announced that it was halting all production as a result of the late-2000s recession, but would still provide parts and support for the existing fleet. With the injection of Chinese capital after the company's purchase, production of the M20 resumed in February 2014. Since then, the company has released two more M20 models.
With the exception of the earliest models which had wings and tails with wooden frames, M20s are entirely constructed of metal. All are low-wing aircraft, and the wing skin is aluminum. Slotted flaps cover 70% of the trailing edge. Earlier models use a hydraulic hand pump to extend the flaps, while later models have electrically operated flaps. The forward fuselage has a steel-tube cabin structure covered in aluminum skin; the aft portion of the fuselage is of semi-monocoque design. In many places on the skin of the airplane, flush-mounted rivets are used to reduce drag.
The landing gear legs on the Mooney M20 are made of heat-treated chrome-molybdenum steel. The main gear legs are attached to the main wing spar, while the nose gear is mounted onto the steel cabin frame. Stacks of rubber discs around the legs act as shock absorbers. All models, with the exception of the M20D Master, came with retractable landing gear; on these models, the nose wheel retracts rearwards and the main wheels retract inwards. Early models use a hand-operated lever system to raise and lower the gear. Starting in 1969, electrically operated landing gear became standard.
The Mooney M20 has medium aspect-ratio tapered wings with 1.5 degrees of washout and 5.5 degrees of dihedral. Later models were equipped with stall strips to improve the stall characteristics.
The empennage of the Mooney M20 is easily recognizable by its unique tail fin with a vertical leading edge. (The tail fin looks as though it is "leaning forward", but it is approximately vertical in level flight, depending on trim setting.) The horizontal tailplane, which consists of fixed stabilizers and trailing elevators, has no trim tabs. The entire tail assembly pivots at the rear of the fuselage to provide pitch trim.
All M20s store fuel in two separate "wet wing" tanks, which are located in the inboard sections of each wing. Fuel is driven from the tank to the injectors or carburetor by an engine-driven pump, backed up with an electric boost pump.
For increased power, many M20s also have a ram-air induction system, called the Mooney "Power Boost". For normal operations, the intake air is filtered before it enters the induction system. When ram air is selected, partially unfiltered air enters the induction system with a higher pressure and consequently the manifold pressure increases about a full inch of mercury flying at 7500 feet above mean sea level, giving a greater power output. The turbocharged variants omit this feature, as the turbocharger provides a far greater increase in manifold pressure.
The Mooney M20 series has been produced in three fuselage lengths: the "short-body" (M20 through M20E), "medium-body" (M20F through M20K), and "long-body" (M20L through M20V). Although all M20s have four seats, the fuselage length increase provided more rear passenger legroom, but with a slight performance decrease: for a similar engine and vintage, a long-body plane is 4 to 6 knots slower than the short-body plane