Garrison OM-1 Melmoth
The Melmoth first flew in 1973 and was developed by Peter Garrison from the British Practavia Sprite (also partly a Garrison project). The Melmoth represented considerably more work than the average homebuild and was more of a research prototype than a backyard project. The Melmoth was conceived and designed as an exercise in extreme efficiency in all aspects of flight. It carried an unusually large amount of fuel for an aircraft of its size with a 41-gallon main tank and two 35-gallon tip tanks on each wing, which yielded the exceptional range. Some of the Melmoth’s extras included double-slotted flaps, adjustable incidence ailerons, autopilot, and retractable landing gear.
Melmoth weighs 1,500 pounds empty, seating three, and carrying 940 pounds of fuel in wing and tip tanks. The area of the 23-foot wing is only 92 square feet. No additional fuel is used for ocean flights, the standard tankage providing a range of about 3,000 nm.
Double-slotted Fowler flaps keep the stalling speed within reason; wing-mounted spoiler/airbrakes provide sudden drops and other surprises. The ap-proach speeds and the ride resemble those of a medium twin, but the control forces and responses are more what you would expect from a small, short-coupled airplane. The roll rate, for instance, is about 100 degrees per second, and the airplane is stressed for aerobatics. High cruise at normal weights is 170 to 175 knots, but flight-plan 160 block to block, at about nine gallons an hour.
Melmoth carries full IFR equipment, with Collins Micro Line and Narco avionies, Silver Fuel Guard, Safe Flight angle of attack indicator, Edo-Aire Mitchell Century 1 autopilot, Sanyo stereo radio and cassette player and a Sunair H F radio for ocean flights. There is also a homemade electronic gadget that automatically switches fuel tanks every five minutes. The retractable tricycle landing gear, flaps and airbrakes are all hydraulically operated by an electric pump.
The flying qualities are generally good, but some areas need improvement. Melmoth yaws excessively in turbulence, and neutral lateral stability makes it a poor instrument airplane without the aid of the wing leveler. The cabin, though very roomy, is noisy, and the seats are not comfortable on long flights; the rear seat, furthermore, is not only uncomfortable but also hard to get into and out of.
The high approach speeds and the potential for excessive sink rates with full flaps take pilots new to the airplane by surprise, though with practice and planning Melmoth can be satisfactorily operated on 2,000-foot unpaved runways
The aircraft was destroyed in a highly unusual accident in which a landing aircraft struck Melmoth while waiting on the ground at the end of a runway. Garrison survived the accident and proceeded to design and construct a replacement.
Engine Continental IO-360-A, 195-hp.
Wingspan 23 ft
Length 21 ft 6 in
Gross Wt. 2950 lb.
Empty Wt. 1500 lb.
Fuel capacity 154 USG.
Top speed 209 mph.
Cruise speed 201 mph
Stall 80 mph.
Climb rate 1800 fpm.
Takeoff distance (50’) 2500 ft.
Landing distance (50’) 2500 ft.