2006
pres: Carl Dietrich
Woburn MA.
USA
Roadable aircraft builder
Geely, the Chinese company that also owns Volvo, agreed to acquire Terrafugia in 2017. Geely was particularly interested in the Terrafugia’s FAA approval last year allowing the transforming car to be certified as a light sport aircraft.
Single or side by side two seat single engined high wing monoplane with conventional three axis control. Wing has unswept leading and trailing edges, and constant chord; cruciform tail. Pitch control by elevator on tail; yaw control by fin mounted rudder; roll control by full span ailerons; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from below by struts; wing profile NC; double surface. Undercarriage has three wheels in tail dragger formation; nylon rope suspension on tailwheel and steel spring sus¬pension on main wheels. Ground steering by differential braking. Brakes on main wheels. Aluminium tube framework, partially enclosed (totally enclosed optional). Engine mounted above wing driving pusher propeller.
One of the revelations of Sun ‘n’ Fun in March 1983 at Lakeland was the prototype Tierra with which Teratorn Aircraft made a spectacular entrance into that section of the ultralight market which is in direct competition with traditional light air¬craft. This machine offers the facility to be used either as a single seat ultralight or to be transformed into a US category experimental aircraft by the addition of a second scat, the problem of centre of gravity shift being resolved by positioning the single seat in the centre of a wide cockpit, so that it only has to be moved sideways to make room for two. The single stick is central and, as the Tierra has two rudder bars, it becomes a dual control machine when fitted with both seats.
The fuel tank is mounted behind the seating low down at the rear of the cockpit which closes with the clever use of zips for the side panels, the windows coming down to the lower longeron of the cabin. This enclosure is available as an option, as are isolation panels for the cabin. These are made of soundproof material and fit behind the cabin and above the wing and are easily removable. The structure of the Tierra is formed from triangular frames. All the joints in the airframe are reinforced with a strong high density elastic foam pressed into the tubes which absorbs vibration and eliminates metal to metal con¬tact.
Engine location is above the cabin, the motor using dyna focal mounts as in modern conventional aviation. It is a Rotax 377 cc unit fitted with a reduction drive and Teratorn’s own Flexidyne type clutch system. Finally comes an accessory which is still rare in ultralight aviation: the horizontal tail surface of the Tierra is fitted with a trimmer permit¬ting maximum stability in flight regardless of the load carried or its position.
Tierra
Engine: Rotax 377, 36hp at 6600rpm
Propeller diameter and pitch 60 x 36 inch, 1,52 x 0.91 m
Toothed belt reduction, ratio 2.6/1
Max static thrust 245 lb, 111 kg
Power per unit area 0.24 hp/sq.ft, 2.7 hp/sq.m
Fuel capacity 5.0 US gal, 4.2 Imp gal, 18.9 litre
Length overall 18.5 ft, 5.64 m
Height overall 6.0ft, 1.83m
Wing span 31.5ft, 9.60m
Constant chord 4.5 ft, 1.37 m
Sweepback 0 deg
Total wing area 142 sq.ft, 13.2 sq.m
Wing aspect ratio 7.0/1
Empty weight 253 lb, 115kg
Max take off weight 550 lb, 249 kg
Payload 297 lb, 135 kg
Max wing loading 3.87 lb/sq.ft, 18.9 kg/sq.m
Max power loading 15.3 lb/hp, 6.9 kg/hp
Load factors; +6.0, 3.0 ultimate
Max level speed 63 mph, 101 kph
Never exceed speed 63 mph, 101kph
Cruising speed 50mph, 80kph
Stalling speed 25 mph, 40 kph
Max climb rate at sea level 800 ft/min, 4.1 m/s
Min sink rate 300ft/min, 1.5m/s
Best glide ratio with power off 10/1
Take off distance 50 ft, 15 m
Tierra 1
Engine: Rotax 277
Empty wt: 253 lb
Max wt: 650 lb
Wing span: 31ft
Wing area: 154 sq.ft.
Wing loading: 4.22 lbs/sq.ft
Power loading: 23.21 lbs/hp
Max speed: 62 mph
Cruise: 55 mph
Stall: 26 mph
Vne: 75 mph
Seats: 1
Tierra 11
Engine: Rotax 532
Empty: 385 wt. lbs
Max wt.: 850 lbs
Wing span: 36ft
Wing area: 190 sq.ft.
Wing loading: 4.38 lbs/sq.ft
Power loading: 13.08 lbs/hp
Max speed mph: 75
Cruise mph: 60
Stall mph: 30
Vne mph: 80
Seats: 2
Tierra UL
Engine: Rotax 277 (268 cc) 28 hp
Static thrust: 180 lbs
Empty wt: 249 lbs
Wing span: 30’6”
Wing area: 155 sq.ft
Height: 5’8”
Length: 18’6”
Fuel cap; 5 USG
Construction: Aluminium, Dacron, Steel
Max wt: 500 lb
Stall: 24 mph
Max speed: 60 mph
Vne: 70 mph
Climb rate: 500-600 fpm
Design limit: +6, -3g
Glide ratio: 10-1
Wing loading: 3.23 lbs/sq.ft
Power loading: 17.86 lbs/hp
A single-seat aerobatic/ competition monoplane (first flown 1991)
A two-seat lightplane (first flown 1990) for club and private flying, training, surveillance.
Italy
Product range encompasses T-9 Stiletto two-seat lightplane (first flown 1990) for club and private flying, training, surveillance and more; T-30 Katana single-seat aerobatic/ competition monoplane (first flown 1991); and Windspider inflatable sailing craft.
Finnish company Eiri Avion started to build the PIK-20 B sailplane, an all-fiberglass/epoxy high-performance glider designed by a group of engineers (Tammi, Hiedanpää, Korhonen).
In 1975 an agreement was signed between Tervamaki and Eiri Avion to develop a retractable engine installation for the PIK-20B glider. The designation for the prototype was JT-6. It is a one-of-a-kind experimental machine used as a test bed for the production model which later emerged as PIK-20E (E for the engine).
The modifications necessary to convert a PIK-20B glider into a JT-6 motorglider were as follows:
Engine installation including a retraction mechanism with automatically opening and closing doors, fuel tank, a 16-Ah battery plus engine gauges and controls.
The engine and propeller necessitated enlargement of the fuselage aft of wing and, therefore, a new fuselage center-section mold was made. The fuselage was bonded together from three sections.
The engine compartment opening required a strong beam around it to carry the loads.
All of the above modifications added some 70 kg of mass and moved the CG 100 mm (4 in) backwards. To compensate for this CG shift, the wings were swept 2 degrees backwards, necessitating new wing spars and new wing root fittings.
The wing spars were strengthened due to the increased fuselage mass.
The main landing gear was moved 100 mm (4 in) backwards and a steerable tail wheel was added, as was retractable outrigger wheels into the wings.
Tervamaki first flew the JT-6 in August 1976, registered OH-520X. There were numerous difficulties in the beginning, and the first flight was a near disaster. The first engine, a Canadian Kohler, was of too low power (33 hp). In addition, the Kohler factory ceased working in 1977 but, a good, new choice was found in the Rotax 502. It was the first Rotax 502 installation in an aircraft. With the Rotax 502 the plane had a climb rate of 3.5 m/s.
Since the machine was an experimental prototype, a lot of things changed during the test flights and thereafter during the 20+ years of flying. The most serious ones are a couple of engine seizing due to too lean mixture.
An article about JT-6 appeared in Homebuilt Aircraft, August 1980. Self-Launch!, a book by Peter A. Williams from 1998 thoroughly describes motorglider history including the JT-6 in detail.
The JT-6 logged 1621 hrs in 23 years of flying of which less than 5 percent was by power, the rest was soaring.
The JT-6 was handed over in an airworthy condition to the Finnish Aviation Museum in May 2007.
The 1966 Shushonik, N302HT, was a single place cabin, low-wing monoplane midget racer, built by Howard L Terril.
The 1962 Special HLT-101 was a single place cabin, low-wing monoplane, built by Howard L Terril.
Engine: 180hp Lycoming
Wingspan: 20’0″
Length: 21’0″
Useful load: 600 lb
Max speed: 250 mph
Cruise speed: 180 mph
Stall: 55 mph
The 1957 Poopsi-Doll HLT-100, N95P, was a single place cabin, mid-wing monoplane, built by Howard L Terril.
Engine: 130hp Lycoming O-290
Wingspan: 16’8″
Length: 21’0″
Useful load: 410 lb
Max speed: 240 mph
Cruise speed: 205 mph
Stall: 55 mph
Range: 540 mi
Howard L Terril
Torrance CA.
USA
Circa 1957-66 built aircraft
