Slingsby T-31 Tandem Tutor
T-31B Tandem Tutor Trainer
The T. 8 Kirby Tutor (RAF Kirby Cadet T.X. Mk. 2) with a 13.24 m/ 43.4 ft. tapered wing evolved into the T.31 Tandem Tutor (RAF Kirby Cadet T.X. Mk. 3) two-place trainer.
The Tandem Tutor can be flown either dual or solo, and differs from the single-seat Tutor chiefly in having the forward fuselage lengthened to accommodate the second cockpit. An extra V-strut over the rear cockpit windscreen supports the wing leading edge, and wing spoilers are usually fitted in the upper surfaces, although some Tandem Tutors do not have them, and flaps are not fitted. The forward fuselage is plywood-skinned and the rear fuselage is fabric-covered; the pilots have full dual controls. Landing gear is basically the same as the Cadet's with a monowheel, a skid under the forward fuselage and a tailskid.
The Tandem Tutor was designed by F. N. Slingsby, first flew in prototype form in September 1950. A two-place development of the single-place T.8 Tutor using the same wings with additional bracing. Early production T.31’s had no aids for approach control, but spoilers were added to later models, and retrofitted to most examples.
This was selected as a standard ATC trainer, being known as the Cadet TX Mk 3 by the RAF, and altogether 131 were built for the ATC and 69 for gliding clubs and other civil customers; 14 more were built from Slingsby-supplied kits and a number of Tandem Tutors were also built from Government surplus spares. The Royal Air Force used T.31B’s (known as the Kirby Cadet T.X. Mk. 3) in its air cadet organization from 1950 to the mid 1980’s. One ‘Mark 3’ made over 120,000 flights totaling 6,000 hours in this period.
Martin & Wilkinson Cadet III
Wing span: 13.2 m / 43 ft 3.75 in
Wing area: 15.8 sq.m / 170 sq.ft
Airfoil: Go 426
Length: 23 ft 3.75 in
Empty Weight: 176 kg / 388 lb
Payload: 442lb/ 200kg
Gross Weight: 830 lb /376 kg
Wing Load: 4.88lb/sq.ft/ 23.8kg/sq.m
Aspect ratio: 11.1
Max speed: 81 mph
L/DMax: 18 @ 73 kph / 39 kt / 45 mph
MinSink: 1.05 m/s / 3.48 fps / 2.06 kt at 42 mph
No. of Seats: 2
No. Built: 200