Beechcraft 99 Commuter
In production until 1978 the Beechcraft 99 Airliner was the first turbine-powered retractable landing gear aircraft to meet FAA approval for commuter air carrier service (regulations requiring a flight attendant for aircraft with 20 or more passengers). The test and development aircraft, which first flew in December 1965, was again a stretched fuselage Queen Air, initially with piston engines but was quickly upgraded to Pratt & Whitney PT6-A-27 turboprops. It was flown in July 1966, with type approval obtained in May 1968. With only capacity for two pilots and 15 passengers, it was less economical than the Twin Otter and required longer runways to operate from.
First delivered in 1968, the Model 99 was powered by twin 550-shp Pratt & Whitney turboprops driving reversible propellers. These enable the Beechcraft 99 to cruise at more than 250 mph and pull a gross load of 10,200 pounds or more. Introduced in 1969, the 99A Airliner housed 680-shp Pratt & Whitney free-shaft turbines flat rated at 550 shp. Except for the engines, the 99A is identical to the original 99.
The 99B, announced in 1972, featured engineering improvements for increased reliability, maintainability and passenger comfort. The ship has an air-conditioning unit as an option with its high pressure continuous-flow oxygen system. Also, an optional cargo door and cargo pod, installed beneath the fuselage, increases its cargo capability. Seating can be varied to suit specific needs. After building only 164 Model 99 aircraft, Beech withdrew from this market in 1975.
However, with the Air Deregulation Act of 1978 the upgraded Model 99 was brought back into production as the model C99 Airliner powered by the P&W PT-6A-36, with a further 75 of these C99s being built.
Engines: 2 x Pratt & Whitney (UACL) PT6A-20 turboprop, 550 shp.
Props: 6 ft 7in (2.02 m) dia 3-blade.
Wing span: 45 ft 10.5in.
Length: 44 ft 6.75in (13.58m).
Wing area: 279.7 sq ft (25.88 sq.m).
Gross Wt. 10,400 lbs (4,717 kg).
Empty Wt. 5675 lbs.
Fuel capacity 374 USG.
Max cruising speed: 254 mph (409 kph) at 10,000 ft (3,050 m).
Range: 1,100 miles (1,770 km) with 1,800 lb (816 kg) payload.
Pax cap: 15.
Stall 75 mph.
Initial climb rate 1910 fpm.
Ceiling 25,000 ft.
Takeoff distance (50’) 3200 ft.
Landing distance (50’) 2470 ft.
Engines: 2 x Pratt & Whitney PT6A-27 turboprop, 680 shp.
Engine: 2 x P&WAC PT6A-27, 680 hp.
Wing loading: 38.97 lb/sq.ft.
Pwr loading: 8.02 lb/hp.
Gross wt: 10,995 lb.
Empty wt: 5891 lb.
Equipped useful load: 4784 lb.
Payload max fuel: 2318 lb.
Range max fuel/cruise: 749nm/3hr.
Range max fuel /range: 1097nm/5.3hr.
Ceiling: 26,313 ft.
Max cruise: 245 kt.
Max range cruise: 209 kt.
Vmc: 85 kt.
Stall: 75-91 kt.
1.3 Vso: 98 kt.
ROC: 2070 fpm.
SE ROC: 561 fpm @ 117 kt.
SE ceiling: 13,000 ft.
Min field length: 2800 ft.
Fuel cap: 2466 lb.
Takeoff distance (50’) 2480 ft.
Landing distance (50’) 1810 ft.
First built: 1981.
Engines: 2 x P&W PT6A-36, 715 shp.
Props: Hartzell 3-blade, 93-in.
Length: 44.6 ft.
Height: 14.4 ft.
Wingspan: 45.9 ft.
Wing area: 279.8 sq.ft.
Wing aspect ratio: 7.5.
Maximum ramp weight: 11,380 lbs.
Maximum takeoff weight: 11,300 lbs.
Standard empty weight: 6124 lbs.
Maximum useful load: 5256 lbs.
Maximum landing weight: 11,300 lbs.
Wing loading: 40.4 lbs/sq.ft.
Power loading: 7.9 lbs/hp.
Maximum usable fuel: 2466 lbs.
Best rate of climb: 2221 fpm
Service ceiling: 28,080 ft.
Maximum single-engine rate of climb: 539 fpm @ 119 kts.
Single-engine climb gradient: 270 ft/nm.
Single-engine ceiling: 14,360 ft.
Maximum speed: 226 kts.
Normal cruise @ 8,500 ft: 249 kts.
Fuel flow @ normal cruise: 740 pph.
Endurance at normal cruise: 2.8 hrs:
Stalling speed clean: 94 kts.
Stalling speed gear/flaps down: 83 kts.
Turbulent-air penetration speed: 169 kts.