de Havilland Canada DHC-7 Dash 7
de Havilland Canada, in response to a market survey, estimated interest in a large STOL aircraft with advanced STOL capability, so that higher standards of comfort, comparable with much larger aircraft, would be available to those airlines which operate from runways about 915m in length.
With backing from the Canadian government the, construction of two pre-production de Havilland Canada DHC-7 aircraft began in late 1972, and the first was flown on 27 March 1975 (C-GNBX-X) at Downsview, Ontario. Certification was gained in 1977 and the Dash 7 proved not only to be very quiet, but could take off with full load in only 2,260 ft (689 m) and land in 1,950 ft (594 m).
The DHC-7 has four large-diameter propellers turning slowly (and therefore quietly) in front of double-slotted trailing-edge flaps, and a T-tail keeps the tailplane well clear of the propeller wash. There are four spoilers in the upper surface of each wing. The inboard pair serve as spoilers or lift dumpers, the outboard pair as air spoilers which can also be operated differentially in conjunction with the ailerons to augment lateral control.
The fuselage is of fail-safe construction to permit pressurisation, and the landing gear is of the retractable tricycle type, with twin wheels on each unit,
Powered by four Pratt & Whitney Aircraft of Canada PT6A-50 turboprop engines, to reduce noise levels to a minimum, each drives a large-diameter 3.42m, Hamilton constant-speed full-feathering reversible-pitch four-blade propeller made from fiberglass. The props are slow-turning to reduce noise levels, so that the landing approach noise level on a three-degree glideslope is 92.4 EPNdB.
Accommodation is provided for 50 passengers, with access to the main cabin via a single door, incorporating air-stairs, at the rear of the cabin on the port side. There are provisions for optional mixed passenger/cargo or all-cargo operations, and a large freight door can be installed at the forward end of the cabin on the port side. Up to five standard pallets can be carried by the Dash 7 in an all-cargo configuration. The flight crew of two is accommodated on a separate flight deck, and advanced avionics to enhance their efficiency include an autopilot/flight director system which incorporates flight and air data computers, and weather radar.
The first operator to receive the Dash 7 was Rocky Mountain Airways, on 3 February 1978.
The company offered a coastal reconnaissance model as the Dash 7R Ranger with Litton LASR-2 radar with its antenna in an underfuselage radome for 360x surveillance coverage, but in fact the only military sales have been three aircraft each to Canada and Venezuela. Two of the Canadian aircraft were designated CC-132 and used for communications from the base at Lahr in West Germany by No.412 Squadron, while the third is designated Dash 71R and used for ice reconnaissance by the Canadian Coast Guard in the Gulf of St Lawrence. The Venezuelan aircraft are transports with a secondary coastal reconnaissance.
When production finished in December 1988 113 had been delivered to 35 customers in 22 countries. Military use of the Dash 7 was restricted to two used as VIP/transports (designated CC-132) by the Canadian Armed Forces in Germany from August 1979 to April 1987, and a single aircraft delivered to the Venezuelan Navy in May 1982 used in the patrol and transport roles.
Dash 7 Series 100: standard passenger version seating 50 passengers.
Dash 7 Series 101: all-cargo version of Series 100 able to accommodate five standard pallets.
Dash 7 Series 150: developed passenger version introduced in 1978 with higher gross weight, increased fuel capacity and improved passenger amenities.
Dash 7 Series 151: all-cargo version of Series 150.
Dash 7 IR: single special ice reconnaissance version of the Series 150 built for the Canadian government. Equipped with SLAR and computers to track ice formations and flow patterns, the aircraft was delivered in May 1986 and is operated by Bradley Air Services for the Department of Environment.
DHC-7 Series 100
Engines: 4 x P & W Aircraft Canada PT6A-50 turboprop, 835kW
Max take-off weight: 19958 kg / 44000 lb
Empty weight: 12542 kg / 27651 lb
Wingspan: 28.35 m / 93 ft 0 in
Length: 24.58 m / 81 ft 8 in
Height: 7.98 m / 26 ft 2 in
Wing area: 79.89 sq.m / 859.93 sq ft
Cruise speed: 436 km/h / 271 mph
Ceiling: 6400 m / 21000 ft
Range w/max.payload: 1279 km / 795 miles
Engines: 4 x P&W PT6A-50, 1120 shp.
Props: Hamilton 4-blade, 135-in.
Length: 80.5 ft.
Height: 26.2 ft.
Wingspan: 93 ft.
Wing area: 860 sq.ft.
Wing aspect ratio: 10.
Maximum ramp weight: 44,100 lbs.
Maximum takeoff weight: 44,000 lbs.
Standard empty weight: 27,044 lbs.
Maximum useful load: 17,056 lbs.
Zero-fuel weight: 39,000 lbs.
Maximum landing weight: 42,000 lbs.
Wing loading: 51.2 lbs/sq.ft.
Power loading: 9.8 lbs/hp.
Maximum usable fuel: 9925 lbs.
Best rate of climb: 1200.
Service ceiling: 22,800 ft.
Max pressurisation differential: 4.7 psi.
8000 ft cabin alt @: 22,000 ft.
Maximum engine out rate of climb: 700 fpm @ 124 kts.
Engine out climb gradient: 338 ft/nm.
Engine out ceiling: 14,800 ft.
Maximum speed: 231 kts.
Normal cruise @ 16,000ft: 225 kts.
Fuel flow @ normal cruise: 1639 pph.
Endurance at normal cruise: 5.5 hrs:
Stalling speed clean: 100 kts.
Stalling speed gear/flaps down: 66 kts.
Turbulent-air penetration speed: 171 kts.
Engines: four 1,120-shp (835-kW) Pratt & Whitney Canada PT6A-50 turboprops.
Maximum speed 266 mph (428 km/h) at 8,000 ft (2,440 m)
Service ceiling 21,000 ft (6,400 m)
Range 1,347 miles (2,168 km) with a 6,500-lb (2,948-kg) payload.
Empty weight: 27,650 lb (12,542 kg)
Maximum take-off 44,000 lb (19,958 kg).
Wing span 93 ft 0 in (29.35 m)
Length 80 ft 7.75 in (24.58 m)
Height 26 ft 2 in (7.98 m)
Wing area 860.0 sq ft (79.89 sq.m)
Payload: 50 passengers or 11,310 lb (5,130 kg) of freight.