THE DEHAVILLAND DHC7 100 SERIES AIRPLANE
Technical Discussion

Performance Specifications
The first prototype test airplane flew on March 27, 1975 and two pre-production aircraft were built for testing and certification. The first production Dash 7 (C-GQIW, S/N 3) flew on 30 May 1977.

Certification by the Canadian Department of Transport to FAR 25 was received on 2 May 1977; STOL performance is approved under conventional FAR 25 and FAR 121 regulations. In addition, certification has been given for 7° 30' glideslope and 10.7 m (35 ft) landing reference height adopted by the FAA for STOL aircraft.

The first Dash 7 to enter service was S/N 4, with Rocky Mountain Airways (USA), on 3 February 1978. Deliveries of the Dash 7 by June 1, 1985 had reached a total of 102, versions including the passenger Series 100/102 and the all cargo Series 101. Series 103 aircraft are combination passenger and cargo (Combi) with a large cargo door and 48 passenger max configuration. Certification was planned for 198 and 5 of a version with higher weight and greater fuel capacity, known as the Series 150. First customer for this version (one aircraft for use on ice reconnaissance duties) is the Canadian Government, whose aircraft is a specially equipped non-standard example and is described separately. The standard 150 was intended to replace the series 100 on the production line in 1986 but never reached production levels. One hundred and (113) were built between 1975 and 1988.

The following description applies to the Series 100 aircraft.

Type: Four-engine short/medium-range quiet STOL transport.

Wings: Cantilever high-wing monoplane, with 4' 30' dihedral from center-section. Wing section NACA 63A41 9 (modified) at root, NACA 63A415 (modified) at tip. Incidence 3 degrees at root. Conventional all metal two-spar bonded skin/stringer structure. Double-slotted flaps, extending over approximately 80 per cent of trailing edge, are actuated mechanically for take-off by irreversible screw jacks and hydraulically for landing. Two inboard ground spoilers/lift dumps and two outboard air spoilers in each upper surface, forward of flaps, are also actuated hydraulically. Outboard sections can be operated symmetrically or differentially in combination with the cable-operated ailerons. A trim tab is in the starboard aileron and a servotab in each aileron. Pneumatic boot de-icing of leading edges outboard of the inner nacelles supports ice protection.

Fuselage: Conventional all metal stressed skin pressurized structure of bonded skin/stringer construction. Basically circular cross-section, with flattened profile under floor level.

Tail Unit: Cantilever all-metal T tail, with large dorsal fin. Fixed incidence tailplane, and one-piece cable operated horn balanced elevator with spring tabs. Fore and trailing serially hinged rudders are actuated hydraulically. Pneumatic boot de-icing of tailplane leading edges and elevator horns is provided.

Landing Gear: Menasco retractable tricycle type, with twin wheels on all units. Oleo-pneumatic shock absorbers. Hydraulic retraction, main units forward into inboard engine nacelles, steerable nose unit rearward into fuselage. Goodrich mainwheels and Tires size 30 x 9.00-15pressure 7.38 bars (107 lb/sq in): nosewheel Tires size 6.50-10, pressure 5.31 bars (77 lb/sq in). Larger, low-pressure tires optional, with pressures of 4.83 bars (70 lb/sq in) on main units, 4.76 bars (69 lb/sq in) on nose unit. Goodrich anti-skid hydraulic braking system for all units. Small retractable tailskid under rear fuselage at rear of cabin. Optional arrangements include movable bulkhead for mixed freight/passenger loads and (Srs 101/151) large forward freight door on port side. Up to five standard pallets can be accommodated in an all-cargo role. Quick-change cargo handling system available optionally. Entire accommodation pressurized and air-conditioned.

Power Plant: Four Pratt & Whitney Aircraft of Canada PT6A-50 turboprop engines, each flat rated at 835 kW GRP, with forged aluminum spars and foam cores. Fuel in two integral tanks in each wing, total standard capacity 5,602 liters (1,232 Imp gallons), increasable optionally in Srs 150 to 9,747 liters (2,144 Imp gallons). Single pressure refueling/defueling point on underside of rear fuselage, aft of pressure dome. Pneumatic de-icing of engine air intakes; electric de-icing for propellers. Oil capacity 23 liters (5 Imp gallons).

Accommodation: Flight crew of two, plus one or two cabin attendants. Dual controls standard. Seats for 50 passengers at 81 cm (32 in) pitch standard, in pairs on each side of Center aisle, with generous provision for underseat carry-on baggage. Optional high-density seats for 54 passengers at 74 cm (29in) pitch. Outward opening airstair door at rear on port side. Emergency exits on each side at front of cabin and on starboard side at rear. Baggage compartment in rear fuselage (capacity 998 kg; 2,200 lb) with external access on starboard side and internal access from cabin. Galley, coat rack and toilet at rear of cabin. Optional arrangements include movable bulkhead for mixed freight/passenger loads and (Srs 101/ 151) large forward freight door on port side. Up to five standard pallets can be accommodated in an all-cargo role. Quick-change cargo handling system available optionally. Entire accommodation pressurized and air-conditioned.

Systems: Cabin pressure differential 0.294 bars (4.26 lb/sq in). Two air cycle systems, driven by engine bleed air, for cabin air-conditioning. Two independent hydraulic systems, each of 207 bars (3,000 lb/sq in). No. I system actuates flaps, rudder, wing spoilers and mainwheel brakes; No. 2 system actuates landing gear, nosewheel and backup mainwheel brakes, parking brakes, nosewheel steering, rudder and outboard wing spoilers. Primary DC power provided by four Phoenix 28V 250A 7.5kW starter/generators. 115/200V three-phase AC power at 400Hz from four lOkVA Lucas brushless generators for propeller and windscreen de-icing and standby fuel pumps. Lucas static inverters supply constant frequency 400Hz loads, including engine instrumentation and navigation systems. Nickel-cadmium batteries for engine starting. APU, for cabin air-conditioning and electronics and engine starting, available optionally.

Avionics and Equipment: Standard avionics include crew interphone system; cabin PA system; flight data recorder; flight compartment voice recorder; emergency locator transmitter; two independent VHF communications systems; two independent VHF (VOR/ILS) radio navigation systems; one LF (ADF) radio navigation system; one ATC transponder; one DME; one RCA Primus 40 weather radar; one marker beacon receiver; Sperry SPZ700 autopilot/flight director system, incorporating Z-500 flight computer and ADC-200 central air data computer; Sperry STARS ADI and HSI; Sperry AA-215 radio altimeter; and two Sperry C-14 slaved gyro compasses and VG-14 vertical gyros. Provision for variety of optional avionics to customer's requirements. Standard options include Collins 618M-3 COM transceiver, Collins 51RV-4D nav. receiver, Collins 51Z-4 glideslope/marker beacon receiver, and Collins 621A-6 transponder.

Performance Specifications

DIMENSIONS, EXTERNAL: |
Wing span: | 28.35 m (93 ft 0 in)
Wing chord: At root | 3.81 m (12 ft 6 in)
At tip | 1.68 m (5 ft 6 in)
MAC | 2.99 m (9 ft 9 ¾ in)
Wing Aspect Ratio: | 10
Length Overall: | 24.54 m (80 ft 6in)
Height Overall: | 7.98 m (26 ft 2 in)
Tailplane Span: | 9.45 m (31 ft 0 in 2.79 in)
Fuselage Max Diameter: | 2.79 m (9 ft 2 in)
Wheel Track: | 7.16 m (23 ft 6 in)
Wheelbase: | 8.38 m (27 ft 6 in)
Propeller Diameter: | 3.43 m (11 ft 3 in)
Propeller Ground Clearance: | 1.60 m (5 ft 3 in)(inboard engines)
Min propeller/fuselage Clearance | .75 m (2 ft 5.4 in)
Passenger door (rear, port): |
Height | 1.75 m (5 ft 9 in)
Height to sill | 1.09 m (3 ft 7 in)
Emergency exit doors (fwd, ea.): |
Height | 0.91 m (3 ft 0 in)
Width | 0.51 m (1 ft 8 in)
Height to sill | 1.09 m (3 It 7 in)
Emergency exit door (rear, stbd): |
Height | 1.35 m (4 ft 5 in)
Width | 0.61 m (2 ft 0 in)
Height to sill | 1.09 m (3 ft 7 in)
Baggage hold door (rear, stbd): |
Height | 1.02 m (3 ft 4 in)
Width | 0.84 m (2 ft 9 in)
Height to sill | 1.47 m (4 ft 1.0 in)
Cargo door (fwd, port, optional): |
Height | 1.78 m (5 ft 10 in)
Width | 2.31 m (7 ft 7 in)
Height to sill | approx. 1.22 m (4 ft 0 in)
DIMENSIONS, INTERNAL: |
Cabin, except flight deck: |
Length | 12.04 m (39 ft 6 in)
Max width | 2.60 m (8 ft 6 ft 1/4 in)
Floor width | 2.13 m (7 ft 0 in)
Max height | 1.94 m (6 ft 4 1/2 in)
Height under wing | 1.85 m (6 ft 1 in)
Volume | 54.1 m3 (1,910 cu ft)
Baggage Compartment (Rear Fuselage) |
Max Length | 2.30 m (7 ft 6 1/2 in)
Volume | 54-1 m3 (1,910 cu ft)
Areas: |
Wings Gross | 79.9 m2 (860.0 sq ft)
Ailerons (total) | 2.16 m2 (23.22 sq ft)
Trailing edge flaps (total) | 27.33 m2 (294.20 sq ft)
Spoilers (total) | 3.63 m2 (39.04 sq ft)
Vertical tail surfaces (total, excluding dorsal fin) | 15.79 m2 (170.0 sq ft)
Horizontal tail surfaces (total) | 20.16 m (217.0 sq ft)
WEIGHTS AND LOADINGS: |
Basic weight empty (standard 50-passenger layout): |
Srs 100 | 12,247 kg (27,000 lb)
Operating weight empty: |
Srs 100 | 12,560 kg (27,690 lb)
Max payload (50 passengers or cargo): |
Srs 100 | 5,130 kg (11,310 b)
Max fuel: | 7,938 kg (17,500 lb)
Max T-0 weight: Srs 100 | 19,958 kg (44,000 b)
Max zero-fuel weight: Srs 100 | 17,690 kg (39,000 lb)
Max landing weight: Srs 100 | 19,050 kg (42,000 lb)
Max cabin floor loading: | 366.2 kg/m2 (75 lb/sq ft)
Max wing loading: Srs 100 | 249.7 kg/m2 (51.16 lb/sq ft)
Max power loading: Srs 100 | 11.95 kg/kW (19.64 lb/shp)
PERFORMANCE (Srs 100 at max T-0 weight, FAR Pt 25, at S/L, ISA, except where indicated): | Max cruising speed at 2,440 in (8,000 ft) at AUW of 18,597 kg (41,000 lb) 231 knots (428 km/h; 266 mph)
| Max cruising speed at 4,575 in (15,000 ft) at AUW of 18,597 kg (41,000 lb) 227 knots (420 km/h; 261 mph)
En route rate of climb, flaps and landing gear up: | 4 engines, max climb power 372 in (1,220 ft)/min
| 3 engines, max continuous power 220 in (720 ft)/min
Service ceiling at AUW at 18,597 kg (41,000 lb): | 4 engines, max climb power 6,400 in (21,000 ft)
| 3 engines, max continuous power 3,855 in (12,650 ft)
T-0 field length: Srs 100 | 686 in (2,250 ft)
T-0 field length at 3,050 m (10,000 ft), 15 degrees flap | 1,829 m (6,000 ft)
Landing field length at max landing weight: Srs 100 | 45 degrees flap 658 m (2,160 ft)
Landing field length at 3,050 in (10,000 ft) at 18,915 kg (41,700 lb) landing weight: Srs 100 | 45 degrees flap 823 in (2,700 ft)
Min ground turning radius: | 8.84 m (29 ft 0 in)
Runway LCN with 32 x 11-50-15 low-pressure tires rigid, 30 in relative stiffness | 16.2
Range at 4,575 in (15,000 ft) with 50 passengers and baggage, at ong-range cruising speed, IFR reserves: Srs 100 | 690 nm (1,279 km; 795 miles)
Max range at 4,575 in (15,000 ft) with standard fuel and 2,948 kg (6,500 lb) payload, long-range cruising speed: Srs 100 | 1,170 nm (2,168 km; 1,347 miles)
OPERATIONAL NOISE LEVELS (FAR Pt 36 at S/L, ISA + 10'C, Srs 100 confirmed): |
T-0 | 80.5 EPNdB
Approach on 3' glideslope | 91.4 EPNdB
Sideline | 82.8 EPNdB

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