The DH-20 helicopter was tested in 1968. No series production.
Engine: 2 x AiResearch GTP-30-100 turboshafts
Rotor diameter: 4.88m
Take-off weight: 500kg
Max speed: 135km/h
Range: 180km
Del Mar DH-20
Post WW2
Del Mar Engineering Laboratories
USA
A weapons systems support and training systems designer/manufacturer of Los Angeles, California; produced a series of very original experimental ultralight helicopters from 1940, as well as a helicopter training system. Production ended by 1974.
Delhamende
Belgium
Took over production of the D-158 Tipsy Nipper from Avions Fairey Beige, designed originally by M. Tips to be sold as a kit. Delhamende marketed it under the name Cobelavia from the early 1960s. and sold all Nipper rights to Nipper Aircraft in the U.K. in 1966.
de Lackner DH-4 Heli-Vector / HZ-1 Aerocycle
The flying platforms grew out of research conduction by the US National Advisory Committee on Aeronautics in the early 1950s on the feasibility of one-man flying platforms for combat use. The tests involved pilots “flying” tethered platforms, at first lifted by compressed air, and then by rotors.
The concepts investigated in the tests were based on thinking by NACA engineer Charles H. Zimmerman, who proposed that if the rotors of a helicopter were placed on the bottom of the aircraft, a pilot would be able to steer it just by shifting his or her weight, a concept Zimmerman called “kinesthetic control”. It was hoped that kinesthetic control would allow a pilot to fly such platforms with little training. The tests demonstrated the technical validity of the concept. The NACA results were released to the public, resulting in flying platform prototypes from three companies: de Lackner, Bensen, and Hiller.
de Lackner company privately developed a rotorcraft named the “DH-4 Helivector”, later renamed the HZ-1 Aerocycle. The de Lackner machine consisted of a frame that supported the engine of a 30 kW (40 HP) Mercury outboard motor, with landing gear consisting of an arrangement of airbags on the ends of spars. The airbags were later replaced by metal skids. The engine drove a pair of 4.6 meter (15 foot) contra-rotating rotors directly beneath it, while the pilot stood vertically on a platform above the engine, protected from falling into the rotors by a safety harness, and hanging on motorcycle handlebars with it a twist-grip throttle. He used kinesthetic control to fly the machine.
The Helivector / Aerocycle first flew in January 1955, and the Army ordered twelve examples ‘off-the-shelf’ shortly after. The aircraft was initially designated YHO-2 (a designation which was later also applied to five Hughes H-55 helicopter prototypes), though this was subsequently changed to HZ-1. De Lackner claimed the machines could fly at up to 105 kph (65 mph), carry up to 55 kilograms (120 pounds) payload besides the pilot, and fly for an hour. However, while the thing looked like it would have been a lot of fun to fly, it was also dangerous. Not only did the pilot stand above the whirling rotors, but the rotors were wide and close to the ground, making them a hazard on landings and takeoffs since they could easily kick up rocks and other debris.
The Aerocycle carried its single pilot and 32kW engine on a circular platform located just above two belt-driven, contra-rotating fifteen-foot propellers. The engine throttle and a few basic instruments were attached to bicycle-type handlebars fixed to a three-foot tall pedestal atop the main platform. The pilot stood to the rear of the pedestal and was secured to it by safety belts, and guided his craft by simply leaning in the desired direction of travel. The machine’s landing gear initially consisted of a single large air bag placed directly beneath the propellers and augmented by four smaller air bags fixed to outrigger bars, though this system was ultimately abandoned in favor of helicopter-type metal skids. The HZ-1 was surprisingly stable despite its appearance, and its top speed of more than 110kph made it considerably faster than most of the other unconventional one-man flying machines evaluated by the Army.
The Army’s research was to explore the feasibility of inexpensive, safe, and easily operated personal aircraft. The Aerocycle was especially successful in the ease of operation category, for during the service tests soldiers required only about twenty minutes of instruction before flying the aircraft.
Some sources claim that the Helivector / Aerocycle was easy to fly, others state that the test pilot insisted that novices could not pilot it safely. After two flight accidents in which the contra-rotating rotors flexed and collided, the project was abandoned as impractical. At least one survives as a museum display.
De Lackner HZ-1
Engine: 1 x Kieckhaefer Mercury Mark 55, 32kW
Main rotor diameter: 4.57m
Height: 2.13m
Take-off weight: 206kg
Empty weight: 78kg
Max speed: 120km/h
Cruising speed: 90km/h
Service ceiling: 1520m
Range: 24km
Crew: 1
de Havilland Canada DHC-6 Twin Otter
In 1964 de Havilland Canada announced that it was developing a twin-turboprop high-wing monoplane with STOL capability to provide accommodation for 13 to 18 passengers as the de Havilland Canada DHC-6 Twin Otter. Design of the aircraft’s wing includes double-slotted trailing-edge flaps and ailerons which can be drooped simultaneously with the flaps to enhance STOL performance. Fixed tricycle landing gear can have optional float or ski installations, as well as the standard wheels.
Jointly funded by the Canadian Department of Defence and de Havilland Canada, the first of an initial batch of five made its maiden flight on 19 May 1965. The first three aircraft were powered by two 432kW Pratt & Whitney Aircraft of Canada PT6A engines, but the fourth and subsequent examples of this first Twin Otter Series 100 production version had PT6A-20 engines of similar output.
de Havilland DHC-6 Twin Otter Article
Its design philosophy is directed towards operation from short semi-prepared runways for services in localities where air connections have not previously been practical, and its emphasis is on engineering simplicity and operational versatility. This is reflected by such features as urethane blocks as shock absorbers in the main undercarriage shoulders. Another selling point is the quickly convertible 384 cu.ft cabin from passengers to a maximum freight load of 4250 lb carried over 100 nm stage lengths with reserves.
The principal impact of the Twin Otter, and a feature which has already resulted in sales and options for about 30 aircraft, is probably its STOL performance to and from 50 ft of about 1000 ft. The CAR 3 distances are still only 1700 ft for take-off and 2160 ft for landing. At the start of its European tour at the Hanover Air Show, the Twin Otter demonstrator was able to join the Do27s and Porters ferrying passengers across the town to the small airstrip of the main industrial fair, and it was also able to get in and out of Heligoland’s 190m strip off the German coast.
The Twin Otter has full-span double-slotted flaps, with the outer sections also operating as ailerons, but has no exotic high lift devices. Its tricycle undercarriage has an electrically-driven hydraulic pump providing power for steering, toe brakes and flaps, with a nosewheel – tiller on the port control wheel. The Twin Otter cockpit has entry doors each side so that the crew can get in and out when the cabin is packed to capacity with freight.
The Twin Otter has roof-mounted engine controls, which increase available cockpit space and the PT6s can be left in the flight idle gate for taxying except for occasional aft movement into the Beta range, to prevent excess speed building up on the ground. Further aft movement of the power levers through the idle gate selects reverse pitch, which enables the Twin Otter to back out of restricted parking spaces.
There are two main power references-torque, in lb/sq.in, and turbine gas temperature, with respective limits of 42.5 and 750 deg C.
During take-off, it would be easy to over boost the engines by opening the power levers to their full extent, so if the outside air temperature is on the low side, the torque-meters have to be watched to avoid exceeding the limit. In hot weather the limiting factor becomes exhaust temperature.
After raising flap, the Twin Otter climbs at 110 kt on 41 lb/sq.in torque, with the airscrew rpm pulled back to 90 per cent and climbed at nearly 2 000 ft/min. Levelling out with power reduced to 33 lb/sq.in torque and 78 percent rpm (330 shp per engine) gives an indicated 140-145 kt., which trued out to 155-160 kt. for a fuel flow of 225 lb per hour per engine.
One of the most useful aspects of Twin Otter performance is the’large usable speed range between Vno Of 160 kt. and a flapdown stall with power of well below 40 kt. IAS, including a manoeuvre speed for bush flying of around 55 kt. with about 25 per cent power and full flap.
To eliminate large changes of trim with flap movement, the Twin Otter retains the same trim tab interconnection that was introduced in its single-engine predecessor. This ensures a comfortable limit to, the nose-up pitch accompanying flap retraction during an overshoot. Clean and power off, slight aileron snatch precedes pre-stall buffet, with some lateral hunting at 65 kt. which continues after the mild break-away at about 60 kt. IAS. With the full 40 degrees of flap extended, a gentle and straight stall break occurs at about 42 kt. IAS, power oft. Aerodynamic buffet gives about 8 kt. stall warning in all configurations
With 30 degrees (take-off) of flap extended, Vmc is 64 kt., and single-engine flight is completely uncomplicated. Feathering the port (critical) propeller from a 92 kt. climb resulted in light rudder loads, even before wind milling stopped, although the Twin Otter runs out of rudder trim at just below 85 kt, a long way before Vmc. There was no difficulty in showing a single engine en route climb of more than 300 ft/min.
Before landing, the nosewheel tiller has to be checked for centering, and then a spectacularly steep approach is achieved with full flap and just a trickle of power at only 65 kt. With restricted reverse pitch a 250 ft ground run is achieved.
The price, in basic form, in 1966 was (Canadian) $275000 approx. The PT6A-20 starts operational life with an overhaul period of 1200 hours.
Some 30 Twin Otters were due for completion by the end of 1966, and production was to continue at the rate of about six per month.
Delivered in July 1966, the first Twin Otter Series 100 entered service in 1966, and, following manufacture of 115 of that version, production switched to the Twin Otter Series 200. It differed by having increased baggage capacity in a lengthened fuselage nose and was certificated for operation at a higher gross weight. After 115 had been built the production Twin Otter Series 300 was introduced, this having more powerful 652 shp PT6A-27 engines which make possible an increase of almost 454kg in maximum take-off weight. Later production aircraft had a 20-seat commuter interior as standard and all floatplane versions, irrespective of series, retain the shorter fuselage nose of the original Series 100. Specialised equipment that has been developed to enhance the capabilities of these popular aircraft includes a ventral pod to carry 272kg of freight and an expendable fabric membrane tank holding 1818 litres of water for water-bombing fire-fighting operations.
The 300S model features several improvements: high-capacity brakes, an antiskid system, wing spoilers, refined electrical and hydraulic systems, propeller automatic feather, and improved fire protection. In addition, six 300S enhanced STOL performance DHC-6-300s were built in the mid 1970s. Earlier models, the series 100 and 200, were fitted with 570 shp engines. Access to the two man cockpit is through a car-like door on each side or through the cabin. The standard “Commuter” version will accommodate 20 passengers, but optional arrangements are available.
In 1982 DH Canada offered two specialised military versions designated Twin Otter Series 300M basic military transport (15 troops, 20 passengers or 2,270kg of cargo) or COIN version armed with cabin-mounted machine-guns and four underwing hardpoints, and the 300MR maritime reconnaissance version equipped with undernose Litton AN/APS-504 360 degree scan search radar, comprehensive avionics, an infrared linescanner, and a wing-mounted searchlight. Although a prototype 300MR was flown, the only buyer as Senegal with a single aircraft.
The Twin Otter has seen wide use with air forces and government agencies. Military operators include Argentina, Canada, Chile, Ecuador, Ethiopia, France, Haiti, Jamaica, Nepal, Norway, Panama, Paraguay, Peru, the USA and Venezuela.
When the last Twin Otter was delivered in December 1988 production had reached 844.
Field Aviation Co of Mississauga, Ontario, developed an update package for the aircraft which has prompted a first contract by Wideroe Flyveselskap to modernise that airline’s fleet of nine aircraft. Principal differences are the four-bladed propellers on the two Pratt & Whitney Canada PT6A-27 turboprops and a brand new interior.
Viking announced the re-launch of the type and in 2010 ten Twin Otter 400s were in various stages of assembly at Calgary with production ramping up to build one-and-a-half aircraft every four weeks.
Viking Air completed a ten-minute maiden flight of the first new-build DHC-6 Series 400 Twin Otter on February 16, 2010. The aircraft (c/n 845) flew from the company’s assembly facility at Calgary in Alberta. It has been assigned the registration C-FMJO and is configured with a commuter cabin and was to be delivered to launch customer Zimex Aviation of Switzerland for use on oil and gas industry contracts throughout North Africa.
By 2016 the Twin Otter series 400 was in series production by Viking Air and a number were in service, including two operated by Loganair, Glasgow, Scotland.
Variants:
Twin Otter 300S: designation of six aircraft fitted with 11 seats, an improved high-capacity anti-skid braking system and wing spoilers, built for the 1973 experimental Air Transit service linking downtown STOL airports in Montreal and Ottawa.
Twin Otter Series 400: proposed development to meet US FAR 36 noise regulations. Not built.
UV-18A: two standard Series 300s delivered October 1976 onwards to the US Army Alaska National Guard, followed by four more in 1979 and 1982. Operating on wheels, floats or skis they are used for command, personnel or logistic flights within Alaska.
UV-18B: two standard Series 300s delivered to the US Air Force Academy in 1977 and used for sporting parachuting activities.
Specifications:
De Havilland Canada DHC 6 Twin Otter
Engine: 2 x Pratt&Whitney Canada PT6A 20, 643 shp
Wingspan: 65 ft (19.81 m)
Length: 49.5 ft (15.1 m)
Height: 18.6 ft (5.67 m)
Wing area: 420 sq.ft (39.02 sq.m)
Max take off weight: 11,000 lb (4990 kg)
Weight empty: 5850 lb (2653 kg)
Max. fuel: 2488 1b (1128 kg)
Max. payload: 4250 lb (1928 kg)
Max. speed: 239 kt / 442 km/h
Max. cruise at 10,000 ft (3050 m): 158 kt (293 kph)
Service ceiling: 25,500 ft (8354 m)
Single-engine ceiling: 8500 ft (2590 m)
Initial climb: 1550 ft/min (7.87 m/sec)
Single-engine climb: 315 ft/min (1.59 m/sec)
Cruising altitude: 10007 ft / 3050 m
Wing loading: 25.01 lb/sq.ft / 122.0 kg/sq.m
Range full fuel / 2420 lb (1105 kg) payload: 710 nm (1320 km)
Range with max. payload: 100 nm (185 km)
STO to 50 ft (15 m): 1090 ft (332 m)
Short landing from 50 ft (15 m): 980 ft (298 m)
CAR 3 distance take-off: 1700 ft (518 m)
CAR 3 distance landing, 2 160 ft (658 m)
Crew: 2+20
DHC-6 Twin Otter
Engine: 2 x PT6A-27, 620 hp.
Seats: 22.
Wing loading: 29.8 lb/sq.ft.
Pwr loading: 10.08 lb/hp.
Gross wt: 12,500 lb.
Empty wt: 7387 lb.
Equipped useful load: 4944 lb.
Payload max fuel: 1754 lb.
Range max fuel/cruise: 763nm/4.1hr.
Range max fuel / range: 895nm/6.1hr.
Ceiling: 26,700 ft.
Max cruise: 182 kt.
Max range cruise: 148 kt.
Vmc: 68 kt.
Stall: 58-74 kt.
1.3 Vso: 75 kt.
ROC: 1600 fpm.
SE ROC: 340 fpm @ 80 kt.
SE ceiling: 11,600 ft.
Min field length: 1500 ft.
Fuel cap: 2583/3190 lb.
DHC-6 Twin Otter
Engines: 2 x Pratt & Whitney (UACL) PT6A 27 turboprop, 652 shp.
Prop: 8 ft 6 in (2.59 m) dia 3 blade.
Wing span: 65 ft 0 in (19.81m).
Length: 51 ft 9 in (15.77 m).
Wing area: 420 sq ft (39.02 sq.m).
Gross weight: 12,500 lb (5,670 kg).
Max cruising speed: 210 mph (338 kph) at 10,000 ft (3,050 m).
Range: 745 miles (1,198 km) with 3250 lb (1474 kg) payload.
Crew: 1 or 2
Accommodation: 20 passengers or equivalent freight load.
DHC 6-300
Engines: 2 x P&W PT6A-27, 620 shp / 486kW.
Props: Hartzell 3-blade, 102-in.
Seats: 20.
Wingspan: 19.81 m / 65 ft 0 in
Length: 15.77 m / 52 ft 9 in
Height: 5.94 m / 20 ft 6 in
Wing area: 39.02 sq.m / 420.01 sq ft
Wing aspect ratio: 10.1.
Maximum ramp weight: 12,508 lbs.
Maximum takeoff weight: 5670 kg / 12,500 lbs.
Standard empty weight: 6873 lbs.
Maximum useful load: 5635 lbs.
Zero-fuel weight: 12,300 lbs.
Maximum landing weight: 12,300 lbs.
Wing loading: 29.8 lbs/sq.ft.
Power loading: 10.1 lbs/hp.
Maximum usable fuel: 3190 lbs.
Best rate of climb: 1600.
Service ceiling: 8140 m / 26,700 ft.
Maximum single-engine rate of climb: 340 fpm @ 79 kts.
Single-engine climb gradient: 258 ft/nm.
Single-engine ceiling: 11,600 ft.
Maximum speed: 182 kts.
Normal cruise @ 10,000ft: 182 kts.
Fuel flow @ normal cruise: 664 pph.
Endurance at normal cruise: 4.3 hrs:
Stalling speed clean: 74 kts.
Stalling speed gear/flaps down: 58 kts.
Turbulent-air penetration speed: 136 kts.
de Havilland Canada DHC-5 Buffalo
Developed from the DHC-4 Caribou, being an enlarged fuselage version of that aircraft, the de Havilland Canada DHC-5 Buffalo was known originally as the Caribou II.
de Havilland Canada DHC-5 Buffalo Article
Four were ordered for evaluation by the US Army, their development cost shared by the US Army, together with the Canadian government and de Havilland Canada; the first of these transports made its maiden flight on 9 April 1964.
To meet the requirements of the US Army for a transport, the DHC-5 can carry loads such as the Pershing missile, a 105-mm howitzer or 3/4-ton truck. The Buffalo can accommodate 41 troops, 35 paratroops, 24 stretchers, or up to 18,000 lb (8,164 kg) of freight (Including vehicles).
No further orders resulted from US Army evaluation of the DHC-5 (designated originally YAC-2 by the US Army, and later C-8A), but the Canadian Armed Forces acquired 15 of the DHC-5A which it designated CC-115: six were converted subsequently for deployment in a maritime patrol role. Following delivery of 24 to the Brazilian air force and 16 to the Peruvian air force, the production line was closed down.
In 1974 production of an improved DHC-5D Buffalo was initiated. This had more powerful engines which permitted operation at higher gross weights, and offered improved all-round performance. Production of the Buffalo ended in 1982, but the last of 122 aircraft built was not delivered until April 1985. DHC-5Ds were bought by the armed forces of Abu Dhabi (5), Cameroun (3), Chile (1), Ecuador (3), Egypt (10), Kenya (8), Mauritania (1), Mexico (3), Sudan (4), Tanzania (6), Togo (2), Zaire (3) and Zambia (7).
With interest being shown by civil operators, DH Canada developed the DHC-5E Transporter, certificated in Canada in 1981. Generally similar to the military Buffalo, it could seat 44 passengers in a standard layout but with quick-change passenger/cargo and VIP/executive interior. Two were acquired by Ethiopian Airlines.
The de Havilland Canada XC 8A research aircraft, modified by the addition of an air cushion landing system (ACLS) designed by Bell Aerospace, made its first flight on 31 March 1975. An air cushion beneath the aircraft was created by an inflated rubberized nylon trunk pierced with hundreds of vent holes, making it possible to take off from or land on virtually any surface, including water.
Variants:
DHC-5B: designation of proposed version with General Electric CT64-P4C engines, not built.
DHC-5C: designation of proposed version with Rolls-Royce Dart RDa.12 engines, not built.
NASA/DITC XC-8A: designation of C-8A following conversion for use as an augmentor wing research aircraft; extensively modified, it has clipped wings, fixed landing gear, two Rolls-Royce Spey engines with vectored nozzles complementing the augmentor wings.
XC-8A ACLS: redesignation of C-8A following conversion for use as an Air-Cushion Landing System research aircraft; instead of conventional landing gear it has an inflatable but perforated rubber air cushion which permits operation from and to almost any type of surface, including ice, rough airfields, soft soils, snow, swamps and water.
NASA/Boeing QSRA: redesignation of C-8A following conversion for use as a Quiet Short-haul Research Aircraft; this aircraft has a new wing incorporating upper-surface blowing and boundary-layer control; engines are four Avco Lycoming F102 turbofans.
DHC-5D
Engines: 2 x General Electric CT64-820-4 turboprop, 3,133 shp / 2336kW
Max take-off weight: 22317 kg / 49201 lb
Empty weight: 11412 kg / 25159 lb
Wingspan: 29.26 m / 96 ft 0 in
Length: 24.08 m / 79 ft 0 in
Height: 8.76 m / 29 ft 9 in
Wing area: 87.79 sq.m / 944.96 sq ft
Wing loading: 52.07 lb/sq.ft / 254.00 kg/sq.m
Cruise speed: 420 km/h / 261 mph
Ceiling: 7620 m / 25000 ft
Range w/max.fuel: 3280 km / 2038 miles
Range w/max.payload: 416 km / 258 miles
Payload: 41 Pax. / 8160kg
Crew: 2-3
Passengers: 44
Gemini
Engine: 2 x General Electric CT64 turboprop, 3,133shp.
Installed pwr: 4680 kW.
Span: 29.3 m.
Length: 24.1 m.
Wing area: 87.8 sq.m.
Empty wt: 11,410 kg.
MTOW: 22,320 kg.
Payload: 8165 kg.
Cruise speed: 420 kph.
Initial ROC: 555 m / min.
Ceiling: 7600 m.
T/O run: 700 m.
Ldg run: 260 m.
Fuel internal: 7980 lt.
Range/payload: 1112 km with 8165 kg.
Capacity: 41 pax.
DHC-5 Buffalo CC-115
Engines: 2 x General Electric, 3055 shp.
Wing span: 96 ft 0 in (29.266 m).
Length: 79 ft 0 in (24.08 m).
Height: 28 ft 8 in (8.73 m).
Max TO wt: 49,200 lb (22316 kg).
Max level speed: 261 mph ( 420 kph).
de Havilland Canada DHC-4 Caribou
The decision to build the de Havilland Canada DHC-4 Caribou was taken in 1956, the object being to develop an aircraft combining the load-carrying capability of the Douglas DC-3 with the STOL performance of the Beaver and Otter.
de Havilland Canada DHC-4 Caribou Article
First flown on 30 July 1958 the de Havilland Canada DHC 4 Caribou is powered by two 1,450hp Pratt & Whitney R 2000 Twin Wasp radials. It can carry 36 troops, 26 paratroops, 22 stretchers, or freight (including vehicles) up to 8,740 lb (3,965 kg) in weight.
The Caribou is a twin-engined high-wing monoplane with full-span double-slotted Fowler flaps and fully-reversible propellers, which allow it to achieve steep approach and very short take-offs and landings. The high wing centre-section has marked anhedral and distinctive high placement of the tail provide easy access to a large cargo compartment, while the low-pressure tyres permit operation on unprepared runways. The rear door was designed as a ramp for items weighing up to 3048kg. The Caribou is not pressurised and is not fitted with auto-pilot or weather radar.
The Canadian army placed an order for two and the US Army followed with five, the US Secretary of Defense waiving a restriction which limited the US Army to fixed-wing aircraft with an empty weight less than 2268kg.
The Caribou served with the RCAF as the CC-108 and with the US Army as the AC-1 (1962 designation CV-2A). As a result of its evaluation of the first five aircraft the US Army adopted the Caribou as standard equipment and placed orders for 159.
The second batch of aircraft was designated CV-2B. Following tension on the border between China and India, the US Army handed over two Caribous to the Indian Air Force in early 1963. In January 1967 the 134 Caribous still in service with the US Army were transferred to US Air Force charge as C-7A and C-7B transports.
A YAC 1 Caribou evaluation aircraft, fourth off the Downsview line and redesignated as a CV 2A in 1962, was used by the ‘Golden Knights’ parachute team.
Eighteen Caribous were ordered for the RAAF in May 1963 and the first aircraft, A4-134, was handed over at Downsview, Toronto in Februrary 1964. Three aircraft were then ferried by No.38 Sqn crews to Australia via Europe. Three later Caribous on ferry were diverted to form RAAF transport Flight Vietnam.
In total the RAAF received 29 Caribous.
In 1964 three US Army CV-2 Caribou flew Travis AFB, California, via Hawaii, Wake Island, Guam, the Philippines to Vietnam in elapsed time of just under 65 hours. Manned by crews from 10th Air Transport Brigade from Ft. Benning, Ga. The Caribou flew combat missions in South Vietnam. The Army CV-2s were joined by three from the RAAF.
It was the last piston-engined aircraft in the Royal Australian Air Force. The Caribou was last operated by No 38 Squadron from RAAF Base Townsville.
In Canadian service the Caribou was replaced by the DHC-5 Buffalo and surplus examples were sold to a number of nations including Colombia, Oman and Tanzania. Many of the Canadian aircraft had been loaned to the United Nations, seeing extensive international service. Production ended in 1973. The DHC-4A model supplanted the DHC-4 on the production line from aircraft no. 24: the two models are very similar apart from the later model’s increase in weight, maximum take-off weight of the DHC-4 being 11793kg. Total production was 307.
The newly independent Kenya built a small air force, assisted by British advisors. The first planes to be acquired were DHC Beavers and Caribou. Kenyan pilots were trained by the RAF in Britain.
DHC-4A Caribou
Engines: 2 x Pratt & Whitney R-2000-7M Twin Wasp, 1,450 hp / 1081kW
Max take-off weight: 12927 kg / 28499 lb
Empty weight: 8283 kg / 18261 lb
Wingspan: 29.15 m / 96 ft 8 in
Length: 22.12 m / 73 ft 7 in
Height: 9.68 m / 32 ft 9 in
Wing area: 84.72 sq.m / 911.92 sq ft
Max. speed: 348 km/h / 216 mph
Cruise speed: 293 km/h / 182 mph
Service Ceiling: 7560 m / 24800 ft
Range w/max.payload: 389 km / 242 miles
Crew: 2
Passengers: 32
de Havilland Canada DHC-3 Otter
In the late 1940s de Havilland Canada developed a larger version of the Beaver, with cabin space for some 14 passengers or a freight load of up to 1016kg. The de Havilland Canada DHC-3 Otter, which was essentially a scaled-up Beaver, with an all-metal airframe and a 447kW Pratt & Whitney R.1340 Wasp radial, and which was initially known as the King Beaver.
de Havilland Canada DHC-3 Otter Article
Pratt & Whitney powered, a high-wing monoplane with a single bracing strut on each side, its parallel-chord wing with double-slotted flaps for good STOL performance.
The prototype first flew on 12 December 1951, and first deliveries were made in 1952.
When production ceased in 1968, 460 had been built, including 66 for the Royal Canadian Air Force and 227 for the US armed forces (223 of the U-1A for the US Army and four of the UC-1 [changed to U-1B in 1962] for the US Navy). An initial order for 84 had been placed for the U.S. Army by 1955 under the designation C-137.
Delivery of a substantial number of DHC Otter to the Indian Air Force was completed in mid-1958.
When released by military operators, many Otters joined those already on the civil market, where again the type had found ready acceptance for its versatility. Like the Beaver, the Otter can operate on wheel, ski, float or amphibious float landing gears.
Despite its already impressive STOL performance, the Otter was selected as the basis for a Canadian experiment in advanced STOL characteristics, a programme undertaken by the company in conjunction with the Defense Research Board. As part of this programme an Otter was fitted with extremely large flaps inboard of the strut/wing junction points; this also necessitated an enlargement of the tail surfaces, and ground stability was ensured by the replacement of the original tailwheel landing gear with a float chassis fitted with quadricycle wheels instead of the floats. The STOL modifications reduced the Otter’s stalling speed by 16km/h. The flaps were then removed, and a 1112kg thrust General Electric J85-GE-7 turbojet installed, in the fuselage aft of the wings, with adjustable nozzles protruding one through each side of the fuselage. This arrangement permitted far greater control of speed, and allowed spot landings. Finally, the single Wasp radial was replaced by a pair of wing-mounted Pratt & Whitney Aircraft of Canada PT6 turboprops, whose slipstream was found beneficial to the controllability of the aircraft.
Under the designation DHC-3-T Turbo-Otter, one aircraft has been modified by Cox Air Resources to turboprop power, a 494kW PT6A-27 replacing the standard Wasp. Empty weight is thus reduced to 1861kg, resulting in a useful payload increment.
Airtech Canada of Peterborough, Ontario, has converted a number of Otters to take either the 800 hp / 447kW PZL-3S or 1000 hp / 746kW Kalisz ASz-621R nine-cylinder air-cooled radial engines manufactured in Poland, each driving a PZL four-bladed constant speed propeller. The re-engined aircraft offer increased climb rates and greater fuel economy at lower power settings. The first PZL-3S conversion flew in August 1983.
Variant:
Texas Turbine Conversions DHC-3 Otter
Engine: 1 x Pratt & Whitney R-1340-S1H1-G Wasp radial, 600 hp / 447kW
Max take-off weight: 3629 kg / 8001 lb
Empty weight: 2010 kg / 4431 lb
Wingspan: 17.68 m / 58 ft 0 in
Length: 12.75 m / 42 ft 10 in
Height: 3.84 m / 13 ft 7 in
Wing area: 34.84 sq.m / 375.01 sq ft
Max. speed: 246 km/h / 153 mph
Cruise speed: 195 km/h / 121 mph
Ceiling: 5485 m / 18000 ft
Range w/max.payload: 1408 km / 875 miles
Fuel consumption: 30 Imp.Gal/hr.
Accommodation: 2 crew plus 14 troops or 6 stretchers and 4 passengers, or freight.
Engine: PZL, 600 hp.
MTOW: 8000 lbs.
Wing span: 58 ft.
Engine: PZL, 1,000 hp.
ROC: 2000 fpm.
T/O time (water): 10 sec.
Fuel consumption: 40 Imp.Gal/hr.
Cruise: 144 mph.
MTOW: 8000 lbs.
Wing span: 58 ft.
de Havilland Canada DHC-1 Chipmunk
A design exercise team was assembled under the direction of W.J. (“Jackie”) Jakimiuk for a primary trainer in both Canada and the United Kingdom. The team began production in December 1945 of detailed parts of what was to become known as the Chipmunk, culminating in the first flight on 22 May 1946 at Downsview, Toronto. The prototype, flown by Pat Fillingham from the parent company at Hatfield, was powered by a 108kW de Havilland Gipsy Major 1C. Chipmunks built to the prototype’s specification were designated DHC-1B-1, while those with a Gipsy Major 10-3 were designated DHC-1 B-2.
de Havilland Canada DHC-1 Chipmunk Article
Seating is tandem fashion under a sliding bubble canopy. A 145 hp Gipsy Major four-cylinder engine turns either a fixed-pitch wood propeller or a metal Fairey-Reed airscrew. The fuselage and wings are of all metal construction, but the ailerons, elevators, and rudder are fabric covered.
Downsview built 218 Chipmunks, the last in 1951.
The first batch being built in Canada, a total of 153 aircraft. Examples from this initial production run were sent as demonstrators to the UK, South Africa, South American and India, as well as the RCAF which accepted 45. These original aircraft went to the 14 flying clubs in Canada which participated in the ab initio air force training and refresher flying scheme.
In 1955 a further order of 60 aircraft was placed by the RCAF. In all, the Canadian production totalled 218, the majority of this number sporting the distinctive one piece bubble canopy and designated the Chip¬munk T.30. The main external difference between the British and Canadian aircraft lay in the design of the canopy, the British version having the metal formed pattern. The RCAF accepted its first DHC-1 Chipmunks in 1948 and did not retire the last one until 1972.
Two were evaluated by the Aeroplane and Armament Experimental Establishment at Boscombe Down. As a result, the fully-aerobatic Chipmunk was ordered from Hatfield and Chester to Specification 8/48 as an ab initio trainer for the RAF. The value of the Chipmunk had also been realised by the RAF, which placed large orders, eventually taking on charge 740 examples of a total production run of 1000 aircraft manufactured in Britain.
Beginning in 1950, the University Air Squadrons were the first RAF units to receive Chipmunks, shortly followed by the twenty Reserve Flying Schools. The first to wear RAF roundels were flown by the Oxford University Air Squadron from February 1950; thereafter, the type replaced the Tiger Moth with all 17 university air squadrons. National service pilots underwent their initial training on the Chipmunk, which served intermittently at the RAF College, Cranwell.
The selection of the Chipmunk as the RAF’s primary trainer during the early 1950s expansion of its pilot training programme transformed the aircraft’s story. With increased orders to meet these expanded needs, eventually totalling 735 out of 1,014 manufactured in the UK.
In 1952, the aircraft received the royal seal of approval when HRH the Duke of Edinburgh took his first flying lessons in Chipmunk (which can be seen at RAF Museum Cosford) operated by a special flight at White Waltham, Berkshire.
New trainers such as the Scottish Aviation Bulldog entered service with the RAF but they did not completely replace the Chipmunk. Many Air Experience Flights continued to operate Chipmunks through the 1980s and into the mid-1990s.
Although best known as a training aircraft, RAF Chipmunks operating from Berlin were converted for covert reconnaissance missions. A few Chipmunks of No. 114 Squadron were pressed into service in Cyprus on internal security flights during the troubles of 1958.
Chipmunk production was also under¬taken by the Portuguese, who purchased an initial batch of 10 UK built aircraft and produced a further 60, built under licence by the state run General Aeronautical Material Workshops (OGMA) aircraft factory. Manufactured from 1955, the Portuguese air force Chipmunks were due for retirement in 1989, but many examples are still in service with the RAF, Sri Lankan air force and the Royal Thai Air Force.
Other users included Burma, Ceylon, Chile, Colombia, Denmark, Egypt, Eire, Iraq, Jordan, Lebanon, Malaya, Saudi Arabia, Syria, Thailand and Uruguay.
On 27 March 1997, the Army Air Corps flew their last sortie in the Chipmunk T.10.
As a civilian replacement trainer, how¬ever, the Chipmunk was never really a great success, due almost entirely to the cost. In 1948 a new Chipmunk cost $C10,500 which, compared with a war surplus Tiger Moth at $NZ500.
Only six DHC 1Mk.21s were made in the UK specifically for civilian use, coming off de Havilland’s production line at Chester in 1952. The six were built as Mk.20s the export version of the Chipmunk but were converted to yet another model, the Mk.21. Differences included the replacement of the military cartridge starter with an electric unit and the fitting of two 12 gal fuel tanks in place of the 9 gal tanks of the RAF Chipmunks.
A total of 1277 Chipmunks were built in either Canada, the UK or Portugal.
Variation:
Sasin SA-9 Spraymaster
de Havilland Canada DHC 1 Chipmunk
Engine : DeHavilland Gipsy Major 8, 143 hp
Length : 25.427 ft / 7.75 m
Height : 6.988 ft / 2.13 m
Wingspan : 34.35 ft / 10.47 m
Wing area : 173.3 sqft / 16.1 sq.m
Max take off weight : 2015.4 lb / 914.0 kg
Max. speed : 120 kts / 222 km/h
Service ceiling : 15814 ft / 4820 m
Wing load : 11.69 lbs/sq.ft / 57.0 kg/sq.m
Range : 244 nm / 451 km
Crew : 2
Chipmunk T.Mk 10
Engine: 1 x De Havilland Gipsy 8, 108kW
Max take-off weight: 914 kg / 2015 lb
Empty weight: 646 kg / 1424 lb
Wingspan: 10.46 m / 34 ft 4 in
Length: 7.75 m / 25 ft 5 in
Height: 2.13 m / 7 ft 0 in
Wing area: 15.97 sq.m / 171.90 sq ft
Max. speed: 222 km/h / 138 mph
Cruise speed: 187 km/h / 116 mph
Ceiling: 4815 m / 15800 ft
Range: 451 km / 280 miles
DHC1B-2-S5 Chipmunk II
Engine : DH Gypsy Major 10 Mk1-3A, 146 hp
Wing Span : 34ft 4in (10.5m)
Length : 25ft 5in (7.8m)
Height : 7ft (2.1m)
Range : 485 miles (781 km)
Speed : 120 Mph(193 km/h)
Mk.21
Mk.22
Wing span: 34 ft 3 in (10.5m).
de Havilland Canada
Formed in 1928 at Downsview, Toronto, as a constructional and service facility. Built 1,553 Tiger Moths (1938- 1945), erected about 40 D.H.60M Moths, a Giant Moth, some 25 Puss Moths, and 200 Tigers (from U.K.-built parts). Developed ski and float installations for DH products. Built 1,134 Mosquitoes (1942-1945) and 54 Fox Moths (postwar). Undertook design and construction of the Tiger Moth replacement, the DHC-1 Chipmunk, built in Canada, Britain, and Portugal. Further Canadian designs have concentrated on STOL capability: the DHC-2 Beaver transport, DHC-3 Otter transport, DHC-4 Caribou pistonengined freighter (company’s first
twin), DHC-5 Buffalo twin-turboprop freighter (first flown 1964), DHC-6 Twin Otter twin turboprop transport (first flown 1965), DHC-7 Dash 7 quiet STOL four-engined airliner (first flown 1975), and DHC-8 Dash 8Q short-range twin-turboprop regional airliner (first flown June 1983 and remaining in major production, with latest Series 400 for up to 78 passengers first flown January 1998). Special variants of its aircraft have included maritime surveillance, navigation training and airborne over-the-horizon telemetry relay models of the Dash 8. The company became part of the Hawker Siddeley Group in 1960, but retained the name de Havilland. From 1974 owned by Canadian Government, then Boeing (as Boeing Canada) from 1986.
In 1992 Bombardier purchased 51 percent of de Havilland Canada. In January 1997, they purchased the remaining 49 percent of DHC from the Province of Ontario, as part of Bombardier Aerospace Group in 1992 and since known as de Havilland Inc.
By 2007 Viking Air owned the rights to all early de Havilland Canada products from the Chipmunk through to Beaver, Otter, Caribou, Twin Otter and Dash 7.
All Aero 