Given the political climate of the era, the nationally owned airlines practically dictated the specifications of the airliners produced by British companies in the 1950s and 60s. Due to a temporary downturn in air travel, BEA deemed the original DH121 design too large and demanded it be reduced in size. This resulted in the Trident 1C for with a lower capacity of just 96.  This proved to be only temporary and BEA later regretted this decision.  The original Trident design features a complex nose gear bay door arrangement, Krueger flaps and leading edge droops and the APU is mounted in a pod above the central engine. As the 1C was only sold to BEA, Hawker Siddeley realised an export derivative was needed and this model became the Trident 1E.  The 1E and its derivatives were based on essentially the same airframe, but had a new leading edge slat arrangement, uprated engines, greater range and most importantly a higher capacity. The 1E sold in small numbers to British airlines BKS and Channel and to PIA, Kuwait, Iraqi, Cyprus Airways and Air Ceylon.

Trident 1C, Photo: Steve Williams

Trident 1C

Trident 1E

Trident 1E-110/140

Length

114 ft 9in

114 ft 9in

114 ft 9in

Wingspan

89ft 10in

95ft

95ft

Engines

3 Spey 505 @ 10,050lbs 

3 Spey 511 @ 11,400lbs

3 Spey 511 @ 11,400lbs

Fuel capacity

3,840 Imp Galls

6,000 Imp. Galls

6,000 Imp. Galls

Wing area

1,358 sq ft

1,407 sq ft

1,407 sq ft

Cruise speed

511 kts

525 kts

525 kts

Cruise altitude

27,000 - 36,000 ft

27,000 - 36,000 ft

27,000 - 36,000 ft

Range

1,150 m

2,000 m

2,000 m

Pax. capacity

96 (typ)

103 typ, 149 max

103 typ, 149 max

MTOW

117,300 lbs

134,000 lbs 

135,580 lbs

The seating capacity of the 1C was typically 96, whereas the 1E with essentially the same internal space, could be configured to accommodate 149 passengers in seven abreast layout as shown above.  The original Trident wing featured Krueger flaps and a leading edge droop and short wing tips compared to the 1E and 2E.  Although the wing was low drag (permitting high cruise speeds), it was necessary to fly with the droop down at speeds below 225kts IAS below 300ft as the aircraft had a relatively high stall speed, given that the wing was optimised for low drag in the cruise, permitting the (by today's standards) very high cruise speed.  The 1E featured 3 foot wing tip extensions and the Krueger flap/droop arrangement being replaced by a more conventional leading edge slat arrangement.

Seven abreast seating in the Channel Airways Trident 1E,
Neil Lomax Collection

The Trident 2E was developed as a higher capacity, longer ranged version of the original Trident and feature an enlarged wing with new high lift devices and uprated engines.  BEA and CAAC were the biggest customers, making the 2E the most produced model.

The fuselage of the Trident 2E is virtually identical to that of the Trident 1.  It features a simplified nose gear door arrangement.  Accommodation is typically 103 (varied from 91 up to 149 high density, seven abreast) in six abreast seating configuration.  The wings of the 2E are larger (greater area and span), than those of the previous models (1C & 1E).  The leading edge droop was replaced by slats on the leading edge of the wing.  The increase in area of the 2E over the 1E is marginal and is due to the revised "Kuchemann" wingtips used.

Trident 2E, Photo: Steve Williams

Length (overall)

114ft 9in (34.98 m)

Wingspan

98 ft (29.87 m)

Engines

3 Rolls Royce Spey Mk512 @ 11,960lbs each (53.2 kN)

Fuel capacity

6,400 Imperial Gallons (29,094 l)

Wing area

1,493 sq. ft (138.7 m²)

Cruise speed

525 kts / Mach 0.91 (604 mph / 966kph)

Cruise altitude

27,000 - 36,000 ft (8,230 - 10,970 m)

Range

2,400 m (3840 km)

Passenger capacity

91-149 (103 typ)

MTOW

143,500 lb (65,149 kg)

The 2E was the first to feature the Mk 512 Spey engine - the final derivative to be used on an airliner.  This provided 560lb more thrust than the Mk 511 fitted to the 1E and kept the cruise speed the same despite the increase in weight of the 2E airframe over the series 1.

The Trident 2E has the distinction of probably also being the last derivative of the aircraft to fly, most probably a Chinese example was still flying until as recently as 1997. The example preserved at Duxford museum (UK) was one of the aircraft originally leased to Cyprus Airways which was attacked by Turkish fighters before being repaired and retrieved by owners, British Airways. To this day, patches which repaired bullet holes in the wings from the guns of the Turkish Air Force F-100 Super Sabres that attacked the aircraft, can be seen.

Cabin of the Trident 2E, Hawker Siddeley Aviation via Neil Lomax Collection

By the mid 1960s, BEA was once again, in need of a yet larger aircraft. The government would not provide funding for either the HS132 or the very promising HS134 derivatives. The latter had a general arrangement very similar to the later Boeing 757 and Airbus A321 and would have been powered by Rolls-Royce RB178 engines. Being denied the possibility of purchasing the Boeing 727 by the British Government, BEA were to adopt the Trident 3 as a cheaper solution to the requirement for an enlarged capacity airliner.  As further developments of the Spey engine (by now realistically incapable of providing any more power efficiently), an RB162-83 boost engine would be installed into the tail to provide additional thrust on takeoff and thus shorten takeoff runs. This resulted in the “3B” designation.  The RB162 was a development of the RB108 vertical lift engine used in the previous to decade in experimental vertical takeoff aircraft.  Another, subtler, modification was a small increase in wing incidence angle which would produce additional lift.

Trident 3B, Photo: Johan Ljungdahl

Length (overall)

131ft 2in (39.97 m)

Wingspan

98 ft (29.87 m)

Engines

3 Rolls Royce Spey Mk512 @ 11,960lbs each (53.2 kN)

Boost Engine

1 Rolls Royce RB162 @ 5,250lbs (23.35 kN)

Fuel capacity

5,620 Imperial Gallons (25548 l)

Wing area

1,493 sq. ft (138.7 m²)

Cruise speed

505 kts / Mach 0.88 (581 mph / 929kph)

Cruise altitude

27,000 - 36,000 ft (8,230 - 10,970 m)

Range

1,500 m (2400 km)

Passenger capacity

180 (136 typ)

Maximum takeoff weight

155,000 lb (70,370 kg)

Twenty-six of this version were ordered by BEA, who were also investigating larger still aircraft, such as the BAC 3-11 and Lockheed L-1011 Tristar, which was eventually chosen after the cancellation of the former. In the late 1970s, wing cracks were detected in the 3B fleet and modifications were made to all remaining Tridents to ensure this did not become a problem. The Trident 3B would find a new role, late in its life, on the London to Manchester shuttle service. Other similar domestic services were also operated by the Trident fleet as they became progressively replaced on short haul routes by the Boeing 737-200 and Boeing 757.  A further two aircraft, slightly modified and designated Trident Super 3B were built for CAAC of China.  The main difference was additional fuel capacity (6,000 Imp. Gal as opposed to 5,620) which resulted in an additional range of 400 miles and an increased MTOW of 159,900 lbs. Both are believed to still exist, in storage in China.

Trident Super 3Bs at Hatfield, Photo via Neil Lomax Colection