Designs that led to the Hawker Siddeley Trident

[zebedee]

And now some evolutions of the Trident*... from the June 1987 Hatfield Future Projects Newsletter, design studies for the Trident 4 & 5 projects.

Trident 5 is the most modified with its cabin section and nose based on HS146 and wing based on A300B and HS146 design principles.

Zeb

"The following is a statement included in a departmental note of July 1975, which describes our participation in the development of this aircraft that led to both the Trident 4 and 5 projects.
Bearing in mind the size and design features of the Trident family, the twin engine developments are best suited to ratings of 24,000 lb and above. However, the possibilities with the CFM56 at its initial rating of 22,000 lb have merited serious consideration and means whereby a logical family development could be exploited, have been explored.

Derivatives have been examined with standard Trident wings, modified wings to give improved lift/drag characteristics, increased span and area and new wings based on developed A300 technology standards.

Capabilities with the standard wings are obviously limited. The Trident wing was designed for high speed capability, an attribute which pays off under certain operational conditions. The span (aspect ratio) however was matched for three low by-pass ratio engines and greater span is desirable for the twin configuration with high by-pass ratio propulsion. Consequently versions with the standard wing have been considered largely in the retrofit context and current proposals are based on the Trident 3B with or without the booster. If the booster is retained it will require hushing by some 6 - 7 PNdB.

Various modifications to the Trident wing have been considered. Some improvement in lift/drag characteristics is possible by adjustments to and cleaning up of the slat/flap configuration and this can be coupled with tip modifications or increased span.

For higher weight developments an increase in area is desirable and this can be achieved either by means of a centre section insert giving increased span and fuel capacity or by modification of the outer wing. Several schemes for the latter have been examines and involve a reduction of wing sweep from 35˚ to 27˚ on the outer panel, which in itself increases span.

Although such developments are feasible, study of the cost effectiveness in terms of the relationship between development costs, mission capability and economics, leads to the conclusion that a new wing, cashing in on all the advanced technology accumulated in the development of the A300 wing, is the best solution.

Such a new, reduced sweep, higher aspect ratio wing enables a progressive development of the derivative with development of engine thrust from 22,000 lb upwards. These developments with CFM56 and JT10D) engines are the basis of the present submissions for the Trident 4. "

*Apologies if this is the wrong thread but I can't find one for the Trident...!

I had read in another book that there was one Trident 5 design that had a Trident nose, T-tail, but RB.211 engines on wing nacelles and it looked a lot like the early 757 designs that had a 727 nose and T-tail. Was there such a design evolution of the Trident 5?

Are you thinking of 1967's HS134 with the RB178? Will dive into the archive as I think there is a picture of it somewhere in my Hatfield documents. Derek Wood mentions it in Project Cancelled on p.227-229 and certainly looks very 757 like...

Edit: Found it, will post later after I've scanned it... along with what may be a 1977 refresh with a 146 style nose simply named JET 001...

Zeb

 

[zebedee]

From the Hatfield Future Projects Newsletter No.19 November 1987

Investigations into possible stretches of the Trident (HS 132 and 134) for the short-medium range role during 1965 showed that an attractive possibility was the HS 134 with 183 seats at 34" pitch. This aircraft used the Trident cockpit and fuselage diameter and hence many of the components and details appropriate to the Trident fuselage. Two RB 178-14 engines were mounted on a new 25° swept wing. Trident system components were to be used wherever appropriate, but the air conditioning system and other systems affected by passenger capacity and aircraft size were, of necessity, new.

The passenger capacity of the Airbus, on which HSA expect to agree an outline specification with Sud Aviation very soon, is dependent upon the engine finally chosen by the governments concerned, and its seating could range from 240 seats with the JT9 at approximately 41,000 lb. thrust, to 260-270 seats with the RB 207 of 48,000-50,000 lb. thrust.

Market surveys have indicated that such an aircraft is on the large side for BEA and other European operators in the early 1970s, with the exception of Air France and Air Inter who have stated a requirement for a 250 seat arrangement. It is quite possible that a decision mild be taken to proceed with a new Rolls-Royce engine of 28,000-30,000 lb. thrust, since such an engine couldd have a wider application in a new four-engined long range aircraft, as proposed by Douglas, or in a three-engined aircraft, such as those being considered by Lockheed, Douglas and Convair. Further examination has therefore been made of the HS 134 fitted with two RB 207s scaled to 28,000 lb. thrust, the design incorporating the increased knowledge obtained during the last year of Airbus design work.

2x RB207 of 28,000 lb Take off thrust static
Wing Area 1,900 sq.ft.
Sweep 25°
Span 123 ft. 2 ins.
Overall Length 158 ft. 6 ins.
Fuselage external diameter 12 ft. 11 ins.

Image No.1 shows the Mid 1967 Final Configuration, with the earlier T Tail version from 1966 inset.
Image No.2 shows the T Tail Configuration
Image No.3 Shows a similar design from 1977 simply labelled JET 001. Drawn by CFD Clarke this is I think part of the early 'Jet' studies that led to the Airbus A320 and whilst smaller makes use of 'Derived Components'... of note is the 146 style nose...

Zeb

 

[Sentinel Chicken]

From the Hatfield Future Projects Newsletter No.19 November 1987

Investigations into possible stretches of the Trident (HS 132 and 134) for the short-medium range role during 1965 showed that an attractive possibility was the HS 134 with 183 seats at 34" pitch. This aircraft used the Trident cockpit and fuselage diameter and hence many of the components and details appropriate to the Trident fuselage. Two RB 178-14 engines were mounted on a new 25° swept wing. Trident system components were to be used wherever appropriate, but the air conditioning system and other systems affected by passenger capacity and aircraft size were, of necessity, new.

The passenger capacity of the Airbus, on which HSA expect to agree an outline specification with Sud Aviation very soon, is dependent upon the engine finally chosen by the governments concerned, and its seating could range from 240 seats with the JT9 at approximately 41,000 lb. thrust, to 260-270 seats with the RB 207 of 48,000-50,000 lb. thrust.

Market surveys have indicated that such an aircraft is on the large side for BEA and other European operators in the early 1970s, with the exception of Air France and Air Inter who have stated a requirement for a 250 seat arrangement. It is quite possible that a decision mild be taken to proceed with a new Rolls-Royce engine of 28,000-30,000 lb. thrust, since such an engine couldd have a wider application in a new four-engined long range aircraft, as proposed by Douglas, or in a three-engined aircraft, such as those being considered by Lockheed, Douglas and Convair. Further examination has therefore been made of the HS 134 fitted with two RB 207s scaled to 28,000 lb. thrust, the design incorporating the increased knowledge obtained during the last year of Airbus design work.

2x RB207 of 28,000 lb Take off thrust static
Wing Area 1,900 sq.ft.
Sweep 25°
Span 123 ft. 2 ins.
Overall Length 158 ft. 6 ins.
Fuselage external diameter 12 ft. 11 ins.

Image No.1 shows the Mid 1967 Final Configuration, with the earlier T Tail version from 1966 inset.
Image No.2 shows the T Tail Configuration
Image No.3 Shows a similar design from 1977 simply labelled JET 001. Drawn by CFD Clarke this is I think part of the early 'Jet' studies that led to the Airbus A320 and whilst smaller makes use of 'Derived Components'... of note is the 146 style nose...

Zeb

The second matches the description of the "Trident 5" mentioned in Flight of the Titans: Boeing, Airbus, and the Battle for the Future of Air Travel

by Kenny Kemp. Virgin Books, 2006, p100-106.

In that book, they talk about how Boeing and BAe had very serious discussions about making the Boeing 757 a joint US-UK program and the investment on the British side was less than what was needed to rejoin Airbus.

 

[alertken]

very serious discussions about...757.
The Labour Party won 1974's Elections inc a commitment to Nationalise the shipbuilding/repair sector, much employment in Labour seats, and in decline. They had added Aero manufacture (not repair), in part as they already enjoyed parentage of Shorts, RR, Ferranti, so thought they understood that industry, and in part to broaden the business to be managed, in hope some element might generate black ink. In due course new Ministers would let the non-Defence marine sector quietly expire (most yards were in the wrong place to handle long, deep hulls), and the Aero sector was unloaded to risk-capital. But in 1977 what-to-do-with Aero came to PM Callaghan's desk.

He picked up Industry contacts with MDC and Boeing and flew over to talk to them. He judged they were interested in Brit wallets, not in Brir brains, so he rejected US, to join Airbus Industrie as a voting owner. More discussion in the what-should-have-been-built thread.

 

[hesham]

From Aeroplane 1956.