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View Full Version : Corp Twin (dissimilar) Jet C/Line Engines


dogcharlietree
25th Sep 2003, 10:07
Some time ago, prob 5-6 years, I read an article, again prob in Pro Pilot mag, about the feasibility of designing a corporate jet, with 2 engines providing centreline thrust. (one above the other).
The interesting point about this concept was that the engines were of dissimilar thrust, ie one large and one small.
The idea was to use both for takeoff/landing and then in the cruise shut one down (can't remember whether it was the large or the small).
If anybody remembers this article or can point me to a website, it would be greatly appreciated. TIA.

safetypee
25th Sep 2003, 23:55
My ‘corporate’ twin-engine jet with centreline thrust - engines mounted over / under, flew extremely well on one engine or with dissimilar power. Unfortunately early versions tended to catch fire during relight! BAC Lightning F1 – F6

kabz
26th Sep 2003, 00:54
I think there was a trident variant with a fourth smaller engine planned, vertically above the middle tail engine.

Hawker Siddeley offered a Trident 3B (Boost) model incorporating a fourth engine mounted above the central Spey jet just below the rudder. This would be an RB.162-86 engine derived from a military vertical-takeoff engine

Web site is here Trident History (http://www.miskin.demon.co.uk/trident/trident_history.htm)

ICT_SLB
26th Sep 2003, 12:30
This sounds a lot like a proposal that was kicking around our Powerplant group a few years ago. The basis is that a high bypass ratio fan is great for takeoff thrust, noise etc but its efficiency is much less than a pure turbojet at altitude.

Guess the problem would be what do you do with the other half of the pair when you don't need it - don't think any (civilian) pilot would intentionally shut down his main engine twice in a flight...