Trident engine locations ?
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Trident engine locations ?
I was just wondering why the dehavilland designers went for the three and a half engines at the back of the aircraft ?
Im not knocking the idea as the Trident looks great, but at around the same time the bac 1-11 went for two engines at the back of the aircraft and Boeing went for three at the back as well.
Even the VC-10 went for engines at the back.
I was just wondering at this time (in history) why the aircraft designers went down this route ?
Why were design's like this abandoned (I.E two or four engines under the wing is now the common / boring way of doing things) ?
Im not knocking the idea as the Trident looks great, but at around the same time the bac 1-11 went for two engines at the back of the aircraft and Boeing went for three at the back as well.
Even the VC-10 went for engines at the back.
I was just wondering at this time (in history) why the aircraft designers went down this route ?
Why were design's like this abandoned (I.E two or four engines under the wing is now the common / boring way of doing things) ?
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There was a great deal of debate about the position of engines on jetliners in the 1950s.
The Avro Canada C102 Jetliner, the Comet and the TU104 had engines close to the wing root. The Comet's were more "buried" than the other two designs but engines close to the wing root - a design used by many large and small military aircraft - have some benefits over engines slung under the wings in terms of airflow and lack of FO damage. On the other hand they can be difficult to service, more susceptible to causing major, perhaps catastrophic, damage in the case of fire or turbine blade fragmentation and the noise and vibration in the cabin tends to be the greatest of all three engine positions.
Underslung engines (the design came out with the Me262 and was copied by the one off Tay engined Viscount) was adapted by Boeing to place the engines further below the wings by means of pylons - though they reverted to the Me262 position for the 737-100/200 srs.
The engines in this position are easier to service, are designed to break off if suffering catastrophic damage, are less likely to damage the empennage if they fail but have the disadvantage of spoiling the aerodynamic cleanliness of the wing.
Rear engines have the great advantage of leaving an aerodynamically clean wing which is important for short field performance - thus the application in the 1960s when jet engines were not as powerful for their size as they are today - and reputedly clean wing aircraft are more economic on fuel. BOAC wanted "hot and high" performance for the VC10. The Caravelle, Trident, 1-11, DC9, B727, F28 all needed to get into places where field length was restricted. All airlines putting rear engined jets into service made much of the lack of noise and vibration in the cabin.
The down sides of rear engines are many. More difficult to service (especially a buried centre engine). Extremely difficult, and therefore expensive in cost and weight, to prevent catastrophic damage to the airframe and systems passing the engines and the most important, the T tail deep stall, which at the cost of lives and airframes in the Trident and 1-11 testing programmes, only came to light after the design was built leading to the innovation of stick pushers.
The advent of more powerful small engines which could fit under the wing of medium sized jetliners saw the end of the rear engine except for the 1990s crop of regional jet designs where the same problem of engine size and power, linked to a small airframe, could only sensibly be overcome with rear engines. The same goes for a host of biz jets.
BTW, the three and a half engined Trident came about because the Trident 1 and 2 had poor climb performance (they were known as Grippers due to their unwillingness to leave the ground) and the larger size of the Trident 3 needed more power which the three Speys could not give. In practice, BEA/BA found little use for the extra engine on most of the Trident 3 routes and many were blanked off and I seem to remember most were removed.
The Avro Canada C102 Jetliner, the Comet and the TU104 had engines close to the wing root. The Comet's were more "buried" than the other two designs but engines close to the wing root - a design used by many large and small military aircraft - have some benefits over engines slung under the wings in terms of airflow and lack of FO damage. On the other hand they can be difficult to service, more susceptible to causing major, perhaps catastrophic, damage in the case of fire or turbine blade fragmentation and the noise and vibration in the cabin tends to be the greatest of all three engine positions.
Underslung engines (the design came out with the Me262 and was copied by the one off Tay engined Viscount) was adapted by Boeing to place the engines further below the wings by means of pylons - though they reverted to the Me262 position for the 737-100/200 srs.
The engines in this position are easier to service, are designed to break off if suffering catastrophic damage, are less likely to damage the empennage if they fail but have the disadvantage of spoiling the aerodynamic cleanliness of the wing.
Rear engines have the great advantage of leaving an aerodynamically clean wing which is important for short field performance - thus the application in the 1960s when jet engines were not as powerful for their size as they are today - and reputedly clean wing aircraft are more economic on fuel. BOAC wanted "hot and high" performance for the VC10. The Caravelle, Trident, 1-11, DC9, B727, F28 all needed to get into places where field length was restricted. All airlines putting rear engined jets into service made much of the lack of noise and vibration in the cabin.
The down sides of rear engines are many. More difficult to service (especially a buried centre engine). Extremely difficult, and therefore expensive in cost and weight, to prevent catastrophic damage to the airframe and systems passing the engines and the most important, the T tail deep stall, which at the cost of lives and airframes in the Trident and 1-11 testing programmes, only came to light after the design was built leading to the innovation of stick pushers.
The advent of more powerful small engines which could fit under the wing of medium sized jetliners saw the end of the rear engine except for the 1990s crop of regional jet designs where the same problem of engine size and power, linked to a small airframe, could only sensibly be overcome with rear engines. The same goes for a host of biz jets.
BTW, the three and a half engined Trident came about because the Trident 1 and 2 had poor climb performance (they were known as Grippers due to their unwillingness to leave the ground) and the larger size of the Trident 3 needed more power which the three Speys could not give. In practice, BEA/BA found little use for the extra engine on most of the Trident 3 routes and many were blanked off and I seem to remember most were removed.
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The three engine formula pioneered by the De Havilland division of Hawker Siddeley Aviation has been accepted as giving the best economics for short -to-medium-haul operations.Three engines are less conplex than four.Engine out asymmetry is less than with two or four wing mounted engines.The power loss percentage with one engine "out" is nearer the four engine case than the two-engine case-a fact which is particularly important at take off.Ferrying on two engines is possible.
The practcability of three engines is one of several advantages of the rear engine position-a possibility that was considered when the Comet 1 formula was being determined.
Other advantages are the clean wing unencumbered by engine pods,the quiet passenger cabin,engine protection against stone damage,the virtual elimation of the noise damage problem,superior handling qualities in asymetric-thrust and reverse thrust conditions.
philbky,The Trident 3B used the RB162-86 throughout it's flying life and were never removed,only when unservicable and then replaced with a servicable one.
The practcability of three engines is one of several advantages of the rear engine position-a possibility that was considered when the Comet 1 formula was being determined.
Other advantages are the clean wing unencumbered by engine pods,the quiet passenger cabin,engine protection against stone damage,the virtual elimation of the noise damage problem,superior handling qualities in asymetric-thrust and reverse thrust conditions.
philbky,The Trident 3B used the RB162-86 throughout it's flying life and were never removed,only when unservicable and then replaced with a servicable one.
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I had many jump seat rides on Trident 3s in the 1980s in Europe and on the Manchester Shuttle. I was told by crews that the engine had either been disconnected or even removed when the 3s went in for the wing cracks to be fixed.
Certainly, in over 60 flights on 3s, many up front, I don't recall the fourth engine ever being used. Also the engine produced a very distinctive howl, rarely heard.
Did WZK still have the RB162 when it was delivered to MAN?
Certainly, in over 60 flights on 3s, many up front, I don't recall the fourth engine ever being used. Also the engine produced a very distinctive howl, rarely heard.
Did WZK still have the RB162 when it was delivered to MAN?
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(I appreciate the two possibilities are not mutually exclusive)
See: http://www.pprune.org/forums/showpos...&postcount=201
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"Did WZK still have the RB162 when it was delivered to MAN"?
The boost was indeed still installed,but i decided to remove it for display purposes as the Trident was the only commercial aircraft to have one fitted,crews say that other aircraft radioed in saying the aircraft in front was on fire (boost start up with flame out!!) i have to laugh.
The boost was indeed still installed,but i decided to remove it for display purposes as the Trident was the only commercial aircraft to have one fitted,crews say that other aircraft radioed in saying the aircraft in front was on fire (boost start up with flame out!!) i have to laugh.
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quote:
Perhaps you are thinking of the twin Bristol-Siddeley Orpheus engined prototype of the Lockheed Jetstar. The engines were rear mounted though.
The Orpheus was one of the selected engines .............................but the RB162 was selected for it's thrust to weight ratio and the Orpheus was dropped because it was heavy and less thrusty!!!
for more Trident stuff visit
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Perhaps you are thinking of the twin Bristol-Siddeley Orpheus engined prototype of the Lockheed Jetstar. The engines were rear mounted though.
The Orpheus was one of the selected engines .............................but the RB162 was selected for it's thrust to weight ratio and the Orpheus was dropped because it was heavy and less thrusty!!!
for more Trident stuff visit
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Ah the "plastic engine" - gave you an extra 6 tonnes payload at take-off, except the b#gger wouldn't start in icing conditions or on hot days when you had already accepted the increased weight!
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Originally Posted by Dr Jekyll
Was there once a prototype of a 4 engined business jet with wing mounted engines or is my memory failing?
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Trident man I gather you have a slight interest in the Manchester Trident. Excellent job well done. Had a memorable flight back from Hamburg to LHR on that aircraft on 24 November 1982.
We were delayed at Hamburg as the weather had been lousy at LHR and 23 was in use so flow control was in operation.
Things hadn't improved when we got to Lambourne and the crew told us to expect a 30 minute hold - at 20.00, not the busiest time normally. I was beginning to think I'd miss my connection for the Manchester Shuttle back up, let alone the scheduled flight.
Eventually we started an approach only to be turned off at five miles due to the aircraft in front of us (Aeroflot IL 62 from Tokyo) losing his way and sticking at the end of 23.
A quick 360, back to third in the queue and we eventually touched down (the only time I ever landed on 23 in countless flights into LHR) with one of the roughest landings I can remember - presumably using reverse thrust prior to touch down.
Thanks to a few calls on the radio, I did make the back up to Manchester.
I was also on the last service flight of WZL on 21 November 1983 - again a Manchester Shuttle back up.
We left immediately behind the scheduled flight and, on a bitterly cold, frosty but very clear, windless night proceded to Congleton. The crew told the pax that the aircraft was being retired that night and would be ferried empty to LHR next day.
At Congleton we were vectored for an approach to 24. For some reason the scheduled flight elected for 06 and, with a quick word to approach we cut the corner and established somewhere over the centre of Stockport - unusual for Tridents at MAN where a eight to ten mile final was usual on Shuttle flights.
Again a rough landing, which the Captain thanked his F/O for in a joking way when, as we were taxying in, the scheduled flight landed parallel to us and the Captain claimed taking the back up was always the better option - more room and faster! He had to eat his words as the scheduled beat us to the gate, having stopped short and turned in left to the domestic pier, forcing us to give way.
We were delayed at Hamburg as the weather had been lousy at LHR and 23 was in use so flow control was in operation.
Things hadn't improved when we got to Lambourne and the crew told us to expect a 30 minute hold - at 20.00, not the busiest time normally. I was beginning to think I'd miss my connection for the Manchester Shuttle back up, let alone the scheduled flight.
Eventually we started an approach only to be turned off at five miles due to the aircraft in front of us (Aeroflot IL 62 from Tokyo) losing his way and sticking at the end of 23.
A quick 360, back to third in the queue and we eventually touched down (the only time I ever landed on 23 in countless flights into LHR) with one of the roughest landings I can remember - presumably using reverse thrust prior to touch down.
Thanks to a few calls on the radio, I did make the back up to Manchester.
I was also on the last service flight of WZL on 21 November 1983 - again a Manchester Shuttle back up.
We left immediately behind the scheduled flight and, on a bitterly cold, frosty but very clear, windless night proceded to Congleton. The crew told the pax that the aircraft was being retired that night and would be ferried empty to LHR next day.
At Congleton we were vectored for an approach to 24. For some reason the scheduled flight elected for 06 and, with a quick word to approach we cut the corner and established somewhere over the centre of Stockport - unusual for Tridents at MAN where a eight to ten mile final was usual on Shuttle flights.
Again a rough landing, which the Captain thanked his F/O for in a joking way when, as we were taxying in, the scheduled flight landed parallel to us and the Captain claimed taking the back up was always the better option - more room and faster! He had to eat his words as the scheduled beat us to the gate, having stopped short and turned in left to the domestic pier, forcing us to give way.
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Trident 3 boost engines
I worked in BA engineering during the last days of the Trident and can assure you that the boost engine was never "blanked off" or removed however it was an uphill battle to keep them all servicable.
A post on another thread tells the tail of how myself and another who I shall not name got very close to setting fire to a Trident 3 when trying to get a boost engine started!
A post on another thread tells the tail of how myself and another who I shall not name got very close to setting fire to a Trident 3 when trying to get a boost engine started!
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Boost engine
A & C says, A post on another thread tells the tail of how myself and another who I shall not name got very close to setting fire to a Trident 3 when trying to get a boost engine started!
Was this me?? I had some very "interesting" happenings at LHR when trying to start them!!!!!
I can confirm that the boost engine was not removed when the aircraft was in service. If it was U/S the c/b,s were pulled and the aircraft dispatched.
tristar 500
Was this me?? I had some very "interesting" happenings at LHR when trying to start them!!!!!
I can confirm that the boost engine was not removed when the aircraft was in service. If it was U/S the c/b,s were pulled and the aircraft dispatched.
tristar 500
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Re the boost engine, as mentioned above, I was given the impression that these engines were removed and I'm sure I've seen this in print. As the guys above have said, they obviously weren't but I'd be interested to know just how often these engines were used in service and how reliable they were.
As I said, I had many Trident flights, a good number with time in the cockpit and saw hundreds of Trident 3 take offs in the 1970s/80s and can only remember a handful of times when the engine was used.
As I said, I had many Trident flights, a good number with time in the cockpit and saw hundreds of Trident 3 take offs in the 1970s/80s and can only remember a handful of times when the engine was used.
