I was recently searching for information on Hawker Siddeley Trident and was very surprised to find out that there is no such entry in the Aircraft Data and Specifications section on Airliners.net. Is this possible or was I searching for it using a wrong name?

Accidentally, Trident was not very successful with 117 frames built (compared to 282 Caravelles of the same time), what was the reason for it? Was it killed by the Boeing 727? The safety record with 17 aircraft lost in accidents is not impressive either.

It seems to have been abbrieviated to HS-121 Trident. Try that and it should work.

Regards

Quoting konrad (Thread starter):

It was built far to much to the requirements of BEA with little room for adaption to the needs of a wider market and this sadly killed it from a marketing point of view.

First autoland airliner. It was also fast in the air, just took a bit of time to un-stick from the runway. Offset nose wheel, 4 wheel in line main wheels and first 4 engined tri-jet. She was good looking too. Very successful, to me anyway, sadly only two flights on this baby before they took her away because of a bit of noise. On board it was much quieter than a 77W.  

Quoting col (Reply 3): away because of a bit of noise

LOL. Used to love to hear the crackle and roar of those Speys at takeoff. We had to halt our casual cricket matches at the west end of LHR every time one went by, due to the racket!

Not sure what the local school masters thought!

Quoting konrad (Thread starter): Accidentally, Trident was not very successful with 117 frames built (compared to 282 Caravelles of the same time), what was the reason for it? Was it killed by the Boeing 727? The safety record with 17 aircraft lost in accidents is not impressive either.

Can't argue with the success of the aircraft, but just about everything else you wrote is open for some debate. The Caravelle was not exactly "of the same time" as the French plane was a first-generation jet in much the same way the B707 and DC-8 were. The Trident was more of a second-generation jet, and when it was first delivered the Caravelles had been flying for about a decade. In theory they might have overlapped some potential buyers as they were both short to medium haul airliners, but as has been previously pointed out, the Trident was built very much to the tailored need of one carrier (BEA) and not developed into what it could have been. Of course, we will never know what it fully could have been, but in most respects it should have stolen lots more sales from the burgeoning medium-haul airliner category, later dominated by the B727. The politics of the day, the reluctance of American airlines to buy foreign airliners at that time, and most importantly the limited development of the Trident, all but secured its fate.

As for the safety, I always felt that besides the one lost in testing, the basic aircraft was very safe, certainly within the context of its day. BEA/BA lost two during their operations with the type, but for very different reasons. Neither was to do with a fault on the aircraft. (The loss of the Trident in BA Flight 476 over Zagreb in 1976 was the first and only time a BA-operated aircraft has crashed with the loss of all onboard - a record we hope never changes, of course.) Most of the 17 hull losses were non-fatal, and besides those mentioned, only five other Trident crashes resulted in fatalities, all of them in China with the Chinese Air Force or CAAC. (I'm not making judgments here, but Chinese aviation in the 1970s and 1980s was not up the standards they are today.)

The last BA Trident operations were in 1985, and they had successfully completed tens of thousands of intra-UK and intra-European flights by that time. That the plane was not a larger success is a bit of a tragedy in itself.

Quoting richierich (Reply 5): As for the safety, I always felt that besides the one lost in testing, the basic aircraft was very safe, certainly within the context of its day.

When did the Trident crash during testing? I know a BAC-111 crashed in a deep stall during flight testing.

Quoting BoeingGuy (Reply 6): When did the Trident crash during testing?

50 years ago: http://en.wikipedia.org/wiki/Hawker_Siddeley_Trident#Accidents

Quoting col (Reply 3): Offset nose wheel, 4 wheel in line main wheels

I always wondered how this must have felt in the cockpit when making a left turn.


Picture taken in the China Civil Aviation Museum near PEK

The second fatal BEA Trident crash was pilot error, due in part to the captain having a heart attack.

https://en.wikipedia.org/wiki/British_European_Airways_Flight_548

British European Airways Flight 548 was a scheduled passenger flight from London Heathrow to Brussels that on 18 June 1972 crashed near the town of Staines, England, soon after take-off, killing all 118 people on board. The accident became known as the Staines air disaster and as of 2016 remained the deadliest air accident to take place in the United Kingdom (the Lockerbie bombing, which killed 259, was a terrorist act, not an accident).

The aircraft involved, a Hawker Siddeley Trident, suffered a deep stall in the third minute of its flight and crashed to the ground, narrowly missing a busy main road. The ensuing inquest principally blamed the captain for failing to maintain airspeed and configure the high-lift devices correctly. It also cited the captain's heart condition and the limited experience of the co-pilot, while noting an unspecified "technical problem" that the crew apparently resolved while still on the runway.

The Trident 3B also had a '4th engine', a turbojet, which added to the noise and killed off any hope of sales.

Quoting art (Reply 9): Had the original design been pursued, I think the aircraft could have secured many more sales.

Wasn't it also the case that the aircraft was originally designed to takeoff on relatively short airfields?

As the UK has fairly well developed airfields with long runways, BEA instead asked for the aircraft to be made more efficient by using a longer takeoff run. This again all but killed off any chance of further sales, particularly in France, where it could no longer operate from a number of the regional airports?

Quoting nighthawk (Reply 12): Wasn't it also the case that the aircraft was originally designed to takeoff on relatively short airfields?

I don't think so (or at least being any better than contemporaries), remember that the plane was proposed and designed in response to BEA's wishes from the onset.

It was the resizing of the Trident during development to be smaller with less range, per BEA's insistence, that basically killed off its prospects. Its original design was almost identical to the 721 (leaving many in the UK to believe that Boeing stole designs from HS when they were in talks about Boeing possibly building the jet as well).

BEA was still government owned and the UK had a strong public policy preference for using British built airplanes. The earlier posts are correct and accurate in that this airplane was designed to meet BEA's needs, and, as a result, was simply too small. The original Trident 1 was designed for 74 seats in a mixed, two class configuration, which is about the same size as the BAC 1-11 and the U.S. Douglas DC9. so there were more efficient short haul airplanes in those aircraft, and a much more efficient Boeing 727 (both the -100 and the -200 series) on the larger end.

Quoting richierich (Reply 5): The politics of the day, the reluctance of American airlines to buy foreign airliners at that time, and most importantly the limited development of the Trident, all but secured its fate.

As part of the Polaris deal, UK aircraft manufacturers were encouraged to technology share across the Atlantic, rather than across the Channel, which definitely assisted Boeing and McD with the development of competing designs. There was even the threat of legal action at the time. It did subsequently encourage closer collaboration in Europe.

Quoting col (Reply 3): first 4 engined tri-jet

An oxymoron, but a very good one.  

Quoting col (Reply 3): It was also fast in the air, just took a bit of time to un-stick from the runway.

I recall reading somewhere that some BEA pilots used to refer to the Trident as the 'Gripper' because it didn't want to let go of the runway.

Quoting uta999 (Reply 11): The Trident 3B also had a '4th engine', a turbojet, which added to the noise and killed off any hope of sales.

This is the second mention I've seen of a 4th engine on a tri-jet. Can anyone elaborate? How exactly does a "tri-jet" have 4 engines? Did the APU provide thrust? Or was the #2 engine a "dual" engine? Wikipedia mentions that only the 3B had a 4th engine ducted above the center duct, but photos of all Tridents show that extra duct above #2 that I always thought was the APU intake.

Quoting vatveng (Reply 18): This is the second mention I've seen of a 4th engine on a tri-jet. Can anyone elaborate? How exactly does a "tri-jet" have 4 engines? Did the APU provide thrust? Or was the #2 engine a "dual" engine? Wikipedia mentions that only the 3B had a 4th engine ducted above the center duct, but photos of all Tridents show that extra duct above #2 that I always thought was the APU intake.

There was literally a fourth engine located just above the center engine. A small RB162 turbojet only used when needed for take off. The intake was at the front of the engine I believe. Closed on the left photo although you can still clearly see the outline, open on the right (harder to see because tail is dark blue):

View Large View Medium Photo © Baldur Sveinsson

View Large View Medium Photo © Wolfgang Mendorf

[Edited 2016-04-20 13:26:59]

Quoting col (Reply 3): Offset nose wheel, 4 wheel in line main wheels

What was the purpose of such a layout? I read somewhere that is was some sort of space saving trick. Can someone explain?

Better photo of the Trident 3B RB162 booster engine, 5,250 lbs. thrust. It was only used for takeoff and climb when necessary (hot weather, shorter runways etc.) and was then shut down.


View Large View Medium

Photo © Paul Markman

Quoting polot (Reply 19): There was literally a fourth engine located just above the center engine. A small RB162 turbojet

This engine was built as a vertical lift jet, It was very light. The compressor blades were mostly fibreglass and the oil system had no return, it went overboard. It was automatic in operation. The crew switched it on (like an APU) during taxy out. It was so noisy you could not start it at the gate!. Then when it was running at idle, opening two throttles and it went to take off thrust, and shut down when climb selected.
The Garrett APU was relocated into a space above the Nbr 2 engine intake. You can see it's exhaust in reply 21. Made for easy access on the ramp 

Quoting col (Reply 3): 4 wheel in line main wheels

This weird mainwheel rotated ninety degrees during retraction. Actually there were only two wheels on each leg, but each wheel had two tyres on it!

The front gear reminds me of the B-52 main

Quoting polot (Reply 13): It was the resizing of the Trident during development to be smaller with less range, per BEA's insistence, that basically killed off its prospects. Its original design was almost identical to the 721 (leaving many in the UK to believe that Boeing stole designs from HS when they were in talks about Boeing possibly building the jet as well).

Does anyone know when Boeing fixed the 727 to a T-tail rear trijet?

de Havilland certainly met with Boeing wand they both had access to each others plans. de Havilland wanted Boeing to drop the 727 and license the 121. Once Hawker Siddeley took over those talks ended and there were no further discussions. Although the two aircraft are very similar it is only superficially so. The 727 has the 707 cross section and Section 41. The 707/720 had several changes to the wing over time and the 727 wing incorporates those changes. The undercarriage 727 is far simpler. So while the basic shape of the 727 may have been influenced by the 121 the design is all Boeing.

Aircraft development has always been decided by engine size and capability. So, it really is not all that surprising that airframe manufacturers come up with similar looking aircraft when presented with the same requirement and using similar engines.

As stated above, had the Trident used the original RR Medways and larger airframe, it would have been B727-100 sized and a real competitor.

What I always found curious, is that early in development when deciding on the smaller aircraft for BEA, I wonder why a twin-jet using RR Medways was not considered. That too would have been a worthy competitor.

The Trident is a marvel of British engineering, sadly not a marvel of economics. The four-engined version Trident Three (five if you count the APU!) was an economic disaster. Although, in BEA's Speedjack paint scheme I always thought it a very handsome aircraft.

Quoting col (Reply 3): First autoland airliner. It was also fast in the air, just took a bit of time to un-stick from the runway. Offset nose wheel, 4 wheel in line main wheels and first 4 engined tri-jet. She was good looking too. Very successful, to me anyway, sadly only two flights on this baby before they took her away because of a bit of noise. On board it was much quieter than a 77W.

And you forgot to mention that it could seat 4+3, unique in aviation. An odd airliner it was, very sexy indeed, and much nicer than the yankee jets  .

Quoting art (Reply 9): I believe de Havilland's original design was for a larger aircraft (comparable in size to the 727) but BEA wanted a smaller aircraft, so the design was altered to better match BEA requirements. Later on BEA decided the Trident was too small and wanted a larger version, leading to the Trident 3. Had the original design been pursued, I think the aircraft could have secured many more sales.

That's right, BEA were worried because of a bad winter season in one year, when the design was being drawn up.

The original design, assuming too engine improvements meaning longer versions like the 3 but without that booster engine would have sold more, probably in Northern Europe where the auto-land would be most needed as well as others, still it would still have been up against the might of Boeing, with a family of aircraft, much greater resources, with not just the 727 but later 737's, engine and other systems in common.

So I don't think the 'original' Trident would have got near the 727 sales but might have done 2 or 3 times than it actually did as built.
Which would have turned a profit and helped the balance of payments.

Quoting Ty134A (Reply 25): An odd airliner it was,

Very true.

Quoting Ty134A (Reply 25): very sexy indeed

      Looking more like a flying brick than anything sexy.

Quoting Ty134A (Reply 25): and much nicer than the yankee jets .

   Nice joke.

Quoting Tristarsteve (Reply 22): the oil system had no return, it went overboard.

!?!? Wow, so after each take-off they had to fill up the oil again?

Quoting Ty134A (Reply 25): And you forgot to mention that it could seat 4+3, unique in aviation. An odd airliner it was, very sexy indeed, and much nicer than the yankee jets .

The 4+3 was a special setup with Channel Airways. The 'four' side was basically two adults and two children. Alternatively, two adults might have fit if they were anorexic
 

As far as Bringing Sexy Back, it's a matter of taste. Some observers saw rat-like characteristics in the nose and dubbed it the 'Rodent'.

Overall though, a nice break from Boeing Boeing Boeing everywhere.

Quoting CF-CPI (Reply 29): The 4+3 was a special setup with Channel Airways. The 'four' side was basically two adults and two children. Alternatively, two adults might have fit if they were anorexic

Poor old Channel. They made Dan Air look up market.

Quoting N14AZ (Reply 28): Quoting Tristarsteve (Reply 22):the oil system had no return, it went overboard.!?!? Wow, so after each take-off they had to fill up the oil again?

The engine only ran for 10minutes about once a day. It was not used on every takeoff.
But yes, at LHR BEA had an engine oil wagon that met all the arriving flights. We used to fill up the Speys as well on every LHR transit using this air operated pump.

Quoting CF-CPI (Reply 29): The 4+3 was a special setup with Channel Airways.

yep i know... is there actually any detailed pictures of the 4+3 layout? i know it was for families, but what was the certification? could you legally sit 4 adults there as well - even though not fitting? were the seats all measured the same, or were the two in the middle of the four "baby" size, and the two others normal ones?

Quoting CF-CPI (Reply 29): Overall though, a nice break from Boeing Boeing Boeing everywhere.

exactly!!! and add airbus.

although i never flew on one (never had a chance with my age...) it would be nice to have a comparison to the great three narrow body trijets, the TU5, TRD and 727. it's so much fun to actually see all the differences in these three airliners, and the different concepts. all are great examples of a giant leap forward and show how modern airliners in their aspects are great airliners.

i was lucky enough to have been on a 722 and a TU5 in the last 2 years, and must say that the difference is striking. and both are much more enjoyable rides than the sorry A320/B737NG crap.

Quoting Ty134A (Reply 32): is there actually any detailed pictures of the 4+3 layout?

Why did the Trident have an offset nose gear?

Quoting TWA772LR (Reply 35): Why did the Trident have an offset nose gear?

The nose gear retracted sideways into the gear well. Apparently this made more room available in the avionics bay for extra equipment.

IIRC BA had a row of backwards facing seats just in front of the main emergency exit, which always made for an interesting flight, where you were actually facing the passengers in the row directly in front of you.

Quoting Braybuddy (Reply 37):

My recollection is that the front half of the seating was all backward facing. At the time it had been realised that backward facing seats were safer in a crash, so maybe it was an experiment to gain customer reaction. I think maybe the RAF fitted backward facing seats in some of their Transport Command aeroplanes at that time.

[Edited 2016-04-23 01:53:59]

Quoting Egerton (Reply 38): My recollection is that the front half of the seating was all backward facing.

Definitely don't remember that, but it's always been cited as being more safe. There is absolutely no reason for airlines not to do this, and people wouldn't even notice it after a while.

Quoting Egerton (Reply 38): My recollection is that the front half of the seating was all backward facing

There were backward facing seats from the centre galley back to the overwing exit. In the exit row you sat with your legs mixed with the pax opposite you.
The fwd cabin of the Trident had first class seats in 1971, two rows of four. Got to sit there once and enjoyed the BEA cigar!
As an aside the front cabin on the BEA Vanguard had a large table with six seats, three facing back. As apprentices in 1969 we sat there all night playing cards from GIB to LHR First class on the Vanguard was at the rear of the aircraft.
We had arrived in GIB that morning from Tangier on the Gibraltar Airways DC3. It was a Sunday morning and we were the only passengers, and were invited into the flight deck for the 20min trip.

[Edited 2016-04-23 03:10:43]

Quoting TWA772LR (Reply 35): Why did the Trident have an offset nose gear?

Initial specs for the aircraft on first offer to BEA (the larger B727-100 sized version), had an optional ventral airstair behind the nose gear for entry into the cabin from the ground. To accomodate this airstair, the nose gear had to retract sideways to save space.

When the smaller version was finally designed and built, this nose gear layout remained. It DID save a lot of space!

Quoting Tristarsteve (Reply 40): There were backward facing seats from the centre galley back to the overwing exit. In the exit row you sat with your legs mixed with the pax opposite you.

The Trident One and Trident Two had that layout. With rear facing seats from the overwing exit to the forward bulkhead of the main Economy cabin. The Trident Three had only one row of rear facing seats, and that was at the overwing exit. If the aircraft was all Y class, (as it was toward the end of its service) the forward row too was rearward facing, with a table between the seats.

Quoting Tristarsteve (Reply 40): The fwd cabin of the Trident had first class seats in 1971, two rows of four.

The One and Two had that layout. There were actually two cabins ahead of the central galley, each with two rows. Those seats were F to Y convertible, so it could be 4 rows of F (16 seats), 4 rows of Y (24 seats), or two rows of each, (8F and 12Y)

Quoting Braybuddy (Reply 39): Quoting Egerton (Reply 38): My recollection is that the front half of the seating was all backward facing. Definitely don't remember that, but it's always been cited as being more safe. There is absolutely no reason for airlines not to do this, and people wouldn't even notice it after a while.

I remember flying on several BEA/BA Tridents with several rows of rear-facing seats. Many people do notice and find that facing backwards in a moving vehicle makes them dizzy or more prone to motion sickness. I know a few people like that.