View Full Version : Trident help

Shaggy Sheep Driver
21st Nov 2002, 18:59
The DH Trident was capable of incredible rates of descent, aided by in-flight reverse thrust on the outer engines. But I remember hearing somewhere that it also had a facility to use the main gear as an airbrake mains only deployed, and the gear doors closed afterwards (they were left in the open position when the gear was lowered conventionally for landing). Can anyone confirm this? If true, was there a speed limit to allow the gear doors to cycle?


22nd Nov 2002, 09:39
Yes, the Trident had a phenomenal rate of descent when called for.
Back in the 70s I was working G-AVYB, a Trident 1E North East Airlines
Newcastle to Spain. FL290 overhead MIDHURST (MID) Cracked windscreen and emergency descent. Turned him left onto east and he got the height off and got a straight in at Gatwick 26.
Happy ending. Never heard how the passengers ears were though !!

Mr G.

PS: Just thinking, shame it didn't go up as fast as it came down.

Shaggy Sheep Driver
22nd Nov 2002, 10:27
Thanks for that, Mr G. Can you (or anyone else) confirm whether or not the main gear could be used as air brakes , as per my original post?


23rd Nov 2002, 02:15
Any gear in any airplane can be used as "air brake" (drag) to increase rate of descent, or to slow down. The only limitations are not to exceed gear extend speed and gear extended speed. I recall that in the L1011, a larger cousin of the Trident, the gear could be dropped up to M.85 or 300 KIAS, but it couldn't be retracted above something like 230 KIAS or so.

Shaggy Sheep Driver
23rd Nov 2002, 11:17
Quite so, Glueball, but I'd heard that the Trident had a specific 'air brake mode'. Using this, the main gear (not nose gear) was deployed and the gear doord closed afterwards (when the gear was deployed for landing, doors remained open). Thus the aeroplane could be dived a high airspeeds with loads of drag. The Trident's main gear had 4 wheels per side, 2 each side of the gear leg rather than the more conventional 4-wheel bogie, so was particularly draggy.

But - is it a myth or did the DH121 indeed have this facility??


vintage ATCO
23rd Nov 2002, 17:53
I should be seeing Des Penrose in a week or so at Old Warden. Des did a lot of the test flying on Tridents with John Cunningham.

If I remember I'll ask him! :)

Shaggy Sheep Driver
23rd Nov 2002, 20:04
That would be most helpful VA, since it's possible this was a feature tried on early models but not put into production.



A and C
24th Nov 2002, 11:24
from my time working on the trident I cant remember any way that just the main gear could be used as a speedbrake but I have no doubt that in "full drag" mode the Trident could fall out of the sky in a spectacular fashon , this seems to be a bit of a Hatfield thing as the only thing that the BAe 146 could do better than any other aircraft that I have flown was go down !.

26th Nov 2002, 12:30
While we are on the Trident subject, can anyone tell me the history of the Trident that is at Heathrow painted in BEA colours? I guess is doesn't fly but what is it used for now?


A and C
26th Nov 2002, 16:59
Further to my last post I have talked to people who flew all the Trident marks ( I only worked the 2 and 3 ) and yes its true that the main landing gear could be used as a speed brake , there was a switch near the gear lever to isolate the nose gear the main gear was then dropped in the normal way and you would get TWO greens when it was down and locked.

I can only wonder at how meny people came close to landing with the nose gear up !.

To make matters worse this option was only fitted to the Trident 1E.

I hope this answers the question fully.

Lump Jockey
26th Nov 2002, 17:27
GAWZK Trident 3, LHR. Retired Nov 85. Owned by the TPS, Trident Preservation Society. Basically used as a living museum!

26th Nov 2002, 18:44
The aircraft is preserved with most of its internal fittings. It was used for towing practice but alas it cannot accomodate the modern towbarless tractors. I believe at this time it is not used by conventional tractors either as there is some concern about the undercarriage. As space is money i.e. parking fees it is rumoured that it will not be long before BA wants it off the base and ultimately off LHR.

Shaggy Sheep Driver
26th Nov 2002, 19:04
many thanks, A and C.

I knew I'd heard it somewhere!


Dr Jekyll
27th Nov 2002, 06:46
I remember boarding an LHR to Edinburgh shuttle early in 1980 and noticing a Trident nearby still in BEA colours. Was G-AWZK still in that colour scheme then?

27th Nov 2002, 08:44
Probably a different Trident. G-AWZK has spent several years in the grey/blue Llandor scheme and was only repainted into BEA colours sometime in 2000/2001.

You can read about it on the Trident website (http://www.hs121.org.uk/).

27th Nov 2002, 10:41
I once read that the Trident's nosewheel was offset because the autoland was so accurate, that the nosewheel strut would take too much of a battering from constantly running over the centreline lights!

Shaggy Sheep Driver
27th Nov 2002, 14:36
I was very sorry to read from the Trident Website that G-AWZO was cut up at Hatfield in August.

I travelled on ZO on its last day in service - 31st December 1985 on a 'tribute' flight from Manchester. We did a low pass at Liverpool and Isle of Man, and one back at Manch before landing. Later that evening (around 18:00) ZO operated the Shuttle flight to Heathrow - her very last flight in service.

She then flew to Hatfield for 'preservation', but when I saw her about 1999 she was still on the north side at Hatfield, and in very bad shape. She had obviously just been left parked since 1985.

Shortly afterwards Hatfield was used for filming 'Band of Brothers', ZO was towed to the main apron, and the runways were lifted.

When I spoke to the guys at the DH museum at Salisbury Hall a while back they were hopeful that they might at least get the nose section. I presume that didn't happen.


29th Nov 2002, 12:14
The Trident's nosewheel was offset because it retracted sideways. This was so that the nosewheel bay would fit between two complete bulkheads without the cutouts required for a conventially retracting nosewheel. After the structural failures of the Comet 1 De Havilland were a bit obsessed with structural strength!

30th Nov 2002, 16:44
:) What I would like to know is , what was the need for this aircraft to go down so fast? I mean engines that could be used as speed brakes, landing gear that could be used as speed brakes, speed brakes that could be used as speed brakes..........................why so much????

A and C
11th Dec 2002, 15:11
i think that this may have been an over reaction to the fact that modern airliners are not that easy to slow down and most of them will not slow down and go down at the same time.

At the time the Trident was being built most of the aircraft flying with the airlines were props or turbo props and when you put a propeller into fine pitch at speed it acts like a very big speed brake , I can only think that it was invisaged that the Trident needed to match the braking performance of the other trafic.

The landing gear speedbrake was only fitted to the 1E so it sujests that it was found to be an unnessesary complication and so omitted from later aircraft.

vintage ATCO
11th Dec 2002, 17:00
I've posted off-forum to SSD.

I spoke to Desmond Penrose last Friday about this. Desmond did much of the test flying on Tridents with 'JC' - John Cunningham. He said to come down quickly in a Trident, you put the outer two 'motors' in reverse, drop a stage of flap and drop the gear, all the gear, and it would come down at 12,000fpm. When I asked if there was ever a procedure for lowering the mains only as a speed brake, he said he had never heard of it. I asked if it were possibly done on just the 1E and he said he doubted if DH would have done a mod for just one series, and it would have been a feature of the Trident which he had never heard of. So there, the thot plickens.

He added when probing the deep stall they would come down at 18,000ft, which was quite exciting as they use to start at 18,000ft!!

I wish people like that would write all this stuff down.

A and C
12th Dec 2002, 08:49
My info on the 1E came from guys who flew the thing for what was then BEA , I guess the only way we will clear this one up is to find a 1E flight manual !.

vintage ATCO
12th Dec 2002, 11:25
Did BEA ever operate the 1E? I don't remember them doing although the memory isn't what it was! :)

12th Dec 2002, 12:58
Neither is mine Vintage ATCO, but strange stutterings from within the grey matter do seem to recall BEA acquiring Northeast (the UK one!) and Channel Airways (?) both of whom operated Tridents... 1Es?

12th Dec 2002, 20:02
BA had four 1Es:
SWU ex-Kuwait, VYB, VYC and VYE ex-Channel/BKS/Northeast (VYD was written off before the takeover).

vintage ATCO
12th Dec 2002, 21:11
Ah ha! Now all we need is a manual! :D

13th Dec 2002, 19:42
As far as I am aware it was the 1C that had the option of dropping the main gear, for use as an airbrake, not the 1E.

The option was apparently dropped quite early in the Trident's life. According to the book - Classic Civil Aircraft 5 - Hawker Siddeley Trident, by Max Kingsley-Jones, there was a rumour that someone had tried to land with the nose gear retracted. How true that rumour is, I don't know.

Unfortunately I only have a flight manual for a 2E (G-AZXM), which had the usual speedbrakes. I also have a load of maintenance manuals for Trident 1s, 2s and 3s, but alas not one that covers flying controls, so I can't confirm.

BTW for any Trident fan, the above book by Max Kingsley-Jones, ISBN 0 7110 2132 5, is an excellent read.

17th Dec 2002, 21:34
When looking through some old engineers lecture notes on the Trident, there was a diagram of the central pedestral, with the switch and warning light, for quote.......

'main landing gear lowered as an additional airbrake'

Shaggy Sheep Driver
19th Dec 2002, 08:48
Hmmmm. The plot thickens....

I wonder if anyone will produce definative evidence - documentary or photographic.


19th Dec 2002, 11:00

I could email you a scan of the diagram/picture if you want.

I got another bunch of Trident manuals yesterday, and I'm in the process of searching through them.