View Full Version : How many engines on a Trident Three?

31st Mar 2008, 10:10
I have seen a picture of a Trident Three in Airliner World (Page 74, April Issue) Looks like it has a 'little engine' just above number 2. Is that a APU or an extra engine for take off?

31st Mar 2008, 10:17
That sounds like the Trident 3 series.

They had a fourth engine as a booster engine for 'Hot and High' Airfields to assist in take off.

The advisory was to only use the assistance if fully loaded but sometimes the aircraft took off empty with the booster engine running for an impressive take off and climb performance.

(wish I was on one)

31st Mar 2008, 10:37
Ahhhh. I see. thats very interesting. Any pilots out there that have used the fourth engine? Could you really feel the extra performance on takeoff? Seems like a zero bypass, proper jet. Must have had one hell of a scream when in use.

31st Mar 2008, 12:07
5 if you include the apu. Often did wet starts with the booster at Glasgow (always used booster for departure); vapour followed by a gout of flame sometimes causing 'distress' to the BCal 1-11 behind it!

31st Mar 2008, 12:36
Did the booster have throttle or was it just Off/Max ?

31st Mar 2008, 14:03
The 'Ground Gripper' needed the boost at high wts & above 18c.

(Lucky the Earth is a spheroid, otherwise the Gripper would never get airborne- CFU 27c 67 pax wait 'til 1900lt for temp to moderate, even then a tech stop in NCE. I know I was on it as our Vomet AOG in CFU & me on @ 0630 next day)

Shaggy Sheep Driver
31st Mar 2008, 18:33
Trident two was a Trident 1 airframe with uprated Speys, probably the 'best' Trident. Trident 3 is a stretched 2, but the Spey couldn't be further developed so the '3' was a tad underpowered for hot and high takeoffs. Hence the boost engine.

Liffy 1M
31st Mar 2008, 19:09
Ahhhh. I see. thats very interesting. Any pilots out there that have used the fourth engine? Could you really feel the extra performance on takeoff? Seems like a zero bypass, proper jet. Must have had one hell of a scream when in use.

The Trident was so noisy on its three Speys anyway that the addition of the booster made no noticeable difference to the noise level!

31st Mar 2008, 19:26
This image clearly shows the extra exhaust nozzle
(for a larger image click here http://www.abpic.co.uk/photo/1043418/ )

31st Mar 2008, 20:36
The Boost Engine was a RB162 which was originally developed as a lift engine for one of the VTOL aircraft which never got built. The engine had a total loss oil system and needed to to be "oiled" on every flight even if not used. The RB162 contained a lot of composite (plastic) parts. Initially it was only to be used on take off and up to Fl100 with a maximum speed of (if I remember correctly 235kts)and not in icing conditions.It subsequently was permitted to be started below FL100 for approach and possible G/A if a main engine had failed. I tried that once with Number 3 engine shut down, the boost started ok (suprise) but failed with a loud bang some 2 minutes later. On inspection after landing the complete rotating assembly was missing and only a casing remaining!

1st Apr 2008, 11:55
I seem to remember travelling in a Trident 2 with rear facing seats.
Didn't bother me but I understand it wasn't a popular layout.
Only other type I know of with similar layout was RAF VC10, but I am sure others can list several more.

old,not bold
1st Apr 2008, 13:31
The front row faced aft, as I recall, which was strangely uncomfortable for those in it, as they were gazed at by all the other passengers and vv. And you did have to hold yourself in the seat during the initial climb.

Also being up against the bulkhead the seats would not recline (and maybe had no hinge anyway, to stay within 9G stress requirements?)

The RAF Britannias were also aft-facing, and very comfortable too. But less of a climb angle, I suppose.

I tried to introduce rear-facing seats with an oil charter operation, for safety.

Penalty was no recline (not a problem) and greater weight for the stronger seatback and mounting, resulting in loss of 2/40 seats.

"You must be joking", said the bean-counters as they killed the idea dead. "Lose 2 seats? For safety? Are you mad?"

1st Apr 2008, 16:56


1st Apr 2008, 17:00

Just to complete the picture. A non T3 tail.

A and C
1st Apr 2008, 19:27
As far as I can remenber the Boost engine was (on a good day) about as reliable as a second hand lawnmower, as soon as summer came we would be inundated with boost engine "failed to start" snags.

As said above the front en of the engine was mostly plastic and was likely to melt if any heat was conducted forward to the compressor so in the air the intake doors stayed open for 2 min to let the engine windmill after shutdown to cool the thing down. On the ground it was nessesary to dry cycle the engine after shutdown to cool it.

The engine had no starter motor so bleed air (from main engines or APU) was used to start, this was ducted over the turbine to spin the engine! start as automatic and thrust setings controled by micro switches in the main engine throttle quadrant.

1st Apr 2008, 19:38
From memory - and I did fly in them a lot in the 70s and very early 80s - the T1s and T2s had one row of aft facing seats, the T3s had several rows. In those days there was a First Class cabin as well.

A and C
1st Apr 2008, 19:53
One night shift Myself and one other went out to try to clear a "no start" snag on one of these "engines"after three or four attempts it was clear that something was amiss, there was lots of fuel so we guessed that it might be an ignitor problem.

This was to create a bit of difficalty for us as the automatics only put the ignitor on during the start sequece and to check the ignitors were working I needed to be able to hear them.Unfortunatly this was imposable over the noise of the APU so it was decided to (after a dry cycle to clear any fuel) to stop the APU during the boost engine start to allow me to go to the back of the aircraft under the engine and do an audable check for the loud "crack" of the ignitors.
All went well the APU was shut down during the boost engine start and I went to the back, the "crack" of the ignitors cofrmed that they were working so I turned arount to walk back to the flight deck to report this fact, just as I reached the bottom of the steps at the mid door there was a very loud WHOOOOOMPH and a sheet of flame higher than the aircrafts tail could be seen reflecting in he glass of the terminal lighting the whole ramp as if is was daylight.

By the time I reached the cockpit the guy with me was starting the APU as he was fully aware of the problem due to the reflection in the glass of the
terminal. Slowly as the APU got up to speed we got the bleed air to the boost engine an continued the start in order to blow the flames out.......... within a what seened like an eternity the engine started and the flames diapeared back insde the jet pipe.

About 30 seconds later 5 or 6 fire engines showed up looking for the aircrft on fire all we said was "just a wet start mate" as we reflected on how near we has come to setting fire to the aircraft!

It is an indication of how far aviation has come to reflect on the post above about the Tridents performance out of CFU on a hot day, now the Boeing 737-800 can lift 189 pax out of CFU on a +35C day and get them back to Gatwick without having to stop and this with the same fuel load as the Trident required to get to Glasgow or Belfast.

1st Apr 2008, 20:40
Posting as SLF here, when I flew to London (various) in the 70's, I was always struck by the difference in takeoff noise between the Trident and a 1-11. I tended to sit up the back (given a choice) 3 or 4 times a month and this thread has brought back some memories. After getting airborne of course the noise subsided... Thank you for explaining it to me - I'm humbled to realise some of the posters here must have flown me there and back (from Turnhouse - old terminal!) :8

2nd Apr 2008, 10:37

...forgive the thread drift here but, can anyone tell me why the "airways" as in British airways starts in lower case in your picture?


2nd Apr 2008, 12:52
Cliver029, the lower case "airways" was presumably simply "design" and I suppose emphasises "British". As you see in Beamender99's pic of 'ZK they dropped "Airways" altogether for a while around 1980, which I recall was a sort of "proud to be British" stance.

But conversely there were those world fins in the 1990s...

Brain Potter
2nd Apr 2008, 15:29
Did you reject the take-off for the failure of the booster engine below V1? I guess you must have done - otherwise why fit it in the first place.

If no more thrust could be wrung from the Spey, maybe they should have tried fitting the reheat from the Spey F-4 - possibly on No2 only. That would have been quite something. :}

5th Apr 2008, 11:12
Good question Potter. I was going to ask something similar. Some of the posters said it was a very unreliable engine. I was wondering if it was the last engine to be started, they probably did it on the taxi out to save gas. So if it failed to start they must have had to taxi back in to off load some weight.

5th Apr 2008, 15:48
Had the HS121 been built as originally designed, along with the growth potential, without BEA (Britain's Excuse for an Airline) downsizing the thing, it would have been a good platform to go head-to-head with the 727.

BOAC & BEA have a lot to answer for in the decline in the UK airframe building arena in the 50s & 60s. The Viscount wanted by BEA was too small, oohh dear then pax figures grew just as it started flying, then we got the -800!

Rant over, back to me pint & thoughts of summer, maybe next year!

5th Apr 2008, 17:16
I have a couple of friends who had a really bad time on the T3. They promptly jacked in their lot with BA and went to work for Britannia on the simple and reliable 737-200! :hmm:

Shaggy Sheep Driver
5th Apr 2008, 21:23
I have a couple of friends who had a really bad time on the T3. They promptly jacked in their lot with BA and went to work for Britannia on the simple and reliable 737-200!

In what way? The T3b can't have been that bad - none came to grief except for the Zagreb mid-air, which obviously was not type-related.


3rd May 2009, 11:53
Just to advise you all that there is a preserved Trident three (G-AWZI)nose section on display at the Farnborough Air Sciences Trust (FAST) museum. It's complete inside and live with instrument, ceiling and floor lighting operable along with some of her systems such as the CWS, stick shaker, engine fire bell and stall warning horn. 'Zulu India' is painted into her BEA colours from 1971. The FAST museum is open every weekend 1000-1600 and entrance is FREE. The address is 85 Farnborough Road, Farnborough Airport, Hampshire. Located at the end of the runway next to the Swan Pub. WWW.G-AWZI.CO.UK (http://www.G-AWZI.CO.UK) is the dedicated website of the Trident three G-AWZI and tells the story of her history, retirement and restoration of the nose section. The museum is also open on Bank Holiday Monday's too. A dedicated 'Trident Ground Crew' made up of former pilots, ground engineers and enthusiasts open her up most weekends to visitors.

3rd May 2009, 14:13
Ahh happy days, the banshee whine of 1-11 apus, feeling the heat blast of a wet start even from a distance, unfettered Speys sans hush-kits rearranging my internal organs whilst supping a pint of Robbie's in the garden of the Airport Hotel.....(or was it the Robbie's rearranging my guts?)

3rd May 2009, 16:06
So folks,

Where did the APU sit in a Trident 3...

3rd May 2009, 16:37
The APU on a Trident three sits above the No. 2 (centre) engine air intake. If you look closely at any photograph of a T3 you can just see it.

Agaricus bisporus
3rd May 2009, 16:56
Give us a clue, where is CFU?

Tyres O'Flaherty
3rd May 2009, 18:20
Corfu, perchance....

4th May 2009, 08:54

I think the Banshee wine on the 1-11 was the Plessy CSDS (constant speed drive & starter) during engine start.

I used to work at Gatwick in the early '80s. At night there would be 2 or three departures in the small hours and the Dan-Air 1-11s would wake up half of southern England when they took off.

4th May 2009, 11:34
Thank you dixi188. Yes, on a still, crisp morning I could hear them 20 miles or so north of MAN. Couldn't think of any other type that had that particular signature tune, I suppose it was just BAC and only the 1-11.

4th May 2009, 19:39
Surely a Trident would have three Tynes.

pax britanica
7th May 2009, 05:58
Ahh nostalgia. I loved flying on the Trident possibly because I did most of it on my fathers staff travel rights for next to nothing but I was a nice plane to fly on in my mind.

Living right next to Heathrow until my mid 20s I certainly heard enough Tridents and while it was noisy it was mild compared to the VC10 and Caravelle on take off and much less mind numbing than the scream of the early PW fan engines on 70s and DC8s on approach. I am pretty sure you could distinguish the boost engine sound on the Trident three as well as it was a quite distinctive noise although not unecessarily much louder.

As I recall the Trident was pretty fast for an airliner and easily outpaced DC9s and early 737s, but at a cost of course and once fuel got expensive it was the end of the line for what was virtually the symbol of Heathrow during its heyday



7th May 2009, 07:15
Going back a few posts, "treadigraph" mentions the truncation of "British airways" to "British". I think this was a "spoiler" move, designed to frustrate another operator's plans to change its name.
I can't be sure which airline, but seem to recall it was Dan Air. Can anyone confirm that it was/wasn't?
P.S. Could it have been British Air Ferries??

8th May 2009, 07:11
I never quite got all this "Gripper" stuff, for in my experience from back in the cabin the Trident seemed to have perfectly adequate rate of climb, and to prove the point I have an old photo taken looking backwards on a Heathrow 9R (possibly 10R !) departure to Glasgow, on a Shuttle Trident 1, looking back over the airport from high above Osterley. More than can be said for some other contemporary types such as the old Pan Am 747-100s which they used on nonstops to California (BA never attempted this), which on summer afternoons were apparently known to ATC as "Hedge Clippers".

The Trident didn't give me my first flight, but it did give my first flight On Company Expenses :) . First of very many.

Regarding the rear-facing seats, the Trident 3s latterly configured for the Shuttle had the forward cabin all rearward-facing. At mid-cabin there was thus a facing set of 6 seats each side of the aisle, good for groups, such as the one I conducted back from Manchester one afternoon. Of course we sat the clients in the forward facing seats, while I was rearward facing. On rotation, goodness, if it hadn't been for the seatbelt I would have been in the lap of Mr Prospect, Senior, sat opposite. The angle was most pronounced.

I'm humbled to realise some of the posters here must have flown me there and back (from Turnhouse - old terminal!)There was a short interval between the Trident taking over from the Vanguard on Edinburgh, and the opening of the new terminal (and runway)but not long. During all the runway discussions in the early 1970s BA maintained they had to keep the Vanguards staggering on because the old runway was inadequate for jets. After all the arguing was done and it was approved, BA promptly withdrew the Vanguards and used Tridents during the construction time. I was always surprised nobody picked them up on this.

Taff Missed
8th May 2009, 11:52
Oxenos - That was awful.

8th May 2009, 13:04
The gripper nickname has always seemed a bit odd to me too. I never flew in one but on my occasional visits to the top of the Queens Building at Heathrow in the mid-sixties the Trident had a far steeper climb angle than anything else. Did they get worse with the later variants?

8th May 2009, 13:23
At Lutterworth, in the early 50's I saw a booster poking out of a Lancaster rear turret, it took off.

Has anyone any data or further information on that.

8th May 2009, 15:22
'twas named so by the crews:ok: Also you may wonder why the 737 is called the "FLUFF":E

8th May 2009, 19:02
Taff M

It was. First quoted in Straight & Level about a million years ago. Been waiting to come out with it ever since. I was beginning to think no one had noticed. O Xenos

8th May 2009, 19:24
I was beginning to think no one had noticed.
We had all thrown our Notebooks across the room in disdain and lost our connections ..... :)

9th May 2009, 07:45

Off topic, but to correct something you wrote (post 37). You say that BA "never attempted" nonstops to California in 747-100s.

Yes they did! I flew P&W powered BA 747s nonstop between Heathrow and San Francisco in the late '70s.

I'll take that anorak off now......

9th May 2009, 08:23
Well I'm surprised, because BA wisdom was the -100 did not have the range for California, hence the arrangement with Air New Zealand to use their DC-10s on Los Angeles in 1975-78, until the first 747-200Bs came along; LAX was the first route they were used on, they had been desperately short of capacity, BA had been hanging n for the first Rolls-Royce engined -200Bs. San Francisco then started as more -200Bs were delivered, if I recall correctly it was Spring 1978.

Only thing I can think is that maybe freight to San Francisco might have been much less in the initial days, and that gave scope for more fuel on the -100. It was a regular summer event for the DC-10 to go out from London at max weight, and for freight (and occasionally pax !) to have been offloaded. Because of the duration a fuel stop was not normally possible within FTLs, the only way to do it was to plan it a day ahead and send a crew up to Prestwick, and stop there.

I was a regular on these flights at the time as well, mainly LAX but some SFO as well (and, as you can guess from the above, saw PIK a couple of times as well, let alone a deserted Stansted during a handlers strike at Heathrow !). I know both Pan Am and TWA were using -100s to California, and once did a marathon LAX-Bangor (about a 2.5 hour stop)-London with TWA when they couldn't get a transoceanic clearence. The US must have had different FTLs.

9th May 2009, 22:14
WHBM your mention of Tridents on the "Old" 13/31 runway at Turnhouse reminds me of one very wet day when, sitting in my office next to the terminal (the old one), that a Trident landing on 31 came into view from behind one of the adjacent buildings, and almost abeam the terminal, still going like the clappers of hell when normally by that time they were down to near to taxying speed. Best bit of aquaplaning I've ever seen. Off the far end and onto the grass it went, stopping just short of the construction work on the new runway. Fortunately nothing damaged except the skipper's Y-fronts and as I recall it was flown back out the next day.

10th May 2009, 16:22
Sorry to drift back off topic again but some of you may be interested.

The 747-100s struggled westbound (against the prevailing winds) and getting the load and fuel right was quite an art especially on a hot day at LHR. Freight loads suffered last minute bumping on occasions. The PA ones, at least, often could only be legally dispatched part way (usually Edmonton or Winnipeg as far as I recall) and then, all going well, they could do an en route redispatch to LAX (US redispatch is a similar sort of process to the UK 'en route alternate' but relies on company ground based dispatchers' calculation and approval). Usually the crew could keep the fuel burn down enough across the N Atlantic/Canada to make the redispatch possible.

Westbound was almost never a problem except one day when someone (FE I think) misprogrammed the INS co-ordinates before leaving the ramp at LAX so by the time they hit the 49th parallel their INS was telling them they were somewhere else so an arctic and oceanic crossing could not be made accurately. An embarrassing landing had to be made at Winnipeg just for correct co-ordinates to be punched in and of course, for the extra fuel that the diversion had made necessary. :O

There was minimal holding fuel available, though, to deal with any delays eastbound into LHR and an early decision to divert needed to be made on marginal weather days.

When Laker started the LGW-LAX Skytrains in the mid 1970s they used DC-10-10s that had to tech stop Bangor (and slip flight deck crew but not the cabin crew I seem to recall) both ways until the -30s arrived (in late 79 or early 80). Bangor is quite a way off the Great Circle route (see Great Circle Mapper (http://gc.kls2.com/cgi-bin/gc?PATH=lgw-bgr-lax-lgw&RANGE=&PATH-COLOR=&PATH-UNITS=mi&PATH-MINIMUM=&SPEED-GROUND=&SPEED-UNITS=kts&RANGE-STYLE=best&RANGE-COLOR=&MAP-STYLE=) ) so this must have cost Laker dearly for extra fuel and crewing costs.

Brain Potter
10th May 2009, 17:16
Curious as to why Laker would tech-stop at BGR which, as has been said, is quite a way off the UK-West Coast Great Circle. Surely a stop at YWG, YEG or even MSP would have been more economical.

10th May 2009, 20:23
I heard that "The Gripper" went like a scalded cat once it got to altitude though...

10th May 2009, 20:40
The de Havilland GroundGripper (to give it its correct name) must be the only plane to have included the thrust of the APU for take-off calculations.

11th May 2009, 07:06
Curious as to why Laker would tech-stop at BGR which, as has been said, is quite a way off the UK-West Coast Great Circle. Surely a stop at YWG, YEG or even MSP would have been more economical.
There were apparently a series of small issues that added up to Bangor being a benefit, but the main one was that Laker started with shorter-range DC10-10s. They were, as far as I can recall :

1. The DC10-10 was marginal to get to Winnipeg anyway from London, and other intermediate points up in the Arctic had high fuel prices and crew accommodation difficulties.
2. Generally cheaper fuel in the US than in Canada.
3. Because you needed to recrew, good to have the stop for both UK-LAX and UK-MIA in the same place. For LAX Bangor is half way, for Miami a slipcrew can then do BGR-MIA-BGR in one duty.
4. The need to recrew was in part because Laker chose to stop several of their flights at Manchester or Prestwick. This went back to their charter-only days on these routes, when they did the same thing.
5. Bangor did a lot of promotion of themselves with minimal landing fees and cheap fuel.
6. Clearance of customs at Bangor was quick (because they were trying for the business) as compared to LAX, to such an extent that for pax this could more than cancel out the extra journey time.
7. Winnipeg is a poor weather place in winter and is a difficult place to find alternates for given that you have to recrew. Diverting to Minneapolis with unexpected US customs to do and the slip crew over the border in a snowstorm is a real pig to untie.

12th May 2009, 04:30
5. Bangor did a lot of promotion of themselves with minimal landing fees and cheap fuel.
6. Clearance of customs at Bangor was quick (because they were trying for the business) as compared to LAX, to such an extent that for pax this could more than cancel out the extra journey time.
7. Winnipeg is a poor weather place in winter and is a difficult place to find alternates for given that you have to recrew. Diverting to Minneapolis with unexpected US customs to do and the slip crew over the border in a snowstorm is a real pig to untie.WHBM is pretty much on the money but when I flew as SLF LGW-BGR-LAX and return the pax customs clearance was not done at BGR, as I expected it to be, but at LAX. I did wonder how they managed that - there were no pax boarding at BGR but the F/D crew did change and US Customs were usually pretty strict about such things from memory. It must have been a deal BGR aiport managed to arrange to get the business. I wonder if they got fuel duty free both ways and, if not, how badly that would have affected profit margins?

BGR was very popular due to the points mentioned and even airlines like PanAm with lots of facilities at nearby airports such as BOS chose to use BGR for tech stops on many charter flights. I imagine BGR is a much quieter place nowadays with not so many short range aircraft attempting long range operations.

Given its location, BGR must have had wx issues on occasions. Does anyone know where Laker diverted to and how they got round the crewing issues that diversions must have caused?

12th May 2009, 04:41
I can recall BA flights in the early 70s filing FPLs for Seattle with first div SFX; if they had enough fuel left approaching SEA they would 'divert'!!