Concorde question

[Shem Malmquist]

I have a different question. Does anyone know what happened to the engines on Concorde? I know the airframes are about, but all seem to be sans engines.

[Shaggy Sheep Driver]

I think they mostly still have their engines, except AD in NY. Our AC at Manchester certainly does.

[EXWOK]

AB had them removed for balance reasons, given that it has no interior.

[Shaggy Sheep Driver]

Would the lack of an interior make that much difference? Museum Concordes have no fuel in the forward tanks (or, of course, any tanks), and are therefore in danger of becoming 'tail sitters'. Our AC at Manchester has (I'm told) ballast loaded in the forward fuselage to prevent that happening.

[EXWOK]

It must make a fair difference: On average, much of the 'interior' is ahead of the CG and remember AB has no cockpit, which is a fair chunk of weight a long way forward,

I vaguely recall that AB was filled up with old 'High Life' magazines initially.

[tdracer]

If memory serves, the Concorde at the Seattle Museum of Flight has engines (or at least something that looks like engines).
It also has an interior and flight deck - visitors are allowed to walk through the passenger portion of the aircraft (can't comment on the completeness of the flight deck since there is a big chunk of Plexiglas preventing close inspection).

[Thridle Op Des]

Every time I taxi past 'AB in Heathrow I really feel sorry that somehow it hasn't become a centrepiece for one of the terminals, I half expected T5 to have it hanging off the ceiling. Are there any plans to bring it in from the inclement UK weather or is this an issue of elf n safety? It would be great if it were moved, if only not to distract me from heading up a non-code F taxiway.

[grumpyoldman]

Mine is one of the 202 development units, and 'knitting' is too kind... 'kludge' describes it better. I'll post a photo, if you like.
That myth was amplified substantially by BA removing those "secret" AICUs from the aircraft after the final delivery flights.
The way I understood the story was that they tried to collect as many reasonably reliable spare AICUs for the last few delivery flights, so as not to have to suddenly cancel a flight.
The AICU was right at the top of the list of "unscheduled removals". IIRC the tea maker was second...
The one I know about is the ADC/DAC board (analog-digital and digital-analog converter board). The supply of either ADCs or DACs ran out literaly worldwide, and the board had to be redesigned, requalified and recertified with more recent components, and a new batch manufactured. The cost, for the replacement of that board alone, came to about 3 million euros.
Somebody passed me a photo taken at Casablanca of a table full of AICUs waiting to be programmed... of course every software mod had to be programmed into all eight computers!
"... 'burning' each individual logic gate with a 9v battery." I believe you, thousands wouldn't... Didn't you have at least some sort of programming unit?
I went through a similar exercise around 1976, but at that time at least we had a programming "suitcase", that let you copy the original in RAM, modifiy bit-by-bit with a keyboard, then 'burn' the PROM (or EPROM, by then) 'automatically'. Still took half the night....

Funny in a way how these things have stuck in our memories... But then, yes, Concorde was unique.
I've said this elsewhere, but I don't mind repeating it... in those days, there were two programmes to be part of. One was Apollo, the other was Concorde. And I've had the chance to be part of one of them.



Well, I can claim some input to this Control Unit. The adc/dac was in fact AICU 1. I designed the PCB at BAC Electronic and Space Systems Div. in Bristol in 1971/72 as I remember. Both the A to D and D to A modules on the board were made by Analogue Devices in the states. There was an array of DG103 FET Switches as i recall. The circuit design engineer and the electronic packaging engineer and I had a few rethinks about component placement on this board. As I recall , AICU1 thru 5 were all control and processing boards. AICU6 thru 9 were memory , harris h512 PROMS mounted on heatsinks which were bonded to the PCBs and all mounted in their own sockets.
The inter board wiring was random, no harness arrangement other than for power supply. Cross talk was even considered by the design engineers then. Wire wrapped in 30awg OFHC single core cables.
I could go on about a lot of things used in the system as it was also my job to keep a record of all the components and which board they were used on. This also applied to the Sensor Unit, The Test Unit, The Management Control Panel. We were busy Bees in the DO for a few years on AICS. Happy Days

[MurphyWasRight]

The inter board wiring was random, no harness arrangement other than for power supply. Cross talk was even considered by the design engineers then. Wire wrapped in 30awg OFHC single core cables.
Days
( guessing you meant "Cross talk was not even considered"

The inter board (backplane I surmise) random wiring may be what allowed it to work.

"Way back when" I used wire wrap proto boards (socket for each IC) and found out the hard way that neatly bundled routing, Manhattan no direct cross country, greatly increased crosstalk compared to random 'rats nest' routing.

I once made everything start working by dropping a single ferrite bead over the clock driver pin (before adding the wires) to slow edge rate enough to damp reflections.
This was with a 66Mhz clock which is the upper limit for wire wrap.

[Rush2112]

Every time I taxi past 'AB in Heathrow I really feel sorry that somehow it hasn't become a centrepiece for one of the terminals, I half expected T5 to have it hanging off the ceiling. Are there any plans to bring it in from the inclement UK weather or is this an issue of elf n safety? It would be great if it were moved, if only not to distract me from heading up a non-code F taxiway.

It's a great disappointment on the odd occasion I go through LHR to see it mouldering away half-forgotten like that. It's also disappointing when you arrive at the airport to see an EK model on the roundabout. Surely BA could afford to put something there? I cannot imagine any other country that would have someone else's flag carrier advertising at their main airport.

[Casper]

https://youtu.be/fqOcYhzWUZY

I am ignorant of Concorde operations. I am an aircraft accident investigator, however, after many years of PIC international operations.

With respect to the above site, I'd be most grateful if the following points were to be confirmed in regard to AF4590:
* A spacer was not installed on the LH undercarriage
* The a/c was above its MAUW and outside its C of G limitations
* The take off was commenced with a downwind component
* The T/O run was commenced over tarmac still under repair
* No runway inspection was conducted, as required before any Concorde T/O
* No extra protection to fuel tanks had been provided, as had been done by BA
* The FE completed engine fire and engine shutdown without consultation with PIC

If the above is true, then the accident was unavoidable and I am astounded that the French authorities had the gall (Gaul) to blame Continental Airlines for FOD that should have been detected had the runway inspection been conducted as mandated. Shame!

[atakacs]

https://youtu.be/fqOcYhzWUZY

I am ignorant of Concorde operations.

Welcome to France...

[condor17]

TD Racer , Had the privilege of bringing home to LHR from SEA the engineers who de-commisioned her . Was able to make them and their other halves comfortable as a thank you . Some had worked on Conc. for the whole of her BA career , and were retiring with her .
No mention of removing engines whilst chatting with them . However after decades of keeping her running , it was sacrilege for them to drain all fluids , cut pipes ; allowing air /moisture into hydraulic / fuel / oil lines . Disconnecting all electrics , cutting through many wiring looms , removing sections . They were told to make impossible to renovate back to flying condition .
On her delivery flight , via Toronto IIRC . The Canadians graciously allowed her to take a Northerly route over the Tundra with NO speed restictions . It all happened at the last minute , and the last sector had 30 , or was it 70 ? empty seats . A lost opportunity .

[Shaggy Sheep Driver]

Casper, I'm not aware of any fuel tank protection by either BA or AF prior to the accident.

Overweight & aft GC was due too much fuel as well as captain authorising baggage to be loaded (in the rear baggage cabin) when the aeroplane was already about 5 tons overweight.

Something else germane to the accident was that the fuel tanks were overfilled leaving no airspace to absorb any shock waves on the basis this extra fuel would be burned off during taxi, but the change of runway (to a downwind one) meant a much shorter taxy so it wasn't burned off and the FE didn't ask for a delay while it got burned off. They just 'went'.

Worse - realising they had a rearward CG, fuel was being transferred from tank 11 (in the tail) to the wing tanks DURING THE TAKE OFF ROLL. an absolute no-no in Conc ops. The idea being as fuel was burned off from the wing tanks and replaced by fuel from tank 11, the CG would move foreward.

The result was the wing tanks were always overfull even though they were supplying fuel to the engines, so when one tank was hit by a big piece of tyre the shock waves travelled up through the fuel, bounced off the top surface of the tank, having found no gap of compressible air to absorb the overpressure, and travelled back down and burst the tank floor from inside.

[CliveL]

Casper

You might find it useful to read the BEA accident report (in English) f-sc000725a which has all the information you are looking for

[nicholas_c]

Good Evening Stilton, M-2 Dude and others.
I am having a nostalgia evening as 20 years ago today I had a flight in G-BOAC from CYYZ to “no-where”.
Actually, it was down to New York out over the ocean for around 30 minutes at FL 550 and Mach 2. For one in the “industry” it was a real treat to be able to have a flight in such an iconic aircraft.
Things I will always remember going out of “reheat” (a more elegant description then afterburner) after noise abatement from being pushed back into one’s seat to being momentarily weightless, the brilliance of the sky at FL 550, the cabin windows being hot at Mach 2 and seeing the gap between the flight engineers panel and the bulk head at Mach 2 due to the aircraft heating. I could go on about the engineering, observing the crew coordination from the cockpit visit (sadly pre-9/11) and there is a certain story about how our group sweet talked our way into the first-class lounge in YYZ and drained all the bubbly British Airways had in the fridge that day but…….
Reading the thread on this aircraft has been fascinating and thank you to all that has contributed to this wonderful story a sincere thank you.
I hope you will be interested in the following:- many years ago, when BA192 was a Concorde LHR-JFK, I asked if I could sit in the jump seat for take off. The captain agreed (maybe becuae I'm an engineer), and off we went. Pretty fun stuff. I was still up there when the reheat was re-engaged for the M 0.95 and up, and the captain said "we have a slight over temperature reading in engine #?, so I need to throttle back slightly" [it was almost a nervous tick I had noticed on this and previous flights that between reheat re-engagement and the final descent into JFK, the person flying pushed the throttles every few minutes - though omitting engine #? in this case]

Anyway the captain then says "never mind, we'll be in JFK 5 minutes early because of the "issue" - you can stay up for the whole flight if you can explain why".

After some serious cogitation, I sussed it out - any body else want a crack at it - and why wasn't an attractive option?

[Lancman]

I understand from that excellent interview that refuelling automatically cut off at about 83% of full tanks for safety reasons: to provide an air space that would absorb any shock wave travelling through the fuel caused by the impact of a foreign object striking the tank. What I don't understand is why there was a facility provided to over-ride this protection, and under what circumstances it was authorised.

[CliveL]

@Lancman

Not so on several counts

1. The phenomenon of structural damage arising from internal pressure waves in fuel tanks was unknown when Concorde was designed. Consequently the design made no specific provision for it.
2. 17% ullage is ludicrous on an aircraft for which fuel capacity is of vital importance. The correct value for tank 5 on Concorde is 6%.
3. Tank 5 was filled to 94% capacity at start of roll which would have been normal for any long distance flight. No more fuel was added to it; on the contrary, a very little might have been pumped into tank 1. The fuel transferred forward from tank 11 was put into the engine feeder tanks 1 to 4. This of course was not enough to compensate for the demands of OL593s operating at TOP with afterburner, so these tanks were running down and would have been topped up (tanks 1 & 2) from tank 5 at some point.
5. What actually happened was that the take off acceleration threw the fuel to the back of the tank so that the free surface volume was confined to a small zone in the upper forward region of the tank. When the rubber struck the rear part of the tank undersurface the fuel above it was constrained by a solid wall, which was enough to generate the reflected shock waves.

[Lancman]

@ CliveL

Thanks for that detailed and very interesting description of the fuel handling on Concorde and I agree that 17% ullage does seem to be very high, I've never come across a figure that high, ever. But your paragraph 5 seems to indicate that it was a jolly good idea from a flight safety point of view. The risk of tank rupture was increased because of the limited free surface volume. I'm just interested in what the circumstances were that allowed this restriction to be over-ridden.

[Shaggy Sheep Driver]

. I'm just interested in what the circumstances were that allowed this restriction to be over-ridden.

Extra taxi fuel I should think, which should be burned off before take off (it wasn't on the accident aircraft because of the change to a nearer runway).

[CliveL]

@Lancman

There a a lot of misinformation sculling around on this.
The final report states that the overfill was 300 litres (237kg) put into the engine feeder tanks 1 to 4. These tanks are grouped to have approximately equal moment about the CG so if it was, as seems likely, 75 kg in each there would have been negligible effect on the CG.

There was no overfill into tank 5.

It is all a long time ago, but as SSDriver says the overfill capability was probably there to cater for extended taxi or waiting time operations.

In this particular case the dispatcher ordered 2000kg rather than the standard AF allowance of 1000 kg to be loaded for taxiing presumably because he/she believed a more distant runway would be used because of maintenance work, but in the event the pilot asked for and was given the usual runway which meant that the aircraft was overweight for take off because only 1000 kg of taxi fuel was used. [Plus of course the additional baggage]

[Lancman]

@ CliveL.

Thank-you for your replies. As you say, it was all a long time ago.

[Shaggy Sheep Driver]

The final report states that the overfill was 300 litres (237kg) put into the engine feeder tanks 1 to 4. These tanks are grouped to have approximately equal moment about the CG so if it was, as seems likely, 75 kg in each there would have been negligible effect on the CG.

There was no overfill into tank 5.

So Hutch is wrong when he says in the interview that tank 5 was being continuously topped up from tank 11 as fuel was burned off during the T/O? I've had a quick look at a simplified fuel system diagram and while it shows no direct transfer route from tank 11 to tank 5, would there be an indirect one via the forward trim tanks?

And as the extra baggage was in the rear hold, and Tank 11 was full, that would explain the rearward CG and the desire of the crew to get fuel out of tank 11 ASAP and into the wings, Did it all go to tanks 1 to 4 via the forward trim tanks, with none going to tank 5 ( the 'accident' tank)?

[CliveL]

If the intent was to get the CG forward, what would be the point in transferring fuel to anything other than the forward trim tank? In particular why to the engine feed tanks which are arranged to be CG neutral?

However, the BEA report says:
It has been established that the aircraft began taxiing with tanks completely full. Before line-up, the crew carried out fuel transfer so as to bring the CG to 54% for takeoff. During this operation, the fuel burnt from the feeders during taxiing was replaced by the fuel contained in tank 11.
As a result of the transfer, feeder tanks 1 to 4 were full before line-up. In addition, main tanks 5 and 7, which had not been called on during taxiing, had remained full.
Between 14 h 41 min 55 s and 14 h 43 min 10 s, the time when the tank ruptured, the quantity of fuel burnt by each engine is estimated at 219 kg (15 kg between 14 h 41 min 55 s and engine power-up, 204 kg between power-up and the rupture). This was therefore the quantity of fuel taken from each feeder tank.
The transfer of fuel from tank 5 to feeder tank 1 deliberately only starts when the level in the feeder reaches 4,000 kg, that is to say 198 kg less than full. This leads to estimate that 219 kg – 198 kg = 21 kg was the quantity of fuel taken from tank 5.

I can't make that compatible with tank 5 being continually topped up no matter how I try

[Shaggy Sheep Driver]

Because the forward trim tanks were already full so not an option to put it there, unless there is a route from there to tank 5, in which case it might be being transferred to the trim tanks from tank 11, and on to tank 5? The only place to put fuel (if all tanks are brimmed) is into a tank(s) which are being emptied by feeding the engines. If there is no route from the forward trim tanks to tank 5, then perhaps in normal ops tank 5 would be topping up the feeder tanks as the engines drain them, but topping up the feeders from tank 11 meant tank 5 remained full?

The objective is to get it out of tank 11 ASAP to try to get the CG further forward.

[EXWOK]

Tanks 5 and 7 inlet valves have an ‘override’ position, do they not?

During the t/o roll, while the trim transfer pumps in 11 will be off, the de-air pump would allow flow through the trim transfer pipes to any tank with an open valve. The valves *should* be closed, unless someone had been creative with any override selections and failed to return them to normal.

[Shaggy Sheep Driver]

During the t/o roll, while the trim transfer pumps in 11 will be off

Hutch says they should be 'off' for T/O roll, but on this occasion, to shift CG forward, they were 'on'.

[CliveL]

@SSDriver

You are quite right; I should have checked that :O
A simple check of BEA's figures shows that they were assuming transfer into the feeder tanks.
Their sums say one needs to transfer about 700kg to make a CG shift from 54.2% to 54% (starting with a ZFCG of 52.4%). However, the engineer's panel after the crash showed that he had dialled in the loadsheet ZFCG at 52.3% so the fuel system would have transferred only 350 kg.
I can't see anything to suggest otherwise than that fuel transfer was stopped when TO began and that tank 5 remained at 94% total capacity throughout

We crossed in post, but where did you get the information that transfer was continued through take off? I didn't find anything in the official report

[Shaggy Sheep Driver]

CliveL

From this video. Have you not seen it? Ignore the garish sensational 'cover'. John is a highly experienced BA Concorde captain.

https://www.youtube.com/watch?v=fqOcYhzWUZY

[EXWOK]

I’m not sure we *know* the tank 11 txfr pumps were on.

The 5/7 inlet valves were in the override position.

Even if the T11 txfr pumps were off, the de-air pump would pump fuel to the trim txfr pipes and hence to 5/7.

All assuming I remember the report correctly.

The nub being, if you ‘hide’ fuel and forget to return the 5/7 inlet valves to normal, you will still feed 5/7 even if the 11 pumps are off.

[CliveL]

@SSDriver

Yes, I had seen the video, but although he states things with apparent confidence his view is not supported by the formal report.
Consider the final report wording quoted in my post 2025:
Before line-up, the crew carried out fuel transfer so as to bring the CG to 54% for takeoff. During this operation, the fuel burnt from the feeders during taxiing was replaced by the fuel contained in tank 11.
The French (definitive) version uses "a effectué" rather than "carried out" which suggests they completed that task. If so, why abandon the standard Concorde procedure?

The BEA went to some trouble to establish the amount of fuel in tank 5 at the time of rupture. The process they describe makes no mention of any transfer from tank 11 into tank 5, or indeed any transfer of fuel into that tank during the take off run. In fact they concluded that there was a reduction of 21 kg as a result of normal transfer from tank 5 to tank 1 when that tank became depleted.

[ThreeThreeMike]

To the top for users that have expressed an interest in the thread. What great reading this thread provides.

Thanks to all that have contributed.

[CMM]

Excellent thread and may it continue!

I have a question I don't think has been previously posed. In terms of the BA fleet, what was the typical fleet rotation routine?

Out as BAW1, return as BAW2, then off to the maintenance area, with a new airframe for BAW3 and 4? Essentially, was there a pattern (presumably to keep the cycles even across the fleet?).

I appreciate this may have changed after 'fleet reduction', so to speak...

Thank you!

[mexican bandit]

During my 27 years as a licensed aircraft engineer on the Concorde fleet I can not recall any type of rota for flying the aircraft. Whilst in theory it would be nice to equal their flying hours it was not possible as A/C engine hours would often dictate. The engine was made up of different modules & when that module became time x then the engine was changed & went away for the module to be replaced/overhauled.

You would often face a situation where you tried to limit flying hours of an A/C so you could change an engine to coincide with a service check. Also bearing in mind the delivery dates of each A/C G-BOAC was the first due to it having the BOAC reg. followed by OAA,OAB,OAD,OAE . OAF, & OAG both arrived later.

OAC returned to Filton under warranty for a while & OAG was laid up for a long time before being recommissioned . Whilst we had 28 engines on the wing through out the fleet there were only about 8 spare engines. Don't know about Air France Engines. Like all engines they suffer from ingestion of FOD & oil leaks etc. so engines never really went to their full time x hours. As a flying spanner on several charters you always prayed for G-BOAD as it was always the most reliable of the fleet.

They all had their own characteristics. Most Captains had a favourite A/C

[CMM]

Thanks Mexican! I am pleased to have tempted you into the thread. I would be intrigued to find out if there are any other favourites that our friends here could declare. The cynic in me makes me wonder if they chose AD for the ITVV video for the reason you say! :P

[EXWOK]

Favourite: OAF for fuel burn and subjective personal preference.

OAC second for the reg!.

OAD was indeed the schedulers' favourite for long charters although I have to say that I didn't have fewer or greater tech issues with it c.w. the others. Def. not a favourite on BGI because it burnt a bit more fuel than some others (e.g. Fox and Golf).

[Shaggy Sheep Driver]

OAC was the first off the Filton line, and therefore the heaviest (they learned to add lightness as production progressed!). That would have had an effect on range and possibly CG for that aeroplane. It also had a wing repair (following an engine fire I believe) which added even more weight.

[atakacs]

Regarding the fuel burn differences would you have a ballpark number to quote?
.1%? 1%? More?

[Dan_Brown]

"BRITISH AIRWAYS Concorde at Kai Tak (1996)" on youtube.

It's been many years since I flew into Kai Tak. If memory serves me correctly, landing on the Southern Runway, it was a mandatory go around should the extended centre line be crossed on approach. In this clip the aircraft executes a shallow left turn on short final, proving to me at least, they went through the extended centre line.

Was BA or Concords exempt from this rule?

[nicolai]

Hopefully this falls within the limits on commercial activity on PPRune, I have no connection with this other than being a satisfied customer a few years ago. If not, mods please be gentle with me...

The Concorde flight deck DVD produced by ITVV featuring Senior Flight Engineer Roger Bricknell, who also gave a fascinating talk on Concorde at the RAeS a few years ago, is soon going out of "print". So if you want a copy, you'll need to get an order in soon, or get a copy at an air show. I doubt anyone else will reproduce it soon.

It's an excellent and in-depth video, well worth it if you didn't manage to fly in her and interesting even if you did.

[GLIDER 90]

I've flown on G-BOAF.

[consub]

( guessing you meant "Cross talk was not even considered"

The inter board (backplane I surmise) random wiring may be what allowed it to work.

"Way back when" I used wire wrap proto boards (socket for each IC) and found out the hard way that neatly bundled routing, Manhattan no direct cross country, greatly increased crosstalk compared to random 'rats nest' routing.

I once made everything start working by dropping a single ferrite bead over the clock driver pin (before adding the wires) to slow edge rate enough to damp reflections.
This was with a 66Mhz clock which is the upper limit for wire wrap.
The reason that "birds nest wiring" was used for the backplane wiring on the AICU was indeed to prevent crosstalk.
I carried out a prom change at Cassablanca just days before the C of A flight, and used a prom blower that I carried out from Filton in my hand baggage together with boxes of proms, i remember the strange reaction by the customs man , until someone rescued me by telling him that I was taking them straight through to air side for Concorde. I programmed the proms by selecting the switches for the 8 bits of the line in the program for that particular prom, and then pressing the "blow" button that destroyed the fusible links in the input circuits of the prom. Of course all 64 lines of program in the prom that was changing had to be blown, even if only one line of program was changing. I carried out the programming on all 8 AICUs in 201, and the prom boards were laid out on a desk in the Air France office. Andre Turcat popped in to see what I was doing.

[tdracer]

Decent article at Smithsonian.com with a brief history of Concorde and the crash that doomed it.
https://www.smithsonianmag.com/smithsonian-institution/freak-aviation-disaster-brought-supersonic-idealism-down-flames-180970459/?utm_source=smithsoniandaily&utm_medium=email&utm_campaign=20181004-daily-responsive&spMailingID=36536091&spUserID=NzQwNDUzMjM0MTgS1&spJobID=1380440527&spReportId=MTM4MDQ0MDUyNwS2

[garylovesbeer]

How many commercial flights did the fleet of Concordes actually make before they were sadly decommisssioned?

[DaveReidUK]

How many commercial flights did the fleet of Concordes actually make before they were sadly decommisssioned?

BA's Concordes performed almost 50,000 flights.

AF had a similar sized fleet, though I think their utilisation was a bit less.

About Concorde (https://www.britishairways.com/en-gb/information/about-ba/history-and-heritage/celebrating-concorde)

[Lord Bracken]

Hopefully this falls within the limits on commercial activity on PPRune, I have no connection with this other than being a satisfied customer a few years ago. If not, mods please be gentle with me...

The Concorde flight deck DVD produced by ITVV featuring Senior Flight Engineer Roger Bricknell, who also gave a fascinating talk on Concorde at the RAeS a few years ago, is soon going out of "print". So if you want a copy, you'll need to get an order in soon, or get a copy at an air show. I doubt anyone else will reproduce it soon.

It's an excellent and in-depth video, well worth it if you didn't manage to fly in her and interesting even if you did.

For a time the whole video was available on YouTube - certainly long enough for one to rip a copy (and before Plod catches up with me, I used to own the twin-pack VHS version so felt somewhat entitled...)

[MATELO]

I may have missed this over the thread, so apologies, but...

Given today's advances in technology. Could a replacement Concorde be built (better engines, better/lighter software/computers, redundant F/E :uhoh:) from the original plans to actually make it a viable success.

[tdracer]

I may have missed this over the thread, so apologies, but...

Given today's advances in technology. Could a replacement Concorde be built (better engines, better/lighter software/computers, redundant F/E :uhoh:) from the original plans to actually make it a viable success.

Short answer is no. The advances in material technologies and manufacturing methods since the Concorde was designed would make a clean sheet design a much better and easier (read cheaper) to build aircraft.
Further, changes in the regulations/cert requirements would make it very difficult (if not impossible) to certify not just a Concorde clone but any future SST. I honestly don't know how any aircraft can meet the existing Part 25 depressurization requirements when operating at SST altitudes.

[pattern_is_full]

It takes a confluence of technologies and market structure to make something viable.

Concorde could not fly as anything but a very expensive subsonic aircraft over populated land, due to sonic-boom noise pollution - ruling out a lot of the marketplace. London-Africa/South Asia, for example, or Paris-Beijing. Or even NY-LA.

Flying the Pacific non-stop requires a doubling or even tripling of range to avoid refuel stops (sitting on the ground once or twice part-way, for 90 minutes or so, plus acceleration/deceleration time, defeats a lot of the speed advantage). Technology has advanced a lot, but nowhere near doubling/tripling the efficiency/range of an Olympus-type turbojet (which, counting the thrust recovery from the brilliant nacelle designs, was already amazingly efficient).

That's why regular Concorde service (and thus aircraft sales) was, practically speaking, limited to trans-Atlantic routes only.

Work is being done on shockwave/boom attentuation, which might open up far more markets. But it is still small-scale experimental.

Airbus recently proposed - on paper - a boom-defeating flight profile: rocket-assisted vertical acceleration to supersonic (boom travels sideways rather than towards the ground) combined with Mach-4.5 cruise at 104-115,000 feet (30-35km altitude attenuates the boom effects at ground level) and near-vertical descent while passing back to subsonic. Quite a roller-coaster ride!

Using liquid H2 fuel that gets it range from London-LAX at Mach 4.5 - but carrying only a dozen or so pax (hydrogen tank fills the rest of the fuselage).

[Stationair8]

For Ppruners in Australia, SBS are running Concorde Designing The Dream commencing 2040.

[tdracer]

Pattern, I didn't bother to address the viability question, but unless there is a massive technological breakthrough we're not going to see another commercial SST. The costs and fuel burn of an SST compared to a conventional subsonic airliner make the potential number of paying passengers too small for it to be economically viable. There simply are not that many people who are willing and able to pay a massive price premium to save a couple hours of flight time. No matter how efficient the engines and the airframe, fuel burn is always going to be much higher going supersonic (as one of my college professors put it, 'it takes a lot of energy to break windows ten miles below'), and the stresses of supersonic flight mean high maintenance costs.
The one possibility for a future supersonic passenger aircraft is for a (relatively) small biz jet. Something targeted for the super rich who are willing and able to pay a huge premium to save a few hours (I'm talking about the sort of people who have a 747 as their private jet). The business case would have to assume a small production run (less than 100 aircraft) meaning the massive nonrecurring development and certification costs would need to be spread over a correspondingly small number of sales. On the plus side, the biz jet regulations are somewhat more forgiving than those for large commercial aircraft (i.e. Part 25).

[HarryMann]

M2dude,

Re the MEPU at the Le Bourget museum...
The story I just got was that it was taken off F-WTSA or F-WTSB at Roissy for a fault and replaced (both 'SA and 'SB operated out of Roissy around '74 / '75 for things like route proving, etc.).
It got left on a shelf in a store, and was only discovered again in 2003 during the "big clean-out" and was saved 'in extremis' by somebody who recognised it for what it was, stopped it from being 'binned' and took it over to the museum.

Initially of couse it was. It was not until the return to subsonic, towards the end of the flight, that the contents of the n° 11 trim tank were moved forward again to the other tanks.
So yes, you're right, essentially all of it was "useable" fuel, it did not serve only for the trim.

Don't we all....
Jock Lowe seems to have stated there is a photo.... and we all still wonder if there is some footage taken from the Lear Jet during the filming of "Airport 79". But none is publicly known to exist ... we just know it's been done!

.. just like the Lancs that were barrel rolled !

[stilton]

If you value technical accuracy and a well written book on Concorde avoid ‘last days of the Concorde’ by Samme Chittum

Its about the Air France crash and has an accompanying short history of the program


it’s riddled with historical, factual and technical errors however, for instance ‘Concorde commercial service was inaugurated with a BA flight from London to Rio while AF operated from Paris to Bahrain’


Who knew ?


Best avoided

[stilton]

Was Concorde certified for this and was it ever done ?

[Lauren Pilla]

Mr Vortex

Finally as promised, here is a schematic of the AFT part of the fuel vent system. As you can tsee the fin intake pressurises the air space above tank 11, and hence, via the Scavenge Tank air-space, the remaining tanks. (Also you can see the Trim Pipe Drain Vaves you were asking about.



Regards Dude


hi! I know I may be super late to the party here, wondering if you have another picture of that fuel vent schematic? I can’t seem to see that one, maybe it’s been too long. Anyway it’d be much appreciated. Thank you!

[Bergerie1]

There have been many books written about Concorde. Here is an excellent one by Mike Riley, a Concorde training captain, who not only flew Concorde, but also a large number of other types as well. In his book A Concorde in my Toy Box this unashamed flying enthusiast describes his airline career with BEA and BOAC, as well as taking part in international aerobatice contests with the likes of Neil Williams. His descriptions of the challenges of flying Concorde and the handling qualities of the many aircraft he has flown, including the Antanov An-2, are both analytical and amusing.

His writing contains pearls of aeronautical wisdom that bear comparison with those to be found in John Farley's book, A View from the Hover.

You can find it here on Amazon:-

ttps://www.amazon.co.uk/Concorde-Toy-Box-Pilots-Barrier/dp/1861519516/ref=sr_1_1?crid=LTDLNVK9L6H2&keywords=a+concorde+in+my+toy+box&qid=1582873397&s=books&sprefix=a+concorde%2Cstripbooks%2C156&sr=1-1

[artee]

I've attached a couple of photos of Concorde at JFK in 1992.
If anyone would like full size copies (2,240x1,488 - ~3MB) PM me and I'll gladly send them.
If anyone thinks this post shouldn't be here, let me know and I'll delete it.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1024x680/1992_11_29_concorde_1_large_2198c12209c028a9bd1e79b6f83fc1d3 6b1cb847.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1024x680/1992_11_29_concorde_2_large_3199917b6faaf6231faba86f31dabe35 23c5d376.jpg

[NineEighteen]

Seventeen years ago today, she touched down for the very last time...:(

Pre-retirement Concorde fun...

[Bergerie1]

For those of you who are interested in Concorde, may I recommend Mike Riley's blog in which he writes about Concorde and many other aircraft too:-
https://www.flyingthings.org/

[oldchina]

Mike Riley wrote: "On June 18th, 2020, the President of France and PM of Britain celebrated the 60 years since President de Gaulle gave his speech from 10 Downing Street to encourage his countrymen to maintain heart and resist all attempts to extinguish the character of their country"
1960?

[megan]

Probably the speech he made 18 June 1940, link contains speech text, 80 years, but who's counting..
,
https://wiki2.org/en/Appeal_of_18_June

[consub]

I have noticed that I missed a bit in my earlier reply, You will not find a CPU chip as you suggested ,instead an ALU was used with sub-routines it was a RISC before they were invented.].

[Kiltrash]

Fastest Transatlantic Crossing 2 hr 52 min and 59 sec by Concorde JFK- LHR on 08 Feb 1996. 25 years ago.
How time flies

[ATC Watcher]

a quick question : was it possible to have 2 supersonic runs on the same flight?
Meaning 2 separate Supersonic legs with a subsonic one in the middle for say tech reasons or just sonic bang suppression over a sensitive area ..
And another while I am here , on the LHR -Bahrein route when did supersonic flight actually started and where it ended...?

[atakacs]

Regarding your first question I don't see any regular routing where this would have happened. I think there would not be any technical impossibility, though.
For the second part I guess somewhere above the Adriatic? But would be curious to know too...

[dixi188]

Did the BAH to SIN route involve slowing down over India?
I saw a night T/O from BAH, impressive afterburner flames.

[osborne]

Probably the early marketing flight planning software had no means of calculating that.
I believe a double acceleration-deceleration on a single sector was considered to be too fuel thirsty.
There may have been other limitations such as managing the c.g.

[25F]

Hi all,
thanks for the read. I think I've managed every single post (although I skimmed some of the *deeply* technical stuff).
As SLF (but always subsonic) I hope I can ask a question.
The registrations used by BA are clear in their origin - but for Air France, any particular reason for F-BVFx and F-BTSx?

[pattern_is_full]

ATC Watcher

it was possible - if the total route was short enough. And you had ~60000 kilos of fuel to waste.

Key points:

- Concorde's speed was directly related to altitude - going subsonic required descending to FL400 or below. With a corresponding decrease in Mach/true airspeed. Very poor fuel efficiency below Mach 1.7 - couldn't hold speed without afterburner/reheat. Don't forget how much Concorde's flight profile and range absolutely depended on turning the engine/nacelle system into a ramjet from Mach 1.7-2.02 to work "commercially" at all. The old "at Mach 2.02 cruise, 85% of the thrust came from the nacelle" idea.

- to get back to supersonic flight required repeating the whole climb-and-accelerate profile with AB/reheat fuel flowing by the tonne, until re-acquiring Mach 1.7 at FL400±.

which leads to:

Did the BAH to SIN route involve slowing down over India?

Nope. It was far more efficient to simply maintain Mach 2.02 and bypass India (and Sri Lanka) to the south. Circling all the way around them while maintaining supersonic speed and altitude used less fuel than: descend - slow to subsonic - cross India on a direct route - climb and accelerate back to supersonic.

You can google up some maps of Concorde routes (e.g. Paris-Dakar, Dakar-Rio). Actual routes, not airline "schematics." And see that it was almost always preferable and more efficient to get out over an ocean ASAP and get the ramjet effect going at Mach 1.7+, and then stay out over water as long as possible. Even if it meant an indirect "dogleg(s)" route covering more miles. Except for some intentionally "transcontinental" routes like KHI-CCU, Perth-Sydney, Dulles-Dallas.

[TURIN]

Sounds like a topic for a new thread. If it's as good as this one I can't wait.

[megan]

Also did they have the same fuel transfer complexity to maintain CoG during cruiseIt's the only way they would have available to control the effects of the movement of the wings lift centre of pressure rearwards when supersonic.

[stilton]

I thought the Tupolev had to stay in after burner continuously to maintain M2

[megan]

It did stilton, paper on a NASA in flight evaluation.

https://ntrs.nasa.gov/api/citations/20000025077/downloads/20000025077.pdf

[Lord Bracken]

megan

I thought the Tu-144 had canards instead, leading to an entirely new world of weight and complexity pain.

[TURIN]

I think the canard were for low speed control and stability as I think they retracted for supersonic flight.

[megan]

They did retract, you can see the mechanism here.
https://cimg7.ibsrv.net/gimg/pprune.org-vbulletin/800x497/u_66d0cfb7ad1161395dc010dd752b0d1c38676286.jpg

[washoutt]

Interesting picture, first time I see this. It does show the effective Sovjet engineering capabilities, however course. Thanks.

[Alpine Flyer]

There are various sources on the web that claim varying Mach/supersonic time restrictions for the the Pepsi-branded Concorde, mainly based on the inability/reduced capability of the dark livery to "deflect heat". This seems a bit strange given the black paint of the SR-71 and I'd appreciate comments by anyone in the know about this.

[CliveL]

This extract from Norman Harpur’s 1966 paper on “The Structure of the Concorde” explains it pretty well I think. Norman was the chief structures engineer on the British side so he can be classed as someone with definitive knowledge.
“At Mach numbers of about 2 it pays to paint the external surface white. Despite what the textbooks say, a white surface can be made almost as good as a black surface at radiating heat away from itself whereas it is much better than a black surface in reflecting solar radiation. Under these circumstances, at these speeds, a white surface will result in a cooling of something like 10 deg C. If we increase the speed of the aircraft, up to say a Mach number of 3, far more heat is transmitted by skin friction and the effect of solar radiation is relatively small. In these conditions it now becomes important to have the highest possible emissivity on the surface to reduce the heat as much as possible and here, even though relatively small, the gain between white paint and black paint is important. Therefore the Mach3 supersonic transport should really be painted black.

[tubby linton]

Would anybody be able to post a picture of one of the Pooleys sliderules developed specifically for Concorde operations? It was used for descent planning and is mentioned in the book Flying Concorde.

[paulc]

After the Air France incident at Washington DC in 1979 where events similar to those that caused the Paris crash occurred, did BA install any extra protection to the fuel tanks. Ie skin doublers in the most vulnerable areas?

[EASAPARTACADEMY]

Point taken GF, but it was discovered during development flying that that the Olympus 593 could be relit, given sufficient IAS, at almost any altitude within the normal flight envelope. The variable inlet would even be automatically scheduled, as a funcion of N1, in order to improve relight performance at lower Mach numbers. I certainly agree that you would decelerate and lose altitude fairly quickly under these conditions, however a multiple flame out was never experienced during the entire 34 years of Concorde flight testing and airline operation. There was, as a matter of interest an un-commanded deployment of a Concorde RAT AT MACH 2!! (The first indications of the event were when the cabin crew complained about 'a loud propeller sound under the rear cabin floor'. A quick scan of the F/E's panel revealed the truth of the matter). The aircraft landed at JFK without incident, and the RAT itself, apart from a very small leak on one of the hydraulic pumps, was more or less un-phased by the event. Although it sounds horrific, a prop rotating in a Mach 2 airstream, the IAS it 'felt' would be no more than 530 KTS at any time. The RAT was of course replaced before the aircraft flew back to LHR.
Not quite sure about your reference to the RAT on an F16 being Hydrazine powered; a Ram Air Turbine is just that, using the freely rotatting propellor to power hydraulics, electrics or both. Or do you mean the the F16 has an emergency power unit? Either way, it's fascinating stuff.
Yes, I do remember that the Germans used Hydrazine as a fuel during WW2: The father of one of our Concorde pilots was on an air raid to destroy one o the production plants there, this aviation business is such a small world.:)
Thanks for the reply, Concorde expertise is always interesting. I should not have called the F-16 Emergency Power Unit a RAT, it is indeed not. The Concorde RAT was located aft between the engine pods, correct?

What I found interesting is that the AC generators would remain on-line at all; they drop instantaneously at subsonic speeds and the associated N2 rpm. I believe the hydraulics on the 747 will power flight controls down to a pretty low IAS.

Four engine flameout is a very unlikely event, unless one runs into a volcanic cloud.

[Speedbird223]

What an amazing thread, thank you for all the contributors....I've been reading through it for the last week as I pass about the half way point!

I'm just SLF with a huge interest and passion for Concorde and was lucky to bag a LHR-JFK flight in 2002 as an 18th birthday present. One of the contributors here in the left seat as it happens...At that time it was before the retirement announcement and I just assumed for my next NYC trip I'd be able to get onboard...:(

I grew up in North Hampshire and went to school in West Berkshire. My school was on a hill just west of Reading and our morning break would coincide with the BA001. I could sit outside the library that faced eastwards and watch the familiar shape materialize as it came from the Woodley NDB and went right overhead enroute to the Compton VOR. It never got old and caused much amusement when the Heathrow chaplain came to do a sermon one Sunday and was interrupted by the aircraft :D

Home was under the path of the inbound BA002/BA004 and would always listen for the distinctive sound and head to the garden...and if I happened to be in the area of Heathrow within 30mins or so of a Concorde arrival or departure my father would always suggest stopping by for a look. One of my very earliest memories was sitting high on the white fence by Avis on the North Perimeter Road and watching one land, this would have been late 1980s....

We had a Concorde captain in the neighbouring village that my parents were friendly with. In 1996 he took my Christopher Orlebar book to NYC for a roundtrip getting it signed by the crew in both directions and then gave me all the Jeppesens, flight paperwork and a whole host of passenger "items" that I treasured, and still do. That really sowed the seed for 12yr old me to *really* find a way to get onboard...(and those 250 tier points and 14,000 BA miles were the first entry on my Executive Club account as I couldn't join until I was 18! All downhill from there!)

Anyways, this Concorde captain was by all accounts a bit of a legend so I'm sure those of you insiders knew him. I recall one Sunday afternoon, this would have been late 1990s, I looked out the living room window and saw a BA Concorde at low level, banked streaking across the sky maybe a mile away, a quite incredible sight. It turned out that this local Captain was doing one of the round the bay charters and got ATC permission to do a little tour of North Hampshire. A couple of acquaintances from the village played tennis every Sunday at this specific time and had complained about aircraft noise to him. Well, what better way to piss them off than to do a low buzz of their tennis club... :D A year or so later he moved a little further south and opened up the village fete in similar fashion. He retired from BA after the 2000 grounding and the last I heard he was flying a large maroon business jet...that business jet being one of the Qatar Amiri 747SPs...

A question, finally! I now live fairly close to JFK and the 31L Canarsie departure is obviously extremely well known and one I've taken countless times in the "blunties". Given the noise abatement situation what happened if the weather didn't play ball? Were there other departure options? I've seen photos of arrivals on 13L, the Canarsie arrival and my own BA001 arrived on 4L. I assume therefore that arrivals were a lot less liberally governed,,,

Thanks in advance for your replies and I look forward to reading the other 1000 posts I haven't got around to!

[Bellerophon]

Speedbird223

…the 31L Canarsie departure is obviously extremely well known … Given the noise abatement situation what happened if the weather didn't play ball? … Were there other departure options? …

If the runway in use at JFK was not suitable for our departure, we would request a different runway, which JFK ATC were extremely helpful at providing, even though this caused some disruption to their landing/take-off pattern. For our part, we had to accept this request could entail a delay to our departure whilst waiting for a suitable gap in their traffic flow.

Remember that we had two take-off calculations to consider. Firstly, could Concorde get airborne from that runway under the prevailing conditions? Secondly - and this was usually the limiting factor at JFK - could the aircraft then stay with the noise limits at that take-off weight and under those ambient conditions of wind and temperature? If the answer to either question was no, then we needed another runway.

An example might be when JFK was using 04R for landing and 04L for departure. We might have been able to lift the weight off 04L, but would have been way over our noise limit, so we would request 22R for departure.


… I assume therefore that arrivals were a lot less liberally governed …

Did you mean a lot less strictly governed? If so, the answer is yes.

Concorde would use whatever landing runway was in use at JFK without problem, save requiring a bit more of a gap between herself and the preceding landing aircraft (due to her higher approach speeds maintained to much closer to touchdown) which ATC at JFK were well aware of and which they managed very professionally.

Even so, on the Canarsie approach, it was instructive to see just how quickly Concorde could close the spacing between herself and a preceding lightly loaded and therefore much slower B757.

31R was our preferred runway due to its proximity to the BA terminal, the Canarsie approach onto 13L was good fun and a frequent approach. 04R was also used and was an Autoland runway with Cat3A limits down to 15R / 700 ft RVR, useful in bad weather. Concorde had landing limits on all JFK runways, but, at least in my experience, the others were rarely, if ever, used.

I'm glad you enjoyed your flight on Concorde, it all seems so long ago now – probably because it was!

Best Regards

Bellerophon

[Speedbird223]

Amazing, thank you for all the details!


An example might be when JFK was using 04R for landing and 04L for departure. We might have been able to lift the weight off 04L, but would have been way over our noise limit, so we would request 22R for departure.

Wow, a great show for those in line for the 04L departure if you guys were using 22R!


31R was our preferred runway due to its proximity to the BA terminal, the Canarsie approach onto 13L was good fun and a frequent approach. 04R was also used and was an Autoland runway with Cat3A limits down to 15R / 700 ft RVR, useful in bad weather. Concorde had landing limits on all JFK runways, but, at least in my experience, the others were rarely, if ever, used.

By the 31R approach was right by my first home in the NYC area....alas some 10yrs after a Concorde last ever flew it, sadly. My father took the subsonic BA001 shortly after I moved to NYC and I would leave my place when I saw it come over and he'd be through baggage claim by the time I got to T7 :O


I'm glad you enjoyed your flight on Concorde, it all seems so long ago now – probably because it was!


20yrs ago on Monday...:sad:

[ConcordeKin]

Greetings to all, I thought there might those in this thread who would be interested to know that my Grandfather, Alan Radford, who many will know from the Filton and Fairford Concorde design and development days, is still with us and continues to talk so fondly of both Concorde (His Miss Moses Lake) and of all who he worked alongside during that wonderful time. I'd be delighted to pass on contact details if anyone wished to get in touch - he recently loft his wife Peggy (another former BAC employee who was fiercely proud of Concorde and all who made her happen) so I thought it might be nice to see if there are any old faces who we might re-connect.
Thank you to you all for keeping this wonderful thread going for all these years, and for keeping the memory of such a proud time in both our nation's and my own family history alive.
Kindest regards, Tim Radford, grandson of Alan.

[NineEighteen]

Gatwick Airport's History webpage (https://www.gatwickairport.com/business-community/about-gatwick/company-information/our-history/) states that in 1985 "Concorde starts flying commercial flights from Gatwick". Does anyone know any details on this please? Does it mean that the occasional charter left from LGW or was there ever a scheduled service from there? I know it was a diversion airport but presumably that was already the case from when Concorde started operating from LHR?

Many thanks
0918

[DaveReidUK]

Gatwick Airport's History webpage (https://www.gatwickairport.com/business-community/about-gatwick/company-information/our-history/) states that in 1985 "Concorde starts flying commercial flights from Gatwick". Does anyone know any details on this please? Does it mean that the occasional charter left from LGW or was there ever a scheduled service from there? I know it was a diversion airport but presumably that was already the case from when Concorde started operating from LHR?

I'd be surprised if you need more than one hand to count the number of visits to LGW by Concorde over the years (though that does include a visit by an Air France example).

Methinks Gatwick are being a tad disingenuous on their website.

[megan]

My guess would be charter, they were made from a number of UK cities.

https://www.youtube.com/watch?v=312VCTZBBsA

[BigBoreFour]

I'm curious how the shorter legs worked, such as the Washington to Miami (also Dallas at one point?) flight. Did it go supersonic on a 'shorter' flight? Was there a minimum leg distance needed for the Concorde to fly supersonic? And was there an 'optimum' altitude when it was only subsonic? Could it fly comfortably (fuel efficient) at Mach One point something as opposed to 2.0 where I thought it was probably designed to operate?

[pattern_is_full]

There are folks here who can correct me, but in the meantime, what I think I know is....

The DC-Dallas route, entirely over populated land, could not be flown at supersonic speeds (regulations, noise pollution, sonic booms), but Concorde could do it in high-subsonic cruise at around Mach 0.95, somewhat faster than the norm for regular subsonic transports.

I believe the DC-MIA route was flown mostly supersonically, by climbing subsonically at Mach 0.95 straight down the Potomac to the Atlantic at Norfolk, Va., and then, 20+ miles offshore, turning SW towards Miami and making the supersonic acceleration-climb out over the water. Remained offshore (dodging the coastal bulge of the Outer Banks) until about 250nm from Miami. where the descent/deceleration phase would slow it to subsonic speed before getting too close to the shoreline.

Once at ~28,000 feet at Mach .95 - and over the water - it only took a few moments, after turning on the reheat/afterburners, to punch through Mach 1, and maybe 20 minutes (depending on weight) to reach 51000 feet* and Mach 2.02 (air termperature permitting.) And maybe 20 minutes for the deceleration/descent to Mach 0.95 at ~34000 feet.

(*I believe the afterburners were switched off at Mach 1.7 - usually about 42000 feet? - at which point the dry thrust of the engines and fancy shockwave-pressurized nacelle design could maintain the IAS and (reduced rate) climb (and increase the Mach) all by themselves.)

Across the Pond, short "experience flights" from both Paris and London were made from time to time - get out over the Atlantic, light up the afterburners, and tool around at supersonic speeds for some part of an hour before returning to base.

I'm pretty sure subsonic flight was never really efficient at any speed. Concorde was dependent on Mach 1.7 or so (and high altitudes) to maintain the efficiency of nacelle thrust modulated by supersonic intake shockwaves, without very thirsty afterburners. I think that over the Atlantic, losing just one engine (25% of thrust) was enough to make it instantly a fuel emergency situation - you were going to come down into thicker air and fuel burn would skyrocket.

[India Four Two]

Remember that we had two take-off calculations to consider. Firstly, could Concorde get airborne from that runway under the prevailing conditions? Secondly - and this was usually the limiting factor at JFK - could the aircraft then stay with the noise limits at that take-off weight and under those ambient conditions of wind and temperature?

Bellerophon, Could you expand on the second point?

Was it an issue of not reaching a sufficient altitude at the noise monitoring locations?

[Jhieminga]

I suspect that it was both a specific altitude and a specific, reduced, thrust level. Atmospheric conditions also influence engine performance and may have led to a higher needed thrust level for the same altitude, or a lower altitude at the reduced thrust level, or both.

[BigBoreFour]

There are folks here who can correct me, but in the meantime, what I think I know is....
.


Oh interesting stuff. Thank you so much.

[megan]

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/969x856/ab240_37b1c5fe33e12a4f406d1a1e2852e8303edc43bc.png

[BigBoreFour]

Whoa. Nice.
Optimum altitude subsonic at MTOW is FL250 in the Concorde. Who would've thought? :ooh:

[EXWOK]

PATTERN-IS-FULL...

A pretty accurate summary, I'd say; nice work!

One correction I'd make:

losing just one engine (25% of thrust) was enough to make it instantly a fuel emergency situation

Is over-egging the pudding somewhat. There was a significant penalty on 3 engines, but it was hardly a 'fuel emergency'. In my experience it was more of a fuel irritation.

My current work aircraft also suffers a significant range penalty with an engine out, but that hardly matters because we will be landing at the nearest suitable airport. Concorde had an even bigger range penalty with two engines out (although we always had fuel to reach an airfield in this situation) but, again, with two engines out it still had far more range flexibility than the 777...:)

[EXWOK]

BIG BORE FOUR -

Remember we were never at MTOW for long in this machine! Initial subsonic cruise ex-LHR was 280-300. In the case of engine failure enroute, it usually ended up in the mid-30's (with its subsonic 4 engined contemporaries).

The process explained in the extract from the OM is worth thinking about...you fly Mach, but the IAS still plays a dominant role on drag as you climb. Most unlike conventional types.

[dixi188]

Someone I used to know,(TO), was a F/O on a Concorde that had a double engine failure mid Atlantic. One engine surged and coughed an inlet door out of the front and it went down the adjacent engine, The vibration was very high and both engines were shut down. The Mayday call to Shanwick was that they may not make Shannon. The reply was that they would alert the coastguard.
IIRC they restarted the engine with the lowest vibration and made it to Shannon.
I saw some photos of the engine that ate the door and the compressor was a mess.

[BigBoreFour]

BIG BORE FOUR -

Remember we were never at MTOW for long in this machine! Initial subsonic cruise ex-LHR was 280-300. In the case of engine failure enroute, it usually ended up in the mid-30's (with its subsonic 4 engined contemporaries).

The process explained in the extract from the OM is worth thinking about...you fly Mach, but the IAS still plays a dominant role on drag as you climb. Most unlike conventional types.

Makes perfect sense (not easy for my small brain)

Thank you. Appreciate it.

[Check Airman]

https://www.airliners.net/photo/British-Airways/Aerospatiale-British-Aerospace-Concorde-102/7172541

Not much to add, apart from picture taken from a unique angle.

Was a link to the FCOM / AFM ever published in this thread? I bet it’d make some interesting reading.

Thanks to those in the know, who’ve contributed to perhaps the most interesting thread on this forum.

[megan]

CA, manuals can be found here, you may have to sign up to access, no fees involved though. There's enough info there to build one. ;)

https://ww2aircraft.net/forum/threads/british-airways-concorde-supersonic-jet-historical-manuals-afm-amm-wdm-srm-ipc.58385/

[Check Airman]

CA, manuals can be found here, you may have to sign up to access, no fees involved though. There's enough info there to build one. ;)

https://ww2aircraft.net/forum/threads/british-airways-concorde-supersonic-jet-historical-manuals-afm-amm-wdm-srm-ipc.58385/


Awesome resource. Thanks a bunch!

[atakacs]

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/929x758/f2r16rpxiaeiogd_c8d4c329457e0a38de6485247feef2cb4960dfac.jpg
Lego Concorde

I want one !

(apparently EUR 195 from Sept 23 - no ordering link found so far...)

[tdracer]

Since we're on the subject of Concorde, I was watching an "Air Disasters' episode last weekend that touched on the Paris Concorde crash.

It got me thinking - what was the final straw that led to the crash? Was a very heavy Concorde unable to maintain altitude with two engines out? Or did the raging fire do critical flight control damage? Combination there of?

[MechEngr]

Since we're on the subject of Concorde, I was watching an "Air Disasters' episode last weekend that touched on the Paris Concorde crash.

It got me thinking - what was the final straw that led to the crash? Was a very heavy Concorde unable to maintain altitude with two engines out? Or did the raging fire do critical flight control damage? Combination there of?

Too many factors cascading, but the ignition of leaking fuel led to major changes, including the crew shutting down an engine due to fire warning and the melting of considerable portions of the wing. Per the accident report a large contributor was a defective landing gear that, with one tire gone, swiveled and forced the plane off the runway where one engine ate a light. There was also a suggestion that additional drag from the misaligned gear slowed the takeoff which would otherwise have left the runway before contacting the metal strip. There were also overweight, tailwind, and leaving the ground below the calculated minimum airspeed.

Final Destination and Dead Like Me both offered more likely scenarios than the stack up of factors required for the Concorde crash.

[atakacs]

There have been ample discussion about it, including here. I think one can safely say that the "final straw" was the rupture and ignition of tank 5 after V1. Their fate was sealed after that.

[hans brinker]

None of the reports suggested that the crew made errors in handling the plane after they elected to continue the takeoff after the first warnings.
None of the reports suggest that handling the situation different after they decided to continue would have changed the outcome.
So the only possible difference in the outcome could have been from two earlier points.
They elected to continue the take off after the bells went off, after V1 complying with SOP.
They elected to start the TO with 8kts tailwind, and questionable M/B numbers.

If they had rejected after V1 there is a chance more people would have survived, but it would have been the wrong decision as far as operating procedures, based on the information the pilots had.
If they had delayed the T/O, in all probability the same thing could have happened, and if it hadn't because they didn't hit the piece of metal it would not have prevented the crash for the right reasons.

That 25 year old airplane had less time in the air than the crew had on average, and the entire fleet had only around 300.000 hours in 25 years with 14 airframes. From inception till 2013 the 737 fleet flew over 250 million hours, and 1 crash per week over 40 years would have been equivalent in safety. The concord was an anomaly from the start.

[Commander Taco]

If memory serves, best L/D speed was somewhere around 315 knots. Never mind the other issues at play, but with two failed engines it would have been impossible to have achieved that speed.

[BigBoreFour]

If it didn’t crash, would any airline(s) still fly it today? Or would the economics have become too much for it to continue?

[tdracer]

Perhaps I wasn't completely clear in my question - I'm not questioning the crew's actions in any way. They knew they were in deep trouble and were looking to set the aircraft down again at another airport but were unable to maintain sufficient altitude and crash.
My question is why couldn't they maintain altitude - not enough thrust or fire related flight control damage (or some combination thereof).

[atakacs]

My question is why couldn't they maintain altitude - not enough thrust or fire related flight control damage (or some combination thereof).
A mix, with the fire eating into the right wing.
Of course shutting down a working engine didn't help but the eventual outcome was sealed anyway.

[MechEngr]

Too slow - they got into the drag bucket and couldn't leave. AoA is high, so drag is high. Getting out requires more thrust, but they lost one and shut down the other on the fire warning. Even leaving the ground they started behind - a little too heavy and too much tailwind. If they drop the nose to get a better drag situation they lose altitude and crash. If they don't the plane just mushes along without enough thrust to get out of the bucket. Had there been no fire they might have lost enough fuel to climb out, but with the fire they weren't able to wait long enough.

[fill_ot]

This may be a bit of a long shot.
I am trying to identify the function of two printed circuit boards from an Olympus 593 Engine Engine Control Unit (ECU). I worked on Concorde and its ECUs at Filton for many years in the 1970s and 80s.
When Concorde retired in 2003 I requested from British Airways and was given 2 ECU PCBs as a souvenir.
There were of course 8 ECUs on each aircraft, 2 per engine. Each ECU had about 20 different PCBs. I have sometimes wondered just what the function was of my 2 PCBs. Maybe someone knows or has the relevant ECU Overhaul Manual. I have already asked various organisations for help - Ultra Electronics the manufacturers of the ECUs, British Airways, Rolls-Royce Heritage Trust and some museums. I've had some helpful replies but no actual answers.
Marked on the PCBs ae their drawing numbers: 46546-629-0 and 46456-602-0.
I have tried to attach some photos but there seems to be some forum setting that's preventing this!
Thanks

[howiehowie93]

Just re-read the whole thread from the beginning - still as fascinating as the first time I came across it :-)

[stilton]

Just re-read the whole thread from the beginning - still as fascinating as the first time I came across it :-)


All I asked was a question about not having an APU, what a delight this thread has been

[Jhieminga]

This may be a bit of a long shot.
I am trying to identify the function of two printed circuit boards from an Olympus 593 Engine Engine Control Unit (ECU). I worked on Concorde and its ECUs at Filton for many years in the 1970s and 80s.
When Concorde retired in 2003 I requested from British Airways and was given 2 ECU PCBs as a souvenir.
There were of course 8 ECUs on each aircraft, 2 per engine. Each ECU had about 20 different PCBs. I have sometimes wondered just what the function was of my 2 PCBs. Maybe someone knows or has the relevant ECU Overhaul Manual. I have already asked various organisations for help - Ultra Electronics the manufacturers of the ECUs, British Airways, Rolls-Royce Heritage Trust and some museums. I've had some helpful replies but no actual answers.
Marked on the PCBs ae their drawing numbers: 46546-629-0 and 46456-602-0.
I have tried to attach some photos but there seems to be some forum setting that's preventing this!
Thanks
That's an interesting challenge, but one that is very hard to solve. Have you tried asking on the Concordesst.com website and their forum? As you say, you would need to find a very specific overhaul manual and I don't know if a manual like that is even around, other than in a heritage collection somewhere.

[Winemaker]

Holy Toledo, went back to the start of this thread and was amazed. It will take some time to read through this, but thank you all for the contributions. Amazing. Thanks Stilton for your original question.

[megan]

My question is why couldn't they maintain altitude
They never managed to attain the V2 of 220kt td, highest speed reached 211kt, not helped by having to avoid the holding 747 which they flew over missing the 747 by a matter of feet according to the cockpit crew. Last airspeed recorded was 136kt immediately prior to the crash.

For the weight they were at the zero rate of climb speeds were,

Gear Retracted - 0ne engine out 193kt - Two engines out 262kt
Gear Extended (the condition they were in) - One engine out 205kt - Two engines out >300kt

They had two engines effectively out.

[atakacs]

Gear Retracted - 0ne engine out 193kt - Two engines out 262kt
Gear Extended (the condition they were in) - One engine out 205kt - Two engines out >300kt


So all things being equal two engines out would "need" 80kt to maintain VZRC (give or take). Wow...
Amazing that they managed to (barely) fly at 140 kt.

[megan]

Amazing that they managed to (barely) fly at 140 ktThey weren't flying, the last data point showing 136kt airspeed they had a fraction over 108° left bank and had turned from the take off heading of 267° to 193°, the aircraft then impacted the ground practically flat with little forward speed on a heading of 120°.So all things being equal two engines out would "need" 80kt to maintain VZRC (give or take)They would have needed something in excess of 300kt to maintain level flight.

[Lawrence2725]

Rolls Royce will hold a copy of the CMM for the ECU. Airbus probably do as well.

Whether either of them would release it to you, even now, I am doubtful.

[Lawrence2725]

This may be a bit of a long shot.
I am trying to identify the function of two printed circuit boards from an Olympus 593 Engine Engine Control Unit (ECU). I worked on Concorde and its ECUs at Filton for many years in the 1970s and 80s.
When Concorde retired in 2003 I requested from British Airways and was given 2 ECU PCBs as a souvenir.
There were of course 8 ECUs on each aircraft, 2 per engine. Each ECU had about 20 different PCBs. I have sometimes wondered just what the function was of my 2 PCBs. Maybe someone knows or has the relevant ECU Overhaul Manual. I have already asked various organisations for help - Ultra Electronics the manufacturers of the ECUs, British Airways, Rolls-Royce Heritage Trust and some museums. I've had some helpful replies but no actual answers.
Marked on the PCBs ae their drawing numbers: 46546-629-0 and 46456-602-0.
I have tried to attach some photos but there seems to be some forum setting that's preventing this!
Thanks

Rolls Royce will hold a copy of the CMM for the ECU. Airbus probably do as well.

Whether either of them would release it to you, even now, I am doubtful.

[howiehowie93]

Rolls Royce will hold a copy of the CMM for the ECU. Airbus probably do as well.

Whether either of them would release it to you, even now, I am doubtful.

Trying to find a picture but didnt the black boxes have the Lucas Aerospace green flash logo on them ? I remember seeing that on the Tornado / RB199 MECU & DECU Black Boxes and being amazed that Lucas made both. Shouldn't have been so surprised though

[tdracer]

Stumbled on an interesting program on the TV last night - "Concorde - The Untold Story"
Two-part program (one hour each - closer to 45 minutes after commercials) but shown back-to-back. A good history of the three country 'race' to build a commercial SST, with what ultimately happened with the Boeing 2707 and Tupolev 144 (including how fitting the "Concordski" nickname was given the level of Soviet espionage that went on to steal Concorde technology so they could make the thing work).
A bit simplistic in some of the explanations of the technology and such, but understandable given that most people who watch won't have Aerospace Engineering degrees :p
Produced by MTV, at least on this side of the pond it's being shown on The Smithsonian Channel.
Hopefully it'll be made available on other sources for those who don't get Smithsonian.

[DogTailRed2]

In regards the Concorde crash, assuming the pilots knew what the dire situation with the aircraft and fire was, would they have been able to have put the aircraft down?
Was there any clear ground in front of them?
I've often wondered if the aircraft was bellied along the ground whether it would have had a chance? All speculation based on hindsight of course.

[netstruggler]

Stumbled on an interesting program on the TV last night - "Concorde - The Untold Story"

Two-part program (one hour each - closer to 45 minutes after commercials) but shown back-to-back. A good history of the three country 'race' to build a commercial SST, with what ultimately happened with the Boeing 2707 and Tupolev 144 (including how fitting the "Concordski" nickname was given the level of Soviet espionage that went on to steal Concorde technology so they could make the thing work).

A bit simplistic in some of the explanations of the technology and such, but understandable given that most people who watch won't have Aerospace Engineering degrees. Produced by MTV, at least on this side of the pond it's being shown on The Smithsonian Channel. Hopefully it'll be made available on other sources for those who don't get Smithsonian.

Being shown on Channel 4 in the UK at the moment. Episode 2 is this Saturday.

(Well I assume it's the same programme - it certainly sounds the same.)

[tdracer]

In regards the Concorde crash, assuming the pilots knew what the dire situation with the aircraft and fire was, would they have been able to have put the aircraft down?
Was there any clear ground in front of them?
I've often wondered if the aircraft was bellied along the ground whether it would have had a chance? All speculation based on hindsight of course.
A problem with Concorde was that its stall speed was quite high - well above 200 knots. An emergency landing in a field (gear down) is not apt to end well going that fast with a full load of fuel and an aircraft already on fire (granted, perhaps better than what ultimately happened, but a 'damned if you do - damned if you don't' choice at best). They reportedly tried to raise the gear (which would have helped reduce drag greatly) but the damage already done prevented that.
In 20-20 hindsight, I suspect they would have been better off to not shutdown the engine with the fire warning (#2?) and use whatever thrust they could still get from it to try to make another airfield, but something that would be next to impossible to realize real-time. The rapidly spready fire damage may well have made it a moot point anyway.

[stilton]

Not sure if this question has been answered in this thread yet, was Concorde approved for three engine ferry flights ?

[EXWOK]

Not sure if this question has been answered in this thread yet, was Concorde approved for three engine ferry flights ?
IIRC, it was...but I can't remember it being done while I was on the fleet.

[dixi188]

Back when the Concorde was in development, a guy I used to work with was in West Africa with G-AXDN doing hot weather trials. The aircraft had an engine issue and an engine had to be changed.
This aircraft had production standard engines. No spare was available so an earlier variant was installed and some of the accessories were left off and the air bleeds blanked, as they would not fit this installation.
The aircraft was ferried back to Fairford with 4 engines but only 3 sets of systems.

[stilton]

Back when the Concorde was in development, a guy I used to work with was in West Africa with G-AXDN doing hot weather trials. The aircraft had an engine issue and an engine had to be changed.
This aircraft had production standard engines. No spare was available so an earlier variant was installed and some of the accessories were left off and the air bleeds blanked, as they would not fit this installation.
The aircraft was ferried back to Fairford with 4 engines but only 3 sets of systems.


Fascinating, a quite unique solution and 3 engine ferry protocol

[tdracer]

Concorde engine sells on ebay:
Concorde Engine Finally Sells On eBay, Afterburner Included (msn.com) (https://www.msn.com/en-us/autos/enthusiasts/concorde-engine-finally-sells-on-ebay-afterburner-included/ar-AA1lH3mq?ocid=msedgntp&pc=HCTS&cvid=45b641d7a2354f1389da0f225f4a3e08&ei=13)

The Concorde (https://jalopnik.com/this-is-what-the-sonic-boom-from-the-concorde-sounded-l-1832597786) turbojet engine spent years listed on eBay (https://www.ebay.co.uk/itm/116001533010?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=3X5IDjxbSpS&sssrc=4429486&ssuid=guVqnn7EQqq&var=&widget_ver=artemis&media=COPY) before it finally sold for £565,000 (or $714,500). This particular Rolls-Royce (https://jalopnik.com/even-rolls-royce-isn-t-bothered-about-supersonic-travel-1849534062) Olympus turbojet spent its service life fitted to a British Airways Concorde. It’s been 20 years since the supersonic airliner’s final flight, but the Concorde is still remembered fondly (https://jalopnik.com/here-s-how-you-move-a-concorde-from-the-deck-of-an-airc-1850725096) as emblematic of a more ambitious era (https://jalopnik.com/new-supersonic-passenger-plane-future-concorde-1849748957) of commercial aviation.

​​​​​​​

[artee]

Concorde engine sells on ebay:
Concorde Engine Finally Sells On eBay, Afterburner Included (msn.com) (https://www.msn.com/en-us/autos/enthusiasts/concorde-engine-finally-sells-on-ebay-afterburner-included/ar-AA1lH3mq?ocid=msedgntp&pc=HCTS&cvid=45b641d7a2354f1389da0f225f4a3e08&ei=13)



​​​​​​​
Bugger! I missed it.

[TURIN]

A question has come up regarding air brakes on Concorde. It started off with this image...
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/592x436/_20240520_170347_aafe861e16975434597a4e04bbd7cbff6a7f1ff5.jp g
Is that an air brake on one of the prototype aircraft?

[Alpine Flyer]

A question has come up regarding air brakes on Concorde. It started off with this image...

Is that an air brake on one of the prototype aircraft?

Probably a braking chute housing/door. Looks a bit like the one around 2:50 into this video. (https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.facebook.com/AIRLINESECRETS/videos/concorde-001-2-march-1969-he-landed-gently-and-used-the-parachute-to-brake-the-p/452168600705542/&ved=2ahUKEwjJx4qY1J6GAxX2YPEDHbuMBsQQwqsBegQIERAF&usg=AOvVaw1f0P0o9DG0AORCxOnc4xYQ) (Turn down the volume.)

https://assets.isu.pub/document-structure/211107215116-3499aa28b383b8dc722388c7e69678ec/v1/d06df7fb7dc3041684cb7b1f41d5c017.jpeg

[TURIN]

That's what I thought but the chute door seems to open upwards not sideways.

[luoto]

This may be a dumb question (!) but why have the parachute at the back slowing the aircraft down. I mean I know why, but "why"? Is it something to do with test flights and not knowing how well the brakes may perform, or does it somehow contribute to other testing data received.

[megan]

luoto, don't know specifically re Concorde but aircraft under test often have a parachute in case testing in the low speed regime turns to worms, given the nature of delta platforms in low speed flight my guess is the chute was to give the aircraft a nose down moment, a delta wing doesn't stall in the traditional sense.

https://r.search.yahoo.com/_ylt=AwrjebCWtE5mbLMQCbo36At.;_ylu=Y29sbwNncTEEcG9zAzEEdnRpZ AMEc2VjA3Ny/RV=2/RE=1716462871/RO=10/RU=https%3a%2f%2fairborne-sys.com%2fwp-content%2fuploads%2f2016%2f10%2fspin_stall_parachute_recover y_systems_ss_17543100.pdf/RK=2/RS=6O5.PUZ9uOTSyuMKpFtn_fcB77o-

https://www.youtube.com/watch?v=rGluIqLtRSo