Agreed Nick, this has been such a superbly informative thread. Let's not spoil it. (Good news about the Brooklands sim' videos though).

Dude :O

Oshkosh 1994
 

One very long winded piece of personal nostalgia, I hope you’ll all bear with me:
In 1994 a Concorde (can’t remember the registration) flew out to Oshkosh Wisconsin (OKS) for the bi-annual EAA fly in. The aircraft was scheduled to fly from LHR to YYZ via MAN, where it would pick up 100 charter passengers in Manchester for a five day holiday in Toronto. The aircraft would then fly empty from YYZ to Oshkosh for the five day air show, before returning to YYZ to bring home the passengers to MAN. At Manchester another 100 charter passengers were then carried subsonically back to London. While the aircraft was in Canada and the US, it would be looked after by two American BA engineers who were based at JFK. At least that was the plan, but the best laid plans of mice and men….
The aircraft was catered for the MAN-YYZ sector in London, and flew up to Manchester with just the three flight deck crew but no cabin crew (no passengers, so no need). At Manchester there would be a change of crew, plus a full complement of cabin crew for the on-going sector to Toronto (Plus of course 100 passengers). This is where things started to go rather wrong; when the aircraft landed at Manchester one of the bar trolleys , which had not been correctly secured by the catering twits, broke loose and flew through the open flight deck door (pre-911 the door was usually always open anyway). The trolley hit the back of the E/O’s chair and subsequently damaged a couple of fuel transfer switches on his panel. You can imagine what the three crew thought; they were just landing the aircraft when a high speed trolley decides to join them on the flight deck in an extremely noisy and spectacular entrance. (The language went something like ‘what the ***** was that!!). The two switches, although damaged still operated normally, and so the crew taking the aircraft to YYZ decided to accept the aircraft with just a couple of ADDs for the broken but still funtional switches.
So the aircraft, plus FOUR flight crew (an extra crew member, a captain in this case, was taken along to do the PR over the PA, as was usual on charter operations). Everything seemed to be going smoothly, or so it seemed, when there was a warning that the number 2 secondary nozzle ‘buckets’ had travelled towards reverse (the blue transit light was flashing) although the indicator on the E/O’s panel still apparently showed the nozzle at the correct zero degree position for supersonic flight. As always (at least with BA!!) the correct drill was applied, and a precautionary engine shut down was carried out. This now meant that the aircraft would have to decelerate to subsonic speed, and as a consequence would not be able to reach YYZ safely, and so a technical diversion to YQX (Gander NFLD) was carried out, the aircraft and passengers having an unscheduled night stop there. (This eating into the first night of the passengers stay in Toronto). The two JFK engineers who had been waiting patiently in YYZ had to quickly jump on a Lear Jet to Gander, and on arrival there got on the phone to London, that’s where I come in. The nozzle itself had not run away at all, it was merely an indication problem, but we all decided that the best course of action for now was to have the secondary nozzle physically locked at the intermediate position of 10 degrees as a performance ADD. This would still allow supersonic operation (although from YQX to YYZ there would be precious little of that), but with a fuel penalty of at least 1.5 tonnes per supersonic sector, plus of course no reverser operation on that engine. I still had concerns about the aircraft being able to return on the YYZ to MAN sector with a bucket locked out, but at least the passengers could now start their delayed holiday in Toronto, and the aircraft could happily fly on to the wilds of Wisconsin.
Every day during the EAA fly in, Concorde would do some charter flying, and the JFK guys would be on the phone every day letting us know how things were going. It seemed now that the secondary nozzle defect had ‘cleared up’ on it’s own, and the guys had decided to reinstate the secondary nozzle air motor to its normal position. We were all very apprehensive about this, and started to think about what the possible cause of the original defect was and maybe see about provisioning a spare part if necessary. On the final day of the EAA event, the aircraft was taxying out when another warning light for the number 2 bucket illuminated. The aircraft returned to the ramp where the JFK engineers again locked out the air motor at 10 degrees before leaving on its charter. We had discussions over the phone as to what the symptoms were, and it looked like the culprit was the switch pack that lived underneath the bucket assembly. I spent several hours getting spare parts shipped via MAINTROL to YYZ, the idea being that the bits could be flown out to Toronto on the next scheduled subsonic flight. It was generally agreed that the aircraft could not fly the YYZ-MAN sector with a bucket locked out due to performance considerations and so a fix was essential. (The spare parts included by the way the two switches that had been broken on the first landing into Manchester).
I was at the airport until quite late that night making sure that from the information that we’d been given the correct course of action had been chosen, and I only got about four hours of sleep before I had to head back to Heathrow the following morning. I had a feeling that I’d be possibly be asked to fly out to Toronto (the JFK guys requested this also) , so I took my passport, a change of clothes etc. with me just in case. Sure enough before I knew it I was on the 10:30 BA001 Concorde to JFK, a Limo taking me immediately across town from JFK to La Guardia. From there I was put on an Air Canada A320 to Toronto, arriving there at about 14:30 local time. (19:30 ‘my’ time, I was knackered already). When I got to our Concorde the JFK guys told me that the bits I’d sent the previous evening were stuck in Canadian Customs, and it took another hour or so to get our hands on them. We proceeded to get her ‘fixed up’ between us, and by about 20:00 local we were serviceable. I phoned the crew at the hotel, telling them of the good news, and was told that as soon as I’d checked in and had a shower, we were all going out to dinner (my body clock was now at 02:00). Now the flight crew and cabin crew are well [FONT='Calibri','sans-serif']acclimatised, having been in Canada and the States for FIVE days, but I am now a total wreck, (more so than usual), and when I finally got to bed it was around midnight Toronto time (05:00 London time). Now no one (including me) expected to see me for the 07:30 pick up from the hotel in the morning, but somehow I miraculously made it. Because one passenger had gone home to Manchester early, there was a seat available for me on the aircraft (I’d expected to have had to fly home subsonic, due to the only other available seat being the flip down flight deck aisle seat; to have sat there for over four hours would have been less than pleasant). So all I now wanted to do was get on the aircraft, collapse into my seat and SLEEP, but I had to wait until all passengers had boarded before I was allocated my seat; 26B right at the back of the aircraft. So here I go, getting onto the aircraft in what I thought was total anonymity when as I get on board the purser in the fwd. galley announces that ‘this is Mr Dude who flew out yesterday from London especially to make sure we don’t have to divert again’. I just wanted to die as I have to walk the gauntlet of 99 passengers all clapping and cheering all the way to the back of the aircraft, my face as red as a beetroot, and when I finally get to my seat I find that I am sat next to this really lovely elderly lady who wanted a blow by blow account of what had gone on, as well as a running commentary on the flight itself. (Of course alll I wanted to do was sleep, I was totally exhausted, but this old lady was absolutely delightful). About an hour after take-off one of the stewardesses informs me that the crew want me up front urgently, so here I go again walking the length of the cabin up to the flight deck. As I go in the guys said ‘I thought you’d fixed the *** ing thing.’ ‘I did’ replies yours truly, and I took a look at the flight deck panels and everything is normal. The four guys are killing themselves laughing, ‘fooled you’ , the flight engineer chirps up with (everything was fine, the joke was on me yet again). I once more stagger back to my seat, and for the rest of the flight I keep my lady passenger friend entertained with Concorde stories all the way back to Manchester. At Manchester there is another few hours wait before we FINALLY fly back down to Heathrow, with yet another load of passengers and I finally go home to bed. In all of my Concorde years I’d had many exhausting episodes, but Toronto ’94 really took the biscuit.

Dude :O

Well, if the price of a Concorde flight was merely sleep deprivation, then we'd all have been propping our eyelids open with matchsticks!

I presume that the fuel penalty for a locked secondary nozzle was due to the reduced expansion of exhaust gas without the maximum divergent shape?

Good point. Only trying to put out fundamental differencies, which I think are important from a technical and historical point of view, which was relevant for this topic.

gordonroxburgh; It sounds as though you may have had an involvement in the Concorde simulators with knowledge such as that...perhaps you could help with a question I have?

How did the simulators manage with the windsheild/nose tilt feature? I assume the relevant lever was present in the cockpit...did moving it cause anything to happen in the simulator?

ASI

Ah, YYZ...

My one flight on Concorde was YYZ to LHR, as part of a birthday treat shared with my parents. They say that of all the things they decided to do and damn the cost, the Concorde trip was the one experience of their lives that far exceeded expectations. (My father is a retired vicar and a PPL, and there's never been a spare penny in the family - when they say that, they mean it.)

I can only agree. Flight of my life. It won't get better. I remember hearing over the PA that this particular leg involved the longest time that Concorde spent supersonic. It could get going before the ocean as there was nobody on the land below to complain about the noise. Is that true?

Anyway: what I remember about YYZ was that the runway was truly abysmal. I am one of those SLF who thoroughly enjoys things going a bit unusual in flight: turbulence, wonky weather, anything with a bit of g in an unexpected direction, all bonuses in the normally mundane business of flinging oneself about the sky in tubes. I trust the engineering, I trust the people, I know how exceptional aviation is as a human endeavour where safety is wired in at every level.

But that runway. Not only did it feel like rattling along a dirt track in a car with dodgy suspension, it went on for so long. Compared to the elegance of every subsequent second aloft, the time in motion before rotation was so unsettling that even my unflappability was flapping. That feeling was heightened by the transparent relief in the voice making the post-takeoff PA: "Now we've left Toronto behind, we can get on with business as usual" - and it's a decent enough city, so I don't think that was any commentary on the pleasures of the place outside the airport.

Was it really that bad, flying out? Or am I being too dramatic?

I have nothing to add about the rest of the flight that others haven't already said, except I'm sad my own son won't have the opportunity.

R

(Oh, one PS: I did hang out for a while with someone who was best friends with one of the Concorde cabin crew. I do hope that some of the stories she told me will one day see the light of day, although they might have to wait for a number of Serious Names -- and cabin crew -- to pass over to the other side, where even the draconian reach of the UK's libel laws have no power. She is a PR and I a journalist, but the British sense of fair play and mischief requests and requires that this teaser is all there is to be said on the matter. That and the law of libel.)

Can't remember a lot of my 20,000 hrs. as pilot but will never forget paxing on Concorde 20 years ago between Washington and Heathrow. Spent the last 2 hours of the flight standing in the flight deck behind the jumpseat ( occupied by an ATCO on famil.). Captain allowed me to remain in situ for the landing, I'm grateful to have experienced an era in aviation where we could share our work environment with colleagues and passengers alike.

Feathers McGraw
The 10 degree lockout position was a bit of a compromise, to allow the aircraft to operate throughout the normal operating envelope with a secondary nozzle (bucket) at a less than ideal position. See the diagrams below, one showing the bucket control schedule and the other the bucket positions at both take off and supersonic flight: If the buckets are too wide at low Mach numbers then the high velocity exhaust will try and 'drag' the low pressure/low velocity air in the exhaust annulus along with it; this results in a huge reduction in thrust and is termed 'base drag'. That is the whole idea of having the eyelids at the top and bottom of the bucket assembly; to admit free ambient air into this void and mitigate the effects of base drag (and reduce the noise mayhem a little too). If however the buckets are too narrow at high speed/high altitude then we really get a problem; The high pressure/high velocity exhause gas immediately expands against the VERY low presuure ambient air and flares outwards at an accute angle, again losing us serious quantities of thrust The wide open bucket angle gives us this wonderful cushion of secondary intake airflow. (travelling over the top of the rear ramp, through the engine bay and into the nozzle annulus. The eflux can now gently expand against this airflow as it exits the secondary nozzle, taking up the shape of the divergent secion of nozzle.
Now if we are locked at the 10 degree position we are at a position that will give us significant but tolerable losses throughout the flight envelope.

http://i1237.photobucket.com/albums/...ND-FIG-121.jpg

http://i1237.photobucket.com/albums/...de/Nozzle2.jpg

Gordon should have more details, but on at least one (and probably both) of the sims there was a nifty arrangement at the front, of flat "masks" that limited the view in the same way as the real thing, and that moved up and down controlled by the nose/visor lever.

CJ

(PS: I've seen it on at least one of them, but have forgotten which...)

The last time that I 'flew' the Concorde simulator at Filton was about 15 years ago. The visuals were the superb Rediffusion (as it was called then) 'Wide' displays and I seem to remember that there was a sort of mechanical mask over the screens that looked somewhat like the visor, and this came up and down with the visor control lever. The very first time that I went on the sim' was in 1980, when the visuals comprised of a TV screen at the central parts of the windsheilds. (The DV and side windows I seem to remember were blanked out). The 'picture' was provided by a TV camera tracking over a huge vertical landscape model, populated with runways, houses, cows, fields etc. (If one of the models became 'unglued' it would appear to shoot horizontally across the screen).:)
I think that these Rediffusion 'Wide' vusuals were installed in the late 80's/early 90's and were as advanced as any simulator visuals anywhere. I believe that the original 'landscape model' was donated to a university.

Dude :O

Self Loading Freight
The aircraft could be very unforgiving regarding rough runways, and was a major design headache in the early days. There was particular concern regarding about runway conditions in JFK, and extensive modifications were carried out to the shock absorbers to help reduce the effects. However simplified solutions WERE sought by the manufacturers, one of these being to try and reduce the damping of the main gear by removing a meausured amount of oil from the cylinders and chage the 'tuning' of the leg, but this proved to be, er... less than successful: :{
In early 1977, aircraft 210, G-BOAE was doing it's pre-delivery test flying out of Filton (Fairford was now closed as a permanent test base, but day flying was carried out from there, the aircraft returning to Filton at night). and it was decided to try this rechnique on 210. A little French guy from the landing gear manufacturer Messier spent all day, travelling from the other side of France to Filton in the west of England, and arrived at the plant at around 23:30. He spent several hours that night, draining off his carefully calculated amount of fluid from each of the main landing gears, and returned to France a happy little bunny the following morning. BIG MISTAKE !! :ugh:
When OAE did it's test flying the following day, everything seemed to be going well, but on the final landing of the at Fairford.. THUMP!!! The barrels of the shock absorbers bottomed, sending a sizable shock through the entire airframe. No structural damage was done, but several systems went off line, and I particularly remember one of the incidence vane heaters being knackered by the force of the vane thumping against the stops. Our poor little Messier rep' arrives home LATE that night, only to receive a message telling him to go straight back to Filton. The poor guy was a wreck, but like a true trooper headed straight back to the UK, and inserted his carefully measured amount of oil back into the main landing gears of G-BOAE. (Always thought that this would have made a great comedy sketch) :D

Dude :O

Thanks for those nozzle diagrams Dude, they are very useful to visualise what's happening.

I remember reading Stanley Hookers book "Not Much of an Engineer" (I know the feeling :ugh:), in which he explains how at Mach 2 the Olympus is only providing about 8% of the total thrust but then goes on to say that at the low speed end of the take-off run it was 100% of the thrust so his designers were not let off the hook. That falls to 82% in subsonic cruise.

Ah, found the figures for Mach 2, the inlet provides 63% of the total thrust, exhaust nozzles 29%. That certainly explains why the thinning and re-profiling of the inlet lip was so important to improving the fuel burn, and hence range.

Something that I'm wondering about.

The reheat thrust increase is only about 6,000 lb per engine, so why is the fuel flow increase so large for a less than 20% thrust increase? Proportionally I think I remember it being mentioned that the fuel flow about doubles.

Feathers, these are the joys of afterburning; a totally gas guzzling way of extracting some more thrust from an engine. With Concorde, at 15 degrees TAT, you got a 78% increase in take off fuel flow for, as you say, about a 6000lb increase in thrust. Normaly adding an afterburning/reheat system is a fairly complex and heavy affair; you need both the system itself plus a variable exhaust nozzle. Because Concorde already required the primary nozzle for N1 control, the addition of reheat was at least a relatively simple and lightweight afair. The original Olympus 593-22R engine was really a little lacking in terms of dry thrust, and the addition of the reheat system was deemed essential. Concorde only had a single reheat spray ring and flame-holder, military systems often have several, with a corresponding increase in thrust growth as well as a hyper increase in fuel burn.
Further development plans for the Olypus 593 included a large increase in dry thrust; the reheat being retained only for transonic acceleration. It is such a pity that it was not to be.

Dude :O

I heard that the combined nozzle and reverser was a unique piece of aviation development.
The story I heard when I was an apprentice at Hurn was that, compared to the prototype multi finger nozzle and separate reverser, the production nozzle was:-
1. More efficient.
2. Lighter.
3. Simpler.
4. Cheaper to make and maintain.

I doubt there have been many developments that meet all 4 items.
Usually the first three can be met, but at great cost.

P.S. I did my bit of Concorde design in the FSDO by re-drawing a cabin bulkhead to reduce weight.

From what I know (mostly quoting fromTrubshaw's book), things would have been even better than that.

Reheat on the existing aircraft supplied about 25% extra "wet" thrust.

The Olympus 593 "B" engine was going to have about 25% more "dry" thrust, so the reheat could most likely have been deleted altogether.
This was achieved mostly by increasing the diameter of the LP compressor, hence increasing the mass flow, and adding a second LP turbine stage.

The "B" engine was destined for the "B" Concorde which, thanks to several aerodynamic improvements, would have had increased performance and more range, allowing direct flights from Frankfurt and Rome to New York.

Concorde #17 would have been the "prototype" for the "B" model... sadly, as M2dude says, it was not to be.

CJ

Long time admirer of the marvel that is Concorde - but no aviation expert at all, just appreciate true genius and beauty! One question I've got is about the Concorde "B". Given it was never built, was there ever a plan to retro-fit some of the modifications back into one of the existing airframes? Specifically I'm thinking the engine - which on its own should have given a large boost to range (or savings on fuel!).

From what I've learned on this thread and elsewhere, when GOAG was put into storage for sometime, its something that I guess maybe could have occured then? Or am I simply being far to dumb and it would have been much to big an undertaking for far too little benefit?

DavvaP,
No I would not say you're "far too dumb".... yours are valid questions.

You're right, "it would have been too big an undertaking for too little benefit".

Don't forget the history... it was the governments that financed development, manufacture and (initially) operations.
By the time the last few aircraft came off the production line they were already unsaleable 'white tails'.

Now, the "B" modifications to the wing were quite major (droop leading edge, extended wingtip, other tweaks) and to reftrofit them would have been difficult and costly.

The "B" engine had a larger frontal diameter, so the engine nacelles would have had to be redesigned and re-manufactured.

All those modifications would then have to have been revalidated and recertified, then applied to each of the aircraft, plus the manufacture of new spares, etc.

Still saddled with five unsold aircraft at the time, there was no way the governments were going to finance such a major upgrade.

As to G-BOAG...
Applying some or all of the modifications to G-BOAG only would have been pure folly, because it would have meant a large separate spares store, revalidation and recertification, separate documentation, etc. etc. all for one aircraft.

Finally, the story doesn't tell if Rolls Royce ever got as far as running a prototype "B" type engine on a test bed. Certainly, none were ever manufactured.

CJ

Dixi188
Actually Rolls Royce always told me that the (new) Type 28 secondary nozzle was a bit of a dissapointment. Aerodynamically it was a far better interface with the wing from a drag point of view than the original design, but fell short of it's design promise in terms of performance. The design responsibility for the secondary nozzle system awarded to the French engine manufacturer SNECMA. They in turn farmed the whole manufacturing side off to STRESSKIN inc., a division of General Motors, and the air motor and electronic control unit were designed and built by Garret Airesearch in the US also.
The original secondary nozzle was 'freely floating, with no actuation; the thrust revereser itself was a pair of cascade doors, driven by an air motor. Tertary air doors opened at low speeds to admit ambient air into the nozzle anulus, instead of the eyelids of the later 'buckets'.
If you look at the diagram below you can see what a complicated animal the prototype powerplant was. The intake dump door (alternative name for spill door) was hinged both at the front AND the rear; either hinge mechanisms automatically releasing at specific Mach numbers. It was the mechanical nightmare that the diagram suggesrs.

Dude :O

http://i1237.photobucket.com/albums/.../Prototype.jpg

DavvaP
There was one small part of the 'B' model that did find it's way into the production aircraft by way of a retro-fit in the late '70's.: The leading edge of the dorsal fin was re-profiled, taking out the original 'dog leg' and the flying control surfaces were slightly extended. The whole exercise was one of supersonic drag reduction, although I never saw the actual gains quantified. (It was due to the extensions of the elevons and rudders that water ingress caused failures in later years. I just hope the fuel, if any, we saved was worth the trouble :{).
As far as ChristiaanJ's point about the Olympus; the only plans I ever saw were for the Olympus 593 Mk 622, which gave a thrust increase of around 4,000 lbs static thrust but retained reheat. I know there were definate plans for a larger diameter engine (not just the LPC) that would have naturally required a larger intake. As far as the intake irself went, believe it or not, the plan was to remove the rear ramp altogether.
The 'B' would have been a hell of an aeroplane; but the 'A' was still absolutely amazing in any case.

Dude :O

Looking at the prototype's nozzle arrangements in comparison with that used in the production aircraft, does anyone know how much the secondary nozzle silencing effect actually gained?

I wonder how close to the noise limits the prototypes would have been at JFK....

Feathers McGraw
In scale model test the silencers produced quite promising results. However on the aircraft itself they proved to be worse than useless, the only real difference they made was that they resulted in a reduction of thrust. (But because the fly over altitudes would consequently be far lower, they did a good job in INCREASING the noise nuiscance).
As far as your point about the prototype engines; they were way down on thrust anyway, (even without the 'help' of the silencers), produced more black smoke than a 1930's coal fired power station, and would not have enabled Trans-Atlantic revenue load crossings. (And what with the noise and the smoke, I guess our environmental friends down there would REALLY have had something to complain about :\).

Dude :O

Another aspect of Concorde.
 

All this talk of a 'B' model is both interesting and a bit frustrating. It must be all the more so for our main contributors - M2Dude and ChristiaanJ - and I guess the crews themselves, that the 'B' never saw the light of day. The discussion about the engines/ intakes/ nozzles is taking place about another flight level above my head :confused: but still riveting stuff nonetheless. :)

May I ask a question about another aspect of Concorde life? In my own job as a CT/MRI scanner engineer, I was for many years a 'Registered Radiation Worker' and indeed I still wear the equivalent of a film badge. My annual dose though was and is tiny, virtually background. However, I remember seeing a chart from the Radiological Protection Board some years ago, that seemed to suggest Concorde Crews had the highest radiation dose in any industry routine operations. :eek:

Was this true and did Concorde crews wear a film badge as I did? I understand that 'ordinary' flight crews get quite a radiation dose, but nothing like the 60,000ft doses the lady permitted?

Roger.

Good question Roger, the short answer to that is 'no they didn't. Radiation (in millirems) was logged after each flight, the data coming from the onboard radiation meter developed at the Harwell nuclear research centre in Essex. (A counter clocked the overall dose and an analog dial indication showed the dose rate). Although the dose rates in Concorde were higher than in a subsonic aircraft, because the sector times were over twice as short everything kind of cancelled out. The indicator itself
I do remember that when the Three Mile Island Pa accident happened in 1979, some spikes were seen on the radiation meter on the IAD-LHR sector, and occasionally throughout the years we got minor spikes when overflying the Atomic Weapons establishment at Burghfield in Berkshire. (All we did in that case was to telephone the duty officer at Burghfield who would say 'thank you' and log the event).

As far as the 'B' model goes, well yes it is a little frustrating to know that the full potential of this wonderful design was never fully realised, but as I said before, 'the 'A' model itself was still totally amazing.

Dude :O

Out of pure curiosity... any chance of finding that chart still?
Did it refer to dose rate or accumulated dose?
As M2dude already said, the dose rate was roughly twice that for a subsonic crew, but because of the shorter flight duration, the accumulated dose was no different from the large majority of crews in general.

CJ

Brooklands Concorde sim
 

A small add-on to the earlier posts about the simulators.

Brooklands sim video

Brief video, taken yesterday (Oct 9, 2010) of a landing on LHR 27L, with the new three-projector visual display.

Also a couple of photosets of the new projectors being installed on the top of the 'cab' and the three overlapping images being aligned. As the photographer (friend of mine) noted , he had to leave before the final tweaks... the borders (overlaps) are now virtually invisible.

Concorde Photos Gallery - 21st September 2010

Concorde Photos Gallery - 25th September 2010

CJ

I wonder if my piggy bank will ever stretch to a sim session down at Brooklands? I can but dream.....

Thanks for the engine nozzle comments Dude, it certainly seems that the secondary nozzles got bitten by the law of unintended consequences. All engineers are familiar with that one!

Wow... quite impressive !

Centre of Gravity
 

I have been thinking (always dangerous!) about CofG movement. I understand the concept that the CofG must be positioned for the particular phase of flight. What I have been wondering is on shorter charter flights was there a mininium ammount of fuel that had to be loaded just to always have enough fuel for CofG movement ie was it possible to be in a position where trip fuel, fuel to an alternate etc was less than the fuel required for CofG movement after take off?
Regards
Nick

radiation
 

As an ATCO we had very specific instructions about how to deal with a Concord(e) radiation overdose. We were told that it would have to make an emergency descent and how to integrate it with other traffic as it descended and what the priorities were.

Has any Concord crew ever had to do this?

I dealt extensively with the London sector (S23) most likely to be involved in this procedure but fortunately it never happened to me.

Dave:ok:

Dave,
I was looking to confirm my own memory on the matter and found this quote, from a personal friend, on another aviation forum.Knowing him, and knowing where he worked, I would trust that statement implicitly!
The "blips" on the radiation meter over certain "hot spots", in the UK, the US and the Middle East, are well-known bits of Concorde folklore.

CJ

You got me thinking too... equally dangerous, since it's not my 'subject' :=
First simplistic answer...
If the charter flight did not involve a supersonic flight, then of course it wouldn't have been a problem, you would just have loaded enough fuel into that vast collection of tanks to maintain a 'subsonic' CG.

So, second answer, which is what I think you're thinking of: the case of a short charter with a supersonic "loop" over the Bay of Biscay, as both BA and AF did quite a number of times, with less fuel.
This is where I start thinking... and I admit I may be wrong.

Take a normal transatlantic flight, with all the tanks full at take-off.
By the time you started the supersonic acceleration (so with still a lot of fuel forward, only the fuel used in take-off and subsonic climb no longer there) the 10-odd tons in tank 11 (the trim tank in the tail) were already enough to shift the CG backwards to what was needed when supersonic.

So, with a smaller fuel load, getting the CG backwards to the right position would already be easier, even without fully filling tank 11. And of course no problem returning to the 'subsonic' CG.... plenty of space in the already partly empty tanks..

So I think the answer to your question is "no".

CJ

Nick Thomas


... on shorter charter flights was there a mininium ammount of fuel that had to be loaded just to always have enough fuel for CofG movement...

Yes, 35,000 kgs, at take-off, for a short supersonic flight. This would allow sufficient fuel to be transferred rearwards in order to achieve a CG approaching 59%.

If the flight was to remain subsonic, the fuel figure dropped to 25,000 kgs, as the required CG for subsonic cruise was 55% not 59%.

Both these figures were at take-off, so the estimated taxy fuel had to be added to these figures in order to arrive at the minimum fuel figure required to be loaded.


...was it possible to be in a position where trip fuel, fuel to an alternate etc was less than the fuel required for CofG movement after take off?...

No, at least it should not have been!

However, a situation was sometimes reached in flight, generally only towards the end of the planned supercruise portion of a LHR-BGI sector, where, with the aircraft at M2.00 and FL600, it was no longer possible to maintain a CG of 59%, as the "ballast" fuel, which had been transferred aft into tank 11, was now required forward again as "fuel" fuel, to top up other tanks which had reached their minimum permitted levels.

In this case, once the forward transfer of fuel had begun, the CG would also be slowly moving FWD, and one would be compelled to commence the decel and descent earlier than desired, something EXWOK touched on here much earlier in this thread.

Best Regards

Bellerophon

Radiation.
 

I'll certainly look out for one Christiaan, but the hospital where I remember seeing it has been closed for seven years and I noticed the developers had moved in the other day! :sad:

Out of pure, vulgar interest in my field, the hospital was Atkinson Morley's Hospital in Wimbledon. This hospital is where Stirling Moss did much of his rehabilitation after his near fatal crash and huge numbers of patients benefited from pioneering neurosurgery . Most importantly from my point of view, AMH where the original prototype CT (Computed Tomography) scanner was installed and all the early clinical work - done by Doctor James Ambrose - was done. This machine is the one that can be seen in the Welcome Medical Gallery in the Science Museum and I used to work on it! :eek:

Roger.

Thanks Bellerophon, I was hoping somebody would come up with the right answer!

And sorry, Nick, indeed I was wrong!

CJ

arearadar

...As an ATCO we had very specific instructions about how to deal with a Concord(e) radiation overdose. We were told that it would have to make an emergency descent and how to integrate it with other traffic as it descended and what the priorities were...

The display, on the radiation meter, was divided into three, coloured, sections.
If the "Red" level on the radiation meter was reached, this would also trigger the central Master Warning System to display a Red MWS RADN light, and also to sound the MWS gong.


The procedure to be followed was simply an Abnormal Procedure rather than an Emergency Drill.
So, even with an instantaneous radiation level in excess of 50 millrems/hour indicating, this was not thought to justify the risk of an emergency, uncleared, descent through flights levels possibly occupied by underflying aircraft, and, in fact, if the warning remained RED below 47,000 ft, the warning was deemed suspect, and the descent could be stopped.

It was of some concern that the sort of radiation levels that would trigger the radiation alarm might very well also be playing havoc with radio communications, particularly HF communications. The possibility of being unable to communicate with ATC was one that had to be considered, and so it was only under these circumstances, with both a Red MWS RADN warning and an ATC communications failure, that the Captain was permitted, at his discretion, to perform an uncleared descent.

It's comforting to know that you were prepared to deal with us if required, but unlikely, I would have thought, that your services would have been called upon in practice.


...Has any Concord crew ever had to do this?...

I not aware of any such descent incident, although obviously I can’t state definitely that one never occurred.

It wasn't unknown for the radiation alarm to go off, I’ve had it, briefly, twice, both times at lowish level over the sea on departure from JFK. On one occasion there was nothing at all to indicate what might have caused it, on the other, we had just overflown a rather large waste barge being towed somewhere!


Best Regards

Bellerophon

Thanks CJ and Bellerophon for your answers.

When Concorde was retired what happened to the pilots and FEs who were too young to retire? Did they have a choice of what to fly next? Did the newer glass cockpits offer less of a challenge? I have always presumed that the FEs would be nearer retirement as by that time all other BA planes would be a two pilot flight deck.

Regards
Nick

I've read in this thread that fuel was transferred at various times to change COG due to changes in the centre of lift(?). The one I had not considered was the change in lift that occurred in ground effect due to the trailing edge of the wing being so much closer to the ground than the leading edge (is that right?)

I believe I heard that fuel was transferred during landing to partially counter this effect.

So my question is: Would it have been possible to land the Concorde with near zero fuel?

And a supplementary (:8) Would it change the handling characteristics, and did this affect fuel calculations at all?

In answer to [Steve]'s question
 

I believe a "Near Zero Fuel" landing was successful....by a certain Chief Pilot :E

There were several appropriate cartoons at the time.

http://www.pprune.org/where-they-now...n-walpole.html

I think that episode has been well documented, and I for one I have a very funny story about it all. However, here is not the place to lambast anyone, especially as they might be lurking within our numbers :=. If the gentleman himself would like to contribute, well....that would be a different matter! As I recall, he was always polite and curteous to the cabin crews, and I've had many a drink with him when he has been a very interesting and funny raconteur. My story will be told one day, but I will seek permission from BW first!

I am just about to throw my weary body onto a sun kissed Caribbean beach, and I intend to drink copious quantities of rum punch, so talk amongst yourselves until I return.

Warm regards,

LL x