Posts about: "Conversion Course" [Posts: 13 Page: 1 of 1]¶

Question for engineering types:

I remember being told in my conversion course that the motors driving the secondary nozzles (buckets) were the fastest rotating devices on the aircraft. Is it true? Have you got a number for it? Was it really more than the gyro in the stby horizon?

If anyone has seen the video of AF landing at BZZ after the first post-grounding test flight, you may have noticed that you can hear the buckets translating to reverse even over the noise of the blustery wind and four Olympus 593's at idle.

Whilst on the Concorde conversion course at Bristol, occasionally crews would have the privilege of meeting some of the original design engineers and draughtsmen who had worked on the Concorde project.

They were always fascinating to listen to, and provided an intriguing insight into a design world, now long gone, inhabited by engineers and draughtsmen armed with slide rules, drawing boards and blueprints. As ever, with people of real ability, they tended to talk more about their few failures rather than their many successes, often in the most amusing and self deprecating terms. It is their stories which really ought to be preserved, although it is not for us, even now, to relate some of their tales, told to us with a chuckle, but in strict confidence!

Suffice to say that the senior fire officer who misread litres-per-minute as gallons-per-minute during an Olympus water ingestion test probably would not want any further publicity, likewise the apprentice who didn\x92t defrost the chicken before firing it into an engine running at full power in the bird ingestion test. My favourite was the supersonic hailstone story, fired as part of a hailstone ingestion test, but with uncertain results, the final resting place of said hailstone still being slightly obscure to this day. If anyone in the greater Bristol area got hit by a particularly hard snowball in the early sixties, the Filton test engineers are very sorry, and would like to apologise!

However, it is often the little insights into the past that amuse one the most and stick in one\x92s mind. During one such conversation, with a couple of thermodynamicists, I ventured to ask how they had settled on the (rather difficult to memorise) various temperature limits associated with Concorde.

For instance, why a nose temperature limit of +127\xb0C, why not +130\xb0C, much easier for a pilot to remember?

\x93Isn\x92t it obvious?\x94 one replied politely, genuinely puzzled by my question.

\x93Computer generation\x94 replied his colleague to him, pointing his pipe stem at me.

\x93Ah yes\x94 said the first, \x93that would be it\x94.

They then went on to explain, in ever such a kindly manner, that, in thermodynamics, apparently the square, and the square root, of the absolute temperature of a material are terms used in many equations. Being armed mostly only with slide rules (and as they were in the vicinity of 120\xb0C to 130\xb0C as a limit anyway) it had been decided to make life easy and settle on +127\xb0C as the limit, a temperature for which they could easily calculate the square and square root in their heads.

Noticing my bewilderment at the thought that anyone might be able to calculate the square or the square root of 127 in their heads, they proceeded to explain it to me still further, very slowly; in the manner that one would speak to an aged and rather deaf great aunt!
These are the people with the amusing stories to tell!

Best Regards

Bellerophon

Extended leave doesn't happen so much in this very commercial world.......

To start with we stayed current in the sim. After a month or so it was obvious that this was a long term event and the company would find something for us to do in return for our salary.

A minor complication was that we knew we were going to need fewer pilots as the decision had already been made to reduce the charter programme, so we weren't all coming back. There were no other FE positions in BA so that was a further issue.

At least one Captain retired during the grounding, which was a sad way to finish. Others who had been on the fleet for less than 5 years went back to their previous fleet (old rating only needing revalidation). Others had the opportunity to bid for positions elsewhere in the normal annual conversion process; some used the tactical skills required to fly Concorde to great effect, and evaded capture for a long time....

For SFOs one was allowed to bid in the normal process or be directed to another fleet. The rules didn't allow direction to the Left Seat, so most bid off to various command positions - the most senior (who would have the seniority to return) and the most junior (who were pretty much doomed to leave the fleet as it shrank). Those in the middle (2 of us!)stuck it out and were directed to the RHS of other fleets, but at least with the knowledge that if the bird flew again we were guaranteed to get back (Quite a gamble at this stage).

I'm ashamed to say I can't remember where all the SFEs went, but they were spread in a diaspora through various departments.

Most unfortunate of all crews were those on the very last Concorde conversion course (No. 30, I think) who finished after the grounding and never got to fly the thing. All that work..................

Interesting & nostalgic thread. Nice to see this monumental aviation achievement still generates such passion...

In case it's of interest (and suitable health warning as the memory fades)...

The heat did evaporate water vapour in the airframe - reducing corrosion. I remember when the 5 BA aircraft were returned to service, after the post-accident mods, their weight and balance certificates were prepared and found to be out by (IIRC) more than a tonne. This represented water in the airframe present after a year on the ground, and was gone again after a couple hours of supercruise on return to service. Back to the weighbridge for new W&B Certificates....

Vortex lift caused buffet which felt very similar to a conventional wing's stall/low speed buffet. At landing weights (I hate the trend of using the term "mass": weight is a force, mass is not!) you felt the buffet start as you reduced speed (CAS: Vc) to about 250kts. It was handy as a reminder that you should select visor down / nose to five below 250kts (the recommendation was as you slowed through 270kts, but latterly we were in the habit of holding at 250kts nose/visor up - I think TCAS was quoted as a backup to the more limited visibility in that config). At takeoff weights, the buffet went at more like 270kts accelerating. So I'm pretty sure there was no vortex lift at AoA > 7 degrees (250kts at LW).

Recommended subsonic cruise at MTOW was F260 / M0.95 which was equal to Vmo of 400kts (CAS). It was best cruise because Vc=400kts was also min drag at MTOW. F280 meant a slightly more draggy speed of 384kts, but some preferred it because when cleared to climb & accelerate supersonic (the official expression was "go for it") it gave you a bit of slack against Vmo when eng put the reheats in. But we tended to ignore the overspeed warning anyway: it was supposed to go really really fast...

We never flew with visor down and nose up unless it was bust - that config was only used during pushback (except one captain who always thought it looked better visor up....). Visor down max Vc was 325kts/M0.8 so it would limit subsonic cruise, and besides it made a racket like that.

It was a beaut in x-winds - a total lack of yaw-roll couple meant you just straightened the 'plane up with rudder and carried on into the flare as normal. No roll to counteract, and the sideways "lift" created by the rudder deflection on the fin pretty much equalled the x-wind drift. Nice.

Wind limits were Crosswind 30kts (15kts contaminated or autoland), Headwind for autoland 25kts (or manual "reduced noise" approach: that's a technical way we used to reduce the noise footprint down to 800' by flying at 190kts then reducing to a target speed of Vref+7kts at that point). Tailwind 10kts. All these limits were, of course, subject to "on the day" performance limits calculated at the time. I seem to remember there was an over-arching limit of 6000' on r/w length, subject again to "on the day" performance limits. OK, I cheated on this paragraph and dug out FM Vol 2a.

There were loads of other limitations which were, by and large, more "esoteric" than a conventional airliner and which had to be learned for the conversion course. It really made the head hurt, and would have been impossible without a big loverrly picture of the beast on the wall chucking out yellow smoke and making noise. Even a static picture of her seemed to make noise...

No one who flew it could really believe their luck, but one thing for sure is "they don't build them like that any more"...

Ahhhhhhhhhhhhhh..........

EXWOK

Was all initial training accomplished in the sim or did new "to type" pilots do touch-and - goes before flying the line? How long was the conversion course? I imagine it was quite thorough.

GF

Once you know how the rating selections work, enabling the throttles to be left fully forward throughout normal flight, you can draw a line to the Airbus FBW thrust lever arrangement - the detents equating to different ratings.

Mercifully no-one had thought of that when Concorde was being designed; I still think it's a diabolical system.

BTW I was told in the conversion course that during the design phase the idea was mooted to only have one thrust lever for all four engines. This would probably have worked - even non-normal engine shutdown drills didn't require the engine's throttle to be closed, the first thing you did was pull the shutdown handle.

NW1 - amen..........

Clive L - the whole aeroflexing of the 'A' tanks thing was something mentioned during ground school on my conversion course; I may have misunderstood or it may have been less than accurate info.

Mr Vortex - the superstab was always available, though clearly it wasn't a regime one could get into during many phases of flight. As for the 'stalling' alpha - it doesn't have any meaning on a delta. By normal standards Concorde lifted off and landed in what would be called a 'stalled' condition on a conventional aircraft; in Concorde this was 'vortex lift' and was the secret to having an 1100kt speed range on one wing section. (We've talked about this much earlier in the thread).

The limiting factors for max alpha are pitch-down control and drag. IIRC the ability to stop pitching up ended at about 21-22degs alpha (CliveL will know exact numbers I guess!).

Stick shake went off at 16.5degs and stick 'nudger' (badly named - nearly tore my arms out when we tried it on the conversion course) at 19.5 degs, although this could go off sooner under phase advance if the rate of increase was high. (NB - all the above from memory; flt crew with manuals or development men with proper knowledge feel free to correct)

Lastly - the thrust recuperator was explained by M2dude much earlier in the thread, I'll have a look for it. Short answer - clever gizmo on the port(?) fwd outflow valve to recover thrust from outflow air.

CliveL -

Many thanks for the superstab explanation -it makes more sense as a manoeuvre-driven input than as low-speed protection as the conversion course implied.

I'm trying to remember what drove the fixed nose-down elevon input at low CAS/high alpha which I alluded to earlier. Presumably it wasn't superstab but some other element of the autostab system; is NW1, Bellerophon or Brit312 able to help me out here?

Hmm. There was, I think, a raft of high-incidence (alpha) protection fitted.

Digging out the old BAe conversion course notes:

The "Anti-Stall" (SFC) 1&2 sytems offered:

Super Stab: Increased authority of pitch autostab as incidence increased above 13.5 degrees - proportional to pitch rate and incidence angle - and a nose down pitch trim with a Vc (CAS) deceleration with incidence > 13.5

Stick "Wobbler": the "unmistakable warning" - when incidence > 19 and Vc<270kts the control columns took a life of their own and tried to fling you into the forward galley. Served you right.

Some other high incidence stuff was fed from the ADC rather than the SFC, like:

The ">13.5d incidence" feed to the SFC

CAS (Vc) feed to the SFC

Incidence from 16 to 19 degrees (rate dependant) to get the SFC to feed in up to 4 degree nose down pitch command and the sticj wobbler trigger.

Increase of authority of yaw autostab as incidence > 13.5d

Autotrim inhibit > 14.5d incidence

Stick shaker >16.5d incidence

AP/FD disconnect > 17.5d incidence

There was loads of other technical stuff which engineers understood, but we had to learn by writing diagrams which made sense to us enough to pass the written exam. The bottom line was an aeroplane which flew beautifully, but which you had to understand well, and which you could not tease beyond its limits. If you ignored a limit or an SOP then you reached an unpleasant place far quicker than with the blunties - it was a challenge which rewarded as quickly and as deeply as it punished.

EXWOK
Clive, I think we need your help here. I was also told, both while I was at Fairford and during one of my two ground school courses at Filton in the early 80s, that the lateral stiffeners (underneath the wing just inboard of the Rib 12 area) were added to reduce outer wing flexure and in themselves gave us a performance penalty. Can you shed any light Clive?

Best regards
Dude

Dude - that really brings back pain form the past! I remember knowing (just) enough about the flying controls to pass the ARB, but a diagram similar to that one was presented at one "Technical Refresher" day (remember those?) by one of our more chatty training EOs (could have been you?!) together with a coloured plastic overhead projector schematic complete with slidey moving jacks and PFCUs and things and it worked! I completely understood the system right up until the first pint of Brains that night...

Flying in mechanical signalling was a different experience - losing the autostabs was bad enough (and proved how good that system was). A mate on the fleet once described it as like trying to fly around on a supersonic dustbin lid. I think that description was too kind - the thing was barely controllable in that configuration. One of our skippers described an airtest when he was on the JS where the crew were trying a decel in MS: as the phugoids were diverging he thought he was about to lose his life so leant forward to restore things. Sadly the switches had been left in MS, so he had to move the switches up to "Blue" as well as then pressing the reset tits - a procedure which he described as almost impossible due to the ever more extreme manoeuvres. Recovery, fotunately, was instant. Resetting electrical signalling and autostabilisation always felt like slotting into a groove on the Concorde.

For that reason, I believe, flight in mechanical signalling was removed from transonic flight on airtests and altogether from Base Training. The simulator was the only sensible way of trying to fly like that...

And that flying control pre-flight check! Learning it was a conversion course rite of passage: one of the sadder parts of reading this thread was realising I'd forgotten it. Great times, great aircraft, great people. Nostalgia isn't necessarily a thing of the past... see you in March?

During the early years there was some doubt from the CAA that the aircraft could be handled in Mech signalling in the transonic region. Lots of meetings were held, and finally on a test flight the gentleman was invited again and one of the original training Captains flew the aircraft perfectly through the transonic area whilst descending in Mech Signalling. With that said it was a delicate area and control inputs had to be gentle and small so I understand



Yes there was an Ignitor selector labelled LH--Both--RH, however the engines would be started using only one ignitor. This caused a few small but annoying delays as if the selected ignitor failed the start would have to be stopped the starter given a cooling period and then a further engine start using the other ignitor would be attempted, however it did give a running check that both ignitors were working.

This was not very popular with the crews and the ground engineers were persuaded to test the ignitors before presenting the aircraft for service. However due to the engine starting Fuel Pump switching, this resulted with a small fire in the hangar, and so the crews were back to starting on Lh or RH ignitors.

If I remember correctly the RR Conways on the VC-10 also had 2 ignitors per engine with a LH--Both-RH selector.

At one time there was a suggestion that BA adopt the Air France technique where the F/E did this check on the ground pumps prior to engine start, which did not go down very well with the F/E. It was fortunate that some one came up with the suggestion that this would wear the ground pumps out , and so this check stayed as apilot check after the engined were running [Thank God]

If you remember, if something went wrong with the Flying control check the F/E was always busy. This gave him a chance to think up a suitable answer or even better the pilots did the check again and it now worked.

No dude we never came to see you boys for the "Pilots Tech Refresher" as we always had to keep those lectures very simple as otherwise the pilots would go to sleep.

Now I have to admit coming across the hangar to consult with you boys when preparing for a new sequence of F/E "Tech Knowledge Checks". Not that we did not understand it, you understand, but mainly to make sure that we were correct before some clever line F/E informed you of your error. Very embarrising that, and I should know

ZeBedie

...Was pilot selection purely on seniority?...

Fortunately, Yes!

It was (almost) exactly the same process as pilot selection for any other aircraft move in BA.

• There had to be a vacancy on the type.
• You had to be "unfrozen" and free to bid.
• You had to be senior enough to obtain one of the vacancies.
• You had to pass the conversion course.

There were two minor differences to the normal BA process that applied once you had been notified of a successful bid and allocated a course date.

• Before starting the course, if you changed your mind, you could voluntarily withdraw without penalty and remain on your existing fleet.
• If the Chief Pilot on your existing fleet felt there were clearly defined technical reasons why you would be unlikely to complete the Concorde conversion course successfully, you could be denied the course.

Over the years, there were a very small number who were denied a conversion course on technical grounds, one of whom I knew personally.

There were several people who voluntarily withdrew from a course they had been allocated. Often this was after a look-see trip and a chat with crewmembers about the conversion course and life on the fleet. This was not uncommon, and I got my conversion course, at shortish notice, after just such a voluntary withdrawal by a more senior pilot.

Finally, often people are surprised to learn that - for various reasons - most BA pilots never put in a bid for Concorde. The year I got my course, there were around 600 captains in BA senior to me who had declined to bid.