Posts by user "Shaggy Sheep Driver" [Posts: 67 Total up-votes: 0 Page: 3 of 4]¶

Here's something I've wondered about; I understand that the proposed 'B' model of Concorde was to have leading edge slats. How does that fit with vortex lift?

Vortex lift relies on controlled flow breakaway at the LE, while slats delay such breakaway.

Many thanks CliveL!

There's a question (OK, 2) I wonder if those on here can answer.

1) I undertsnd that skin temperature is calculated from OAT and Mach number. Why wasn't it simply measured directly by sensors on the nose skin?

2) The Air Data Computer calculates Mach (so skin temp is a calculation on a calculation!). Presumably one parameter it uses is IAS. What else is used in the calculation of Mach?

Thanks Ex Wok but now I'm even more confused!

1) So there is a direct temp reading, from the TAT probe. But where is TAT probe? Is it in the needle nose probe that also measures pitot/static for the intake computers? And how many TAT sensors are there (failure of a single one if that's all there is would not be good)?

2) Mach comes from dynamic pressure (pitots), from static ports, and from temp. But what temp? OAT perhaps?

Thanks Clive but I'm still going around in circles. Those sensors measure OAT do they not? They are spaced out from the (hot) skin to do that, presumably.

Can you confirm just how that tells the crew the skin temp? Are there no direct-reading temp sensors on or under the nose skin or in the probe?

Here's the cockpit temp gauge I photgraphed today:



So the TAT probe provides TAT (obviously) which effectively is skin temp (as evidenced by the TMO legend of 127C just below the TAT window?).

(TAT being static air temp plus the temp due adiabatic heating).

Indeed, but as a pilot you look after the nose temp... and the rest of the aeroplane will be just fine.

So TAT is skin temp at the probes, which are rearward of the hottest skin according to that diagram. Was there a 'compensation' built into the TAT readout to account for the relatively rearward position of the TAT probes?

And.. How was static temp readout derived?

Sorry to keep asking, but I really want to understand this!

Thanks.

OK, so the skin temperature at the stagnation point will be equal to TAT. This can be taken as the hottest part of the aircraft (behind it, the skin temperature will be less than the TAT).

The temperature shown in the top window of the flight deck gauge is TAT, with the legend 'TMO 128C' beneath it. So the aircraft was flown with reference to TAT, and provided TAT was no greater than 128C then the skin rearward of the stagnation point would be <128C?

Thanks EXWOK!

Indeed. Typed in a hurry. Didn't even check my own photo of the temp gauge which clearly shows 'TMO 127C'.

Did Roy Chadwick really contribute to delta wing design? I though Kutchmann and his team did most of the ground work developing the basic delta (as fitted to Chadwick's Vulcan) into the thin narrow delta with vortex lift.

It was indeed! I have spoken to many Concorde pilots and most confirm the unexpected phenomenal climb rate at light weight in base training. They were briefed to level off at 1,500 feet but on their very first flights on the real aeroplane (it'd been all sim prior to that) some went way beyond. I'm told the record was 4,000 feet! One told me "I used to get it turning - that cooled things down!".

My one and only Concorde flight (G-BOAD) was Manchester to Paris via the Bay for 60,000 feet and M2. I was lucky enough to be in the jump seat for the entire flight so didn't suffer 'small window' limitations! My most memorable view was about 50,000' over South Wales looking through the windscreens. The whole of SW UK was visible on that glorious August day in 1999, with the scattered occasional cu looking as if they were on the ground! The bright yellow of the beaches around the coasts of Wales and England stand out in my memory, as well. As do other aeroplanes flying west-east very far below us!

At 60,000' the sky was amazing - dark blue fading to very dark overhead. And of course the curvature of the Earth clearly visible.

Despite flying interesting aeroplanes for well over 30 years myself, that flight in AD is a magnificent highlight I will never forget!

For those who want to sit in the P1 seat and try out those lovely cabin seats, come and see our G-BOAC at Manchester!

I've noticed static ports under the fuselage at the back, between the engines. Are these just additional ports for the aircraft's general static pressure measurement system, or do they have a specific function?

Thanks Clive, I did wonder why the static ports near the doors used those plates.

I'll look for a photo. If I can't find one, I'll take one next time I'm with G-BOAC (next week).

There are others as well, as in the pictures below (but these are not the ones I'm referring to):

https://www.google.co.uk/search?q=co...%3B3912%3B2599

Thanks Bellerophon. Here's a picture:

Many thanks Bellerophon and others. It seems these ports are concerned with cabin pressurisation.

My understanding (may be wrong) is that Julian Amery (a British politician) had the 'interlocking' clause written into the Anglo-French contract because the Brits thought the French might want to pull out. Harold Wilson did want to pull ou, but couldn't because of that clause. Were the French ever prevented from pulling out by the clause?

If both parties had wanted to pull out, presumably they could have re-negotiated the contract to allow that.

Wasn't Concorde extremely fuel-efficient at M2 and 60,000', but the horrendous fuel consumption getting up there more than offset that?

Smokey engines were a feature of the pre-production machines. The production Concordes with a change in combustion chamber design had a much cleaner exhaust.

Turin has it on why Concorde didn't sell - massive increases in oil prices and perhaps more importantly, the advent of the wide body airliner in 1969 that changed the airlines' focus from speed to per-seat operating cost reduction, where it remains today.

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

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.