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-   -   A Different Concorde Question (https://www.pprune.org/tech-log/423992-different-concorde-question.html)

Biggles78 13th Aug 2010 04:32

A Different Concorde Question
 
Watched The Rise and Fall of Concorde on TV last night and was surprised by the seemingly violent way the thrust levers were operated. This appeared to be actual footage of the operation so my question is.
Were the thrust levers actually slammed from idle to full power or were they operated in a normal smooth action?

test7875 13th Aug 2010 05:53

Personally I thought that was "acted", I assumed the actors where just sitting in the concorde "exibits" roleplaying, hence no tension on the throttles?

F/O 13th Aug 2010 06:27

That's how they did it. The sequence of the burners to get the afterburner going was automatic. No mocking around. Get the throttles forward.

breadrollaviation 13th Aug 2010 06:59

The Concorde had throttles that were not mechanically linked, but electrically operated. This from the site concordesst.com:

The Aircraft has an electrically controlled throttle system that is used to control the power delivered from the engines. Moving the throttle leavers asks the computer to apply the power to the engines in a correct and controlled manner. Through throttle master controls on the overhead panel, each engine can be either connected to the throttle lever (main) to an alternate controller or not controlled at all.

M2dude 13th Aug 2010 08:53

Agreed, the electronic control system carefully controlled the acceleration rate of the engines, and the idea was to get take-off thrust as quickly as possible. I agree that at first sight it may look dramatic or even violent, but this was pefectly normal routine. (3, 2, 1, NOW!!....CLICK).
The 'off' position was of course NEVER used with the engine running; you had no control of the engine at all in this case, and the fuel and nozzle actuators were locked by a brake.
:)

Biggles78 14th Aug 2010 11:37

Many thanks for the replies though the action really does look 'weird'.

EW73 14th Aug 2010 12:25

I too watched that same show...

I agree that the afterburner operation governed the manner in which the throttles were operated.

My question is why the countdown, why the "3,...2,...1...Clang" with the throttles?

What were they timing down?

Great show, very impressive indeed.

EW73

M2dude 14th Aug 2010 22:34

I guess that the 'countdown' was just a way of focusing the 3 crew members attention for the commencement of a fairly intense few minutes, that required extreme concentration and discipline. (I suppose in hindsight, the event must seem a little melodramatic, for us it was the only way to do it). :)
In actual fact the 'spool up' thing had not so much to do with afterburner operation, more to do with maximising the runway length available by obtaining as much power from the whole engine in as short a period of time as possible. (Being a pure jet, the handling of the engine did not need to be anywhere as delicate as for a fan engine. However, the N1 & N2 acceleration rates were carefully controlled by the control system, in order to stay within their respective surge margins).
The afterburner in actual fact, itself only contributed about a 17% increase in take-off thrust, and was triggered automatically at 81% N1. (Engine #4 was initially a little 'dimmer' on the take- off roll than the other 3 engines, due to it's N1 being limited to 88% below 60 KTS. This limitation was due to low speed airflow stability issues).
There are a few good Concorde shows doing the rounds at the moment, I've been extremely priviliged to have been involved in one or two. I'm Really glad that you enjoyed the show guys. :)

Dude :O

breadrollaviation 14th Aug 2010 23:08

The 3-2-1-Go countdown was so that they knew when to start the timer, as they needed to adhere to certain procedures on departure. Out of London they would cut the AB to reduce the noise level at a certain time from power on.

A very good DVD set to view all of this and more is the ITVV Concorde Doco. 5 Hours worth of Concorde action!

Capn Bloggs 15th Aug 2010 00:46

Just watched a show (dunno which one); what a fantastic machine! http://www.smilies.our-local.co.uk/i...es/worship.gif

M2dude 15th Aug 2010 07:08

Breadrollaviation
You are of course quite correct here, at the NOW part of the countdown, you started the noise abatement timer. Apologies for me missing the obvious :ugh:
(As a matter of interest, the 'classic' noise abatement manoevr was not so much out of LHR, but out of JFK, RWY 31L. This was really an awsome piece of flying; if you have the chance to see this one on TV, you'll see what I mean :)).
Capn Bloggs
So glad you enjoyed the show. I personally think that all aircraft are amazing in their own individual way, but Concorde really WAS something else.

Dude :O

breadrollaviation 15th Aug 2010 12:39

M2Dude - I have only seen it in the ITVV film but it is indeed great flying. It is indeed a great shame that the Concorde was retired a few years ago.

I only ever saw her once, an AF example at YSSY. The thing I remember most about it was the noise, and that most of the airport stopped to watch her depart!

R2112 15th Aug 2010 14:45


(As a matter of interest, the 'classic' noise abatement manoevr was not so much out of LHR, but out of JFK, RWY 31L. This was really an awsome piece of flying; if you have the chance to see this one on TV, you'll see what I mean
Haven't had a chance to see it, what did it involve!?

ChristiaanJ 15th Aug 2010 15:21


Originally Posted by R2112 (Post 5871324)
Haven't had a chance to see it, what did it involve!?

In brief, it involved a very impressive left-hand bank over Jamaica Bay almost as soon as the wheels were up. This allowed to avoid most of the noise-sensitive areas, and incidentally, most of the noise monitors!

CJ

M2dude 15th Aug 2010 19:56

It was a testament to the manoeuvrability of the aircraft and it's power/weight ratio, but still required PRECISE co-ordination between the three crew members. The only beings that hated it of course were the fish in Jamaica bay; it was amazing, taking off in one of the world's noisiest commercial aircraft and yet causing really minimal noise nuisance to the populated areas around JFK.

Dude :O

bingofuel 15th Aug 2010 20:37

If I recall correctly, after Concorde had demonstrated the noise abatement left hand turn for the local noise protestors, their next plea was ' why can all the other airliners not do that?'
It turned out only Concorde could mange it safely!

Instant converts to Concorde!

Pugilistic Animus 15th Aug 2010 21:07

Descansese En Paz

:{:{:{

Nick Thomas 15th Aug 2010 21:25

The ITVV concorde shows a noise abatment takeoff on 31L at JFK. On that occasion not all of 31L was available so the turn had to be made at 100ft agl. A very impressive sight,
Nick

ChristiaanJ 15th Aug 2010 21:34

M2dude, bingofuel,

There's a very good and detailed write-up about that occasion in "Flying Concorde" by Brian Calvert (p.184-185 in my copy).

V1 - rotate - gear up - 100 ft - roll 25 degrees of bank on - and there it is.
And yes, it was one more illustration of the handling qualities of the aircraft... Many of the pilots liked to hand-fly it on occasions where that wasn't really necessary.
And it could be barrel-rolled just dandy.....

CJ

PS
Nick,
100ft AGL was standard for that procedure.

Bellerophon 16th Aug 2010 01:28

R2112

I wonder if a piece I wrote some while ago may possibly be of interest?

JFK, 31L, Kennedy 9 SID, Canarsie transition, Concorde climb

Speedbird 2, cleared take-off 31L.

Call 3-2-1 Now, start your stopwatch, pre-set to countdown from 58 seconds, and push the throttles fully forward until they hit the stops. Four RR Olympus engines spool up and four reheats kick in, together producing 156,000 lbs of thrust, but at a total fuel flow of 83,000 kgs per hour. A touch of left rudder initially to keep straight, as the #4 engine limiter is restricting that engine to 88% until 60 kts, when it will release it to full power.

The F/O calls Airspeed building, V1, and then, at 195 kts, Rotate. Gently rotate the aircraft, and lift-off occurs at around 10° and 215 kts, but keep rotating to 13.5° and then hold that attitude, and let the aircraft accelerate.

Positive Climb is called, you cross-check and ask for the Gear Up.

Passing 50 ft RA, the F/O, having first checked the aircraft attitude, airspeed and rate of climb, calls Turn. Slowly roll on 25° left bank to turn out over Jamaica bay, and as the speed accelerates through 240 kts, pitch up to 19° to maintain 250 kts and keep the left turn going to pass East of CRI. 54 seconds after the start of the take off roll, the F/O starts the noise abatement countdown with 3-2-1 Noise. At the call of Noise the E/O simultaneously cancels the re-heats and rapidly throttles back to noise abatement power, whilst you quickly pitch down again to 12° to maintain 250 kts. It is now a minute from the start of roll and already 1,000 kgs of fuel have been used.

Speedbird 2, contact departure, so long.

Turning through heading 235°M, rapidly re-apply full dry power and pitch up to 17° to maintain 250 kts, but also reduce the left bank to 7.5°, until passing 2,500 ft, when bank angle may be increased to 25°.

Approaching the 253° radial JFK, you again hear 3-2-1 Noise, and the E/O throttles back to noise-abatement power for a second time. Pitch down to 12°, and tip-toe quietly over the Rockaway Beaches, aiming to pass right over the car park by the Marine Parkway bridge, to minimise the noise impact on the residents. Keep the left turn going and intercept the 176° radial outbound from CRI, and when 5 miles DME from CRI, slowly re-apply full climb power. Call for the After Take Off Checklist and raise the aircraft attitude to maintain 250 kts, you are in the USA, within 12 miles of the coast and still below 10,000 ft.

Speedbird 2, present position direct to SHIPP, climb FL230, no speed control.

Select INS and use it to track towards SHIPP, check the gear lever is at neutral, and call for the Nose Up, and then the Visor Up. Flight deck noise level drops dramatically as the visor locks up. 12 miles away from the US coast, lower the attitude to 9°, and accelerate to Vmo, currently 400 kts.

Speedbird 2, present position direct to LINND, climb in the block FL550-600, accelerate Mach 2.0.

Call for the Climb Checklist at M0.7, which will get the E/O pumping fuel rearwards to move the CG aft, and then go straight into the Transonic checklist. Maintain 400 kts IAS, and around 24,500 ft, at M0.93, select the re-heats back on, in pairs, and raise the nose by 3° to maintain 400 kts as they kick in. Precise flying is required in the high drag transonic region, and as the Mach meter reaches M1.0, a quick flicker on both the VSI and Altimeter confirms that the shock wave has just passed over the static ports, and the aircraft is now supersonic.

A quick glance at the elapsed time indicator shows that you’ve been hand flying for just over 9 minutes since the start of the take off roll.

Another hard day in the office!


ChristiaanJ and Nick Thomas

I haven't got a copy of Brian Calvert's book, and I can't comment on what the procedure was when he helped introduce the aircraft into passenger service.

However, purely for the sake of accuracy, in the later years of passenger service, the initial turn on the Concorde noise abatement procedure from 31L at JFK (full length or intersection) was not triggered by passing 100 ft, but rather by the following three conditions, all of which had to be met, and confirmed by the F/O, before the turn commenced.
  • Stable at the (pre-calculated) target rotation attitude.
  • A Rate of Climb of 500 fpm or more.
  • At or above 50 ft RA.
Once the F/O was happy, she would call "TURN", and that call was the trigger for the turn.

100 ft may well have been a typical or average height at which the turn did in fact commence, but the limit was 50 ft RA (raised from an earlier limit of 20ft RA !) and the trigger was the TURN call.

The only reference to 100 ft on this departure was in the engine failure procedure (for an engine failure after V1) when the initial turn was delayed until passing 100 ft RA, and limited to 15° bank. Happily, I never had to delay the turn until 100 ft RA!


With very fond memories

Bellerophon


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