Tornado Reheat Question
I REALLY SHOULDN'T BE HERE
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Tornado Reheat Question
Hello folks,
A pair of tornados took off ahead of us today at GLA rwy 05. Both used reheat. Is this required with such a long runway? The noise was fantastic.
sr
A pair of tornados took off ahead of us today at GLA rwy 05. Both used reheat. Is this required with such a long runway? The noise was fantastic.
sr
long taxi back to their homebase.
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You probably could get airborne without reheat, if you could garentee no engine failure, but it would be a massively gutsy move and the take off roll would be massive.
If you watched them they will have run the engines up to max dry then lit the burners one at a time and allowed them to stabilise once lit before releasing the brakes. They take a finite amount of time to light up and start producing thrust and they don't always light.
Both of these would pose an unacceptably high risk if the take off was carried out without both burners already lit at the beginning of the take off roll.
If you watched them they will have run the engines up to max dry then lit the burners one at a time and allowed them to stabilise once lit before releasing the brakes. They take a finite amount of time to light up and start producing thrust and they don't always light.
Both of these would pose an unacceptably high risk if the take off was carried out without both burners already lit at the beginning of the take off roll.
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Had a stude on the F4 OCU take off in cold power (ie no reheat) - then he was a Jaguar pilot we were cross-training and his excuse was that the acceleration was better than he was used to so he thought it would be OK.
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They take a finite amount of time to light up and start producing thrust and they don't always light.
Flipflopman
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Using the 'burners gets you to your decision speeds faster and with more runway ahead of you so you can still stay on the ground if (when) you suffer a reasonably serious snag without much drama.
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"And that usually signifies that it's time for the Landrover speedo cable, to take a little trip through the Hot Shot injector again!! "
lol, there's some memories!
Best purging tool the RAF never bought IMHO!!!
"lol, there's some memories!
Best purging tool the RAF never bought IMHO!!!
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The RAF F-4 had enough problems with its engines but at least you could light both burners simultaneously (although taking about 3 seconds) and expect them to work. And you would have to stamp pretty hard on the brakes to stop the machine from moving in full a/b; in fact, I'm not sure if you could stop it moving. But this problem with the Tornado, does it apply to all models?
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It's not a problem. Both throttles can be slammed idle to max reheat for operational use and it is rare that anything abnormal occurs; however, the probability of engine surge or reheat failure is reduced by handling the light-up in a more controlled way and this makes sense for normal training use.
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As Soddim says, certainly not a 'problem' as such.
Failure to light does occur occasionally, but is more likely than not a quick fix, and usually does tend to be a dirty Hot Shot injector. This is rectified either using a bastardised Landrover speedo cable which is passed through the fuel feed pipe from the ABFCU to the Hot Shot head, to remove the offending carbon.
The alternative 'correct' way, is to use the R-R Hot Shot purge tool. This is a 12" stainless pipe, which connects to the Hot Shot injector itself and is pointed to atmosphere through the open engine door. An EGR is then carried out, which reverse purges the head of the injector. Obviously this is a little more time consuming, but the officially favoured way
As an aside, Reheat lights are usually pretty instantaneous, and can definitely be felt as a light 'thump' commensurate with indication of light up on the Aj gauge.
Flipflopman
Failure to light does occur occasionally, but is more likely than not a quick fix, and usually does tend to be a dirty Hot Shot injector. This is rectified either using a bastardised Landrover speedo cable which is passed through the fuel feed pipe from the ABFCU to the Hot Shot head, to remove the offending carbon.
The alternative 'correct' way, is to use the R-R Hot Shot purge tool. This is a 12" stainless pipe, which connects to the Hot Shot injector itself and is pointed to atmosphere through the open engine door. An EGR is then carried out, which reverse purges the head of the injector. Obviously this is a little more time consuming, but the officially favoured way
As an aside, Reheat lights are usually pretty instantaneous, and can definitely be felt as a light 'thump' commensurate with indication of light up on the Aj gauge.
Flipflopman
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Don't know I never tried to hold it on the brakes in Max Reheat but I know a man who started a take off roll in the Falklands on a slushy runway with the parking brake on. The unusual D shaped wheels now adorn the Goose. Strangely he didn't get airborne off that attempt.
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Can confirm that Air Defender.
I was on 1435 at the time, and also the MC of the Eyrie Bar. I was 'Handed' the CVR tapes, which made for an amusing evening in the bar that night!
As I recall the parking brake was applied due to the VC10 taking it's time backtracking along the runway. Indeed, the chat between the Pilot and Nav prior to the incident, was about the Tenerife air disaster and what a cock up it was!! 
Flipflopman
I was on 1435 at the time, and also the MC of the Eyrie Bar. I was 'Handed' the CVR tapes, which made for an amusing evening in the bar that night!
As I recall the parking brake was applied due to the VC10 taking it's time backtracking along the runway. Indeed, the chat between the Pilot and Nav prior to the incident, was about the Tenerife air disaster and what a cock up it was!!
Flipflopman
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Oh how we laughed when he tried to prevent the story getting back to the UK.
Light up might be immediate but the production of significant extra thrust isn't, a few seconds of extra stress in the event of one of RR's finest Sh*tting the bed.
Certainly when tanking, and more oomph is required, light one burner then wait a few bananas for the thrust to come before retarding the donk left in dry. Pull the other back too soon and you fall out, too late and the tanker appears very large in front of you.
Light up might be immediate but the production of significant extra thrust isn't, a few seconds of extra stress in the event of one of RR's finest Sh*tting the bed.
Certainly when tanking, and more oomph is required, light one burner then wait a few bananas for the thrust to come before retarding the donk left in dry. Pull the other back too soon and you fall out, too late and the tanker appears very large in front of you.
I REALLY SHOULDN'T BE HERE
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If you watched them they will have run the engines up to max dry then lit the burners one at a time and allowed them to stabilise once lit before releasing the brakes.
Yep, thats exactly what they did. Thanks for the answers.
sr
Yep, thats exactly what they did. Thanks for the answers.
sr
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....or sometimes tweak the WLLTDB Flip-Flop
As I'm sure you are fully aware, the WLLDTB or Working Line Limiter Datum Test Box (rather than WLLTDB) Is there to ensure that regardless of the PLA (Pilots Lever Angle) the engines will produce Dry Thrust only, and not open the nozzles in anticipation of Reheat, therefore risking LP Turbine overspeed. 70% Aj, as I remember.
Seriously though, it was usually Hot shot trouble, or Reheat FCU trouble that resulted in No Light Up. I'm also sure however that the Phantom also had it's own little quirks, it's just that I'm far too young to remember!!
Flipflopman
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Air Defender,
As I remember, he did all in his power to prevent us from playing the CVR tape too. As I remember, it was the Nav who noticed at 110kts, that the aircraft appeared to be 'skidding'
Accompanied by a very swift "Oh F**k"
Flipflopman
As I remember, he did all in his power to prevent us from playing the CVR tape too. As I remember, it was the Nav who noticed at 110kts, that the aircraft appeared to be 'skidding'
Accompanied by a very swift "Oh F**k"
Flipflopman