139 - Boom!
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Boom it was
Nomex,
I don't think any of the BHA boys will post on here as I heard it was the CP and the HOCT (head of check and training) who were flying the machine.
What I heard was the engine was at 950 degrees C for 1 minute.
Some really experienced guys.
Banger
I don't think any of the BHA boys will post on here as I heard it was the CP and the HOCT (head of check and training) who were flying the machine.
What I heard was the engine was at 950 degrees C for 1 minute.
Some really experienced guys.
Banger
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Mmmm ....
.....I heard was the engine was at 950 degrees C for 1 minute. .....
Now in the 139 that is pretty hard to do unless you work at it .... perhaps 'someone' inadvertantly flipped an engine into 'manual' ... THAT CAN be done pretty easily especially when your new to the type ... and by the time you work out what has caused it ????? .....
Be kind chaps ... be kind!
.....I heard was the engine was at 950 degrees C for 1 minute. .....
Now in the 139 that is pretty hard to do unless you work at it .... perhaps 'someone' inadvertantly flipped an engine into 'manual' ... THAT CAN be done pretty easily especially when your new to the type ... and by the time you work out what has caused it ????? .....
Be kind chaps ... be kind!
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I can see how
would really mess up your day if you were in a 412 however how would going to manual on the 139 increase the ITT? 
I may be missing something here so no offence if I have
perhaps 'someone' inadvertantly flipped an engine into 'manual'
I may be missing something here so no offence if I have
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MMmmm .....
...... how would going to manual on the 139 increase the ITT? ....
Quite simply .... unlike the 412, when going into manual requires the retardation of the affected engines throttle prior to 'flipping' the switch ... with the 139 if the Gov. switch is inadvertently switched to manual the EEC 'Freezes' the engine power setting commanded at the time the switch is selected.
If this is not noted and the collective is then reduced the good engine will drop its output and the naughty engine will/may overspeed/overtemp ??
It may be ... that because of the 2 chaps flying were possibly doing a check flight ... that they might have in fact been doing a 'Simulated Governor Failure' sequence and found out the hard way how very sensitive the manual Gov. 'beep' adjust is to operate .... and unlike the 412 the beep is operated in 'shots' rather than as a continuous 'beep up/down' ..... it can all go wrong so very quickly!
...... how would going to manual on the 139 increase the ITT? ....
Quite simply .... unlike the 412, when going into manual requires the retardation of the affected engines throttle prior to 'flipping' the switch ... with the 139 if the Gov. switch is inadvertently switched to manual the EEC 'Freezes' the engine power setting commanded at the time the switch is selected.
If this is not noted and the collective is then reduced the good engine will drop its output and the naughty engine will/may overspeed/overtemp ??
It may be ... that because of the 2 chaps flying were possibly doing a check flight ... that they might have in fact been doing a 'Simulated Governor Failure' sequence and found out the hard way how very sensitive the manual Gov. 'beep' adjust is to operate .... and unlike the 412 the beep is operated in 'shots' rather than as a continuous 'beep up/down' ..... it can all go wrong so very quickly!
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Chick-Chick BOOM.
Hi Spinwing,
Think more clearly about what you have just said!!!!
i will give you two clues, "freezes" and "over temp" . How do you account for that ????
Regards Mick.
Think more clearly about what you have just said!!!!
i will give you two clues, "freezes" and "over temp" . How do you account for that ????
Regards Mick.
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OK I understand how moving the collective would have and effect on the ITT in the 139 as it was well demonstrated in the SIM. The beep is certainly not very user friendly either once in manual.
The question though was about having an ITT of 950. Switching the Gov's to manual won't have any effect 'until' there is movement of the collective or in fact yaw inputs too I imagine.
I was saying that flipping the Gov's to manual won't do anything to ITT, however further control inputs from the pilot could and more than likely would then have an effect!
The question though was about having an ITT of 950. Switching the Gov's to manual won't have any effect 'until' there is movement of the collective or in fact yaw inputs too I imagine.
I was saying that flipping the Gov's to manual won't do anything to ITT, however further control inputs from the pilot could and more than likely would then have an effect!
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Chick-Chick BOOM.
Spinny and Tinny.
Surely you would cook the "good engine"
Surely you would get a rotor overspeed warning before the engine in manual cooked.
Think about it!!!
Regards
Mick.
Surely you would cook the "good engine"
Surely you would get a rotor overspeed warning before the engine in manual cooked.
Think about it!!!
Regards
Mick.
Last edited by Mike C; 4th Dec 2010 at 09:51. Reason: Finger trouble
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Mmm ...
Hi Mick....
Yes you might get the Nr Nf overspeed warning ... you would certainly get a "Man Gov" CAS and MFD warning ... it all depends really on the power setting at the time of the selection and what pilot commands then happened ...
Remember ... this is rumour ...we really do not know what happened or even IF it happened ...
You would not cook the good engine engine the 'auto engine' would wind down if power demand was reduced.
The engine in 'manual' would hold power and drive the Nr and if the collective were lowered it could then cause an overspeed ... if the power setting was high it MIGHT o'temp .... only the guys in the a/c would know for sure what happened ...
Hi Mick....
Yes you might get the Nr Nf overspeed warning ... you would certainly get a "Man Gov" CAS and MFD warning ... it all depends really on the power setting at the time of the selection and what pilot commands then happened ...
Remember ... this is rumour ...we really do not know what happened or even IF it happened ...
You would not cook the good engine engine the 'auto engine' would wind down if power demand was reduced.
The engine in 'manual' would hold power and drive the Nr and if the collective were lowered it could then cause an overspeed ... if the power setting was high it MIGHT o'temp .... only the guys in the a/c would know for sure what happened ...
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I'd be surprised if it had anything to do with the manual mode with the ITT up there for that long. I could see an inadvertent overspeed in this mode but even then not for that amount of time without recognition.
I had an engine fail a few years back on a AW139 on taxi, the ITT maxed out after the engine failed and dry motoring the engine made absolutely no difference to bring the temp down. However the engine reached 1000 degrees in a matter of seconds after the failure so the engine was finished, motoring or not. Turned out the problem was caused by the engine driven fuel pump pretty much seizing up which obviously dragged the Ng down. I think if I remember the ITT was recorded by the as above 900 for more than 20 seconds.
The only other instance I have heard of ITT getting into that range for that amount of time was during a botched manual mode restart.
Who knows what happened as I wasn't flying, but I sure there is a logical explanation to what happened and I'm sure we'll all hear all about it before long.
I had an engine fail a few years back on a AW139 on taxi, the ITT maxed out after the engine failed and dry motoring the engine made absolutely no difference to bring the temp down. However the engine reached 1000 degrees in a matter of seconds after the failure so the engine was finished, motoring or not. Turned out the problem was caused by the engine driven fuel pump pretty much seizing up which obviously dragged the Ng down. I think if I remember the ITT was recorded by the as above 900 for more than 20 seconds.
The only other instance I have heard of ITT getting into that range for that amount of time was during a botched manual mode restart.
Who knows what happened as I wasn't flying, but I sure there is a logical explanation to what happened and I'm sure we'll all hear all about it before long.
Last edited by platinumpure; 2nd Dec 2010 at 17:13.
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CP & HOCT lol
Happens to everyone I guess, but the fact that the machine would have been doing it's best not to let it happen and it still did is classic.
They'll recover though, who's going to chew those two out with any real vigour????
SpinWing - "IT" Happened.
Happens to everyone I guess, but the fact that the machine would have been doing it's best not to let it happen and it still did is classic.
They'll recover though, who's going to chew those two out with any real vigour????
SpinWing - "IT" Happened.
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I would be asking
Nomex,
If I were a share holder in Bristow I would be asking. I bet if you or I fried that engine we would have our bags packed and have our marching orders. I wonder if BHA has told any of its other operations world wide that it even happened?????
Also heard it happened on shut down?????
Banger
If I were a share holder in Bristow I would be asking. I bet if you or I fried that engine we would have our bags packed and have our marching orders. I wonder if BHA has told any of its other operations world wide that it even happened?????
Also heard it happened on shut down?????
Banger
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Mmmm ...
...... heard it happened on shut down?????...
Even more curious then .... would love to see the EDU download ..... the crew might NOT have been able control the O'temp even if they wanted too ...
Could well be one of those "**** Happening" moments ...
...... heard it happened on shut down?????...
Even more curious then .... would love to see the EDU download ..... the crew might NOT have been able control the O'temp even if they wanted too ...
Could well be one of those "**** Happening" moments ...
I bet if you or I fried that engine we would have our bags packed and have our marching orders.
P1
