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Just a quick question for you powerplant types on the ATS.

In your experience, where is the cut-off for engaging the ATS with core RPM still indicating? For example, does the thing get trashed if it is engaged at any % core RPM above zero, or 20%, or 30%, etc.?

No, I'm not asking because of stick actuator error that resulted in a lifetime supply of beer for the crew chief and engine shop people.

I am asking because several procedures in the -1 talk about introducing an alternate source of air following abnormal occurences with the motor (primarily problems when starting). For example, if I shut down the motor but the fuel doesn't drain and the ITTs remain high, establish an alternate source of air. That's all well and good, but as #1 spins down, what is a safe % core RPM to engage the ATS and motor #1 using #2 as the bleed air source - and not trash the ATS in the process?

Another question regarding the care and feeding of the ATS - on average, what is the highest % core RPM that the ATS can take before it comes apart? For example, if I motor #1 before starting, then put the #1 throttle over the hump and let it start all the way up to the computed min % core RPM (instead of resetting the motor switch back to 'normal' after getting a light-off), will the thing come apart around 60% core RPM, or something higher?

All I remember from the RTU is, 'Never engage the ATS with the motor switch once the engine is running!' OKay, so what is the magic number that allows me to engage it while the core is still spinning?

I searched through the -1 and couldn't find a definitive answer to these questions, so I figured I'd throw them out here and see what the experts have to say. I got varying opinions at my squadron (from the mx side of the house - pilots make shit up if we're not sure), just curious to hear what y'all think. Thanks in advance!

ATTACK!

The start cycle light wont even go off untill you have stable Ng of 64%. I dont think that there is a minimum that I know of as an Ng % for a bad start. You have 20 seconds to light off then 60 seconds untill a stable engine. I would personally use the time frame outlined for a start. But there is a common sense factor involved also. I wouldn't abandon a start if I lost air at (for example) 55% Ng and the temps were in the green. But I think the CORRECT ANSWER that the IG wants to hear is that if it aint if it isnt IAW the
71jg-1-2cl-1 then defer to the boldface..............period. I guess a jet jockey would be the best to comment.

By this time tomorrow I shall have gained either a pearage or Westminster Abbey........Nelson

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YGBSM !

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I am asking because several procedures in the -1 talk about introducing an alternate source of air following abnormal occurences with the motor (primarily problems when starting). For example, if I shut down the motor but the fuel doesn't drain and the ITTs remain high, establish an alternate source of air. That's all well and good, but as #1 spins down, what is a safe % core RPM to engage the ATS and motor #1 using #2 as the bleed air source - and not trash the ATS in the process?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
All I remember from the RTU is, 'Never engage the ATS with the motor switch once the engine is running!' OKay, so what is the magic number that allows me to engage it while the core is still spinning?
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For the "Fuel fail to drain" on shutdown, when you're establishing the alternate air source, you have to do it immediately, prior to the pooling fuel igniting in the can. So for EP purposes, you do it immediately. But also once you've brought the throttle over the hump to cutoff for #1, as soon as it begins winding down, I'd say it's no longer running....just the blades still happen to be spinning down. So as you're pushing #2 up to 85%+ for the crossbleed after having thrown the #1 motor switch to MOTOR, you're not busting the RTU "rule" anyway, IMHO.



Edited by - type 7 on Jun 14 2004 01:27 AM

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<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
I am asking because several procedures in the -1 talk about introducing an alternate source of air following abnormal occurences with the motor (primarily problems when starting). For example, if I shut down the motor but the fuel doesn't drain and the ITTs remain high, establish an alternate source of air. That's all well and good, but as #1 spins down, what is a safe % core RPM to engage the ATS and motor #1 using #2 as the bleed air source - and not trash the ATS in the process?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
All I remember from the RTU is, 'Never engage the ATS with the motor switch once the engine is running!' OKay, so what is the magic number that allows me to engage it while the core is still spinning?
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

For the "Fuel fail to drain" on shutdown, when you're establishing the alternate air source, you have to do it immediately, prior to the pooling fuel igniting in the can. So for EP purposes, you do it immediately. But also once you've brought the throttle over the hump to cutoff for #1, as soon as it begins winding down, I'd say it's no longer running....just the blades still happen to be spinning down. So as you're pushing #2 up to 85%+ for the crossbleed after having thrown the #1 motor switch to MOTOR, you're not busting the RTU "rule" anyway, IMHO.



Edited by - type 7 on Jun 14 2004 01:27 AM
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Thanks Type 7, that's what I was looking for.

ATTACK!