View Full Version : ATR Thrust levers
Just a simple question: Can anyone tell me why the No.1 thrust lever on the ATR is larger than the No. 2? Thats always confused me!
2nd May 2004, 10:01
The ATR was originally designed with go around buttons on both sides of both power levers, thereby having a small gab between the levers. However they realized that this was not the best solution as pilots fingers sometimes got stuck between the levers and they decided to fill out this gab and to have 1 go around button on each lever.. The cheepest solution was to make one lever bigger instead of two and that's why the left one is bigger today.
Hope that helps ??
With all due respect, smiert spionom, that seems a funny explanation to me....
What's the source of your info?
Another urban legend?
I don't have any info about that,, but having a few thousand hours on the ATR I think the right power lever ( not thrust lever, it's not a jet, sadly...) is shorter simply because of the left condition lever, which needs room to move fore/aft.
Standing by to be corrected!
2nd May 2004, 11:52
I too have several thousands of hours on the ATR, I know it's a funny explanation, the ATR is full of them, never the less that is the answer, like it or not. My source of info, ATR toulouse.
Even funnier eplanation, 126.9!
I still think they "cut" the external part of the right power lever to make room for the left condition lever.
The cheepest solution was to make one lever bigger instead of two and that's why the left one is bigger today.
That doesn't make sense.
The left power lever is larger toward it's external, not internal part of it.
If they wanted to fill the gap between the two they would have made a larger left power lever toward the interior.
Don't you think so?
However I might be wrong after some years on other machines.
ps: Smiert, what do you mean with "ATR Toulouse"?
Hope you don't trust blindly certain funny guys over there, and I better keep my mouth shut... :mad: :yuk:
2nd May 2004, 23:39
ATR Toulouse, like ATR training centre Toulouse. If you think your theory is better, fine by me I don't really give a sh*t I just gave the same answer that I once was told by ATR. Maybe you should dig even further to investigate !!?? Good Luck !
3rd May 2004, 08:55
I'll tell you the real reason. I don't know!
But if the cockpit was blacked out or full of smoke my guess would be that the no.1 power lever is on the left and the no.2 on the right unless I'd got so confused or scared that I had to turn my back to the panel in which case I'd also begin to consider an alternative career.
Just to throw another ball into the air. Does it have anything to do with critical engines and the identification of such?
Just an idea though possibly the most plausible so far.
4th May 2004, 14:45
I had a look at the power levers and go-around buttons in question today and I believe I have the answer.
Smiert Spionom is closest to the correct answer.
It appears to me that if the No.2 power lever were the same size as the No.1 then one would indeed get ones finger caught between the No.2 power lever and the No.1 condition lever.
But it is this part of the No.2 power lever which is reduced in length.
I think there is something in the rules about go-around buttons being positioned on both power levers which ATR were probably not aware of and tried to get away with just having the one on the No.1 power lever.
4th May 2004, 14:57
Just for the record... I don't think it is technically correct to call power levers, thrust levers in turboprops. Turboprops power is measured in horsepower not thrust.
4th May 2004, 15:00
smiert spionom answer's is definitely the correct one!
It appears to me that if the No.2 power lever were the same size as the No.1 then one would indeed get ones finger caught between the No.2 power lever and the No.1 condition lever. (Miserlou)
I still think they "cut" the external part of the right power lever to make room for the left condition lever. (LEM)
Just compare the two...
4th May 2004, 16:03
Seems pretty straight forward to me, LEM is on the right track.
Its gotta be about clearance with #1 condition lever, but more importantly from both seats!
ie when the skipper puts his RIGHT paw on the PL's his thumb naturally sits off to the side of the #1 PL. No problem, no snags for the full range of fore-aft movement.
When the F/o places his LEFT paw on the PL's, his right thumb naturally sits of to the side of the #2 PL. IF the lever knobs were the same width then said thumb would definitely snag on the #1 condition lever at some point in the PL fore-aft range.
The fix - shorten the width of the #2 PL slightly to give effo Bloggs and his fat thumb some more space.
This being the case, does seem to be a bit of an afterthought in the design process.
4th May 2004, 17:36
My apologies, it was LEM with the right answer; I just hadn't read all of his post. Sorry.
However, in defence of Smiert, one has to question how well the frenchman concerned made himself understood. Not well enough, one thinks.
6th May 2004, 09:14
Just another reminder - please keep replies in this forum professional and to the point, people.
If you can't disagree with people here in a friendly, professional manner, then don't even think of posting here. Go somewhere else that appreciates childish behaviour.
critical engine on the ATR,has something too do with the power levers ?
7th May 2004, 09:44
One should always know the critical engine if applicable and a difference in the size of power levers would serve as an aide memoire. That was just a idea.
The mystery is solved, though, and that was not the reason.
Tft has it. just back from tls and one of the nuggets of knowledge we were given about the atr (one of many on this aircraft) was about the mismatched levers being like this to indicate the critical engine. Silly as it may seem it is true and i am more likely to believe someone involved in its manufacture.
7th May 2004, 22:34
the reason why they have a diff size its just to let you know that wich one its the critical eng, being 1 PL bigger
I got this Info from ATR performance guide that its given to the Instructor Pilots on during their training
ther you go