ATR Power Levers

[Global Pilot]

Anybody know why ATR power levers are different sizes?
Being asking a few guys who have been flying the machine for a few years and no clear answer as yet. Any ideas out there?

brgds,

GP

[error_401]

maybe same as for many props?

critical engine

[ICING AOA]

critical engine

yes and so what ?? most of the twin engine propeller aircraft (piston and turboprop) have Eng 1 as a critical engine !!! do other A/C have a bigger PL1 than PL2 ? I dont think so !

[FLCH-SPD]

Do you mean that the left is larger than the right, or different from aircraft to aircraft?

[FLCH-SPD]

Ah, sorry just missed the last post.

I've noticed the same with the Aero Commander (turboprop), but I think the reason for this is because the left power lever houses a GA switch and horn silencer, maybe this could be the reason?

[ICING AOA]

http://www.airliners.net/open.file/0943680/L/

on the Dash8 both are the same size ...

[Aussie]

Same as on the SAAB 340, same size!

Aussie

[No_Speed_Restriction]

Is it maybe because, after landing and engaging number 2 prop brake, you would taxi on number 1?

[Aussie]

Wheres all the check and training ATR captains when ya need em!



Aussie

[eastern wiseguy]

Pprune calling Hugmonster..........

[Clandestino]

Reason is severly banal... insufficient clearence between PL2 and CL1, which was easier to correct by cutting off half an inch of PL2 handgrip than by repositioning PLs and redesigning the entire throttle quadrant. In other words, originally there was no room for F/O's LH thumb. Difference is visible here:

http://www.airliners.net/open.file/0706707/L/

BTW, ATR has plenty of rudder and there's no noticable difference in controllability during EFATO no matter which donkey quits (in a sim, anyway). Also all systems can be powered from either engine, therefore there is actually no critical engine on ATR. Also single engine taxiing is done on eng no2 and I have certainly never engaged prop brake during taxiing, nor I can think of any reason why should anyone want to do it. Both PLs have the go-around button, no1 for capt's thumb, no2 for F/Os.

[Aussie]

Is it an SOP to taxi on 1 engine????

Do airlines actually do this?

Aussie

[Global Pilot]

QUOTE=Clandestino;2903149]Reason is severly banal... insufficient clearence between PL2 and CL1, which was easier to correct by cutting off half an inch of PL2 handgrip than by repositioning PLs and redesigning the entire throttle quadrant. In other words, originally there was no room for F/O's LH thumb.

Thanks for that Clandestino... seems like the best suggestion so far. I was kinda thinking that is was possibly some kit left over from a previous design etc.

[ICING AOA]

So why is PL1 not as small as PL2 then ?

Is it an SOP to taxi on 1 engine????

Do airlines actually do this?

Yes, generally, ATR pilots feather engine 1 after landing for taxiing to the stand ! One important thing is to check the hydraulics and obviously the brakes !

[White Knight]

Our SOP's - in my ATR days - were to taxi with BOTH engines running, and props full fine..... Just to avoid the total loss of hydralics

[FLCH-SPD]

in my ATR days - were to taxi with BOTH engines running, and props full fine

Does this mean having the condition levers fully forward? Isn't this rather noisy? I didn't think it was possible to choose the blade angle, I thought this was a function of the overspeed and underspeed govenors? (or dependant on PL position during beta mode)

(not a turboprop driver so just asking)

[sir.pratt]

condition levers control fuel - not prop governor.

power levers control fuel - prop lever control the governor, which sets an rpm, which dictates blade angle.

[FLCH-SPD]

condition levers control fuel - not prop governor.

power levers control fuel - prop lever control the governor, which sets an rpm, which dictates blade angle.

I thought the ATR only had PL's and Condition L's. Where are the prop levers then?

Now I'm confused!

I thought that the Power levers control fuel flow, while the position of the condition lever determines the RPM and hence the U/S and O/S govenors will adjust blade angle to maintain that RPM. When the PL are retarded to beta mode, the PL controls blade angle and fuel flow is used to control RPM????

[ICING AOA]

There are several notches on the condition levers :

Fuel Shut Off
Feather
RPM -> Auto and OVRD (for PEC A/C) or Mini to Max (for classical versions)

[Piltdown Man]

But that depends on which ATR model you fly. The posh ones with PEC's and EEC's use a little rotary knob to select the power rating which in turn selects the RPM. No condition or prop levers here (in the traditional sense!).

PM