Impossible to Taxi with ENG 3-4 Off

[A340-4 4]

Hello;

Is it just me, or is it impossible to taxi her with N3-4 been off? 

Thank you. 

 

Best Regards,

 

Vasily B.

 

[skwaL 36]

Depends on your load.

[A340-4 4]

Not to heavy, as I have tried to taxi after completing a 8 hr flight with her. 

What i mean is that you cant turn her. 

[skwaL 36]

I generally turn off engines 1 and 4. That way it is easier

[77west 139]

I turn off 2 and 3, as those are closer to the fuselage where the ground service vehicles will be wanting to get to. Turning off 1 and 2 or 3 and 4 seems less helpful.

[skelsey 765]

 

 

I generally turn off engines 1 and 4. That way it is easier

 

Bad idea if you want to turn or stop though (think about which hydraulic systems power the brakes and steering...).

 

As Wes says, if you're going to do engine-out taxi on the 747 then the normal thing to do is to shut down 3, or 2 and 3.

[jcomm 5,876]

From Professionals...

 

http://aerowinx.com/board/index.php?topic=3893.msg40803#msg40803

 

http://aerowinx.com/board/index.php?topic=3824.msg40120#msg40120

[A340-4 4]

Lads,

Im not asking about SOP or what some companies do to save money. All I am saying is that if you turn off N3 and N4. You cant turn her. Is that a bug? Or not? 

 

Thank you. 

[jcomm 5,876]

You mean, you can't turn right in that case, at higher GWs right? 

 

Any way, here's another clue:

 

 

and also at the end of this other video:

 

https://youtu.be/lE_aFbaucqA?t=895

[A340-4 4]

I cant turn left. It will turn right on its own with only 3% GW. 

[kevinh 409]

I cant turn left. It will turn right on its own with only 3% GW.

 

It isn't a bug. Hyd system 4 powers the nosewheel and body gear steering. So it's not surprising you can't turn left. It will want to turn right because of the thrust asymmetry you have.

[A340-4 4]

thank you

[tcas_climb 45]

It isn't a bug. Hyd system 4 powers the nosewheel and body gear steering. So it's not surprising you can't turn left. It will want to turn right because of the thrust asymmetry you have.

Wouldn't the demand pumps take over from the engine pumps tho so the NW steering would still work?

[jcomm 5,876]

Wouldn't the demand pumps take over from the engine pumps tho so the NW steering would still work?

 

Yes

[kevinh 409]

Wouldn't the demand pumps take over from the engine pumps tho so the NW steering would still work?

Yes, but at idle thrust on only two engines and with three packs on there might not be enough duct pressure to fully power the hyd system.