Q for pilots: Taxiing and autostart in 777 or similiar ac.
 

First of all, my apologizes for my poor english.

My first question is about taxiing the 777 or similiar heavy aircraft.
How much imput from the engines do You need to keep the plane rolling on taxiway? Of course You need some extra thrust to move it, but what about just maintaining and keeping the taxi speed? Of course it depends on payload and fuel amount, but i wonder if it's possible to taxiing fully loaded aircraft when thrust levelers at idle? And how much of "idle setting" do You use in everyday taxi procedure?

And what about managing with 90 deegree turns? Manuals says, that you have to reduce GS to maximum 10 knots, but what is the most reasonable speed for those kind of turn?

Second question - When reading the manual, I do not understand starting engines procedure, with autostart. Do You swith "on" both fuel cutoff switches before moving engine controls to the "start" position? Or just after this procedure?

Best regards!

From a 747-400 pilot.

Low power used to start roll, minimum to prevent blast damage behind. Once rolling, idle power is usually enough with occasional low power applied to keep moving. Resistance to motion is very dependant on weight and slope of taxiway- they are often not flat!

A hard 90 degree turn should be at about 10 kts, a more gentle one can be at up to about 15kts.

Switching on the fuel cut-off switches during autostart will apply fuel at the correct rotation speed automatically, not when you put the fuel cut-off switches on. The autostart will monitor itself and cut-off the fuel if any parameters are not correct, and even re-apply fuel. I wish we had it on the latest 737NG!

(Don't apologise for your English! Most English people can't write English as well as that!)

Many thaks for reply! It helps a lot! :)

Best regards!