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Hi Captain Lim,
First of all, I would like to compliment you for setting up this site and providing so much information for everyone. Indeed, apart from the other site by the retired United Airlines Boeing 777 lady captain, Meryl Getline, yours is the only other of its kind I know of (and much better as all the FAQs are under one roof).
I just have 3 questions concerning the Boeing 777:
1. When taxiing on the ground, is the 777 affected by the same left-turning tendency that affect many smaller single/twin prop planes (p-factor or gyro effect I think it*s called) and if so, is it strong and requiring constant correction?
2. Pilots normally do 1 of 2 types of takeoff:
a. Rolling takeoff (enters the runway and without stopping, immediately throttles to take off power and start the takeoff run).
b. Standing takeoff (enter the runway stop and hold position, then throttle up and go).
How do you select which way to takeoff? If the tower doesn*t issue a "taxi into position and hold" instruction, how would you choose which to use and which would you prefer - rolling or standing?
3. Is the landing runway and STAR already determined before you start the flight, or do you program them into the FMC when ATC issues them upon nearing your destination?
Many thanks
Jimmy
Hi Jimmy,
Yes, if you were flying a propeller aircraft, the gyroscopic effect is very noticeable. The weight of the fast-turning prop in relation to the size of the small plane creates a gyroscope, which will resist any change in the direction of its rotating axis. As the planes direction is changing, as in a sudden pull-up, gyroscopic forces try to rotate the plane about an axis 90 degrees to the axis you*re forcing it.
This effect is very negligible on a large commercial jet plane. So, on a Boeing 777, any turning tendency due to the gyroscope effect is hardly felt. The plane just turns when the nose wheel steering control is moved left or right immediately.
On a Boeing 777, a rolling take off is recommended on normal operations when no delays are expected as the plane is lined up. It expedites the take off and reduces risk of foreign objects being ingested or engine surge due to tail or cross wind.
A standing take off is selected when the pilot wishes to monitor that the engine parameters are evenly stabilized to minimize directional control problem, especially on a take off during crosswinds or the runway surface is slippery during icing conditions. It is accomplished by holding the brakes until the engines spool up to about 50 % rpm (N1), then release the brakes and promptly advance the thrust to take off thrust (autothrottle TOGA)
So, generally, most take offs are of the "rolling take off" types.
Yes, a smart pilot would normally know the runway in use at the destination based on the forecast wind and also the STAR (Standard Arrivals) as given on the computerized flight plans. However, on establishing contact with the destination airport, he would be given the exact runway and STAR. If he had programmed the correct information into the FMC (Flight Management Computer) earlier, he need not have to modify his original planning again.
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