Finally reading Handling The Big Jets and it is mentioned in the 747 section about using the wing gear as a speed brake. Also, if one wing gear won’t extend for landing, the other one is somehow retracted(not a procedure on the -400).
Also something called Throttle Bar Protection. A mechanical bar is placed behind the thrus levers at altitude to prevent selection of idle power on JT-9D engines that can cause surging. Therefore, a slow initial descent from cruise altitude. Which may be the reason why the wing gear was used as a speed brake with this function being removed soon after the throttle bar was no longer necessary.
Keep in mind that the gear really can still be used as a speed brake or for increased descent rate. Simply extend it once below gear extension speed. Obviously, more applicable for the lower levels but I have done this on more than one type. Can be good for airports where they are keeping you up high fairly close in and then planning on keeping you in tight for the visual.
Any pictures, especially of the throttle bar?
Last edited by punkalouver; 5th December 2024 at 10:30.