warbird1 wrote:
51fixer wrote:
warbird1 wrote:
warbird1 wrote:
Just curious, I've always wondered why the inner gear door on the Mustang has the different piece of metal on it? Is it a structural thing or what?
N3Njeff wrote:
Is it where the tire would rub on the way up? thats what I have always thought...............good question,
Can somebody confirm that this is the reason for the extra piece of metal on the inner gear door - for the rubbing of the tire?
Yes, that is what that is. It is a piece of stainless steel mounted to the alum inner skin. The tire rubs on extension, when the uplock hook is released the tire will drop onto the door as it opens. When retracting the inner doors will not close until both MLG struts are fully up as there is a valve that must be pushed on by both before the inner doors will close.
Rich
Thanks for the confirmation, Rich. So, tell me about the MLG strut and the inner gear doors. Which are hydraulic powered, which are gravity when extending?
How about the tailwheel, same question?
The landing gear has devices to lock the gear in the up and down positions. On the MLG the down lock is spring operated to latch down and hyd to release. The uplock is spring operated to latch up and mechanical to release. The movement of the gear leg and the inner door are by hyd actuators. To control how the gear is synchronized there are valves and plungers with cable and linkages. In essence the timing of the operation of the components is important. With the gear up in flight the MLG is locked up by a hook and the inner door is shut and also locked by 2 hooks. By selecting gear down the latches on the inner door release and the uplock hook is released. This is by mechanical linkage which also moves the gear selector valve to provide hyd pressure from the up system to the down system. Pressure is ported to the timing valve which directs the pressure to the inner doors to open them. The MLG will free fall at 1st pushing against the rub strip on the inner door as they fully open. When the inner door fully open pressure will build in the MLG actuators pushing the MLG to the down position. Also small hyd actuators will extend allowing the spring in the MLG downlock to push against the lock plunger. The plunger will be pushed in as the MLG trunion pushes past and the plunger spring will push the lock into place when the gear is fully extended. When both MLG are extended cables at the top of each will pull the timing valve the other way which will provide pressure to close the inner doors. Then you have gear down and inner doors closed.
To raise the gear the gear handle is placed in up. The linkage moves the selector valve to the up system and also the uplock hooks move from the released position to up position where the uplock rollers will push them out of the way but springs will pull them back to capture the gear when it is at the top of its retraction travel. Pressure then is ported thru the timing valve to the inner doors to open them. When open, pressure will build in the system pulling the MLG downlocks and then porting pressure to the MLG actuator up side which moves the gear. When each gear is up they will lock into the uplock and push on a plunger. Both plungers are tied into a linkage which again will pull the timing valve to close the inner doors. Gear up and inner doors closed.
The tail has mechanical up and down locks which are connected by cables to a bellcrank connected to the gear handle in the cockpit. There is a hyd actuator to move the tailgear up and down using the same hyd selector mentioned above to port pressure to the needed side. The tail gear moves pretty fast compared to the MLG. The tail gear doors open and close by a mechanical linkage which is connected to the tailwheel. As one moves the other follows.
Emergency gear extension utilizes a hyd bypass valve which is connected to a T handle in the cockpit. The linkage also connects to the uplocks on the inner gear doors. Pull the T handle and the inner door hooks are released and any hyd pressure is released and all hyd fluid will flow into the hyd tank. Then placing the gear selector down releases all uplocks on all 3 gears. Gravity will pull the gear down and a slight yawing and the side load of air will lock the gear down.
Kinda long and probably confusing.
Rich