744 vibration on gear up selection. Shakes the sh
out of everyone and aircraft.
At Q this was a problem early in the intro of this aircraft. Main gear wheels out of round were believed to be the problem and subsequently 100s of wheels were changed until defect persisted with 16 new wheels fitted to one of the aircraft with this recurring defect.
White stripes were painted on the tyres (not tires) and take offs were filmed to see if wheels were spinning as the gear lifted into the wheel bay to identify the time of vibration during gear up selection.
For info. When filmed the wheels don't wind down slowly they came to a complete stop within a couple of frames.
At the same time UA BA were having similar defects.
From memory as this was 10 years + ago
The problem was traced to a bad batch of valves that provide the "inflight braking". From memory this valve is sequenced thru the R/H wing landing gear door. Upon gear up selection the gear doors open and this positions a hyd valve to send a hydraulic "signal to the inflight braking ops valve to apply the ALT brake system to stop the wheels rotating. This vave was shuddering/occilating/worn and was creating the vibration by not applying correct braking pressure allowing wheels to shudder as their rotation is slowed by a on-off-on-off-on-off-on braking.
Now that this problem is known. If it is reported a part replacement is scheduled to fix, Most tech crews have seen it so its no drama either.
Remember you are in good hands
Yes I know I haven't used correct nomenclature or techo words but trying to please all reading this post, and most importantly this thread was started by a helicopter pilot
I was once told that the big blades above the helicopter pilots head were put there to keep the pilot cool.
Because you should see him sweat if they stop
