REFLECTOR: Overheated Brakes Causes Landing Gear to Bow

[Dave Philipsen]

Kirk,

It sounds like your warping may have been a little more pronounced than 
mine.  Do you have heat shields?  I recently noticed one of my gear legs 
was ever so slightly splayed outward at the bottom.  It may have been a 
degree or two off from perpendicular.  Here's the solution that worked 
for me.  Your mileage may vary:

I completely removed and disassembled the wheel and brakes and axle.  I 
then mounted the axle on the gear leg in reverse (axle pointing inward 
toward the middle of the plane).  Then I rested the weight of the 
airplane via the end of that axle on a wooden block (the wooden block 
was only supporting the *end* of the axle).  The force acting upon the 
gear leg was exactly opposite as when the wheel is mounted normally.  
Then I used a 250-watt IR reflector heat lamp and heated the leg up at 
about the same place where the rotor would have heated it (on the 
outside edge of the gear leg).  The lamp was about 8-10 inches from the 
leg.  Then, I used a ruler to measure the distance from the floor to the 
bottom of my gear leg.  As the leg heated up and started to bend back, 
the bottom of the gear leg would get closer and closer to the floor.  I 
only let it go maybe 1/16 - 3/32 of an inch and then I took the heat 
lamp off.  This procedure allowed the gear leg to bend back maybe one 
degree or so.  After the leg cooled down I assembled the axle back on 
the correct side of the leg, put the wheel back on (without the brake 
caliper) and moved the airplane forward and back a few times and then I 
checked the camber of the wheel. 

To make a long story a bit shorter, I had to do it again and let the leg 
bend a little bit more.  Total time under the heat lamp was probably in 
the neighborhood of 40-45 minutes. Just for good measure I wrapped that 
area of the gear leg with some 2-inch-wide fiberglass BID tape and 
wetted it down with epoxy.  I've probably performed 15 takeoffs and 
landings since the gear leg "re-formation" and everything is just fine.  
I fashioned a heat shield out of aluminum sheet metal with some glued on 
backing made of exhaust pipe insulating cloth tape and installed it 
while I had the axle off.

This procedure *may* work for you if the leg is not badly disfigured and 
if it has not been heated so badly as to cause the epoxy to actually run 
out of the leg.



Kirk Aragon wrote:
>
> Hi all,
>
> Recently, I overheated my brakes and have noticed that my gear legs 
> have warped inward towards the rotors (in addition to small bubbling). 
> There is currently a very small gap between the rotor and the leg on 
> each side. I remember that someone else had this issue and 
> Reflectorites discussed the procedures to fix this issue. Can anyone 
> point me to that discussion as I can't seem to find it manually in the 
> archives?
>
> Thanks
>
> Kirk
>
> N360TV
> SE RG
> TO-360-E1A6D
> ------------------------------------------------------------------------
>
>   

-- 
Dave Philipsen
Velocity STD-FG
N83DP