LSA Engineering Change - Welding the Brake Caliper Torque Plate Mounting Disk

[jaredyates]

Bob has released an Engineering Change for the LSA. Details are here:

http://bearhawksafety.com/LSA/lsa_2017_A.html

[bway]

I wish some of you welders would explain to me why having a "skip" in the bottom of the axle weld is needed. My quick build has a beautiful weld all the way around. It does have the Marco brakes and wheels. Thx, Bob

[BTAZ]

For simplification, the highest stress will be in landing. The vertical load applied when accidentally "dropping it in" ,means the bottom of the axle will be in tension and the top will be in compression.

A poor weld across the bottom(undercut for example) will be weaker then an un-welded axle.

A good weld I wouldn't expect to be an issue although cracking is always a possibility.

Really no need for a complete circumferential weld for the brake torque plate as it just needs to be strong enough for the max torque applied by braking.

I skip welded mine to make sure I had clearance for the bolts that hold the brake caliper bracket on.

[Mark Goldberg]

I just spoke with Bob about this engineering change. Bob's LSA has the axle welded as shown on the plans with 400 hours on the plane and a fair amount of hard landings from STOL practice for the competitions. No problems. In addition - there is a scratch built LSA like this that was welded by an amateur and is VERY heavy and done a lot of flying with two heavy guys in it. According to the owner who learned to fly in the plane - he has slammed it in pretty good several times. No problems.

So as BTAZ said above - if the welds are good and not undercut then it should be fine. But if you have yours welded around like the plans show - it is something to keep an eye on during inspections. Mark