A320 broken axle

[tubby linton]

A United A320 N453UA today at Newark suffered what appears to be a broken axle on the starboard main gear leg.It is a very odd looking failure.
The aircraft was empty at the time
https://twitter.com/flightorg/status/860806874270023680

[WindSheer]

Oooh. Thatll cost.

[tubby linton]

Sources now saying a manufacturing defect. Any emergency AD been issued?

[sprite1]

I'd say more likely the result of metal fatigue from a recent hard landing.

[DaveReidUK]

If it was metal fatigue, it wouldn't have been initiated by anything recent.

[sprite1]

Fatigue not so much from constant repetitive forces over a number of years as one good hard landing recently. Going over a drain cover or divet on the ramp could be final stressor.

I'm not aware of any material change to the landing gear construction on the 320 compared to years gone by. My response was to the comment about sources already saying it's a manufacturing defect. I'd be surprised, personally.

I've heard of one outfit that had over half its landing gear wheel units over torqued at the hangar and some units (after re-inspection due to cracking) under torqued.

[DaveReidUK]

Fatigue not so much from constant repetitive forces over a number of years as one good hard landing recently.

Then you mean failure, but not from fatigue.

[sprite1]

Indeed I do! Touché!

[Capn Bloggs]

Even I would have picked that up on the walkaround... :ok:

[tubby linton]

New photos show a break in the fesculated part of the leg and into the area underneath it

[lomapaseo]

That sounds like it's been infected for a long time

[tubby linton]

Photo of the break.
https://www.facebook.com/a320systems/photos/pcb.1279170422204657/1279170208871345/?type=3&theater

[tonytales]

More than likely it is from hydrogen embrittlement of the metal. High strength parts require controlled baking after plating to remove hydrogen introduced up during the plating process. Also wrong paint stripper for instance can affect metal. Have seen a landing gear truck break while aircraft sitting on the ramp being fueled. A Service Bulletin had required a dye check of a spot on the truck and the wrong stripper was used to remove the paint. As mentioned too, a machining mark made during manufacturing or overhaul not noticed by inspection can also cause a stress concentration and subsequent cracking.

[underfire]

tubby, simply amazing that it let go while sitting there..this could have been so much worse...