Had a flap actuator arm snap mid-inspection on a 737 yesterday

I was doing a routine flap check on a 737-800, and the actuator arm just sheared off when I applied pressure, no warning at all. Spent the next 3 hours tracking down a replacement part and re-doing the entire test sequence from scratch. Has anyone else run into random metal fatigue on these older models or am I just having bad luck?

3 comments

3 Comments

tarar2726d ago

You said it snapped "when I applied pressure" - was that standard hand pressure or were you using any tools to help it along? I've had a few actuator arms on the 737NGs that felt stiff but never had one actually break off. Did you get to check if there were any stress cracks already visible, or did it just go clean with no warning signs at all?

nelson.nancy26d ago

@tarar27 bet that actuator had hidden microcracks from cold soak cycles.

the_jamie25d ago

Heard from a metallurgist buddy that cold soak cycles can create microcracks that aren't visible until the part is under load... makes you wonder how many other actuators have the same issue but haven't failed yet.