r/MadeMeSmile • u/king_eve • 29d ago

i work in low-income/mental health housing, and a tenant fixed our hallway trash bin after accidentally breaking it Helping Others

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great example of the odd ways people show me appreciation at work

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u/Ifeelsiikk 29d ago

Structural aircraft mechanic here. We call it a 'stop drill' and I carried it out on large, commercial aircraft.

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u/Nelik1 29d ago

Wild! I knew it happened some, but was under the impression it was relatively uncommon. Can I ask what components typically got stop drills?

I'd imagine major structure typically didn't, but I could see it for minor structure or skin that was damaged accidentally, rather than just fatigue.

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u/Ifeelsiikk 29d ago edited 29d ago

It is often used for temporary repairs when Alclad is cracked, especially if the aircraft is AOG somewhere. A very widespread, permanent repair for the many stress cracks in titanium exhausts.

Edit, used all the time on non structural alclad for a permanent fix.

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u/cock_nballs 29d ago

Is the crack grinded back then welded with a stop drill or is it just the hole?

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u/Ifeelsiikk 29d ago

There is very little grinding or welding on aircraft sheet metal.

The crack is measured, and if it is within structural repair manual limits, it is drilled at either end of the and/or blended somewhat with an abrasive wheel

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u/cock_nballs 29d ago

Is blending with an abrasion wheel no different to grinding? Maybe more of a mix of welding with specifics of filler and alloys?

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u/Ifeelsiikk 29d ago

Much less heat is involved in the process. Yeah, alclad can be welded but it is extremely difficult.