Stumbled on a torque spec that blew my mind

Was flipping through the AMM for a 737NG flap track yesterday and found out the bolt torque for the center track roller is only 30 in-lbs. Feels like nothing considering it holds the whole flap on, anyone else ever get tripped up by a spec that seemed way too low?

2 comments

2 Comments

the_wyatt14d ago

Hang on, 30 in-lbs is basically finger tight, that can't be right. I've torqued down suspension bolts on my truck that took my whole body weight to break loose, seeing something that delicate on a flap track is just wild. Is there a lock wire or some other retention method making up for the lack of clamp force?

grantf7314d ago

Wait, you're saying 30 inch-pounds for a flap track bolt? That feels like I could overtighten it with my thumb alone. I've seen similar low specs on fuel pump fittings where you think it would leak for sure but it doesn't. The trick is those small bolts are usually in shear not tension so they don't need massive clamping force. Still messes with your head when you've been torquing big stuff all day. Have you ever had one of those come loose in service or is it just one of those things that works because the engineers know something we don't?