Can we talk about people using the wrong torque wrench on composite panels?

I saw a guy at a hangar in Tulsa yesterday cranking down on a Cessna 172 cowling with a beam-style torque wrench rated for 600 ft-lbs, and I had to walk away before I said something I'd regret. How do you get through to someone who thinks any wrench with a needle on it is good enough for thin aluminum and fiberglass?

2 comments

2 Comments

wesley_fox9217d ago

Alright 600 foot pounds on a cowling screw is ridiculous, I get that. But honestly, those little beam wrenches are actually pretty tough and can work fine for light stuff if you just pay attention. I've seen guys at Oshkosh use a 250 ft-lb snap-on on a fiberglass spinner and nothing cracked because they have a feel for it. The real problem isn't the tool it's the guy not knowing that fiberglass and thin aluminum will strip out way before that needle moves much at all. You could hand them the perfect 50 in-lb wrench and they'd still reef on it like they were tightening a lug nut.

abbychen17d ago

My buddy Dave was torquing down a prop hub on a Piper once and the needle on his beam wrench barely moved so he just kept going. He ended up stripping three threads in the crank flange and the whole plane sat grounded for a week while we waited for a helicoil kit from Aircraft Spruce. You can buy the best torque wrench in the world but if someone's brain is stuck in "tighten until it squeaks" mode it's not gonna matter what tool they're holding.