c/aircraft-mechanics

Just hit my 500th wheel torque check, and 37 of them were loose

I've been doing line maintenance at KDEN for about 4 years now. Today I hit 500 documented torque checks on main gear wheels. I was just flipping through my log (I keep a little notebook, old school I know) and counted that 37 of those were actually loose, meaning more than a quarter turn past spec. That surprised me because I always thought the torque stripe method was pretty reliable, but those were all cases where someone painted over a dirty surface or the stripe just blended in. My foreman always says 'trust the clicker, not the stripe.' Now I'm wondering, do you all count your own checks like this? And has anyone else seen a similar loose ratio, or am I working with a bad batch of hardware?

Finally passed my A&P written after 3 tries in Oklahoma City

Last month I sat down for the general written exam for the third time and walked out with a 78. I barely scraped by but a pass is a pass. The first two attempts I tried studying from memory and old quizlets, which clearly wasn't working. This time I spent 6 weeks going through the ASA prep book one chapter at a time and drilling the practice tests every morning before shift. My buddy who's been a mechanic for 20 years told me to focus on the wiring diagrams and electrical sections, and he was spot on. Has anyone else found that the real test pulls questions from sections you least expect? I'm already looking at the airframe and powerplant written exams next and would love any advice on what to prioritize there.

Torque wrench vs my own arm, I finally learned my lesson

Last month I was putting a nose gear wheel back on a Cessna 172 and figured I could skip the torque wrench for the last few bolts. Just felt it out, you know, like I'd done for years. Turned out I over-torqued one stud and it snapped clean off during a post-maintenance run-up. New stud, new nut, and a solid hour of explaining to the lead mechanic why I trusted my arm over a $150 Snap-on. Anyone else ever get humbled by skipping the calibrated tool?

That time I was torquing spark plugs wrong for way too long

I've been turning wrenches on small planes for about 12 years now, mostly piston engines. About 6 months ago I was doing a routine top end on a Lycoming at my shop in Spokane. I was putting in new spark plugs and just doing the usual, torque wrench set to 30 foot pounds, giving each one a good pull. Then the engine lead on number three felt weird when I was threading it back in, like it was a little loose. I pulled the plug back out and saw the crush washer was totally flattened out, like pancaked. That's when it clicked that I had been overtorquing those plugs for years, probably since I started. The spec is 30 foot pounds but only with a light coating of anti-seize, and I had been putting them in dry without thinking about it. Realized the dry torque is way different than wet, and all those plugs I thought were fine were actually getting cranked too tight. Has anyone else had a brain fart like that where you follow a spec but miss the fine print for years without noticing?

Spent $400 on a premium torque wrench set from Snap-on. Huge mistake.

Thought I was being smart buying the Snap-on set for the lifetime warranty. But two months in the ratcheting mechanism jammed up on the 3/8 drive. Warranty process took three weeks and I lost a job at a regional airline in Ohio. Fellow mechanics swear by CDI torque wrenches for half the cost. Anyone else have brand loyalty backfire on them like this?

Dropped $200 on a Snap-on ratchet and honestly it was worth it

Bought a Snap-on dual 80 ratchet last spring after my old Craftsman finally gave out. Cost me $218 with the student discount through the truck. First week I used it on a tight engine mount bolt and it clicked over like butter. No busted knuckles, no swearing under the cowling. My coworker laughed at me for spending that much but he borrowed it yesterday to pull a starter. Anyone else find that one tool that just makes the job less miserable?

Old timer at the hangar swore by hand-propping a Lycoming. I should have listened

Used to think a torque wrench was a torque wrench until I tried a CDI on a 737 wheel bolt

Borrowed my buddy's CDI 1503 after snapping two bolts with my Craftsman on a main gear hub and the CDI clicked perfect every time at 180 ft-lbs, so now I'm saving up for one but has anyone else had bad luck with the cheaper digital ones clicking way too early?

Warning: Picking a used borescope over a new one cost me 6 hours of rework

Last month I had to choose between buying a new $800 borescope or a used one off Ebay for $200. I went cheap because my budget was shot after buying new torque wrenches. The used one looked fine in the photos but the image quality was garbage when I got it on the hangar floor. Couldn't see a crack in a #4 cylinder on a Lycoming IO-360 until I pulled the jug and found it by hand. That was a six hour job I could have avoided if I just spent the money upfront. Has anyone else burned time trying to save a few bucks on inspection gear?

Almost lost a finger at a shop in Phoenix last month - caught a prop strike from a loose spinner

I finally found a trick for getting stripped screws out of aluminum panels

After fighting with a stuck screw on a Cessna flap fairing for an hour, I tried tapping a torx bit into the head with a hammer and it grabbed tighter than any extractor I've used, has anyone else had luck with that method on softer metals?

Was wrong about using oil on torque wrenches until a compressor line blew on me at O'Hare last week

Showerthought: That leak detection dye they push at every shop I've been to in Phoenix is causing more problems than it solves

I was working on a Cessna 172 at the Mesa airfield about 2 months ago when I saw a mechanic dump a whole bottle of that UV dye into an engine that just had a slow oil seep. Next week that same plane came back with a blown rear main seal and clogged oil passages. The dye is thick and sticky when it dries. I refuse to use it now in anything. Anyone else seen long term damage from that stuff?

Take this with a grain of salt, but the old-timer who told me to stop pressure washing my Avro's engine...

So back in March at the hangar in Burbank, a retired mechanic named Hank watched me prepping a 1967 Avro 748 for a check ride. He said 'kid, if you hit the cylinders with that pressure washer, you'll push the crud right past the rings.' I thought he was full of it because I've been cleaning engines that way for 5 years with no issue. Well, I did it anyway, and after the first climbout, she started burning a quart every 45 minutes. Compression test on number 3 showed a 50 psi drop. Pulled the jug and found a line of grit embedded in the oil ring. Had to R&R the whole cylinder at $400 in parts plus my Sunday. Has anyone else had an old-timer give them advice that seemed dumb but turned out to be spot on?

Am I the only one who misses the old paper logbooks for aircraft? Digital is fine but something got lost.

We had a Cessna 172 come through the shop last week with a digital logbook that had some corrupted entries from 2019. Took me three hours to track down the actual maintenance history through the previous owner's paper records. Anyone else find that the old handwritten logs just held together better over time?

Snap-on guy rolled through the hangar last Tuesday. Spent $250 on a new 1/4 ratchet.

My old Craftsman finally gave up after 8 years. The snap-on feels way smoother. But man, $250 for a ratchet? That stung. Anyone else feel like you gotta pay the tax just to work on these planes?

Saw a guy torque a spark plug with his bare hands on a 737 yesterday

I was walking through the hangar and stopped to watch a new guy finish up an engine job. He just cranked those spark plugs down by feel and walked away like it was fine. I had to pull him aside and show him the torque spec sheet in the manual for that specific plug, which is 20 foot pounds on a CFM56. If that comes loose in flight, you're not just looking at a rough running engine, you're looking at a possible fire or sudden stoppage. I know some old timers say they can do it by hand, but the manual exists for a reason and it's not worth the risk. Has anyone else seen new guys skip the torque wrench on critical fasteners like this?

Stop using WD-40 on aircraft control cables

I keep seeing guys at the hangar in Tucson spraying WD-40 on control cables to silence a squeak. That stuff dries out the cable and attracts dirt, so you end up replacing cables in 6 months instead of 6 years. When was the last time you actually read the maintenance manual for cable lubrication?

Learned a hard lesson about torque values on Gulfstream gear doors last month

I was working a 12-year-old G450 at a shop in Savannah and had a gear door that kept binding after a retraction test. Turns out the torque values in the old manual were for the wrong bolt grade, and I'd been overtightening them for years. Anybody else found outdated specs in older aircraft manuals that caused you headaches?

That damn fuel injector on a 737 took me 8 hours when it should have been 2

I had this one injector on a 737-800 that just would not seat right. First hour I tried the usual tricks, tapping it in, lube, the whole deal. Nothing. Second hour I pulled it back out, cleaned the bore again, still no luck. By hour six I was ready to toss the whole engine, finally found a tiny burr inside the mounting hole from a previous install job. Had to file it down carefully and then it slid in like butter. Has anyone else dealt with hidden burrs that just ruin your whole shift?

Vent: That one Tuesday shift where everything hydraulic decided to quit on me

Back in 2019 I was working nights on a 737 in Memphis and within 4 hours I got hit with three separate hydraulic leaks. First one was a slow drip from a nose gear actuator, then a burst line on the right main, and finally a jammed valve on the cargo door. By 2 AM I had puddles of Skydrol all over the hangar floor and my coveralls were soaked. I spent the next two days flushing and re-testing systems. Has anyone else had a night where the plane just fought back like that?

Debate: Did I do the right thing by grounding a 737 for a cracked windshield that passed stress tests?

I was working line maintenance in Denver last Tuesday when I flagged a 737 with a 2-inch crack near the lower corner of the windshield. The lead inspector said it passed the stress test and could fly another 50 cycles. But I grounded it anyway based on the crack pattern I saw. Turned out the inner ply was delaminating, and it would have blown out at 30,000 feet after a few more pressurizations. My supervisor backed me up, but the crew was furious we lost 4 hours of schedule. So here is the question: Do you follow the book every time even if it costs the company money, or do you weigh the risk if the numbers say it is okay? Has anyone else called a no-go when everyone told you it was fine?

Hit 10,000 rivets set without a single double-hit last week and I'm still weirdly proud about it.

Been turning wrenches on 737s for 6 years and that tenthousandth mark just snuck up on me during a stringer repair in the hangar, has anyone else had a random milestone like that make you stop and think about how far you've come?

Appreciation post: the brake disc job that took me 8 hours on a CRJ200

Honestly, I've been doing sheet metal and brake work for about 6 years now, but last Tuesday I hit a wall on a CRJ200 brake disc replacement. The inboard disc was seized onto the axle flange like it was welded there from the factory. I spent 4 hours just trying to break it loose with penetrating oil and a slide hammer, and nothing budged. Finally I grabbed a torch and heated the hub for a bit, then used a pry bar and some careful taps from a dead blow. It popped off after another 30 minutes, but by then I had already wasted my whole afternoon. The whole job ended up taking 8 hours when it should have been a 2 hour swap. Has anyone else run into seized brake discs that just refuse to come off no matter what you try?

Spent 6 months torquing spark plugs wrong on the 737

Was doing the top plugs on a CFM56 and a lead mechanic watched me for a second and goes "you're overtorquing those by 50 foot pounds easy." Turns out I'd been reading the torque chart wrong the whole time since I started at the hangar in Phoenix. Anyone else find out they'd been doing something basic wrong for way too long?