c/aircraft-mechanics

Factory reman vs. overhauled from the local shop - what's your call?

My chief gave me two options for a PT6 compressor section last month: shell out $18k for a factory reman, or let old Mike down at AeroParts do his hot section overhaul for $11,500. I went with Mike to save the budget, but now I'm chasing a vibration that wasn't there before. Did I get what I paid for, or am I just being paranoid? Who's had better luck with one over the other?

Realized I was using the wrong torque wrench for small hardware for 15 years

Tried a cheap ultrasonic cleaner on some injector nozzles and it wrecked two of them

I grabbed a $60 cleaner from Harbor Freight last week thinking it would save time cleaning some old PT6 fuel nozzles. Ran it for 10 minutes with standard solution and two of them came out with visible pitting on the orifices. Learned the hard way that not all ultrasonics are fine enough for aviation work especially on critical parts. Anyone else run into this with budget shop gear?

Spent 6 hours chasing a fuel leak that turned out to be a loose clamp

I was working on a Cessna 172 last Wednesday and smelled fuel as soon as I opened the cowling. Took me a full afternoon to track it down because I kept looking at the fuel lines near the injector. Turned out to be a $2 clamp on the return line that had wiggled loose over time. Has anyone else had a simple fix take way longer than it should have just because you assumed the problem was somewhere else?

Found a stat about rivet quality control that got me thinking

I was reading through some FAA records last night and saw that over 60% of field repair failures come from bad rivet installation, not the rivets themselves. That surprised me because I always figured it was more about metal fatigue or corrosion. Do you think training or tooling is the bigger issue for most mechanics?

Those fancy torque wrenches with digital readouts finally won me over

I spent 10 years using the old beam style torque wrenches on everything. Figured digital ones were just for guys who couldn't feel the click. Then last month I had to torque some landing gear bolts on a 172 where the manual spec was like 18.5 ft-lbs. My old beam wrench couldn't even get that precise. Borrowed a Snap-on digital from the lead mechanic and it hit the number exact on the first shot. Anyone else switch over after fighting with analog stuff for too long?

That one week where every single torque wrench failed calibration

Last month we had a stretch where three different torque wrenches came back from the cal lab reading off by more than 10%. One was on a 737 flap actuator bolt that I almost signed off. Has anyone else seen a batch of wrenches go bad like that all at once?

Just figured out a cheap trick for cleaning old fuel injectors without a sonic bath

I was fighting a set of injectors from a 1990s Cessna 172 that were all clogged up. Tried carb cleaner and compressed air but they still pulsed unevenly on the test bench. Then I soaked them in a jar of Pine-Sol overnight and hit them with a stiff brush the next morning. Three of the four came back to life and flow matched within 1% after that. Anyone else found a random household cleaner that works better than the expensive stuff?

Switched from paper logbooks to digital tracking 8 months ago

I used to do all my maintenance tracking on paper logbooks at the small shop I work at in Wichita. Every job I wrote down the part numbers, hours, and dates by hand. It worked fine until last March when an FAA inspector came through and I spent 3 whole days looking for a record on a Cessna 172 main gear we did back in 2019. That sold me on switching to a digital system. We got a basic maintenance tracking software for $150 a month and now I just scan the barcodes on parts and type in the hours. The search function alone saves me probably 2 hours a week. Has anyone else made the swap and found a system that actually works for GA planes without breaking the bank?

The before/after on a Cessna 172 cylinder change I did last month blew my mind

I swapped a jug on a 172 that had 1,200 hours and was burning a quart every 3 hours. After the new cylinder and piston rings broke in over 10 flight hours, oil consumption dropped to less than a quart every 10 hours. The old jug had so much scoring on the barrel walls I could feel it with my fingernail. Anyone else seen a worn cylinder go from looking fine to that bad so fast?

Tried using anti-seize on spark plug threads for the first time and it totally backfired

Last month I put a light coat of copper anti-seize on the spark plugs of a Lycoming engine. Thought I was being smart preventing galling. Well, two of them backed out after 15 flight hours and I had to pull the cylinder to fix the stripped threads. Learned that torque values change with lubricants, so now I just install them dry per the manual. Has anyone else had a similar experience with anti-seize on aero engines?

250 hours of sheet metal patching later and I finally realized why the old timers call riveting "zen with a gun"

Did that number hit anyone else like a brick wall when you added up your logbook time on just skin repairs alone, or am I the only one who got humbled by the math?

Took me 3 years to figure out I was torqueing cylinder head bolts wrong

I always just went by the manual's torque spec and called it done. But last month I had a cylinder base nut come loose on a test run, and a senior mechanic watched me torque the replacement. He said 'you gotta lubricate those threads first' - turns out dry torque vs lubricated torque can be 20% different. Ever since I started oiling the threads and going by the wet torque spec, not a single re-torque has moved. Anyone else get caught by dry torque specs on critical fasteners?

Saw a guy torque a spark plug with a ratchet yesterday - is there ever a case for skipping the torque wrench on engine work?

I was at a shop in Tulsa last Thursday helping a buddy with a cylinder change and his new helper just cranked the spark plugs in with a regular ratchet. No torque wrench, just a feel for it. My buddy chewed him out but the kid argued that on older engines like the Continental O-470, you could feel when it was tight enough. I get the efficiency argument - digging out the torque wrench adds time on every plug. But I've also seen a plug strip out from overtorque on a Lycoming and the fix took half a day. Can someone actually feel the correct torque reliably on these things or is that a gamble that always catches up to you? Anyone else see this kind of shortcut on legacy engines?

Shoutout to the guy who showed me a better way to pull a prop governor last Tuesday

I was working a King Air 200 up in Bangor, Maine last week and that governor was just stuck on there. I had been wrestling with it for like 45 minutes, trying the normal tricks with a puller and some heat. Then this older mechanic from the hangar next door walks over and just watches for a minute. He says, 'you're fighting the corrosion, not the bolt.' Then he grabs a 2x4 and a dead blow hammer, taps the flange at a specific angle, and it pops right off. I felt kind of dumb but also super grateful. He told me he learned that trick from a guy who worked on DC-3s back in the 70s. I've never seen anyone do that before, and it saved me a bunch of time. Has anyone else run into those weird little tricks that just aren't in the manual?

Did a quick preflight on a CRJ700 in Oklahoma City and found a cracked engine mount bracket at 6 AM

I was doing a routine walkaround at sunrise last Tuesday. The bracket had a hairline fracture you could barely see without a flashlight. Ended up grounding the plane for 3 hours while we swapped it out. The pilot was not happy but better than having it fail mid flight. Has anyone else caught something that tiny during preflight that could have been bad?

Took me 6 months to admit I was stripping bolts the wrong way

I always thought more torque meant a tighter fit on these panel screws but after snapping my third #10 in a row, a senior guy named Dave pulled me aside in the hangar and showed me the difference between using a torque wrench versus just going by feel. He literally handed me a scrap bracket and had me test it myself on the bench, and I saw the threads getting chewed up under the light. Has anyone else had to unlearn something basic like this after years of doing it wrong?

That one shift where I had to sign off three planes in five hours

Last Tuesday, I had a CRJ come in with a faulty bleed valve, a 737 with a cracked windshield, and a Citation with an oil leak all land within 30 minutes of each other. By the time I finished up the last one at 11 PM, I was running on nothing but coffee and spite. Has anyone else had a shift that just kept stacking like that?

Old timer told me my torque wrench technique was trash

Guy with 30 years at Delta watched me click a bolt and said you gotta pull smooth and steady, not jerk it like you're starting a lawnmower. Anyone else get corrected on something basic that actually made a huge difference in your work?

Took me 3 aircraft to realize people are torque wrenching control cable turnbuckles wrong

I always thought torque wrenches were bulletproof until one cost me a day of work

I've been an A&P for about 12 years and I always assumed my torque wrenches were good to go as long as they clicked. Last month I was doing a flap track rebuild on a 737 at a shop in Tulsa and I kept snapping bolts on the gearbox mounts. I checked the manual, checked the bolt spec, everything looked right. After the third one snapped I grabbed a different torque wrench from the tool crib and it clicked perfectly at the same setting. My old one was about 15 ft-lbs off at the lower end of its range. I sent it out for calibration and sure enough it was way out of whack. Now I'm sending all my click-type wrenches out every 6 months instead of yearly. Has anyone else had a wrench go bad without any signs of damage?

Remember when we had to rebuild carbs instead of just swapping them out

Been in this trade since 1998 and I swear carburetors were built different back then. Worked on some old Wright radials at a museum in Arizona couple years ago and the carb rebuild took me two full days with a jeweler's file and ultrasonic cleaner. My trainee kept asking why I didn't just order a new assembly from the catalog. Told him those parts aren't made anymore and even if they were the fuel flow curves would be off. Anyone else feel like the newer electronic injection systems just don't hold up the same way over time?

Just realized my torque wrench was way off for like 6 months

Old-timer at the hangar named Rick told me to get my torque wrench checked every year. I thought he was just being extra. Then last month I stripped a bolt on a 737 flap track because my wrench clicked way too late. Cost the company like $400 in parts and a half day of downtime. Rick just looked at me and said 'told you so' lol. Now I test my torque wrenches every 6 months with a calibration stand. Anyone else have a tool fail at the worst time?

Shoutout to the old timer who told me to use a torque wrench on spark plugs instead of just hand tight

I was changing plugs on a Cessna 172 last Friday and had a choice: keep doing what I always did, which was snug them up by feel, or borrow the torque wrench from the hangar. I figured why risk a stripped thread in the cylinder head, so I grabbed it. Set it to 30 foot pounds and every single one came out perfect with no issues. Turns out the shop had three engines come in last year from overtorqued plugs. Has anyone else had a close call with hand tightening stuff that should just be torqued?

Had a talk with a 30-year A&P that changed how I look at torque specs

I was swapping a nose gear tire on a Citation last week and he walked over and told me I was torquing the axle nut way too tight, like 50 ft-lbs over the book spec. He said he learned the hard way when a hub cracked on him back in the 90s and ever since he sticks to the manual no matter what the old timers say. Has anyone else had a veteran mechanic drop a piece of advice that made you rethink your whole approach to a job?