c/aircraft-mechanics

Saw a control cable fray on a Cessna 172 last Wednesday, caught it just in time

I was doing a preflight inspection on this 172 that came in for a 100 hour check. Pulled the throttle back and felt this tiny catch, like a snag. Got my flashlight and looked closer, and sure enough three strands of the cable were snapped right where it goes through the pulley. Must have been rubbing for months. Had my A&P buddy double check it and we ordered a replacement right there. Anyone else ever find a hidden cable failure that wasn't obvious from a quick look?

That fancy $800 borescope I laughed at... now I can't live without it

I used to watch guys pull out these expensive scopes and think they were just showing off. Then I spent 4 hours chasing an oil leak on a 737 in Phoenix because I couldn't see behind a duct. Borrowed a Snap-On scope from the lead and found the crack in 5 minutes. Anyone else eat crow on a tool they swore was unnecessary?

Tried a speed handle on a tight engine cowling job and totally whiffed

Last month I had to pull 32 screws off a Cessna 172 cowling and figured I'd finally grab a speed handle to save time instead of using my regular ratchet. Man, that thing was a disaster in tight quarters. I kept slipping off the screw heads and camming out because I couldn't get the angle right in that cramped space. Took me almost twice as long as usual because I had to go back and re-seat half of them by hand. I ended up just tossing the speed handle back in my box and finishing with my stubby ratchet like always. Learned that speed handles are great for open engine bays on bigger birds but absolutely useless on small GA planes with zero clearance. Anyone else find a tool that just doesn't work on certain airframes?

Walked into a regional hangar in Tulsa yesterday and nearly lost it

I saw a mechanic using a 3/8ths ratchet to torque a main wheel nut, you know, just winging it by feel. The torque spec on that nut is 250 foot-pounds, and he didn't even have a gauge on him. Has anyone else seen stuff like this slipping through at smaller shops?

Cracked a stubborn 737 brake line yesterday and this old-timer watched me fight it for 20 minutes before saying something

He just says 'you're trying to muscle it, but that line wants to be coaxed not forced.' I was about to snap a fitting so I backed off and tried his way, gently working it back and forth with some penetrating oil. Took maybe 3 more minutes and it came loose clean. Been wrenching for 6 years at MRO in Atlanta and that little tip saved me a whole lot of headache. Anybody else have something like that where a simple piece of advice from a veteran totally shifted how you approach a job?

Found a cracked bellcrank on a Cessna 172 during annual last week

The bolt was torqued fine but the forging had a hairline split right at the bend. Anyone else run into hidden stress fractures on older airframes that looked fine until the dye check?

Caught a guy torquing spark plugs on a cold engine yesterday, here is why that's a problem

I was walking past a bay at work yesterday and saw a new guy zipping spark plugs into a cold Continental IO-520. He had the torque wrench set to the book spec and everything, but the engine was probably 50 degrees from sitting overnight. The problem is the aluminum head expands when it warms up and the plug gap closes up, plus the torque values are for a warm engine. I told him to run it up to operating temp first, let it cool down just a bit so he doesn't burn himself, then torque them. He looked at me like I was speaking a different language. Has anyone else had to explain this to a new mechanic or am I just getting old?

Hot take: Hitting 10,000 flight hours didn't feel like a milestone, it felt like a warning

I hit 10K flight hours last month and everyone expects me to be proud, but honestly I just felt this weight of all the close calls and overnight shifts. My back is done, my hearing is shot, and I'm still chasing a crack in a 737 bulkhead that nobody else can find. Has anyone else hit a number that made them question how long they can keep doing this?

PSA: Most of those 'overhauled' fuel nozzles from eBay are just cleaned up with brake cleaner not actually rebuilt

Pulled apart three I bought for a CFM56 and found the internal screens were clogged with the same varnish they were supposed to be rebuilt for, found the truth when I posted them on the mtprop forum and a guy who used to work at a repair station confirmed the serials matched a batch they scrapped 5 years ago. Anyone else caught fake overhauls from online parts?

That torque wrench calibration at the MRO saved my 737 main gear job

I skipped the calibration check last minute on a wing job and ended up snapping a bolt on the MLG trunnion. Bought my own digital torque adapter for $180 and it's been dead on ever since. Anyone else think these shop tools are way more off than we admit?

Thought those $20 ultrasonic testers were a joke until I used one on a Cessna 172

Buddy brought his cheap ultrasonic thickness gauge from Amazon to check wing skin corrosion on my annual. I laughed when he pulled it out. Set it up, ran it on a spot near the fuel vent that looked fine. Came back 0.032 instead of 0.040. Pulled the skin and found pitting underneath I never would have caught. Has anyone else had a cheap tool actually save their ass on an inspection?

Tried using a digital torque wrench on a jet engine fan blade job the other day and I'll stick with my old beam style.

The digital one kept giving me inconsistent readings in the cold hangar air, so I went back to the beam wrench that's been in my box since 1998 and it worked perfect on the first try has anyone else had trouble with digital tools in cold weather?

Why does nobody talk about the shift from visual inspections to borescope-first on turbine blades?

I started in this trade back in 2012 at a regional shop in Omaha, and back then we did a visual inspection first, like every single time. You'd pull the cowling, grab a flashlight, and poke around with a mirror if you had to. Fast forward to last year at my current gig, and now we go straight for the borescope before touching anything, like it's the new normal. The change happened around 2018 or so when the engine manufacturers started pushing these high-res scopes with video capture. On one hand, it saves time on tear-downs for minor nicks, but on the other hand, I've caught myself missing subtle cracks that a good visual sweep would have spotted. My old foreman swears the borescope makes us lazy, but younger guys say it's just being efficient. What's your take, do you still do a visual once-over before pulling out the scope, or did the industry leave that behind?

Had to pick between safety wire or speed tape for a temporary fix on a fuel line

I was working a late shift at the hangar in Phoenix last summer and a Cessna 172 came in with a weeping fuel line fitting. My lead said just slap some speed tape on it to get it flying, but I know that's a bandaid that can fail. I went with safety wire to back up the fitting, and the plane passed the pressure test, but I still wonder if the tape would've been fine for the week before the part came in - what would you have done?

Ngl I thought torque sticks were a gimmick until a wheel came off on the freeway

Yeah so I had this 737 come through last month, did the usual lug nut torque by feel like I been doing for 8 years. Customer calls back three days later saying he heard a clunk on I-5 near Sacramento. Wheel almost separated. Now I use the sticks every time. Anyone else have a close call that changed your routine?

Swapped from safety wire to locking clips on engine cowlings. Regret it sometimes.

Used to safety wire every cowling fastener by hand. Took forever but I trusted it. New shop switched us to those locking pin clips. Faster. Less finger cuts. But I've had two pop loose during vibration checks. Old timers swear by wire. New guys love the clips. Which side you on and why?

Swapping out the old pneumatic rivet gun for a cordless one changed my workflow big time

I used to use a pneumatic rivet gun for everything on the line at my shop in Phoenix, but last month I switched to a cordless Milwaukee M12 rivet gun for smaller jobs. The difference is huge for me since I don't have to drag hoses around when I'm working on tight spots inside the fuselage. Anyone else made the switch and found it worth it for just panel work?

I walked off a job in Detroit last month because of a missing torque wrench

I showed up at 6 AM like I always do, coffee in hand, ready to pull an engine on a Cessna 172. The shop foreman told me the torque wrench I needed was out for calibration and they'd 'just use the old one' sitting in the back. I've been doing this for 12 years and I know the old one reads 5 foot-pounds heavy on the low end. They wanted me to sign off on a critical prop flange bolt job with that busted tool. I told them no way and packed up my box right there. Got a call from the lead mechanic two hours later saying I was right and they were sending the old wrench out. Has anyone else dealt with a shop trying to cut corners like that on torque specs?

Spent 20 minutes digging a pitot tube cover out of a #2 engine inlet last Thursday

Cowling was already off and the cover must have blown in during the night shift, has anyone else found random stuff wedged in weird places on a preflight?

Shoutout to the guy who said CRC Electronics Cleaner works better than acetone on old flux residue

He told me after 15 years of scrubbing boards with acetone on airliner nav units, I tried the CRC last Tuesday and it cut my cleaning time in half, has anyone else found a weird cleaner that just works way better than the standard stuff?

Tried using a cheap borescope on a Cessna 172 cylinder and got completely useless footage

Last month I picked up a $40 borescope off Amazon to check some cylinders on a 172 that had a rough running magneto. Thought it would save me a trip to the hangar with the good scope my buddy has. Hooked it up to my phone and the image was so grainy and blurry I couldn't tell carbon buildup from a crack in the cylinder wall. Wasted about 30 minutes trying different lighting angles and wiping the lens. Finally just borrowed his Snap-on scope and saw the issue clear as day in 5 minutes. Learned real quick that cheap tools in aviation just cost you more time in the long run. Anyone else had a bad experience with budget inspection gear that made you second guess your choices?

Hit 10,000 flight hours on a single set of torque wrenches and they still passed calibration

Walked away from a 20 year DC-9 habit after a starter valve let go

I've been a DC-9 guy since I started out in 1998. Last month I was doing a starter valve R&R on an MD-80 variant and the old valve's housing cracked right in my hands during bench testing. That thing had been rebuilt three times according to the log. After that I looked at the new electric start systems on the newer jets and something clicked. They are simpler and have way fewer failure points. I told my lead I wanted to switch over to training on the A320 fleet starting next month. Has anyone else made a big jump like this after a long time on one airframe?

Had an old inspector tell me my torque wrench was my problem, not the hardware

I used to blame bad hardware whenever a bolt stripped or a nut wouldn't torque right. Then this guy who's been doing inspections since the 80s watched me one day and said, 'Stop cranking on that thing like it's a lug nut on a pickup. You're overtorquing everything by about 15 percent.' I thought he was full of it at first. But I borrowed his calibrated clicker and ran the same fasteners again, and sure enough I was way over. Now I check my torque wrench calibration every 3 months with a test stand, and I haven't had a stripped bolt in 6 months. Has anyone else had a similar wake up call about a tool they thought they knew inside out?

Old timer told me to check the bond jumpers first on a no-start Cessna 172

Had a 172 come in last week with a no-start issue on the ramp. I was pulling my hair out checking mag timing and fuel flow for like 2 hours. This retired mechanic who hangs around the hangar told me to check the engine mount bond jumpers first because they crack and cause grounding issues. Sure enough, one was split right at the lug. Put a new one on and it fired right up. Now I feel dumb for not going there sooner lol. Anybody else got a quick check they always skip that ends up being the problem?