c/avionics-technicians

That 20 minute capacitor swap that ate my whole Tuesday in Tucson

Went out to a 737 the other week for what looked like a standard capacitor replacement on the VHF nav unit. Pulled the old one, popped the new one in, did the continuity test, everything read fine. Fired up the system and the display showed garbage. Spent 3 hours chasing it, checked every wire, reseated connectors twice, even swapped in a second cap from the shelf. Turned out the part number on the box was right but the internals were from a bad batch, the manufacturer had a recall notice on their website dated 2 weeks prior. I was one of those guys who never checks the bulletin on a part that small. Who else has burned a morning on a bad new part instead of an old one?

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masonbell•5d ago

A loose cannon plug on the 737 cost us a full day of troubleshooting

Last Tuesday the autopilot kept dropping out on a -800 and after swapping half the LRUs we finally found the ARINC cannon plug with a pin backed out about 3 mm, so has anyone else had pins creep out of those round connectors on older frames or was this just our luck?

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taylor668•5d ago

Spent $280 on a used IFE test set, saved my butt on a Tuesday rush

Picked up a beat up but functional IFE tester off a retiring contractor for $280. Our shop kept borrowing one from the next hangar over and the boss finally said figure it out. Two days later a CRJ came in with three row screens dead and the passenger address acting weird. Took me 45 minutes to trace it to a bad media server card instead of chasing wiring all afternoon. For what these new ones cost, $280 was a steal. Does anyone else run used test gear or am I the only one who trusts it?

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paul346•8d ago

Why does nobody talk about using a thermal camera for connector pin checks?

I work on a lot of old wiring in hangars around Dallas, and chasing intermittent faults in cannon plugs has cost me so many hours. Last month I borrowed a cheap Flir attachment for my phone and started scanning the backshells while the system ran. A pin with high resistance heats up just a few degrees before it fully fails, and I found a burnt pin in a fuel probe connector that multimeter testing said was fine. It feels like cheating because the thermal image shows you the exact spot without cutting into the harness. But I know some techs swear this gives false positives from reflective surfaces or adjacent heat sources. Has anyone else gone down this route, or do you think it's just a toy compared to a proper load test rig?

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hollyg59•10d ago

My boss made me sign a parts log 3 months late, still not over it

Last month, my lead at the hangar in Tucson handed me a stack of sign-off sheets from March and told me to initial them. I told him I never touched those units, but he said the inventory system showed my initials already. Turns out a temp tech used my login code for two weeks back in February. I caught it by checking the serial numbers against my actual work orders. My manager still made me write a corrective action statement even though I proved I was on vacation. Has anyone else had their login borrowed without permission, and how did you get management to fix the log entries?

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faithwalker•11d ago

Pitot static test adapters: buy the expensive kit or make your own? A $600 difference in my hangar

Last week I needed to do a pitot static check on a Cessna 172 and the shop set was out for calibration. The local guy wanted $1,100 for the full adapter set. I sat there doing math on brass fittings and rubber hose from the hardware store. I built a working set for around 50 bucks in an afternoon. It passed the first leak test and the readings matched the shop unit when I borrowed it later. But I'm not a metrology guy. The certified set has traceable tolerances and the FAA can ask questions during a ramp check. My homemade setup works fine for my own plane, but if you're signing off other people's aircraft, does the paperwork matter more than the numbers? I'm split. Half of me says the price is just for the stamp, the other half says you're an idiot if you don't spend it. Anyone else build their own test gear and live to regret it, or did it save your ass too?

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the_charles•15d ago

An old pilot in Dallas argued against my pin test, still think about it

I was doing a wiring continuity check on a 737 flap sensor in Dallas about 2 years ago, and this retired pilot leaned over my shoulder. He said 'you're wasting time with that meter, just look at the connector pins for corrosion first'. I told him the meter catches intermittent faults you can't see, and he laughed saying he'd seen more bad connections from burnt pins than from invisible breaks. We went back and forth for maybe 5 minutes before I finally found a hairline crack in a pin that looked perfect from the outside. He just nodded and walked off, but it made me wonder if I lean too hard on test equipment instead of basic visual checks. Has anyone else had an old hand challenge your method and end up being right in a way that stuck with you?

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masonbell•19d ago

That tarmac at KSAT taught me to hate soft starts on jet bridges

Last summer I was doing a preflight check on a 737 at San Antonio International and the jet bridge kept cutting power mid-cycle. Three times it dropped the ground power feed while I had the avionics bay open. I finally grabbed a multimeter and found the soft start relay was cooked, but because it still gave partial voltage, my normal test routine missed it. Now I always verify the breaker panel voltage under load before I touch anything, and I ask the ramp crew if they've seen flicker. Has anyone else had a soft start unit lie to them like that, or is it just this airport's equipment?

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rowanellis•20d ago

Ground loop testing is being skipped way too often on bench work

Honestly, I keep seeing guys in our shop at KSFO skip the ground loop test after a simple LRU swap, and it's biting us on the next flight. A 0.5 ohm difference on the bonding strap can cause a 60 Hz hum on the intercom that the pilot blames on the audio panel, not the install. I know it adds 20 minutes, but I've traced three write-ups in the last month back to exactly this shortcut. Anyone else tracking this on their 737s, or is it just our hangar culture pushing speed over solid checks?

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henry_martinez•21d ago

Rant: Chasing a ghost on an RJ100 flap fault ate my whole Saturday

Spent 9 hours on a CRJ200 flap position indicator that kept dropping out on the ground but never in the air. Pulled the PSEU, checked all the harness grounds, even swapped the proximity sensor on the left outboard. Finally broke down and looked at the wiring diagram again for the fifth time and spotted a note about a resistor pack on the #2 relay. Sure enough, that thing had a cracked solder joint inside the sealed box. Swapping that part took 20 minutes and the fault cleared. I know we all say check the simple stuff first, but when the intermittent only shows up after thermal soak, it's brutal. Anyone else had a relay box or sealed module hide a fault like that? How long did you chase it before pulling out the magnifying glass?

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nancy524•22d ago

Serious question about that avionics shop in Shreveport I visited last Tuesday

I stopped by a small avionics repair place outside Shreveport last Tuesday to ask about a stubborn 530W unit and the tech there said he never bothers with the factory service manual, just eyeballs wiring diagrams on his phone. He fixed my unit in 20 minutes flat, but it feels like skipping the official docs is asking for trouble down the line. Am I wrong for thinking that's a risky habit, or is hands-on experience just better than the paperwork half the time?

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paul346•23d ago

Update: stopped trusting the schematic after a bad night in Tucson

Last month I rewired an old King radio in a Cessna 172 and trusted the wire diagram over my own continuity test. Turns out a previous tech had swapped pins 14 and 22, so I cooked a brand new audio panel. Now I verify every pin with my Fluke before I power anything up, even if the drawing looks clean. Anyone else run into a bogus diagram that cost them a part?

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victorb74•24d ago

Overheard a guy say he fixed a radar issue by just reseating a connector, made me rethink how often I skip the simple stuff.

Last week at the hangar in DFW, I spent 4 hours chasing a fault code on a Collins WXR-2100 before I remembered that exact trick from a forum post, and it cleared up in 5 minutes after I pulled and reconnected that J1 connector.

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william_jackson65•1mo ago

TIL the hard way that old harness repair trick from a guy in Wichita was garbage

Last year at a regional airport in Wichita, this old tech told me to use dielectric grease on all the cannon plug contacts during repair. I tried it on a 737-300 aft equipment bay harness, and six weeks later the pins started corroding anyway. Took me two full weekends to redo that whole harness because the grease trapped moisture instead of keeping it out. Anyone else get burned by bad advice from a 'seasoned' tech?

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olivia_bailey•1mo ago

PSA: Check your pin crimps before you button up the panel

Spent 6 hours tracing a intermittent fault on a Garmin G5000 only to find a loose pin in a D-sub. The connector looked fine from the outside but the crimp was barely holding. Anyone else had a similar time sink from a bad crimp?

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benc53•1mo ago

That GPS antenna swap turned into a 11 hour nightmare on a King Air

Everyone talks about how simple GPS antenna swaps are, but I just spent 11 hours on a King Air 200 last week and I'm still annoyed about it. The online forums and my lead tech all said it's a 2 hour job max, pull the old one, clean the area, drop the new one, done. But nobody mentions that when the old antenna has been sitting there for 15 years, the sealant is basically concrete and you have to scrape it off in tiny chunks without damaging the skin. Then the new antenna's connector didn't quite match the existing cable length, so I had to re-terminate the coax which added another hour. I get that experience makes it faster but come on, 2 hours is a straight up lie for anyone who hasn't done it before. Has anyone else run into hidden time sinks on jobs that are supposed to be quick? I'm wondering if I'm missing a trick or if the timelines are just fantasy.

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ben206•1mo ago

Bonding straps aren't the silver bullet everyone thinks they are for static issues

I keep seeing guys in the hangar throwing bonding straps at every static problem on the G550s we work on. Last week a tech replaced three straps on a fuel cap door and the issue was actually a worn wick on the aileron trailing edge. I have seen this pattern about 6 times in the last 2 years where the real culprit is a dirty static discharge wick or a broken ground path in the control cable. How do you all actually isolate these problems down to the specific component before just swapping straps out?

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wyattrobinson•1mo ago

Overheard a guy at the hangar say something about bonding and static wicks that stuck with me

Honestly, I was just grabbing a coffee in the break room last Thursday when one of the senior techs was talking to a trainee. He said something like "if your bonding strap fails at 30,000 feet, your static wicks don't mean a thing." It got me thinking because I've always treated bonding straps and static wicks as separate checks, not really connecting them in my head. But he explained how the whole system works together to bleed off static charge, and if the bond path is broken, the wicks can't do their job. That perspective shift made me recheck my inspection order on the next Hawker 800 I worked on. I started looking at the bonding points first before even touching the wicks. Has anyone else had a similar moment where one phrase totally reframed how you approach a standard procedure?

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the_jamie•1mo ago

Last Wednesday I replaced five LRUs on a CRJ and every single one came up green on the first try

No reboots, no false readings, no bad connectors - just perfect green lights across the board, which in 12 years of avionics work has literally never happened before that day, has anyone else ever had a whole shift go that smooth without a single snag?

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gray6•1mo ago

Finally figured out why my ground loops kept coming back

Spent 6 months chasing a ground loop on a Gulfstream GIV that kept coming back after every fix. Turned out I was checking continuity at the wrong reference point, using the airframe ground instead of the actual avionics bus ground. An old tech from Bombardier pointed it out while I was griping over coffee at the hangar in Atlanta. Has anyone else had a similar rookie mistake with reference points on these older buses?

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olivia_bailey•1mo ago

Tried that new silicon gasket sealant on a Cessna 172 oil pan

It leaked worse than the old cork gasket ever did, and I spent 3 hours cleaning the mess off the hangar floor. Has anyone else had bad luck with those fancy sealants on light aircraft?

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logan705•1mo ago

That time an MD-80 pitot tube reading went haywire over Tulsa back in 2002

I was doing a preflight at a regional hangar outside Tulsa when the captain pointed out the airspeed indicator was dead, so I climbed up the ladder and found a mud dauber nest completely blocking the static port, cleared it with a paperclip, and after a quick ground test the rest of maintenance gave me grief for not spotting it sooner, has anyone else run into wasp nests messing with pitot-static systems?

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the_rowan•1mo ago

Took me 6 hours to find a bad solder joint on a LRU yesterday

Was chasing a intermittent fault on a Collins radio and it turned out to be a single cold joint on a connector pin I'd already checked twice. Anyone else have a simple problem eat up way more time than it should have?

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thomas.tyler•1mo ago

That lightning strike near Albuquerque back in '08 changed how I look at bonding straps

I was working a ramp job out at KABQ back in 2008 and a King Air got hit during a thunderstorm that came up way faster than anyone expected. The whole avionics bay smelled like ozone for two days afterward. We found a static wick that had literally melted into a little ball of plastic and carbon fiber. After that, I started checking every single bonding strap with an ohmmeter instead of just a visual once-over. Has anyone else run into weird damage from a close lightning strike that made you change your inspection routine?

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elliot45•1mo ago

Vent: Overheard a manager talking about skipping wire checks on purpose

I was getting coffee near the hangar office last Friday and heard one of the lead techs joking about how they 'saved 2 hours' by only spot-checking wiring bundles on a recent retrofit. I know that plane went out before I could flag anyone about it. It got me thinking about how some guys will cut corners just to hit a deadline, and it scares me how easy it is to hide bad work. Has anyone else run into pressure to skip safety steps like that?

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