c/avionics-technicians

Chasing a ghost squawk for 2 days, ended up being a 50 cent resistor

We had a Cessna 172 come in with an intermittent audio panel issue, static only in the right headset jack. I swapped the jack, checked the wiring, even replaced the intercom unit, still did it. Ended up being a cracked solder joint on a tiny resistor in the audio selector board, took me from Monday morning to Wednesday afternoon to find it. The worst part was the pilot said it only happened when he adjusted the volume knob, which should have been my first clue. Any of you guys ever spend forever chasing something that turned out to be a simple component you could have seen with a magnifier first?

0 comments

-1

linda_clark•10d ago

Old Hawker wiring vs today's looms, night and day

I pulled apart an 1980s Hawker 800 this week for an audio panel swap and the old harness was just cloth tape and bare splices, nothing like the factory engineered looms I see on new Gulfstreams. Over 40 years the military and commercial side really pushed shielded twisted pairs and proper strain relief, and you can see it in the troubleshooting time. Anyone else notice a huge jump in build quality when they switch between vintage and modern airframes?

0 comments

xenar14•17d ago

Two identical crimp dies, one measurement saved my harness

Had to pick between a cheap replaceable die and a calibrated one for our DMC tool at the hangar in Tucson. Went with the cheap one to save $80 for the shop budget. First 12 pin insert came out loose on the pull test, so I borrowed the calibrated die from the next bay. That fixed it instantly, but now I wonder if the cheap die is just bad out of the box or if I got a fake. Has anyone else had a knockoff die fail that way before?

0 comments

lee.jake•18d ago

Old boss swore by dielectric grease on every connector, I fought it for years

My first lead in Tucson insisted we pack dielectric grease into every cannon plug, even on dry bay stuff. I thought it was a waste of time until a deice boot connector fretted and threw a fail light last fall. It's tacky, messy, and I still hate cleaning it off, but has anyone else seen a greased connector outlast a dry one in a high vibe area?

0 comments

harper_gibson2•18d ago

Dropped $800 on a thermal camera, saved my tail on a 737

Picked up a Flir unit last month to chase a intermittent heat signature in the aft avionics bay, found a resistor cooking on the FCC card before it ever showed on the log. That one find paid for the thing since we didn't have to pull the whole rack, have you guys had luck with cheaper handhelds or is spending the money worth it?

0 comments

nora535•18d ago

Wire chafing used to be a suggestion to me, not anymore

I used to blow off chafing checks if the bundle looked fine from the outside. Then last month we pulled a harness off a Gulfstream and found a wire worn down to the copper in a spot that looked totally clean from the top. The guy who caught it has been doing this for 20 years and showed me how it flexes during flight, that was the convincing part. Now I check every tight radius bend with a borescope, even on scheduled stuff. Has anyone else had a hidden chafe sneak up on them like that?

0 comments

skyler_white•19d ago

My $40 cable shielding tester lied for 3 days straight

Troubleshooting a weird intermittent fault on a Cessna 172 nav radio ate my whole Friday shift because I trusted a cheap tester that showed good continuity on a braided shield that was actually snapped inside the jacket. Finally pulled out the old megohmmeter and found it in 20 minutes. Has anyone else had a cheap tester give false passes on shielding and cost them a full day?

0 comments

matthewp52•20d ago

Old wiring diagrams vs. the tablet changeover in our shop

Back in 2019 we still used those big paper binders for every wire run check. I'd flip through 40 pages just to trace a harness from the aft bay to the cockpit. Now everything is on a tablet with searchable PDFs, so I tap in the part number and get the diagram in seconds. The switch happened when our lead bought a ruggedized tablet after two binders got soaked in hydraulic fluid. Has anyone else found that the zoom feature on the tablet beats a magnifying glass for the tiny gauge numbers?

0 comments

cora400•22d ago

That QA note about my solder joints made me redo 40 connectors

A senior inspector told me my fillets looked 'pretty but cold' and after I reflowed them with a hotter iron, the resistance readings dropped like 15 percent on the harness, so am I the only one who was taught to favor aesthetics over actual wetting?

1 comments

derek_dixon78•23d ago

That MD-88 smoke detector false alarm changed my whole wiring approach

We were doing a C check at MRO Orlando and the MD-88 cabin smoke detector kept tripping after every power cycle, turned out a previous tech had pinched the ground wire between the panel and the frame using the wrong length terminal. I spent 4 hours chasing it with the test set before I started pulling panels and found the crushed insulation, so now I check wire routing before trusting any fault code. Has anyone else had a false alarm like that burn a whole day, and what do you do to catch those hidden shorts faster?

1 comments

parkerkim•24d ago

Just learned wire gauge drop tables in the FAA handbook are based on 25C, not cabin temps

Found it on page 14-21 of AC 43.13-1B last night, so all my 20 gauge runs on the Gulfstream might be undersized by a full 15% when the panel hits 45C on the ramp, has anyone else been sizing for real heat instead of the standard?

1 comments

simonbell•26d ago

Rant: my old lead tech taught me more in one hangar walk than 3 years of manuals

Back in 2015 I was working the night shift at a regional MRO in Phoenix. We had this old guy named Dale, must have been 60, and he watched me struggle with a wiring diagram for 20 minutes. He just walked over and said "the drawing lies, follow the wire with your fingers." That stuck with me because I found a chafed bundle behind a clamp that the schematic never showed. Has anyone else had a mentor who showed you a shortcut that no textbook ever covers?

0 comments

jason_robinson•26d ago

That one pilot who swore the static wick was fine, until I showed him my multimeter readout

Had a guy in the hangar near the maintenance office in Phoenix, about 2 months ago. He was a big customer, always in a hurry, and he kept insisting the static wick on his King Air was fine because he could see it with his own eyes. I pulled out my Fluke 87 and put the probe on the base, got a reading of like 15 megaohms, way past the limit. He just stared at the screen and said, 'well, that's just your box lying to me.' I didn't even know what to say, so I left the lead connected and let him touch the end of the wick while I flipped the reading to continuity. His face went blank when the beeper went off. That stuck with me because he never even apologized, just grunted and left, but the next week he asked for me specifically to do his annual. Have any of you had a pilot or owner argue with a meter reading straight to their face?

0 comments

matthewp52•28d ago

Back from the desert and my old test bench felt strange

Got back from a two week stint out at Edwards supporting a flight test and walked into the hangar to do a routine pitot static check. My old analog pressure test set was still sitting there but someone had swapped it for one of those little digital box units with a touchscreen. Took me a minute to find the manual vent valve because muscle memory kept going for the knobs that aren't there anymore. It read the same numbers and probably saves 10 minutes per run, but I kept looking over my shoulder for the calibration log that used to live in the lid. Does anyone else still prefer the old needle and dial setups for quick line checks, or am I just stuck in my ways?

1 comments

the_phoenix•29d ago

Old 727 nav com radios finally made me convert to digital

Been holding out on upgrading my test bench gear for years, kept using the same analog signal generator from 1989. Last Tuesday I was chasing a weird 50 kHz offset on a Collins radio and spent six hours with zero luck. Swapped in a $300 digital unit I borrowed from a buddy in Tulsa and found the issue in 20 minutes. Anyone else stuck on legacy benches because the company wont budget for new stuff?

1 comments

amy692•29d ago

Blew $240 on a fancy test probe that did nothing my $40 one couldn't

Picked up one of those ergonomic, high-flex probes from a vendor at the Dallas air show last spring. Thought it would save me time on a tricky ACARS fault in the CRJ, but it gave the same readings and the grip felt worse. Ended up sending it back and eating the restock fee, which was like $60. Anyone else fallen for the shiny tool trap on the flight line?

1 comments

olivia478•29d ago

My own soldering iron tip ruined 14 hours of work on a 737 harness

Spent all last week building out a harness for a 737NG flap position sensor. Got it all continuity checked and tucked into the tray. Then I realized I left my iron set to 750 for a repair earlier and used the SAME tip without cleaning it. One tiny cold joint on pin 4, the one I swore I hit perfect. Did 3 rework cycles before I found it. Now I keep a separate tip for fine gauge wire, but has anyone else had a tiny mistake like that eat up a whole shift? What's your dumbest 'one thing ruined the whole run' moment?

1 comments

uma306•1mo ago

Wire labels finally clicked after watching a teardown video

I always thought label makers were for desk jockeys, but that tear-down of a 737 throttle quadrant on YouTube showed me how quick messy bundles turn into a 2 hour hunt during a 30 minute turnaround, so I bought a $40 labeler and now I'm redoing every box I touch, anyone else skip labels until a job bit them?

1 comments

robinc66•1mo ago

Old-school schematics vs digital tablets in the hangar, which way do you lean?

Back in 2008 I worked a line maintenance job in Phoenix where every tech had a laminated binder of schematics, and we marked up faults with grease pencils. Fast forward to last month, a new hire pulled up the same wiring diagram on a tablet and had the pinout zoomed in within seconds. One side says paper never crashes or runs out of battery, the other says instant updates save hours on troubleshooting. After 15 years of doing both, I see real strengths and weaknesses, but I'm curious which format you trust when a bird is down on the ramp with MEL pressure. Has anyone else noticed their younger techs skip the manual entirely and just watch a YouTube tear-down video instead?

1 comments

simonw41•1mo ago

Good week tracing a faulty pitot static line on a 737

Had one of those rare weeks where everything clicked. We had a 737 come in with a static port leak that had two other techs stumped for two days. I got assigned to it Wednesday morning, and after about an hour with a digital manometer and a spray bottle, I found a chafed line running behind the aft cargo bay. The weather sealant had dried out and it was bleeding pressure only when the aircraft was pressurized. Replaced the line and did the full leak check with no surprises. The crew chief said it was the fastest fix they had seen on that bird in months. It was just a simple win but it reminded me why I like this trade. Anyone else have a fault that seemed impossible until you found the dumb simple cause?

1 comments

the_skyler•1mo ago

TIL cleaning cannon plugs with a toothbrush beats any fancy tool I own

I used to chase intermittent faults for hours until I tried a stiff nylon brush with isopropyl on a C-130 pitot static harness last Thursday. The corrosion film on the pins came right off and the readings went from flaky to steady in one pass. Anyone else skip the expensive kits and just use basic stuff from the dollar store?

1 comments

brookepark•1mo ago

Hot take: Shelling out $600 for that Fluke DMM was worth every penny

I mean, back in the day I used to get by with a $40 multimeter from the auto parts store, but after chasing a weird intermittent fault on a Garmin G1000 display, I finally caved. The Fluke 87V caught a voltage drop that my old meter just couldn't read, and it saved me from swapping a perfectly good screen. Has anyone else found that spending real cash on a good meter actually pays off in the long run?

2 comments

the_hugo•1mo ago

TIL a $35 pin crimper from a garage sale does cleaner work than my $200 huxter tool

Picked it up at a flea market near Phoenix last month, just tested it on a D-sub connector this morning and the crimps came out perfect with zero burrs, has anyone else found a random old tool that outshines their expensive gear?

2 comments

jordan134•1mo ago

The amount of people who skip bond testing on antenna installs is getting dangerous

I've been in avionics for 22 years now, and I keep seeing guys throw up a new comm antenna without ever checking the bond resistance. Last month I had to redo a job where the reading was 8 milliohms when it should be under 2.5. That kind of slop can cause static bursts and even feedback into the ship's electrical system. It takes maybe 10 minutes with a good micro-ohmmeter, so why would you skip it? Am I the only one who still makes bond check part of every antenna swap?

1 comments

karenm49•1mo ago

Old analog test gear vs digital - which wins for troubleshooting?

Curious if anyone else has strong feelings one way or the other.

1 comments