c/avionics-technicians

Shoutout to the inspector who called out my wire routing

A few months back, a senior inspector at our hangar in Phoenix told me, 'Your bundle looks clean, but that bend radius is too tight for that gauge.' I was just trying to keep things neat, but he was right. I looked it up and was off by almost a quarter inch. Now I always double-check the spec before I secure a run. Anyone else have a small piece of feedback that stuck with you?

Thought I had a genius fix for a sticky autopilot disconnect switch

Had a Cessna 172 in the hangar with a switch that felt gritty. Instead of ordering a new one right away, I figured I'd flush it with some DeoxIT D5. Sprayed it, worked it back and forth, and the switch went totally dead, no continuity at all. Turns out the cleaner washed all the old, conductive grease out and left it high and dry. Now I'm waiting on a $300 part. Anyone have a better method for cleaning these old switches without killing them?

Talking to a new hire about old test gear

I was showing a kid fresh out of school the shop last week. He pointed at our old B&K 2120 signal generator on the bench and asked, 'What's that for?' I told him we used to trace faults with it for hours. He just said, 'Seems slow.' It hit me that he's never known a time without digital fault codes and built-in tests. The whole job used to be about chasing a signal, not just reading a screen. Anyone else feel like that hands-on puzzle solving is becoming a lost skill?

Showerthought: I swapped from generic to proper shielded cable for a GPS antenna run and the noise floor dropped like a rock.

Had a persistent intermittent fault on a Garmin GTN 750 install in a Cessna 182. The GPS signal kept dropping. I first used a standard unshielded Tefzel wire for the antenna run, thinking it was fine for the short distance. After re-running it with a proper RG-400 coaxial cable, the signal stabilized completely. The shielding made all the difference in blocking interference from the aircraft's other systems. Has anyone else had a similar fix with antenna wiring?

TIL my old way of tracing a ground fault was a total waste of time

For the longest time, I'd just start at the component and work my way back, checking every connection (which could take hours). Last Tuesday, a guy at the hangar showed me his Fluke 1587 megohmmeter and we found a fault on a King Air's autopilot circuit in under 15 minutes. The key was isolating the whole circuit first and testing the insulation resistance, not just continuity. It pinpointed a tiny spot of chafing in a wire bundle I would have missed for sure. Anyone have a different method for tracking down those sneaky intermittent grounds?

I finally figured out why my continuity checks kept giving me false readings

I was troubleshooting a nav light issue on a Cessna 172 last month, and my meter kept showing good continuity through a wire that was clearly broken. It turned out I had the meter set to the wrong function the whole time. I was using the diode test setting instead of the actual continuity beep mode on my Fluke 87V. A guy from the hangar next door saw me struggling and asked to check my meter. He pointed at the screen and said, 'That symbol means diode, man.' I felt pretty dumb, but it fixed the problem right away. Has anyone else made a simple meter setting mistake that cost them a bunch of time?

Found a better way to trace intermittent faults in old 737 wiring harnesses

I used to just wiggle wires and hope for a flicker on the test set, but after a 3 hour chase on a 400NG last month, I started using a cheap thermal camera from Harbor Freight to spot hot spots under load. The heat showed a bad crimp behind a panel I would have never pulled, fixed it in 20 minutes. What's your go-to method for finding those ghosts in the system?

Update: My old way of labeling test leads was a mess

I used to just wrap a bit of tape around them and scribble with a marker, but after mixing up a 5V and 28V line during a King Air autopilot check, I bought a Brady labeler. How do you guys keep your bench leads sorted?

Appreciation post: I chose the Fluke 87V over a cheaper meter for my bench at the regional airport, and it saved me a whole afternoon chasing a phantom voltage drop in a Citation's nav system.

Has anyone else had a specific tool choice pay off in a big way like that, or do you think I just got lucky this time?

A pilot at the FBO in Dayton mentioned his new Garmin G5000 system keeps flagging a phantom sensor fault

He said the fault clears on the ground but pops up during climb, and his shop has swapped the sensor twice with no fix. It got me thinking about how often we chase hardware when the real issue might be in the data bus or a software glitch. Has anyone else seen weird faults on the G5000 that turned out to be a configuration problem?

I was using a cheap multimeter for continuity checks on a 787 panel for months

A lead mechanic in Seattle asked why my readings were so jumpy, then showed me his Fluke 87V. The difference in stable readings on the same circuit was immediate. Anyone else get burned by a basic tool on a complex system?

Finally got that intermittent VHF comms fault on a Cessna 172 pinned down

It was a ghost for three days, dropping out randomly on the ground in Denver. Traced it to a corroded BNC connector at the antenna coupler, resistance was all over the place. Anyone have a go-to method for cleaning those up besides just a straight swap?

Heads up about the new Garmin G5000 software patch 2.1.4

Honestly, I was doing a post-install check on a Citation last week and the AHRS was giving me wild pitch errors. I traced it for an hour, checking every connection. Tbh, the tip-off was the MFD kept showing a 'sensor disagree' flag that wasn't in the manual. I finally called Garmin support and they said the patch has a bug that misreads certain serial data streams from the old style ADAHRS units. Has anyone else run into this with the legacy units after updating?

Just read a crazy stat about composite aircraft and lightning strikes

Found an FAA report saying a composite airframe can have over 300 separate electrical bonding checks after a strike. I always thought it was just a few big paths. How do you guys even start that inspection process?

Remember when we had to trace every single wire by hand?

I was working on a 2008 Cessna 172 last week and the old wiring diagram was a blurry copy of a copy. Instead of spending hours with a highlighter, I tried using a cheap tablet with a PDF viewer to zoom in and mark it up. I thought it would be a mess, but it actually saved me like two hours of squinting. The real surprise was how easy it was to flip between the diagram and the actual harness without getting lost. It made me miss the big paper rolls a little less. What other old school tasks have you guys found a simple tech fix for?

Got schooled on a weird VHF comms issue by a retired guy at the airfield in Pensacola last month

A tiny crack in a coax connector cost me half a day

I was finishing up a VHF comms check on a Citation last month and kept getting a weak signal. Everything tested fine at the box. I finally pulled the antenna and saw a hairline crack in the center pin insulator of the BNC connector, probably from overtightening. Replaced the whole pigtail and it cleared right up. Anyone else run into something like that where the fault was in the connector itself?

The week we had three A320s in a row with the same intermittent VHF comms fault

It was last Tuesday at the regional airport in Spokane. First one was a quick squawk, then the next two came in with the exact same issue. Took us two days to finally trace it back to a bad batch of coaxial connectors from a supplier, part number AXC-778B. The intermittent dropouts were driving everyone nuts. Has anyone else run into this specific connector issue lately?

I was crimping coax connectors wrong for two years and only found out because of a weird static issue

I was troubleshooting a persistent static problem on a Garmin G500 TXi install last month. The signal was clean on the bench but garbage in the plane. My mentor, who was helping, asked to see my crimp tool. He pointed out I was using the wrong die set for the specific RG-400 cable we had. I had been using the die marked for 'coax' from the kit, but it was slightly off for that cable's shield. We swapped to the correct die, re-did the connector, and the static was gone. I had probably made a hundred connectors that way. Has anyone else had a crimp tool bite them like that?

TIL a $400 thermal camera found a problem my multimeter missed completely

I was chasing a weird intermittent power drain on a G1000 install in a Cessna 182. My Fluke showed normal voltage drops everywhere I checked, but the plane kept eating batteries overnight. Got fed up and bought a cheap Seek thermal camera on sale. Pointed it at the main bus bar with everything off and saw one terminal glowing warm. It was a tiny crack in the insulator letting just enough current through to heat up, but not enough to show on the meter. That camera paid for itself in two hours of saved labor. I would have been pulling panels for days. Anyone else use thermal imaging for this kind of fault finding, or am I just late to the party?

I finally caved and bought that $80 fiber optic borescope to check behind a panel, and it basically turned into a horror movie.

Found out the FAA's new ADS-B Out rule cost the industry way less than they said it would

I was digging through some old FAA reports last night, bored out of my mind, and stumbled on the final cost analysis for the 2020 ADS-B Out mandate. The industry groups were screaming it would cost over $3 billion for the whole fleet to get compliant. The real number? The FAA's own report says it came in under $1.8 billion. That's a huge difference. They basically cried wolf for years about the financial hit, and a lot of us bought it, thinking it would sink smaller operators. But looking at the data, it seems like a lot of the cost got absorbed through normal upgrade cycles and smarter installs. It makes me wonder what else we get fed that's just fear mongering from the top. Has anyone else seen a big gap between the predicted doom and what actually happened on a reg change?

Update: My bench went from a 2 hour wire harness mess to a 30 minute clean install after I finally built a proper jig

I spent a whole afternoon in the hangar cutting and labeling some scrap plywood to match the connector layout, and now routing those 50-pin bundles for the G1000 retrofit is actually enjoyable, so what's your go-to method for keeping harnesses organized during a big mod?

I was sure about using the factory harness on a G1000 install, but a local shop changed my mind.

We were putting a Garmin G1000 in a Cessna 182 and I insisted on the pre-made harness to save time. The owner of a small shop in Tulsa told me to build a custom one instead, saying it would be cleaner and easier to fix later. I tried it his way, and after about two extra hours of work, the routing was perfect with no extra slack. Has anyone else found a custom harness is worth the extra effort for a clean panel?

Shoutout to the old Fluke 87 I picked over a newer model

I had to choose between a used Fluke 87-V from a retiring tech and a brand new, cheaper multimeter from a different brand for a job on a Citation's autopilot system. I went with the Fluke, and its true RMS reading caught a weird voltage fluctuation the other meter missed completely. Has anyone else had a tool choice make or break a tricky diagnosis?