c/avionics-technicians

Warning: Tried a new contact cleaner on some old cannon plugs and it went weird

I was working on a 737's comm panel last month and grabbed this new brand of contact cleaner, 'AeroClean Pro', from the supply truck. Sprayed it on some crusty 20-pin cannon plugs like normal, but instead of drying clear, it left this white, powdery film all over the pins. Had to go back and scrub every single pin with a fiberglass brush, which added like an extra hour to the job. The can says it's safe for avionics, but I'm not buying it again. Has anyone else had a cleaner react like that, or is there a brand you trust for old connectors?

Unpopular opinion: I thought the new fiber optic crimpers were just hype

Our shop got a set of the Klein Tools VDV226-110 kits last month, and I was sure they'd be finicky. After a week of splicing harnesses for a G500 retrofit, the consistency in my terminations was noticeably better. Has anyone else made the switch and seen a real difference in their insertion loss readings?

The day a single loose coax connector shut down a whole hangar

We spent a full eight-hour shift chasing a phantom comms fault on a regional jet, only to find a BNC that was barely finger-tight behind a panel. The whole crew had signed off the system as operational after a recent avionics upgrade. Anyone else had a simple connector issue cause a major headache like that?

An old inspector in Dallas told me my crimps were 'just good enough'

This was maybe 8 years ago on a CRJ-200 nav system job. He pointed at one of my D-sub pins and said, 'You're getting a seal, but the wire's not seated all the way... that'll vibrate loose in 500 hours.' I was just rushing to close up. Now I use a 10x loupe on every single crimp before I call it done, and I haven't had a single callback for a loose connector since. Do you guys still run into people skipping that final visual check?

Tried a new crimp tool on a Honeywell APU harness and the old one still wins

Our shop got a new set of ratcheting crimpers last month, the fancy kind with the colored dies. Used them on a King Air APU wiring job in Wichita. After three hours of rework, I went back to my old manual tool from 2015. The new one just didn't seat the contacts right, kept leaving a tiny gap you could feel with a pick. Who else has a crimp tool they trust more than anything new?

Spent 8 hours chasing a ghost in a Garmin G1000 at our hangar in Boise

The autopilot kept pitching down intermittently, and I was sure it was a servo or a bad ADAHRS. Turns out a mouse had chewed through a single wire in the static line bundle, but only when the airframe flexed on the jacks would it lose contact. My lead just laughed and said 'check the simple stuff first, Henderson.' Anyone else ever lose a whole day to rodent damage?

Remember when a full avionics bay meant a binder of schematics and a headlamp, not a tablet and a single cable?

Last week, I was troubleshooting a comms issue on a 2005 King Air in Wichita with just my laptop and a digital manual, and it hit me how three years ago that same job would have meant hauling out three massive paper binders and a flashlight to read them in the dark bay.

An old timer in Tucson showed me his trick for tracing a bad coax line

I was helping him on a King Air panel upgrade, and we had a ghost signal in the comms. He didn't reach for the fancy tester. He just took a small flashlight, held it to one end of the cable in the dark avionics bay, and had me look at the other. 'If you see the light, the core's good,' he said. It was a simple check that saved us an hour. Anyone have other old school tricks like that?

Honestly, I used to think all crimpers were basically the same until I had to redo a whole harness on a Citation last week.

A pilot told me my comms checks were 'aggressive' and it actually made sense

I was doing a preflight on a King Air last month, and after my standard 'comms check, one two three' over the intercom, the captain said, 'Hey, you sound like you're yelling at the radio. It's not a fight.' I always thought being loud and clear was the only way. But he was right, I was basically shouting into a sensitive mic. Now I just talk in a normal, calm voice. It sounds way more professional and the clarity is actually better. Anyone else get a piece of feedback that totally flipped a basic habit?

Spent $400 on a thermal imager for intermittent faults

It paid for itself in two weeks by finding a bad connector on a G1000 bus that was heating up under load. What other tools have you guys bought that ended up being worth way more than the price tag?

Update: I just hit 500 flight hours on a single radio I installed and it's still perfect.

Everyone at the shop says you HAVE to bench test a new Garmin GTR-200 for at least 20 hours before install, but I was in a rush for a client in Daytona and just put it in after a basic function check. That was over a year ago and the log shows zero squawks, which really makes me question if all that extra testing time is actually needed. What's the shortest bench test you've ever run on a new comm unit that still held up?

I was checking continuity on a G1000 harness for 3 years before a new guy in Tulsa showed me my meter's auto-ranging was lying to me.

I got a weird 0.8 ohm reading on a known-good ground path that should have been under 0.5, and he asked if I'd manually set the range, which I never did because the auto function always seemed fine until that exact moment. Has anyone else had a meter trick them on a critical low-resistance check?

Why does nobody talk about the 'one more thing' rule for final checks?

A pilot at our local field told me, 'If you think you're done, look for one more thing,' and now I always do a final walk-around after the bench test. Anyone else have a simple tip that changed their routine?

PSA: A trick for stubborn cannon plug pins that actually worked

I was fighting a bad connection on a nav unit for a Citation, and the usual wiggle test and contact cleaner weren't doing it. On a hunch, I gently used a dental pick to lift the tiny spring clip inside the female pin, just a hair, and the resistance went back to spec. Has anyone else had luck with that, or is there a better fix you use?

Overheard a pilot at the Denver FBO talking about our work

He was telling a new co-pilot that the cleanest transponder check he ever saw came from a tech who used a Fluke 87V meter for the whole job. Said it made him trust the whole system more. It hit me that sometimes the right tool isn't just about the reading, it's about the confidence it gives the crew up front. Anyone else had a moment where you realized your gear choice mattered to someone else?

Why does nobody talk about the weird static you get from those cheap crimpers?

Had a King Air in the shop last month and spent two hours chasing a comms glitch, turned out my old crimper was slightly deforming the pins. What's your go-to brand for D-sub connectors now?

Hit 777 on the serial number of a radio I was fixing

So I'm deep in a King KX 155, trying to find a bad solder joint, and I finally pull the main board. I'm cleaning off the old flux and I see it. The serial number ends in 777. I just stared at it for a solid minute. It felt like a slot machine jackpot, but the prize was just this weird, perfect number on a piece of gear that's been flying since before I was born. I've seen a lot of serials, but never a triple like that. It made the whole annoying job feel kinda special, like the plane was giving me a little high five for getting my hands dirty. I even took a picture to show the lead. Ever come across a serial number that made you stop and laugh?

Vent: I always thought the FAA's 'no fault' reporting was just for big stuff

I was reading through an old NTSB report from a 2019 incident in Phoenix, just killing time between jobs. It was about a commuter plane that had a weird transponder glitch. The report said the tech who found the initial fault wrote it up, but the next shift signed it off as 'no fault found' after a quick power cycle. The plane flew for three more days before the issue came back worse. What got me was the stat buried in the footnotes: over 60% of 'repeat squawks' in that airline's fleet that year started as an NFF sign-off. I always treated NFF as a 'problem solved' box to check, not a red flag. Now I'm way more careful. If I can't find it, I leave a longer note for the next guy and flag it for a deeper look. How do you guys handle a true 'no fault found' on an intermittent avionics problem?

PSA: A pilot's joke about 'magic smoke' actually got me thinking about troubleshooting differently

I was doing a post-flight check in Dallas and the captain said, 'Just remember, if you let the magic smoke out, you can't put it back in.' It sounds silly, but it made me stop and actually trace a full circuit path on a faulty transponder, instead of just swapping the LRU. Anyone else have a simple phrase that changed how you approach a problem?

My lead tech said 'a good tech can fix it, a great tech knows when to replace it' and it's been stuck in my head.

We were troubleshooting a persistent autopilot pitch trim fault on a King Air. I spent two full days chasing wires and swapping servo amps, convinced I could find the gremlin. My lead finally pulled me aside and said that line. He pointed out we'd already burned 16 man-hours and the aircraft was still down. He made the call to replace the entire trim servo assembly, a unit cost of about $3,200. The plane flew that afternoon. It made me think about where the line is between diligent troubleshooting and just throwing parts at a problem. Is it always about the most elegant fix, or is getting the bird back in the air safely and fast the real win? How do you decide when to stop digging and just replace the whole box?

Just had to pick between the Fluke 87V and the 289 for a big avionics bench setup. Went with the 87V and it's been perfect for the daily stuff.

Question about the push for all-digital manuals

Overheard a lead at my hangar in Phoenix say 'paper is dead' and we should trash all physical AMMs, but I've had three tablet failures during critical troubleshooting... how do you guys handle a full system reboot with no backup?

Rant: The manual said a certain wire gauge was rated for 400 degrees, but my thermal camera told a different story

I was working on a harness replacement in a Citation last week, following the standard manual. It listed a specific 20-gauge wire as good for 400 degrees Fahrenheit continuous. Out of habit, I checked a repaired section with my Fluke thermal camera after a ground run. The reading showed it hitting 450 degrees at a splice point under normal load. I double-checked with a second probe and got the same number. It makes you wonder how often we just trust the book without a real-world check. Has anyone else caught a spec like this being off in practice?

A pilot at my hangar said we overcomplicate GPS troubleshooting

He argued a lot of 'no fix' issues are just bad antenna placement, not box failures. Made me question our default bench-check process for a solid week.