c/avionics-technicians

Shoutout to the FAA's own data on wiring faults

Read their 2023 safety report. It said 18% of general aviation incidents they looked at had a wiring issue as a primary cause. I always thought it was way lower. Anyone else see that and have it shift their daily inspection focus?

PSA: Check your crimp tool calibration after a shop move, a bad crimp on a 737's AOA sensor line cost us three days of troubleshooting in Seattle last month.

The new bench location had a slight vibration from a nearby air handler that we didn't account for, and it threw the tool's alignment off just enough to create an intermittent connection that passed a basic continuity check but failed under flight loads.

I finally started labeling my crimp tool dies with actual wire gauge numbers.

For years I just kept them loose in a tray and guessed by eye, which worked fine until I mixed up a 22 and a 24 gauge job on a King Air's comm panel. That cost me an hour of rework. Now I used a paint marker to write the AWG on each die and keep them in a foam block. Has anyone else found a better system for keeping those tiny parts sorted?

Just realized a trick for getting those stubborn BNC connectors on the old Collins radios to seat right

I was working on a King Air 200 in Tulsa last week and the VHF comm kept dropping. I tried everything, even swapped the unit, but the issue came back. On a hunch, I cleaned the connector threads with a tiny bit of DeoxIT and gave it a full turn past finger tight with a small wrench. The static cleared up completely. Has anyone else found a fix for those finicky old Collins connectors?

Question about using a thermal camera versus a multimeter for finding shorts

I used to think a good multimeter was all you needed to track down a short in a wiring harness. That changed last month when I was working on a Citation's autopilot system. I spent nearly two hours with my Fluke, checking continuity and resistance, and I was getting nowhere. A guy in the next hangar saw me struggling and brought over his FLIR thermal camera. We powered up the circuit and scanned it. In about 30 seconds, we spotted a tiny hot spot at a connector pin that was barely making contact and heating up. The multimeter showed continuity, but it didn't show the bad connection under load. The visual heat signature made the problem obvious. I was stubborn about the old way, but seeing it work that fast sold me. Has anyone else made the switch to thermal imaging for fault finding, and what model do you like?

Watching my neighbor's kid build a model plane made me think about our work

He was so focused on the paint job, but the wing alignment was way off. It hit me that we see this all the time with new techs rushing the final check on a nav system before a full system test. How do you guys make sure the basics don't get missed when the job looks done?

Bought a $350 portable spectrum analyzer and it saved my weekend job

Was chasing a weird VHF coms issue on a King Air at a small field in Nebraska. My shop's main unit was down for cal. The handheld found a spurious signal from a nearby FM station transmitter in about twenty minutes. Without it, I would have been swapping boxes and guessing for two days. What's your go-to tool for quick signal checks in the field?

Pro tip: a bad day in the hangar taught me to always check the simple stuff first

Last Tuesday at the regional airport, I spent six hours chasing a phantom comms fault on a King Air. I swapped the audio panel, ran new coax, the whole nine yards. My lead finally walks over, pulls the pilot's headset from the storage pocket, and finds the push-to-talk switch was stuck in the mic key position. The whole system was working fine. I felt like a total rookie. How many hours have you guys wasted on something that simple?

I was sure the new fiber optic cleaning pens were just a gimmick

Our shop got a box of them about six months ago, and I kept using my old lint-free wipes and alcohol. Then I had a stubborn intermittent fault on a 787's IFE system in Seattle, with signal loss right at a connector. A senior tech handed me one of the pens and said to try it. The fault cleared immediately after three swipes, and the signal levels jumped back to spec. I've used them on every fiber job since. Has anyone else had a tool they doubted that actually fixed a tricky problem?

A pilot at the FBO said he never trusts a plane's fuel gauge until he's flown it twice

I was grabbing coffee at the airport diner yesterday and overheard a pilot telling his copilot that line. It stuck with me because it's not about the gauge itself, but the system behind it. He said on a new-to-him Citation, the gauge read full but the totalizer showed a 50-gallon discrepancy after the first leg. That means a sensor, the wiring, or the computer was giving bad data from day one. It made me think how often we sign off on a system as 'ops check good' after a single test cycle. Maybe we need to build in a verification step, like comparing computer data to a physical dipstick over a couple of flights. How do you guys handle building confidence in a new installation or repair before the customer takes it?

I finally gave up on that cheap crimper from the online auction site

It mangled three D-sub pins before I tossed it, costing me about $40 in parts and an hour of my time. Anyone know a good brand for hand tools that won't wreck a simple connector job?

A chat with an old pilot changed how I see a simple wire check

I was doing a pre-flight on a Cessna 172 last Thursday, going through the usual pin checks on the main harness behind the panel. A retired airline captain, Mr. Ellis, was hanging around the hangar and asked what I was up to. I gave my standard 'just checking continuity' line. He paused and said, 'You know, for twenty years, I never thought about the person who last touched those wires. I just trusted they felt the connection, not just saw the number on a meter.' That stuck with me. I realized I'd been so focused on getting a green light on the tester that I'd stopped really feeling for a solid pin seat in the connector. The next day, I slowed down on a G1000 avionics rack install and actually wiggled each pin by hand after the meter beeped. Found two with just a tiny bit of play I would have missed. Has anyone else had a simple piece of advice shift a routine task for them?

Bought a cheap fiber optic inspection scope and it bit me

Spent about $80 on a no-name scope to check some connectors in a tight spot on a G650. The image was so blurry I couldn't see if the end face was scratched or just dirty. Ended up having to pull the whole assembly to check it on the bench scope, which added two hours to the job. Should have just used the shop's good one from the start. Anyone have a decent budget scope they actually trust?

Pro tip: I was crimping D-sub pins for years before a guy in Anchorage pointed out my tool was set wrong.

I was getting intermittent comms faults on a G1000 install and couldn't figure it out. He watched me for two minutes and said my crimp tool's die was one notch too open, so the pins weren't biting the wire strands right. How many of you actually check your crimp tool adjustment against a gauge before starting a harness?

Serious question, ever had a whole week where every single LRU you pulled was actually the bad one?

Just happened to me, it was wild. Has that ever happened to you or did I just get stupid lucky?

Choosing between a used Fluke 87V and a new generic meter for my home bench

I had to pick a new multimeter for my home setup a few months back. My old one finally gave out after a good run. The choice came down to a used Fluke 87V I found online for about $250, or a brand new generic brand meter that was only $80. I went with the used Fluke because I remembered how reliable they were in my old shop. It showed up with some scuffs but the calibration was spot on. I've used it to chase down a tricky intermittent fault in a nav light circuit on a buddy's Cessna 172. Having the true RMS and the good leads made a real difference. Has anyone else gone for used pro gear over new budget stuff? How did it work out for you?

Honestly, I was crimping coax connectors wrong for like two years

Tbh, I was taught to just crimp until it felt tight, no torque wrench. Then I got sent to a week long class in Wichita and the instructor showed us a stripped connector under a scope. My crimps were deforming the center pin just enough to cause intermittent faults. The spec sheet said 18 inch-pounds, which is way less force than I was using. Now I keep a little torque screwdriver in my kit and check it every month. Anyone else have a tool they started using way later than they should have?

Warning: I keep seeing people mix up the pinouts on those new Garmin G5 connectors

Honestly, I've seen it three times this month at our hangar in Daytona. Guys are rushing and plugging the 22-pin connector in without checking the keyway against the manual, which is a real bad idea. It looks like it fits, but you can force it one pin off and fry the whole attitude module. I caught an apprentice about to do it yesterday and had to stop him. Has anyone else run into this, or are we just having a weird run of bad luck here?

That $350 for a good crimper felt like a lot back in '05

I remember when I first started, we were using these cheap, worn-out hand crimpers the shop had for years. You'd fight with them on every pin, never sure if you got a good crimp until you did the pull test and hoped. Then I saw a guy at a trade show using a proper ratcheting crimper with the right die set for the connector series we used all the time. I bit the bullet and spent about $350 of my own cash on it. That tool paid for itself in a month just in saved time and rework. These days, the new kids have fancy, calibrated pneumatic ones the company provides, but I still have my old manual one in my box. It's banged up but still makes a perfect crimp every single time. Anyone else still holding onto a piece of kit from way back that just can't be beat?

Bought a $120 thermal camera for my phone to find hot spots in panels, and it paid for itself on one job.

Rant: I thought those new fiber optic test kits were just overpriced junk

My boss made us get one for a job on a Gulfstream in Houston last month, and it actually saved us a full day of chasing a ghost signal. Who else has been forced to use a tool they hated that actually worked?

I finally saw the new touchscreen test set in action against our old manual units.

The touchscreen interface added 15 minutes to a basic transponder check because you have to navigate three menus just to set the RF output, so I'm sticking with physical knobs and switches for speed and reliability, has anyone else had this experience with the newer digital gear?

Update: A 737's autopilot kept dropping out on final approach in Denver

Last week, we had a bird come in with the autopilot disconnecting right at 500 feet, every time. The write-up just said 'A/P inop', so we started digging. After three hours of chasing wires, we found a single pin in the flight control computer connector had backed out just enough to lose contact. Has anyone else seen this on the -800 series, or was this just a weird one-off?

Chat with a pilot in Phoenix about a squawk that kept coming back

He said 'you guys are wizards, but sometimes the magic smoke just wants out.' Anyone else get that feeling on a repeater?

Got stuck on a stubborn LRU fault that came down to two test methods

Had a nav unit on a Citation that kept throwing a 429.1 code, intermittent but enough to ground it. The book said to start with the built-in BITE test, which came back clean every time. After three hours of that, I switched to a full signal injection test with the bench rig, feeding known good waveforms into each pin. Found the issue in under twenty minutes, a tiny drop in voltage on the ARINC 429 output that the BITE just wasn't sensitive enough to catch. The BITE is fast and easy, but it only checks what the box thinks it sees. The signal test is slower and needs more gear, but it shows you the real picture. When the fault is sneaky, which method do you guys trust more, the quick internal check or the full external signal path test?