c/avionics-technicians

Bought a used spectrum analyzer off eBay and got a unit that only shows noise floor

Found an Anritsu on eBay for $400. Looked clean in the photos. Hooked it up to test a VOR receiver antenna and the thing just shows garbage across the whole band. Tried a known good signal generator and still nothing. Learned the hard way that you need to ask for a recent calibration cert before buying test gear used. Anyone else get burned on eBay avionics tools?

Hot take: A pinched wire taught me more than 3 years of reading manuals

I was working on a Cessna 172 at a small shop near Tulsa last Tuesday. Had a weird intermittent fault in the nav lights that the schematic said was impossible. After chasing it for 4 hours, I found a single pinched wire behind the panel where a previous tech had stuffed everything too tight. Fixed it with a splice and some heat shrink, and the lights worked perfect. Made me wonder how many other 'gremlins' are just bad installs from years ago. Has anyone else found a fix that simple after going crazy looking at the prints?

The wiring diagram feedback that changed how I approach every job

I've been doing avionics for about 6 years now, mostly on business jets. Last month I was troubleshooting a faulty GPS antenna on a Challenger 350 and spent 3 hours chasing a signal issue that turned out to be a loose crimp. My lead came over and told me stop trusting the wire labels at face value, always tone out each pin before you even start. I changed my process to always verify continuity first thing on every repair now. Has anyone else had a simple piece of feedback that completely sped up your troubleshooting?

Had a convo with an old-timer at lunch that totally shifted my approach

Guy with 30 years in the field told me he never trusts a wire until he's physically tugged it, no matter how clean the crimp looks. Been thinking about it all week - has anyone else had a mentor drop a simple tip that changed how you work?

Caught a guy in Tulsa using the wrong crimper on D-sub pins last week

I was helping out at a small avionics shop in Tulsa last week and this younger tech was fighting with a D-sub connector for like 20 minutes. Turns out he was using a standard ratcheting crimper on those military-style pins instead of the dedicated M22520 tool. I pointed it out and he looked at me like I was speaking a different language. He said his old trainer never showed him the difference, just used whatever was on the bench. I grabbed the right tool and the pin seated perfectly on the first try, no deformation at all. It's wild how many guys think a crimp is a crimp, but with avionics tolerances being what they are, a bad pin can cause intermittent faults that take days to chase. How did you all learn the right tool for specific pins, or did you just figure it out on the job?

My multimeter gave a false reading on a Cessna 172 and I almost missed a broken wire

Last Thursday I was checking some wiring on a Cessna 172 in the hangar. The circuit was showing continuity on my Fluke meter so I figured everything was fine. But something felt off so I tugged on the wire bundle near the firewall. That's when a wire slipped right out of its terminal strip clean broken but still touching enough to fool the meter. I learned the hard way that a continuity test alone doesnt catch bad connections under load. Now I always do a wiggle test on every wire I check even if the numbers look good. Has anyone else had a false reading mess up your troubleshooting time?

Went from a 727 to a G1000 cockpit and man what a difference

I worked on old school steam gauge planes for like 8 years. Last spring I jumped to a shop that does mostly Cirrus and Cessna glass cockpits. The before and after is night and day. Troubleshooting a bad air data computer used to take me half a shift with test equipment. Now I plug in the G1000 and get a fault code in 5 minutes. The downside is the training - took me 6 months to really get comfortable with the Garmin software. Anyone else struggle with the switch from analog to digital or was it just me?

The day a lightning strike gave me 18 hours of straight work

Back in 2019 I was working at the FBO in Wichita when a King Air came in after hitting a static discharge. The lightning had fried a line replaceable unit in the starboard NAV system and I had to track a burn pattern through the whole wiring bundle. Took me from 7am to almost 1am the next morning with nothing but coffee and a headlamp. Has anyone else had to deal with a full lightning damage check on an older airframe?

Spent 4 hours chasing a wire that didn't exist

I was troubleshooting a no-radio power issue on a Cessna 172 last Wednesday. The schematic said there was a relay behind the instrument panel. I pulled the panel and spent 2 hours looking for it. Turns out the previous guy removed the relay and just hardwired the circuit. Another 2 hours wasted tracing wires that ended in nothing. Has anyone else run into phantom components that just aren't there anymore?

That week in Dallas where everything that could go wrong did go wrong

Last month I was working on a Cessna 172 avionics upgrade at a shop in Dallas. Monday morning I pulled the old panel and found a nest of corroded wires behind it that looked like they'd been sitting in water for years. Tuesday the new GPS antenna wouldn't fit the mounting holes because the previous guy used some off brand bracket. By Thursday I had to redo half the harness because the schematics didn't match what was actually in the plane. Has anyone else had a job just spiral like that where you end up working three times the hours you bid for?

Pro tip: A lead tech in Phoenix told me to stop relying on my DMM for everything

I used to think my digital multimeter was the only tool I needed for diagnosing avionics faults. Then this old-timer watched me chase a ghost signal on a King KX 165 for 45 minutes and said 'put down the meter and grab the headset.' He had me listen for a specific hum in the audio panel that turned out to be a bad ground strap on the tray. I changed my whole approach after that - now I use my ears before my meter every time. Has anyone else had a senior tech call them out on a bad habit like this?

Walked through a Gulfstream 650 at the Signature hangar and changed my mind about glass cockpits

I've always been a steam gauge guy, thought all that digital stuff was just extra failure points. Last month I got to poke around a G650 at KOPF in Opa-locka, the one with the big Honeywell setup. The tech showed me how it flags a bad LRU before it even fails, plus the self-test cycle took like 2 minutes. Has anyone else had their opinion flipped after seeing one of these up close?

Old timer showed me a better way to route wiring bundles

I had a 30 year veteran from Delta look over my harness install last month and he pointed out I was tying my bundles too tight. He said I was basically creating stress points that could crack the insulation over time. Now I leave a little more slack and use a different knot spacing every few inches. Has anyone else had to unlearn something a senior tech called out?

Spent two years soldering harnesses wrong before a QC guy showed me the right way

I was at a shop in Phoenix for about two years doing avionics installs. I always twisted my wires before tinning them. Last month a QC guy comes over and says hey why are you doing that. He told me twisting before tinning actually creates weak points. I felt like an idiot. Has anyone else had a basic thing they did wrong for way too long?

Chasing a bad crimp for 4 hours on a Cessna 172

Had a right nav light that kept flickering intermittently. Checked all the obvious stuff, swapped the bulb, cleaned the ground, even ran a continuity test that passed. Turns out it was a pin in the D-sub connector that looked good but the crimp was barely hanging on. Took me from 2pm to 6pm to figure out something that literally took 2 minutes to fix. Anyone else waste a whole afternoon on a single bad connector?

Was crimping connectors wrong for 8 years until a guy in Atlanta set me straight

I was over at a buddy's shop outside Atlanta last month helping him wire up a Garmin panel and he stopped me mid-crimp. Said look at the barrel after you squeeze it. I'd been using the wrong setting on my crimper the whole time. Turns out I was crushing the insulation instead of the metal part and it still worked fine for years. But one bump or vibration and those things can fail in flight. He showed me the proper way with a D-sub pin and I felt like an idiot. The insulation on the wire should still be visible after the crimp, not pushed back into the pin. How many of you actually check your crimps under a magnifier or just assume they're good?

Hot take: most guys in avionics skip the manual and it costs them big time

I kept having this issue with a Garmin G5000 install where the displays would flicker randomly. Everyone on the line told me it was probably a grounding problem or bad coax. After 3 days of tearing my hair out I actually sat down and read the stupid installation manual cover to cover. Turns out I had the power supply wired in series instead of parallel like the spec called for. Fixed it in 20 minutes and never saw the flicker again. Has anyone else gotten burned by assuming you know the basics already?

Warning: my digital multimeter was lying to me for 6 months

I always trusted my Fluke 87V for continuity testing on the flight line. Turned out the leads had a crack near the probe tip, giving me intermittent false readings on a 737 brake wire bundle. Anyone else have a tool fail in a sneaky way like that?

Worst shift I ever had was last Tuesday on a 737 in Atlanta

Spent 6 hours tracing a intermittent fault in the weather radar system. Turned out to be a loose coax connector behind the radome that someone didn't torque right. Has anyone else found that those old ARINC 429 connectors just get flaky after 15 years?

PSA: Stop using paper logs for your avionics bench tests

I used to be that guy who kept all my test results on a spiral notebook. Scribbled down voltage readings and waveform notes while working on a King KX 155 nav com at my shop in Phoenix. Then about 3 months ago I had a customer come back complaining about an intermittent glitch in their Garmin G5. I dug through my notebook and the ink was smudged from a coffee spill, totally useless. Now I use a cheap tablet with a spreadsheet app and it saves everything to the cloud automatically. No more losing data or trying to read my own bad handwriting. Has anyone else dealt with a similar issue with paper records getting ruined or lost?

Saw a massive difference after switching to a digital multimeter last month

Honestly, I've been using the same analog multimeter for like 8 years at my shop in Chicago. Last month I finally swapped to a Fluke 87V after my old one started giving me weird readings on a 737 comm panel. The difference in troubleshooting was night and day. I caught a faulty comm antenna coupler in about 10 minutes that would've taken me an hour with the old meter. The digital readout is way more stable for those intermittent voltage drops. Has anyone else noticed that analog meters just can't keep up with modern LRU testing? What meter do you guys swear by for line work?

Found a dead short in a frayed wire bundle on a Cessna 172 last Tuesday

I was tracing an intermittent radio issue that had been bugging me for days. Turns out a chafed wire in the wing root was grounding out against a metal bracket every time the plane hit turbulence. I used a simple continuity test with a multimeter and some gentle wire wiggling to find it. Has anyone else dealt with hidden wire damage that only shows up under vibration?

That time I accidentally grounded a whole panel on a King Air at KMWH

Last Tuesday I was swapping out a Garmin GNS 530 in a 2004 King Air C90 at Grant County Airport. I thought I had the master switch off, but I bumped a live bus bar with my ring and blew the CESSATION CIRCUIT breaker. The smell of burnt solder filled the cabin and the pilot just stared at me from the door. Has anyone else shorted something dumb because of jewelry or a loose tool?

Took me 5 years to realize I was using continuity test wrong

I always used the continuity test to check wires end to end. Got called out on a Gulfstream 450 after I traced a fault to a bad relay. Turned out the wire was fine but the pin had a hairline crack where it crimped into the connector. Continuity test passed because the crack closed up under probe pressure. A senior tech told me to wiggle the wire while testing. That simple trick caught three more bad pins on the same harness. Now I never trust a static continuity check on any connector. Anyone else have something dumb they did for years before someone corrected them?

Found a cracked solder joint that was causing intermittent GPS dropouts on a Garmin 430