Old-school terminal blocks vs. modern D-sub backshells, which do you trust more?

I cut my teeth in this trade back in the late 90s working on legacy 727 freighters in Tulsa, and I swear by the old barrier strip and bus bar setups. You could see every connection, hit it with a meter, and torque it down with a screwdriver you've had for a decade. Now I'm on newer Airbus frames and everything is crammed into D-sub backshells with those tiny crimp pins and plastic inserts. Maybe it's just my aging eyes, but I've had three intermittent faults this quarter that all traced back to a pin backing out of a backshell, which never happened to me with the old screw terminals. The new stuff is lighter and faster to swap, sure, but I find myself double-checking every pin with a magnifying glass and a pull test before I close it up. What changed, I think, is the pressure to keep turnaround times down, so we use pre-made harnesses that don't get the same hands-on love. Is it just me getting old and cranky, or do some of you newer techs actually prefer the D-subs over the old terminal blocks for reliability in hard-vibration zones like the tail cone?

2 comments

2 Comments

taylor3051mo ago

Backshells got a lot more popular once the lawyers figured out they could slap a part number on a crimp and blame the guy who squeezed it. Meanwhile my old terminal strip just sits there with a screw loose, and you know what, at least you can see that screw being loose before it bites you. Three intermittent faults this quarter sounds about right, thats why I keep a spare pair of readers in my toolbox and a roll of electrical tape for the harnesses that arrive pre-made suspicious. New techs love the D-subs because they pop together like LEGO, but they never had to trace a single wire through a tail cone with a beeper and a prayer. Give me a barrier strip any day, at least when it fails, it fails loud and proud instead of hiding in a plastic shell.

riverhill29d ago

LEGOs that bite back, huh? Sounds like a lawsuit waiting to happen.