How do you mitigate the risks of mechanic error?

The airline’s have oversight procedures to prevent such mishaps. Similar to what Dan Thomas described but more structured. Each airline has an FAA approved list of required inspection items (RII). Seiner A&P mechanics go through a process to become an RII Authorized Inspector. I held this authority myself on DC9,727, and 757 aircraft. Note: The authorization does not carry over into the GA world. So, even though I was an RII this blessing did not allow me do an annual on my little Cessna!
The airline RII authorized inspector is also not allowed to participate in the actual repair but does monitor critical steps and ultimately signs below the A&P as a final step in the corrective action.
RII Items vary depending on fleet. A short list would include flight control replacement, critical rigging, windshield replacement, heavy inspections, electrical modifications, etc.
Not so easy in GA! This would take deep pockets to accomplish but it’s not totally unheard of. Some corporate outfits send their own trained technicians to oversee large repairs at maintenance facilities. It actually saves money on this level.
I’ve had a few GA customers pay me to check out airplanes coming out of critical repairs. It’s pays off occasionally. Found an improperly installed elevator coming out of the paint shop once. Also found metal shavings in a fuel bladder coming out of TKS modification. More common findings have been with avionics shops. Also the lack logbook discipline and W&B documentation.
I think you could easily compile your own customized list of items that you want to have a second set of eyes look at. Just be prepared to inflate your maintenance budget a bit. And keep in mind that you are not the normal customer in this regard. Most owners want the work done as cheap as possible and would never consider paying for a 2nd look.
 
I’ve had several “maintenance-induced failures.” Mostly caused by not completing a task, like not tightening the nut on the alternator post after replacing the alternator, presumably due to an interuption while doing the task. None of those MIFs in my plane posed an immediate threat to safety.

And some of the MIFs on my plane were the kind you could catch in a preflight-inspection (like when a new battery wasn’t connected to its cable). So do your preflight without hurrying after maintenance. (The aforementioned reversal of aileron controls before a fatal flight could have been caught in a preflight inspection by the pilot in not just one way but two: when checking the aileron from the outside while looking in the cabin at the yoke, and again from the inside while looking at the aileron.)

After I had several MIFs I changed shops, and that problem stopped.

To help reduce MIFs, avoid nonessential maintenance, e.g., don’t replace all your cylinders if only two need it. Mike Busch’s book and columns cover that quite well.
 
Slowly but surely learn more and more about the inner workings of your plane. Learn how to change your own oil. There's tremendous value in removing the cowling and inspecting the entire engine bay while you save yourself $250 doing it yourself.
 
50kttailwind said:
Slowly but surely learn more and more about the inner workings of your plane. Learn how to change your own oil. There's tremendous value in removing the cowling and inspecting the entire engine bay while you save yourself $250 doing it yourself.
Click to expand...

When I'm working on the plane (experimental) I try to keep an inventory of the tools in use to make sure all of them get put back where they came from and none get to ride along after the task is completed ...
 
Daleandee said:
That's a very nice system! How do you like yours? :biggrin:
Click to expand...
Ha. Had I not retired I could have told you. But its definitely something only a company or govt could afford. Feel sorry for the guys who had $$$ personal tool boxes who had to take those home when Level 5 was inplemented.
 
Bell206 said:
Ha. Had I not retired I could have told you. But its definitely something only a company or govt could afford. Feel sorry for the guys who had $$$ personal tool boxes who had to take those home when Level 5 was inplemented.
Click to expand...

Yes sir ... I figured if I could afford that then I wouldn't need to do my own maintenance ...
 
You must log in or register to reply here.
Back
Top