Pilot - MX cooperation

[David36]

I would like to talk a little about how you found the proper way to cooperate with maintenance guys, how to ensure your best as a pilot regarding repairs, works done etc.

It is known by regulations that the pilot is the one who has the ultimate responsibility of integrity and safety of the aircraft he operates, so how do you find from your experience the best way to ensure this together with checking mx logs, have a good preflight after repairs and other tips related? How can a pilot ensure that that work is done as it should, except being itself a mech?

Sorry mech guys, no argue for you, the purpose of the thread is to find out the best way to cooperate, despite that old advice which says to never trust you.

[Shiny Side Up]

How can a pilot ensure that that work is done as it should, except being itself a mech?

While you don't have to be a mechanic, having a good mechanical knowledge is really the only way to guarantee you won't get hosed. The same applies with automobiles. While there are good mech shops out there, it can be nearly impossible to know who is who. Having a good level of mechanical knowledge is critical to being a pilot - remember, no matter the guarantees the mechanic gives you, its your ass in the airplane.

[David36]

Having a good level of mechanical knowledge is critical to being a pilot - remember, no matter the guarantees the mechanic gives you, its your ass in the airplane.

I certainly agree. If possible I would appreciate some advices how to acquire that.

[Beefitarian]

Distrust them politely and with respect. If you could fix it yourself you probably would.

If you work with the people repairing the planes they might want to do their best to help you out. If you work to spite them, they will just want to avoid and maybe ignore you. Not the best way to get things done.

If it's your own plane find someone you can trust. You really have no choice.

The only ways to get real mechanical knowledge is by reading, learning from others and most importantly getting your hands dirty by fixing things.

[Colonel Sanders]

Years ago, kids grew up fixing their bicycles, helping their
Dads fix the lawnmower, maybe work on the family car,
help their dad change the points and condenser and spark
plugs, perhaps service an outboard motor on the boat,
change the oil on their motorcycle.

Those days are gone, and no one works on engines or
anything mechanical any more. People don't even know
how to change a rubber o-ring when their tap is dripping.

This presents a bit of a challenge when the new generation
arrives at the airport for flight training. It's not their fault -
their fathers don't have a clue about anything mechanical -
but if you're going to fly an airplane, you had better learn
a little bit about how it works and how to service it.

Personally, I would strongly recommend getting a toolbox
and some screwdrivers and pliers and wrenches and sockets
and zip ties and tape and lock wire and some spare machine
and sheet metal screws. I cannot imagine not having this. A
friend of mine doesn't fly his airplane anywhere unless he
has a spare kit to rebuild a magneto and a buzz box to time them.

I have tried to write some articles for students arriving at
the airport that didn't have the benefit of a mechanical
upbringing: http://www.pittspecials.com/articles.html

I was lucky enough that by the time I was 10, I was helping
my father change cylinder heads on cars, changing pistons
and honing cylinders, doing maintenance on boats and
motorcycles and airplanes.

Heck, on a recent vacation a friend's engine was running
rough, so I went to the grocery store, bought some dental
floss, ordered a hone, borrowed some MEK, and performed
SI 1425A to unstick his high-time exhaust valves. Also
replaced the magnetos and spark plugs. Engine ran
"butter smooth" afterwards, according to him.

And I'm not even an AME. Never will be. But I have learned
that airplanes aren't about to tolerate a pilot that doesn't
understand them.

[Shiny Side Up]

Those days are gone, and no one works on engines or
anything mechanical any more.

This is partly because they don't make things anymore with the idea that they will be repaired or need to be worked on in mind. Look under the hood of any car these days and there's a big plastic cover on the engine that tells you if you remove it it voids your warranty. All the little things in the world that used to be made in a fashion so one could take apart remove, pieces, make new pieces, fix old pieces are no longer made in such a fashion.

If you work with the people repairing the planes they might want to do their best to help you out. If you work to spite them, they will just want to avoid and maybe ignore you. Not the best way to get things done.

Its a good idea to gain some of this knowledge hanging around people practicing it, though sometimes that irritates the hell out of them, so you can't do it to everyone. If you want to learn bad enough you'll find a way to endear yourself to them. This might entail spending money. Buttering them up with food offerings and beer often helps, though don't give them the beer before the work is done.

The only ways to get real mechanical knowledge is by reading, learning from others and most importantly getting your hands dirty by fixing things.

This ain't an overnight process it must be said. Its easy for someone who does have such expertise to not realise that gaining such expertise is a lifetime's work.

I certainly agree. If possible I would appreciate some advices how to acquire that.

The unfortunate part is that there are no easy ways, though the above suggestions are a good place to start.

[Colonel Sanders]

One thing a pilot can do, is learn to clean his airplane.

Any pilot/owner that isn't lazy or physically handicapped
(eg in a wheelchair) can inexpensively clean his airplane,
which is a big part of doing maintenance.

http://www.pittspecials.com/articles/Cleaning.htm

A thorough cleaning of an airplane is an essential part
of an annual inspection. You can't inspect what you
can't see! You clean an airplane, you start to see stuff
that needs to be fixed: cracking aluminum, smoking
rivets, etc.

PS Cleaning the bottom of the airplane and other
grungy places - belly, wheel wells, engine compartment -
is frankly more important than shining up the frikken
paint, which you can do if you want, but isn't the
highest priority, despite what owners think.

I like to chrome plate the valve covers, polish and
repair the aluminum baffling, replace the seals, etc
so that when you pop open the cowling you see a
bright shiny engine, not some black hellhole.

[just curious]

First, you might track down the idiot who told you not to trust engineers, and let them know that they were seriously misinformed.

Then you might get your engineer to show you what they look for in a daily inspection.

Following that, take the Colonel's advice. But get an engineer to show you how to clean an aircraft. Get a helicopter engineer to show you how to clean plexiglass.

After that, sit down with an engineer and get thrm to show you the best and worst documented aircraft defects they have received.

Try to understand that the very newest licenced engineer has about four more years of varied experience than the newest commercial pilot. For the most part they are limited by the maintenance parts budget and the description of defects YOU wrote up.

JC

[David36]

Heck, on a recent vacation a friend's engine was running
rough, so I went to the grocery store, bought some dental
floss, ordered a hone, borrowed some MEK, and performed
SI 1425A to unstick his high-time exhaust valves. Also
replaced the magnetos and spark plugs. Engine ran
"butter smooth" afterwards, according to him.

And I'm not even an AME. Never will be. But I have learned
that airplanes aren't about to tolerate a pilot that doesn't
understand them.

I'm sorry, it is a very stupid question, but are you allowed to perform this type of repair? Just curious, no argue.

First, you might track down the idiot who told you not to trust engineers, and let them know that they were seriously misinformed.
JC

It was more like a joke heard on hangar talk

Back on the issue, quite interesting advices here. I really appreciate.

I would like some advices regarding post-maintenance flights and also, about the ensurance regarding critical structural repairs like airframe or flight controls.

Also, what interests me particularly is how to ensure the safety condition of the airplane (of course beyond logs and sheets, preflight, I'm really careful on those), considering I'm not yet an owner, I use to fly planes which I don't own.

[Chaxterium]

Another good reason to have a good mechanical understanding of your aircraft is to help out the engineers anyway you can with troubleshooting. If you simply write a snag in the book at the end of the day and walk away it creates a lot more work for the engineers. However if you talk to them and explain what the issue was, and what was going on when it happened, you can greatly reduce the necessary troubleshooting steps. I'll give you an example.

Years ago when I was new on the Dash 7 we had an issue where the landing gear wouldn't retract after take off. The first time it happened I was flying with a relatively new captain so between us our mechanical knowledge of the aircraft wasn't great so when we landed we couldn't help the engineers much. The engineers did their best chasing wires all over the aircraft to figure out what the problem was. Eventually they thought they had it but they were wrong. It happened again so we got a ferry permit and flew the aircraft with the gear down to a heavy maintenance base where the engineers tried and tried to find the problem. Eventually they were pretty convinced they had it solved so they returned the aircraft to service. The very next revenue flight it happened again. This time though I was flying with a captain who had thousands of hours on the aircraft and he knew it inside and out. We called our engineers from the air on the satellite phone and completely ruined his day but in the process we explained everything we were seeing. Eventually my skipper noticed that his flight timer was not counting, but mine was. A ha! The flight timers are based on squat switches on the nose landing gear so they start counting when they sense that the aircraft is airborne. After we landed the engineers had a look and sure enough that was it. One of the squat switches on the nose gear was incorrectly sensing that the aircraft was still on the ground so therefore the gear would not retract. After all the effort they went through and all the money the company spent ferrying the aircraft it came down to a tiny squat switch. It all could have been avoided if me, and the first Captain I was flying with knew the aircraft a little bit better. That experience taught me a hell of a lot and to this day when I have a snag to report it doesn't go in the book until I've spoken to the engineers personally and given them all the info I can. They really appreciate it and it goes a long way to building a solid relationship with the guys and gals who keep your plane in the air.

Cheers,
Chax

[photofly]

If you're thinking about this question from the point of view of a private aircraft owner, bear in mind that AMEs have a slightly different goal when it comes to repairing your aircraft than you do.

An AME's goal, directly or indirectly, is to minimize his own risk. That means every recommendation you get is going to be biased (consciously or subconsciously) towards the replace/repair/overhaul side of the balance vs. the "it's airworthy" side of the balance. It costs an AME nothing to say "that unit needs to be replaced" - and could even benefit him monetarily. Whereas if he signs off something that later turns out to be at fault then that might cost him more, in the end.

Your goal is also safety, of course, but not at any cost.

Basic economics will quickly show you that this difference leads to different decision-making between the two of you.

Sometimes decisions to repair/replace are clear-cut, but sometimes they are not, and you need to have the wisdom to know which is which, and what to decide in each case. If you get in the habit of handing your AME a blank cheque along with your aircraft, then you will be making and paying for the decisions that are best for the AME every time and not the ones that are best for you.

[Shiny Side Up]

First, you might track down the idiot who told you not to trust engineers, and let them know that they were seriously misinformed.

I don't know about that JC. Its like the old saying "trust everyone, but tie up your horse". I doubt my experience is unique, but there's a list of shops and engineers I wouldn't take my plane to, and some stamps and signature in log books who are worth about as much as price of the ink. There's good engineers and some are just parts replacers and there's a few outright crooks. Just like every other similar profession. If you don't know your engineer really well, you better know your airplane really well or a) you'll get taken to the cleaners, or b) you're going to find yourself in the air in a lot of trouble.

Now that said, one doesn't have to be ignorant about it or rude, but don't be afraid to get a second opinion if you think you're being taken for a ride. It doesn't exempt pilots from needing to now their airplanes and pilot/owners doubly so.

[iflyforpie]

In theory, all of the paperwork and procedures should take care of just about any maintenance related issues. The Ops Manual, MCM, and the AMO's MPM ensure that maintenance is properly scheduled, snags are rectified or deferred, and the aircraft is removed and released from service properly.

Your walkaround, run up, control checks, instrument checks, and rolling checks are all part of verifying that the aircraft is fit and safe for flight. However, I think lots of those are just done as rote without further thought other than major deficiencies (bad mag drop.... one wing missing... etc).

From the maintenance side of things, we have procedures to ensure that everything is fit and safe for flight as much as we can without flying the aircraft. This includes function and leak checks, dual inspections for flight and engine controls, tool checks, and a double checking of the work order to ensure that snags have been addressed and access closed.

Of course, we are only human, and just like you might forget an item on a checklist, AMEs have been known to forget things on occasion as well.

For lots of items, there is simply no way to check... even for an AME... because it involves opening up the aircraft.

There are time considerations as well. Given enough time, I could do a really thorough walk-around that would take two hours, but is that really necessary if there is a competent AME who just went through the entire plane a few flight hours ago?


You brought up flights after maintenance, and this is IMHO as an AME one of the most likely times you are going to have issues. On this one, I probably would spend at least 15 minutes doing a walk around (I do a walk around on my own aircraft after I have just released them... even though I have already been around it once). Check under the cowl for tools or rags or loose items. Check the cockpit for the same. Check every access panel to ensure it is installed (the one under the stabilizer of the 172 is a common one to miss, as are the ones under the belly). Check the flight controls to make sure they not only move the correct way, but that there is nothing that sounds or feels out of the ordinary.

When flying the aircraft, it is with the system that has been worked on in mind. Sometimes I will run the aircraft for a while at one location and then taxi to another... looking for oil leakage if I have just changed an oil hose or engine gasket. If I have a new engine or carb or fuel injection system, it is on probation until I can confirm acceptable parameters for fuel consumption. On test flights after major work, I will not use things I don't need like flaps or gear to ensure that emergencies don't compound should I have engine, fuel, or electrical problems.

But the best advice has been given. Know thy aircraft. Borrow a maintenance manual. Bribe an AME with beer. Help out with maintenance checks. Most aircraft--especially light aircraft--are amazingly simple in comparison to most other modern machinery.