Flying after maintenance work

[fxyz]

Keep the questions coming fxyz, there are answers here....

Here it comes, Please jump to the last paragraph if you don't want to read the whole thing. :

Yesterday I went to the practice area for the first time and it's also new for me to fly by myself from engine start to shut down, so I checked everything especially carefully before the flight. On the journey log, I found out that they had just done a 100-hour inspection, fixed some bad mag problems and overhauled the propeller. I'd be the first one to fly it after this.

I remember that it's relatively unsafe to fly a plane right after maintenance work without a test flight. So I asked dispatch to give me another one but he said it's the only one and there's no problem with it. The whole flight I was worried about the propeller falling off and having to look for a field to land, which is probably unnecessary...

I guess it's the word "overhaul" that made me so nerves. What kind maintenance work is intrusive enough that you need to keep an eye on it for the first few flights after? Engine overhaul only?

Thanks.

[photofly]

I hope you were joking about the prop falling off. (Although there is that Youtube video...). Some maintenance work requires a test flight and signature from the pilot to complete the procedure of returning the aircraft for service. But it's not in the mindset of an aircraft mechanic to send an aircraft up in the air unless he or she is 100% sure it's safe to fly. Doubly so with a student pilot. You're not being used as a guinea-pig to assess the quality of someone else's maintenance work, I promise.

If there is work done, it's worth noting it and having a look on the ground, to keep yourself informed about the aircraft you're flying. But, to be truthful, any problems with the flight are much more likely to be caused by the pilot and their lack of skill than anything that's wrong with the aircraft. That goes for all pilots - not just you.

[CpnCrunch]

What photofly says is all true. However AMEs are human and they sometimes make mistakes (although not as often as pilots It is a good idea to be cautious after any significant maintenance work, and not fly if anything seems unusual.

[fxyz]

I hope you were joking about the prop falling off.

Ok maybe I exaggerated it a little I should trust the mechanics but still feel a little nerves when things are out of my control.

[PositiveRate27]

I had a student who was the first to fly an airplane after it had maintenance work done on the elevator trim. They reversed it and sent it out backward. The student missed it on the walk around but picked up on it and flew it on on his short xc and back.

Needless to say I had to have a rather stern talk with both maintenance and my student.

Always be skeptical, people are only human!

[7ECA]

For more minor maintenance items, a cursory check is a nice way to satisfy yourself that everything looks good, or at least how it used to look...

For more major maintenance, I always did a more thorough check, because it seems to me that this is the area where things could have been missed or you may end up with a surprise or gotcha.

Then again, it is good to be a bit paranoid about knowing your aircraft, and being able to spot problems or notice changes, and bring them up with your instructor, an AME, etc.

[cgzro]

Its always wise to double check whatever maintenenace was done if possible. If mags were overhauled make sure you get some drop, if the drop is imperceptable chances are a ground was ledt disconnected. If it pops and sputters perhaps the timing is off a bit. If control work was done check travel direction because very occasionally they get rigged in reverse. Prop work, check for play, make sure its lock wired etc. Somebody says fuel or oil is fine /added, visually check yourself.

Just generally check what you can yourself for signs of trouble before getting in the air.

As far as flying after overhaul, i doubt a student pilot would do this. Usually the first few hours after overhaul require specific engine treatment which is not compatible with training. For example very high power settings for extended periods of time and care and management of the engine temps.

[DonutHole]

Problems out of mtc are rare but they do happen.

Human factors shows us that it is statistically nearly Impossible to do a job properly. So it says a lot about pilots and engineers but be prudent.

If you just had a prop overhaul, on run up when you cycle it pay particular attention to the sounds.. does it work the same or better? Worse? Would you know the symptoms of an oncoming failure? What would you do if the prop did depart?

Mags are huge for me. Dropping good? What are you going to do if you lose a mag? In a turn doing upper air work?

It's a good thinking exercise.

It is the weirdest feeling.. As a human when we get behind to curve we are vulnerable. Generally our mind draws from experience to predict the future and if we aren't getting the right inputs to match our perceptions helpless confusion can set in, so it's important not to get there.

The best thing you can do to become more comfortable with mtc is either do some or Learn a bunch.

There was a guy here who preached airframe and systems knowledge. I agree. The more you know the better you will be and if you lay the foundation for total understanding early you won't be fighting the curve.

Good luck

[Pop n Fresh]

I notice you just soloed recently. That makes me think you are flying a light single with a fixed pitch propeller. I suspect a "prop overhaul" was filing out any nicks and possibly re-painting it. They might have sent it out to be balanced and have non destructive testing. This is pretty simple stuff for the people that do it. It's good to stay alert but this is really a pretty difficult way for maintenance to cause a problem with the plane.

I suspect you are over thinking and wondering if the possible, though very rare issues that could occur after a constant speed propeller has been overhauled might happen to your C-172. Short answer, no.

The magnetos might be a concern but if they do what they should on the run up they should be fine. That's part of why we check them.

[Big Pistons Forever]

Like others have said aircraft maintenance personnel are human and therefore, like everyone else can make a mistake. An airplane out of a 100 hr or other major maintenance should get an extra hard look during the preflight inspection.

Things to look for.

Inside the cabin:
- tools left on the floor particularly under or near the rudder pedals.
- Give the seats a good shake. The seats have to come out to do the airframe inspection so make sure they were firmly re-mounted on the tacks by giving them a good shake. For 172 and up Cessna's make sure that the secondary seat stop inertial reel on the pilot side has been hooked up
- Look for loose interior panels or trim pieces

Outside
- Look for missing screws on access panels and on the cowling
- Check for full and complete control movements. There have been cases where disturbed wiring, particularly behind the instrument panel, has fouled the flight control cables or mechanisms.

BTW the going rate to return a tool to the mechanic who left it in the airplane is a 6 pack of beer

[ahramin]

Am I the only one here who thinks brand new solo students should not be doing first flights for aircraft fresh out of a 100 hour? So much there to go wrong that a student pilot just isn't going to catch.

[5x5]

I'm with ahramin. What everyone else says is true about there likely being no issues after maintenance, but I don't agree that a student working on a PPL licence should be sent solo on the first flight following maintenance. AMEs are people just like pilots are and as such can make mistakes or forget things. It happens very rarely but can have quite an impact on a flight should it happen. As such, I believe that first flights following maintenance should be done dual or at least by a licensed pilot with more experience than a pre-licence student. And I also believe that a school should manage dispatch to insure that first flights following maintenance are dual.

[Rookie50]

Like others have said aircraft maintenance personnel are human and therefore, like everyone else can make a mistake. An airplane out of a 100 hr or other major maintenance should get an extra hard look during the preflight inspection.

Things to look for.

Inside the cabin:
- tools left on the floor particularly under or near the rudder pedals.
- Give the seats a good shake. The seats have to come out to do the airframe inspection so make sure they were firmly re-mounted on the tacks by giving them a good shake. For 172 and up Cessna's make sure that the secondary seat stop inertial reel on the pilot side has been hooked up
- Look for loose interior panels or trim pieces

Outside
- Look for missing screws on access panels and on the cowling
- Check for full and complete control movements. There have been cases where disturbed wiring, particularly behind the instrument panel, has fouled the flight control cables or mechanisms.

BTW the going rate to return a tool to the mechanic who left it in the airplane is a 6 pack of beer

+1. Trust, but verify. A few minutes overhead the airport isn't going to hurt anyone after an annual where engine work was done, and no low Ifr on the first flight either, aren't bad rules.

[KnownIce]

Something else to keep in mind when flying after maintenance is that, if anything should seem unusual, you must as always remember to fly the airplane first. Everyone knows this but actually committing to doing so does not happen 100% of the time. The majority of things that might be worse after maintenance are likely little things. When something catches your eye, decide immediately, does this need my ongoing attention?

ie. after maintenance I have flown an aircraft that
-- GPS wouldn't power
-- vacuum system leaked slowly (during day VFR flight)
-- random bolts/fasteners from instrument panel fell off
-- intercom failure / PTT switch issues
-- door wouldn't seat itself right, not noticed during pre-flight, leading to minor vibration or draft in the cockpit
-- heater ducts mispositioned / disconnected, making feet uncomfortably hot when set high enough to keep cabin warm in winter

None of these should affect the aircraft's ability to fly in a controlled fashion, but a pilot that is preoccupied with troubleshooting all of the above, will affect flight performance.

After any maintenance, at a minimum I always double-check that the control surfaces feel normal, and are appropriate, the seat and seat belts are secure, that the engine makes appropriate power, and I watch the engine gauges a little closer on the first flight. Any maintence that involves engine, fuel, or control system work requires closer attention.

Although not directly your question, something else you will think of later on is would any of the above advice change if you about to embark on a long cross-country? For me, the answer is yes, and as a general rule I will not launch into a multi-day cross country without the aircraft flying at least once or twice after any maintenance. Commercial pilots don't have a choice but as a private pilot you do. Have done it a couple times and almost always something goes wrong. Even if it is something minor it is a hassle to deal with away from home (ie. once I had about 6 cowl fasteners fall off in a row during one flight, obviously were not fastened tightly after maintenance and didn't pick it up on preflight).

[stol701]

... but still feel a little nerves when things are out of my control.

There are way too many things that are out of your control. Don't feel nervous. Find some other way to feel as being nervous is only going to make your decision process worse and will rob you of at least some fun.

[omgwereallgoingtodie]

talk to the maintenance guys, they are usually only too happy to show you what they've done.
Often they are delighted that someone is taking an interest in their work.
you may even learn something

[PilotDAR]

The maintainer will specify a maintenance check flight following some types of maintenance. Such a flight would be experienced pilot stuff. If that has been required, there'll be a journey log entry specifying the requirement, and completion of that flight. If that check flight has not been specified a check flight, the maintenance was probably not of a nature which would affect a new pilot's ability to control the aircraft.

There's no harm, and lots of benefit for you, in understanding more about maintenance in general. So trust in the maintainers, and ask about what was done, and any risks, just so you can learn. And, do your basic prefilght checks as though they matter! I have had some real scares flying maintenance check flights, so it can happen........

[fxyz]

Thanks guys!

talk to the maintenance guys, they are usually only too happy to show you what they've done.
Often they are delighted that someone is taking an interest in their work.
you may even learn something

After talking to the AMEs at my school, I'm feeling a lot better now! You are right, they're nice and eager to show me their work.

If something like this happens again someday, I'll do a thorough walk around and a couple of circuits first before leaving the airport. Thanks PositiveRate27, cgzro, DonutHole, BPF and KnownIce for pointing out things to look for on a post maintenance walk around!

[Heliian]

If control work was done check travel direction because very occasionally they get rigged in reverse.

If control work was done, a dual inspection for proper assembly, locking and sense of operation is required. IF your controls were reversed then 2 people screwed up and this happens EXTREMELY RARELY. If your maintenance company does this occasionally, then you NEED to go somewhere else.

[ahramin]

I've personally seen it done twice. Once ailerons, once rudder trim.

[PilotDAR]

IF your controls were reversed then 2 people screwed up and this happens EXTREMELY RARELY

'Could be three, if you fly it that way! I've had it on a C 206, with elevator trim. The direction of movement was correct, but the travel limits reversed, and on the C 206, that is a BIG problem for controllability. Very poor design there. That is why flight control work should be maintenance check flown, by and experienced pilot. Mag and propeller work, not so much...

[cgzro]

If control work was done, a dual inspection for proper assembly, locking and sense of operation is required. IF your controls were reversed then 2 people screwed up and this happens EXTREMELY RARELY. If your maintenance company does this occasionally, then you NEED to go somewhere else.

The reason for the dual check is precisely because it was happeneng too often but I agree its rare.. But it takes all of ten seconds to check all the controls during a walk around so no reason not to verify after maintenance.

ive not had reversal problems but did have a trim that got stuck full up in flight after the aircraft was totally rebuilt and I was testing it out prior to giving it to the new owner. Cable tension wss wrong and it went loose in flight. Also saw a throttle cotter pin come out leaving no throttle in flight fortunately it happened at high power so landing was easy enough.

[photofly]

You know "check flight controls for freedom of operation and correct movement" is part of the performance criteria for the pre-flight checks on the flight test from the Rec upwards?

The flight examiner guide elaborates:

"The requirement to ensure correct control surface movements is
imbedded in the Aim and is a mandatory part of the checks.

NOTE: A check of flight controls for freedom and correct movement of the corresponding control surfaces
is mandatory and will be conducted before flight. Should the candidate neglect this check, the
examiner will ask the candidate to perform it and a major error will be noted."


So really pilots - students, at any rate - should be doing this check every flight, not just those following maintenance.

Grammatical pedantry: shouldn't "imbedded" read "embedded"?

[GyvAir]

Grammatical pedantry: shouldn't "imbedded" read "embedded"?

I think it just depends if it was ingrained in your mind early on to spell it "embedded", or engrained in your mind early on to spell it "imbedded".

In any case, do a check for free and correct control movement before every flight. After maintenance, for controls you can't see from the pilot seat (trim tabs in particular) position them from the cockpit, then go verify correct direction of movement yourself. Don't trust someone else to say they moved the correct direction, as interpretation of up/down, left/right regularly gets muddled with trim tab directions, especially for people relatively new to aviation.