Maintenance

[Colonel]

As a pilot, you will deal with maintenance all your life.

From their perspective, pilots are people that break airplanes.  Maintenance
gives pilots working airplanes, and they get back broken ones.

That's not really fair ... I'd rather fly an aircraft that's just about to go
in for maintenance, instead of one that's just come out of maintenance.

An outsider would think that's silly, but an aircraft that's just come out of
maintenance is an unknown quantity.  Dangerous, actually.  And the more
maintenance it's received, and the longer it's been apart, the more likely it
is to try to kill you.

My religion is that the same guy that took it apart, has to put it together.
When a different guy puts it together, you are in for a world of hurt.  Mechanics
will say I'm full of shit, because they can look at some book as to how it
goes back together, when they assemble it from a collection of parts in buckets.

Hold on a fucking second.  Ever heard of a documentation error?  There are
plenty of changes over time to aircraft manufacture, and trust me when I say
you want to put an airplane back together EXACTLY THE SAME as it came
apart.  The same pieces of metal touching each other, in the same arrangement.

An extreme example is a new airplane.  The most dangerous of all. It's never
been flown, and they have special pilots - production test pilots -  fly them for
the first time.

Similarly, I would recommend that only senior, experienced pilots test fly
aircraft that are just out of heavy maintenance.  Hopefully they've got a bit
more systems knowledge and flying ability to deal with stuff that breaks.

It's important to know that there are maintenance-induced failures.  That is,
stuff on the airplane was working, before maintenance broke it.  There is a
risk, whenever maintenance is performed, that you will take one step forwards
and two steps back.

I hate checklist maintenance - blindly fixing and changing stuff, which may or
may not be broken.  Not only is it inefficient, there is a real danger that maintenance
may break something that was working.

I firmly believe that you should only fix what's broken.  If it isn't broken, why fuck
with it?  Sure, inspect it, but do it in a manner that has minimal disturbance.

For example, in Canada, if an aircraft doesn't fly for a year, TC wants you to start
pulling jugs to inspect the inside of the engine for corrosion.  I agree that internal
corrosion is a problem, but capricious jug R&R can cause serious problems.  Far
better to use modern technology to inspect the engine internals for corrosion.

People think that maintenance is like candy or sex or cocaine - more is better.  No,
you have to do a cost/benefit analysis on every maintenance task, to be sure that
you are doing more good than harm.

This brings us to a very important subject.

Diagnosis.

People are really shitty at figuring out, what the hell the problem is.  I'm not just
talking about mechanics - I'm talking about doctors, engineers or anyone else that
deals with complex systems.

There's a guy called Mike Busch who incredibly makes a living doing remote diagnosis.

People tell him what's going on, and he tells them what to tell their local mechanic to
do.  This is incredible, when you think that Mike never sees the airplane, which is quite
a disadvantage.  Yet, he does a better job of diagnosis than your local mechanic.

I learned a long, long time ago, that if you want something important done right, you
have to learn to do it yourself.

I remember, in the late 1980's, picking up the Maule from annual on Toronto Island.

I noticed that I couldn't pull the control column all the way back - they had installed
a vacuum filter blocking the flight controls.  And what I didn't notice until later, was
that they had welded the exhaust without a jig, so it didn't fit any more, so two of
the cylinders only had one stud on.  Fuck me.

Some more Transport Canada AMO maintenance .... we had some very expensive
radios installed by a very big name shop.  Comm radio never worked worth shit.
Turned out they had plugged the RG-58 coax connector for the VOR antenna into
the comm.  Smooth.

Had a G430 installed when it first came out, into the M20J.  Strikefinder didn't
work when it came back.  They'd damaged the wiring for it.

Especially avionics/instrumentation, I do not know of a single competent shop.
If there ever was one, you couldn't afford it.

For straight and level aircraft, I guess that sort of clown show is ok.  It's merely
horrible.  But for an aerobatic aircraft, you had better do some higher quality
maintenance, or you're not going to live very long.  Needless to say, this is not
mentioned anywhere in the regulations, but it is the difference between living
and dying, so it might be important.

If you're a white shirt with a checklist, well, you have to fly whatever shit they
put on the ramp.  My condolences.

[cgzro]

Funniest I had was an ELT remote head cable tie-wrapped to the high amperage wire from the starter solenoid to the starter.
Every second or third time I started the engine the ELT went off. 

[Colonel]

I'm pretty sure no one working on airplanes knows what electromagnetic
induction is.  A least, I've never seen anyone take measures to avoid it.
I doubt AC 43-13 mentions it, but I admit I have not read every page.

I seem to recall you having problems with spurious instrument
indications, with your new-fangled gauges.  I say again, I have never
even heard of a competent avionics/instrumentation shop.  If there ever
was one, you couldn't afford it.

I think I've told this story before ... shop makes a quote on a GPS install
on a friend's airplane.  I know at the moment, they have one tech.  Their
quote is for 240 hours of labor, and it will be done in a week.  Think about
that for a moment.  I asked them about the discrepancy, and the shop
shrugged and said they had to make money by overbilling the labor.

[Slick Goodlin]

My avionics high score was a plane in a past work fleet that kept having the Garmin analog to digital converter box blow up.  Tried a different avionics shop and it turns out the first guy plugged 26VAC into the ground or antenna or some such place that definitely wasn’t meant to be powered.

Then there was the one plane that would blow the radar fuse (not in-flight accessible) any time you flew through rain with the radar on...

[Colonel]

Avionics is almost always a train wreck.  It's simply incredible, how many people
cannot implement a wiring schematic that someone put a lot of effort into making.

For me, maintenance starts with simple cleaning and disassembly.  If you own
an airplane, don't be a douche and toss the keys at the mechanic when it's
annual time.  Back when people worked the ramp - I don't think that's a thing
any more - I'd recommend becoming a hangar rat.

At the very least, do a thorough cleaning of the aircraft, and then remove and
clean the cowls and panels.  When you get it clean, you can see the metal
cracking and corroding.  Paint it as required.  Learn about corrosion-X and
ACF-50.  If you live in a hot, humid salty environment, you're fucked.

See, it's all about keeping the metal happy.  Forgetting about wood and fabric
and composites, which are black art ... if you can stop the metal from cracking
and corroding, your airplane will last a very long time indeed.  Until you wreck
it, anyways.  Don't allow metal-to-metal contact.  Learn to use grease, corrosion-X
and spray silicon lube as appropriate, where metal moves against metal.

Cleaning an aircraft is worthy of a book, all on it's own.  Use the right chemicals
and procedures.  Most people clean with detergents that are extremely corrosive,
and that's a really stupid way of getting rid of grease.  Just get a spray bottle from
home depot, and some mineral spirits - just low odor paint thinner - and use that
for de-greasing.

Another spray bottle of watered-down dish soap, to get rid of the smears left by
the mineral spirits.

And lots of cloths.  Paper towel is ok, but shop rags are better.  Just try not to
fill the engine with lint.  Soft bristle brushes, of many different sizes and types,
are golden.  You can clean stuff really well with them, without damaging the aircraft.

I really like Tremclad (or compatible) "rust" enamel paint.  Get some small containers
of colors that match your aircraft.  Gloss black, flat black, gloss white, gloss red, etc.

With some small brushes, you can touch up nicks in the paint with it, and it really
makes a difference.  I remember some douches on AvCan threatening to turn me
in to TC Enforcement, because I touched up paint with a small brush and paint.

Go fuck yourselves, AvCan douches.

On the subject of cleaning the aircraft ... I remember that some kids from Brampton
landed at my old airport for fuel.  When they tried to start their 172, they had the
familiar "zing!" when they hit the starter.  But the prop didn't turn.  So they phoned
their TC-approved AMO, and they were told to stay overnight, and an AME would
be flown down from Toronto.

Fuck me sideways.  Even for Canada, that was pretty stupid.

I walked to my hangar, got a spray can of electrical contact cleaner, put a long red
straw on it, and cleaned their starter Bendix drive without even touching the 172. 
And off the kids went.  Saved everyone a shitload of time and money.

I mad the mistake of mentioning it on AvCan, thinking that someone would learn
from that.  Instead, the AvCan douches threatened that they would report me to
TC Enforcement for doing maintenance on a commercial aircraft without an AMO.

Go fuck yourselves, AvCan douches.  Don't oil your Bendix drives, it just collects
dirt.  Clean it, with electrical contact cleaner, even if TC Enforcement thinks you
need an AMO.