Scudrunners

Everyone suspected he ran it out of gas, but no:

http://www.ntsb.gov/_layouts/ntsb.aviat ... 80c&pgno=3

[quote]the carburetor's main metering jet was unscrewed from its seat and rotated 90 degrees.

The unseated jet would have allowed an increased fuel flow through the main metering orifice, producing an extremely rich fuel-to-air ratio, which would have resulted in the loss of engine power. It is likely that, over time, the jet gradually loosened from its seat, which allowed it to eventually rotate 90 degrees.

The carburetor was rebuilt during the airplane's restoration about 17 years before the accident.

The carburetor maintenance instruction manual contained no pertinent instructions for the installation of the jet assemblies.

[b][u]Had the carburetor maintenance instruction manual identified a means to ensure the security of the main metering jet, it is unlikely that the jet would have become unseated[/u][/b][/quote]

... and this is why you want to do all your own
maintenance.  AME's are always yammering on
obnoxiously about how they religiously follow
the maintenance manual.  And in this case they
did, and caused the accident which destroyed
the aircraft.

Once again, people need to learn the difference
between the paper world, and the real world.

I never understood that.  I thought a
parsec was a measurement of distance?

Read that report the other day
Went right out to the hanger and gave my Kinner a thorough look over
All seems well (knock on wood)
Also I agree with the Colonel , all my maintenance on the Fleet is done by me .
Once I am done work , I get my buddy who is as experienced as me with this type to do a secondary check.
Even if I wanted an AME to work on there are none that even know their way around a Kinner anyway

When it comes to tube+fabric/tailwheel/biplanes/radial engine
it's all up to you!

Helped a friend buy a Maule a couple years back.

It had a Continental engine that had a prop strike
back in the 80's.  Crank dialed ok, new prop installed -
all in the logs.

Young AME goes bananas and says that the aircraft
is illegal - prop strike requires teardown IAW the
CARs.

Sigh.

Explained to the new owner that the young AME
that only shaves once a week doesn't understand
that the CARs came into effect in the 1990's, long
after the prop strike in the 1980's, which was dealt
with IAW the regs and practices at that time.

Regulations are not retroactive.  Duh.  Otherwise
TC would be going after Alexander Graham Bell
for the flight of the Silver Dart in 1906 - no C of
A, no C of R, no pilot licence, no pilot medical.

TC could exhume all the corpses and bring them
into the Tribunal, I suppose.

Duh.

From a practical standpoint, the engine has
run for hundreds of trouble-free hours (and
has continued to do so).

Again, paper world vs real world.  People
should try really hard not to neglect the
real world.

The fact remains that this is a [b]maintenance-induced failure[/b].

If the jets had not been removed and (improperly)
re-installed in the field, they would not have backed
out.

I keep trying to teach people that maintenance has
risks.  Maintenance wears machinery out.  The more
maintenance an aircraft receives, the more likely it
is to try to kill you, when you fly it.

Mike Busch communicates this lesson far better
than I ever could.  He makes a very good living,
remote-controlling maintenance for owners.  He
wrote this back in 2008:

http://www.avweb.com/news/savvyaviator/ ... 909-1.html

[quote]How many of you have had the experience of putting your airplane in the shop -- perhaps for an annual inspection, to correct some squawk or even for a routine oil change or spark -plug rotation -- only to discover when you get the airplane back and take it aloft for the first time after maintenance that something that used to work fine no longer does?

I'd be willing to bet a steak dinner at Ruth's Chris that virtually every aircraft owner has had this experience. Heaven knows I have. More times than I'd like to count. 

Maintenance has a dark side: maintenance-induced failures (MIFs).

The point I'm trying to make here is that maintenance has a dark side that we don't often hear discussed, especially by mechanics:

[b]Although the purpose of doing maintenance is ostensibly to make our aircraft safer and more reliable, the fact is that all too often it accomplishes exactly the opposite.[/b]

When something in an aircraft fails due to something that a mechanic did -- or failed to do -- I refer to it as a "maintenance-induced failure," or "MIF" for short.

It's my distinct impression that such MIFs occur a lot more often than anyone cares to admit. (I sometimes slip and say "mechanic-induced failure," but "maintenance-induced failure" is considered more polite, particularly when conversing with your A&P. Either way, it's a MIF.)[/quote]

If I didn't know better, I would say that Mike Busch
in 2008 was discussing Harry Ford's carburetor.

Mike is completely at odds with what an AME will
tell you, which is that maintenance is always good,
and that more maintenance is always better maintenance.

[quote]this incident I don't think is the best case for that argument[/quote]

Sure it is.  If those jets hadn't been pulled
in the field, they would still be secure.  This
is a maintenance-induced failure.

Now, any good lawyer can spread the blame
around, and try to hang the manufacturer for
not having a better manual which described
everything you can think of, including cosmic
rays and coriolis force.

But keep in mind that plenty of other people
have overhauled carburetors before, and they
knew what wasn't in the manual.

Once again, people are puzzled when they
discover that safety isn't always found in the
paperwork.  Sometimes knowledge, skill and
experience might have something to do with
it, too.

Ever looked at the maintenance manuals
for an older airplane?  Not a Boeing or Airbus,
say a tube+fabric taildragger? 

Somehow, they didn't always fall out of the sky
after maintainence, because they were worked
on by guys who knew more than what was in
the maintenance manual.

To anyone that works on older stuff, this
is blindingly obvious.  Some brains is
required, not just smooth-cheeked blind
adherence to checklists.

As the older generation of guys leave
aviation, tremendous amounts of knowledge
is being lost.  You might disagree and
say that all knowledge is always contained
in a maintenance manual, but that simply
isn't the case in the real world.

It's depressing that people have to keep
learning the same lesson over and over
again.

And they even dispute that there is a
lesson to be learned!

Sigh.

You probably aren't familiar with Whirlwind
props.  They are fabulous (but uncertified)
props used for aerobatics.  There have been
several horrible failures of Whirlwind props
however, after they have been overhauled
in the field.  Maintenance-induced failure.

Sound familiar?  Or is there no lesson to be
learned?  What's the definition of stupidity
again?

In the aerobatic community, everyone with
even a tinge of grey hair knows that Whirlwind
props MUST go back to the factory for overhaul
because the prop shops in the field have no
clue, and they will kill you with improper
maintenance.

See a parallel to Harry Ford's PT-22 carburetor?