Many folks are beginning to report that their
maintenance providers have begun insisting on Bonanza, Travel Air and Baron wing
bolt replacement. This is no small task. The parts are pretty expensive and more
importantly, the risk of disturbing what could be a fine factory rigging job can
occur.
It appears this trend is occurring due to
there being more
recent maintenance manuals citing wing bolt replacement in their
recommended procedures and inspection sections. Here is the classic dilemma:
"I'm doing the annual on my (insert model year here) Bonanza, Baron, Travel
Air and my IA, who is pretty reasonable, says the wing bolts MUST be removed and
inspected every 5 years and replaced every 15 years per the Beech maintenance
manual. I thought all this was optional, but he says the Beech manual is clear
and thus it must be done...."
And so it starts..........
Here are FAA Legal Opinion documents that SEEM
to suggest that unless a requirement is listed in the Airworthiness Limitations
Section of the Instructions for Continued Airworthiness (ICA), they are advisory
in nature and NOT mandatory. Here are the documents
(courtesy of Beech Lister Mike T.)
Here is an excerpt from research by ABS' Tom Turner, on
the issue of wing bolt replacement:
The question frequently arises whether wing bolt inspection
and replacement is mandatory in Beech piston airplanes.
Federal requirements to comply with recommendations in
manufacturers’ manuals (14 CFR 43.16) apply only when the recommendation is
listed in the Limitation section of the manual, or if compliance is required as
part of an Operation Specification for a commercial (i.e., Part 135) Air Carrier
Certificate.
I’ve researched this with ABS’ technical advisors, Beechcraft,
FAA and others in the industry. Everything revolves around Federal Air
Regulation (FAR) 43.16: § 43.16 Airworthiness limitations.
Each person performing an inspection or other maintenance
specified in an Airworthiness Limitations section of a manufacturer's
maintenance manual or Instructions for Continued Airworthiness shall perform the
inspection or other maintenance in accordance with that section, or in
accordance with operations specifications approved by the Administrator under
part 121 or 135, or an inspection program approved under §91.409(e). The
unanimous response is that there are no specifically identified Airworthiness
Limitations in Hawker Beechcraft’s maintenance manuals for ABS-type airplanes,
and consequently that FAR 43.16 places no
mandatory compliance requirements on these airplanes unless
such requirements are specifically adopted as part of an Air Carrier Certificate
(FAR 135 or 121). Therefore, Beech’s stated overhaul schedules are
recommendations, not requirements, for privately operated airplanes under U.S.
rules.
The full text of Tom's comments can be viewed
HERE
As for me, I'm not letting anyone change my
wing bolts unless they show signs of corrosion or other debilitating anomaly.
Stripped Wing Bolt Pirep
The above wing bolt was found by an A&P in a G36 Bonanza.
Below is the verbatim guidance provided by Michael T., of the excellent Beechcraft shop, AVSTAR Aircraft.
"The
first thing to understand is this did not occur from normal
circumstances. My gut is telling me the bolt was over-torqued, which
brings into question the remaining wing attach hardware. Now the mindset
is replacing all 8 sets.
To this particular problem child, I would have two suggestions, and the utmost in care need to be used with either method.
Mark
the wing to fuselage interface so it can be placed exactly where is is
now, disconnect controls and wiring, landing gear, fuel & hydraulics
like you are planning to pull the wing anyway, then...
1.
Relax tension on the three remaining fasteners by several threads, I'd
shoot for 4 or 5. Wing tip can be picked up and insert a shim at the
lower points, 3/16" thick, to act as a fulcrum and keep the tension as
straight as possible on the problem area, then preload the wing and
readdress the disassembly. If the nut is primarily stripped, it should
work. If the bolt is primarily stripped, it may back out a thread or
three, but seize up when the bolt threads that were in the nut lock get
to the bad nut threads.
2.
If #1 does not work, I have heard of this process being used when it
was the internal wrenching area was stripped (rusted) so a wrench
wouldn't grab. Using a small cut-off wheel (think Dremel), cut as far
into the nut barrel as you can without nicking the bathtub fitting - a
stainless retainer wall would be a good idea. Once that is done, open up
the near end to a small "V" that will fit a chisel nicely. You will
want to off-set the chisel slightly toward the center of the fastener
assembly, so if it comes out of the "V", it falls harmlessly into the
barrel of the nut, then take aim with an air-hammer. (Likely much better
control than an armstrong hammer.) Theory is the nut will crack and
open enough to remove from the bolt. You may need to rotate it 180° and
do it again so the nut has become two pieces.
A very good inspection of the fittings after disassembly is a real good idea."
Michael T.
_________________ AVSTAR Aircraft of Washington, Inc. 253-770-9964
Below are the results achieved after the A&P got the bolt unthreaded:
"Ended
up taking many measurements, and made several templates, to preserve
the current wing wash location. Loosened the other three bolts and
loaded the wing with some shot bags. Supported with jacks, and slowly
applied the weight to the wing. I was then able to, using the force of
the wing, get the nut to "thread" off the bolt. No bathtub damage. New
bolts, nut and washers, and presto, back in action."
This wing bolt absolutely meets my personal
standard for immediate removal
Here is the drain hole location that lies
underneath the bathtub cavity where the wing bolt lives:
The spar failed before the wing
bolt????
Here is another tip for wing bolt swappers as
relates to the anti corrosion coating that is referenced in some of the shop
manuals: MIL-C-16173 grade 11 corrosion preventative compound
Bonanza owner Bob N. suggests
CRC SP-400 meets the MIL spec and is available at
Amazon
spec calls for.
If the shipping costs of this product shock
you, Old Bob has found that Grainger stocks the product for just a wee bit more
than Amazon:
"I started to order the CRC SP-400 from Amazon, but the shipping was over
seven bucks per can. I checked at Grainger and they have it for a buck and a
half more than Amazon. Guess I will stop by Grainger next time I am in the
neighborhood!"
LPS 3 also appears to meet the MIL Spec,
available at Grainger:
WARNING: I am not an attorney,
don't play one on TV and did not sleep at a Holiday Inn Express last night. You
are advised to make your own assessment of this information in conjunction with
your responsibilities under the FARs to be the final authority as to the
airworthiness of your aircraft. Consult a licensed A&P Mechanic before acting on
any of this information.