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  Bonanza, Travel Air, & Baron Wing Bolt Replacement Controversy








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.)


FAA Legal Opinion Document #1


FAA Legal Opinion Document #2


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


HERE is a source for Beech wing bolt wrenches



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.

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




See the page on wing bolt cover clip repair HERE




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.