Warbird Information Exchange

I heard a rumor that the Lockheed Vega 5C N13705 located at the now defunct Jimmy Doolittle Center located at the Nut Tree Airport, Vacaville CA was assembled with non-FAA approved glue. So the thing will never fly?

Questions: Is there such a thing as FAA approved glue?
How can the FAA issue certificate if it is non airworthy?

UPDATED The Vega was issued FAA Certificate 07/12/2016, Expiration Date 07/31/2019

The Vega has been looking for a buyer since its arrival. It is almost entirely made of wood and I estimate that less than 1% of the aircraft is original. The data plate is not original.

Any thoughts on the safety of flying a 1933 Lockheed Vega that was reconstructed using a few original parts?

A friend (who was thinking of building a Vega at one time) said when that aircraft was sold to the Doolittle group, a cement fuselage mold and other bits sold to someone at a bargain price.

Anyone know what happened to them?

As far as authenticity....being wood, I'd expect most of it to be new...just like the Mosquitoes...and many other warbirds.

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I figure if you wanted my opinion on items unrelated to this forum, you'd ask for it.

The "FAA Certificate" info provided in the initial post does not match the current FAA database.

http://registry.faa.gov/aircraftinquiry ... rtxt=13705

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It was a good idea, it just didn't work.

AC43-13 Section 1-4, give the guidance on acceptable adhesives. As long as they meet or exceed one of the listed specifications, the FAA doesn't care what is used.

I don't know what Lockheed used in building the Vegas (and others) originally.

The only "FAA approved" glue is resourcinol that dates back to 1943. Sensenich still uese it in the manufacture of wooden propellors.

Home builders have been using epoxies such as T-88 with great success for many years. There are a lot of people that wish the FAA would approve the use of epoxy.

C2j

The Vintage Sailplane Association has discussed the topic of wood adhesives approved by the Feds and has used a variety of glues. Their newsletter "Bungee Cord" has this article:

http://www.vintagesailplane.org/wp-cont ... 3-Fall.pdf
http://www.vintagesailplane.org/classifieds/books/

According to the registry entry, the FAA registration was issued on 7/12/16. The airworthiness certificate was issued on 5/21/1955 in the standard category. Airworthiness certificates don't expire.

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Scott Thompson
Aero Vintage Books
http://www.aerovintage.com
WIX Subscriber Since July 2017

Airworthiness Certificates issued before July 17, 1956 expired every year and had to be renewed by a CAA representative every year. The registration certificate issued 07/12/2016 of course has nothing to do with airworthiness, only ownership. The aircraft could be registered and still not have a valid current AW certificate.
The leftover original Vega parts along with the molds and jigs, and a set of paperwork, went to Don Jones, a well known aircraft parts dealer. If I remember right the price was $2,000, nobody seemed to be interested in bidding on it. There was most of the original fuselage, cut in about four pieces, and the original wing, in rough shape and with no skin, but otherwise pretty complete. And some tail surfaces and other misc. parts. A lot of stuff went for low prices at that auction. Wish I'd brought more money....

Incidentally the company that builds new Wacos got FAA approval to use West System epoxy to build wings, and some individual restorers around the country have gotten approval from local FSDOs to do the same, but the official FAA position is still that Resorcinol is still the only glue approved under AC43-13


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http://www.biplanerides1.com/

The FAA sorta, in a backhanded way, have approved epoxies for use. You have to do a little research to figure it out. In AC43-13b, Section 1, they state an epoxy is approved if it meets Para 1-4a. That points you to the SRM and other guidance from the a/c manufacturer, and then various applicable MIL-Specs, AMS's or TSO's for the qualifying data the adhesive has to meet. It's up to the user to chase it all down. Resorcinol adhesives that meet all the required specs are still available, but not cheap. I suspect as we age out wooden structured aircraft over the next several decades, the FAA will start giving a little more open guidance on what is approved without having to wade through scads of data to make an informed decision.

I believe John Desmond was educated as an engineer, he also owned a furniture factory at one time so he may have known about various types of glue. He was also an accomplished pilot and flew his twin around a good bit.the men who worked in his antique aircraft shop in chalfont were very professional and did excellent work, including this vega. Hard to fathom that their glue selection would be wrong.

I think you can get a field approval for any type of adhesive as long as you can present the case that it is as good or better than what is already approved.

According to a DAR I know who specializes in vintage aircraft T-88 is the only epoxy that meets a mil spec, but the mil spec is for bonding metal, so no epoxy is FAA approved under AC43-13 for bonding wood. However, as bdk said, there have been several people who have gotten T-88 or West System epoxy approved for wood bonding use on a Standard Category aircraft through a field approval from their local FAA office.


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http://www.biplanerides1.com/

Take a look at Section 1.4b (6)...

(6) Epoxy adhesives are a two-part
synthetic resin product, and are acceptable
providing they meet the requirements of paragraph
1-4a.

Which sends you here:

a. Adhesives acceptable to the FAA can
be identified in the following ways:
AC 43.13-1B CHG 1 9/27/01
Page 1-4 Par 1-4
(1) Refer to the aircraft maintenance or
repair manual for specific instructions on acceptable
adhesive selection for use on that type
aircraft.
(2) Adhesives meeting the requirements
of a Military Specification (Mil Spec), Aerospace
Material Specification (AMS), or Technical
Standard Order (TSO) for wooden aircraft
structures are satisfactory providing they
are found to be compatible with existing
structural materials in the aircraft and the fabrication
methods to be used in the repair.

The catch is that when 43-13 was updated, someone at the FAA Small Aircraft Directorate got their panties in a wad and had the wording about Mil Sec/ AMS or TSO for wooden aircraft inserted into the document, sorta rendering the whole exercise moot. There are a number of 337's and some approving information from one manufacturer, that ok's T-88 on production aircraft wood structure.

In chasing down info, I found that CASA ( the Aussies) has approved Araldite AW 134 as a structural adhesive for aircraft wood, even though it doesn't show any data for wood use.

It's an interesting question to delve into.

I agree with all three of you and I think this is the root of the problem. The only wood glue that is specifically approved by the FAA is resourcinol. As with anything, you can attempt to get a field approval for any modification, including a different glue. That is what we have very successfully done on many occasions to legally use West System epoxy. T-88, which was widely accepted because it is "Mil-Spec" was outlawed as soon as someone figured out the mil-spec wasn't for bonding wood then, as CV noted the FAA basically wrote a clause in to clearly exclude it from the approved glues list.

The trouble is getting some other glue approved. If they didn't use resourcinol, then they would have to prove to the FAA that whatever glue they used is sufficient. I'm guessing because it is a laminated, monocoque wood structure that nobody will be able to get an exception/alternate approved. You'd have to pay big, big $$$ to a DER to do the stress analysis on the entire airframe and calculate the loads required by the glue to support. Then you'd have to spend more money doing tensile tests of said glue to prove that it meets the requirements. There has been issues with T-88, Weldwood and Casein glue all deteriorating in high temp and high humidity environments. So not only would you have to do just pure tensile tests, but you'd have to do it repeatedly over a wide temperature/humidity environment that would possibly put restrictions on the airplane in the end. I'd guess that since getting an approval for whatever non-approved glue will be exceedingly difficult the airplane will either remain static or have to fly under an Experimental, Airshow/Exhibition airworthiness. Just my $0.02.

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Ryan Pemberton
www.pembertonandsons.com

When the new production Waco's were being built (maybe they still are?) does anyone know what kind of glue was used in them?

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Defending Stearmans on WIX since Jeff started badmouthing them back in 2005.