Re: Questions about the DH Comet

Date:         03 Oct 97 01:18:33 
From:         kls@ohare.Chicago.COM (Karl Swartz)
Organization: Chicago Software Works, Menlo Park, California
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Ed Mellinger wrote:
>Karl Swartz wrote:
>> In the original design, employed on the 727, 737, and 747, fuselage
>> lap joints were "cold bonded" with epoxy-impregnated cloth, cured at
>> room temperature, augmented by three rows of rivets countersunk in a
>> fairly thin skin.  The bonding and not the rivets was intended to
>> carry the primary pressurization loads.

>Does anyone know of other aircraft, or primary structure on them, that
>rely on "bonding" (c'mon, guys... it's glue!) to carry loads between two
>metal components?

Yes, the Lockheed L-1011 TriStar.  "According to James B. Beach, Chief
Engineer, L-1011 Production Design -- 'The extensive use of structural
adhesive bonding of doublers, triplers and lapped skin panels into
large panel assemblies (up to 15 feet by 38 feet) is an important new
development offering improved fatigue life, corrosion resistance and
durability."  (Douglas J. Ingells, "L-1011 TriStar and The Lockheed
Story," pp. 196-200, Aero Publishers, 1973.)

I've heard that Lockheed developed alpha cyanoacrylate (ACC) adhesives,
more commonly known as Krazy Glue, for the project.  I find that a bit
surprising since the version you can buy at the grocery store tends to
cure into a hard and britle form, but perhaps in higher quality form
or with different curing (the book referenced above mentions using an
autoclave) it behaves differently.

--
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