Man, that's interesting. I used to work at Lockheed in Marietta where their cargo airplanes were mfg'd and use to wander the assembly floor from time to time. Made me feel good to know I was helping build them suckers.

At the time, we were redoing some 141s and C5s and pumping out 130s. And I never noticed any sealed surfaces. Or at least I don't remember seeing any. Of course, way over where the 141 work was going on was too long a walk in that building.

What was the design like? Attached to both surfaces? Was there slack?

Kewl to learn something new.......