framing

[oldredhead52]

Just removed the interior skin of a 75 27' landyacht, of the 8 interior ribs, 4 were cut and sections where removed, for windows, ac unit, etc. How is this possible? The skin is holding it up, they couldn't of moved a rib over? What engineer signed off on this? Commonsense tells me this is wrong. This unit was untouched till today, so this is how it left the factory. I know it's been on the road for 45 years, but is this structurally sound? As an old builder, I've seen it all, but this is really disappointing.

On top of this, there is no framing in the end caps. How do you install segmented aluminum or wood endcaps with no attachment except to the exterior skin?

[Lumatic]

Don't know about your ribs but no framing in endcaps is normal. Can you post a photo?

[CBWELL]

Airstream has been building this way for decades, and there are still lots of them around built in the '50's and earlier. They must be doing something right!! Don't see many box trailers from that vintage on the road. They are built like and aircraft, not like a stick built home. Much similar to the unibody cars built today, with each component helping to supporting the structure. You are in a "learning curve" working on an Airstream!! Have fun with your rebuild!!

[BigSxyWhtGuy]

Not sure if you’re asking a redundant question or not. I can tell you that It’s pretty cool to see it all coming together in the factory.

[kidjedi]

This came up in a recent thread with another forum user installing a window where a rib existed. common practice, but someone else in that thread posted a photo of another airstream where someone went overboard and installed a huuuge door in the side and the thing was basically falling apart. So the lesson seemed to be: you can alter the ribs and rely on skins for structural support to some extent, but don't go crazy.
There are also several threads where people have documented constructing their own end caps from multiple panels similar to the exterior 17 panel end caps on older vintage Airstreams. Common materials are wood or aluminum sheet. One guy even reconstructed his end cap out of fiberglass, but that looked like some serious work.