How common is this type of damage?

[SYC2Vette]

Originally Posted by Ruscal

If there was no hatch opening cut into the shell the shell would have more rigidity to fight the buckling, but it is a lot to ask of aluminum sheet metal to be required to resist the compressive forces exerted during frame flex. The concentrated loads applied at the tongue/shell juncture are I would guess, pretty high. Possible solution could be to create a gap between the shell and tongue members so the load would be transferred elsewhere. The trim strip could also be clearanced. The gap would allow the frame/tongue member to flex as it is designed to, and the shell would not be deformed. How much gap would you need? Maybe start at a half inch and see what happens when towing over undulating terrain. You could put modeling clay under the gap and observe how the clay deforms. The frame is basically a bow, and the body is rigid. Stress is high at the edge of where flex joins rigid. The hatch having to be there does remove a lot a lot of shear strength of the aluminum body which made the problem show up. Giving Airstream feedback of this would help with a future design solution.
Russ

I agree. I would go in the direction of isolating that area from the frame movement, rather than attempting to reinforce the body to carry the load which may not even be possible.

[PeterH-350LE]

Originally Posted by 66Overlander

......
I still believe that a front hold down plate is better than a front hatch from a structural integrity standpoint and that very heavy, 1000 lb to 1400 lb, weight bars are not needed in most cases, especially if towing with a 3/4 or 1 ton truck. We tow our 2016 Classic 30 with a 3/4 ton pickup and 550/600 lb trunnion bars even though the tongue weight is well more than 700 lbs. No issues in over 20,000 towing miles.

Everyone has to decide what they are comfortable with. I am just trying to provide a little historical perspective to the discussion.

Very sound comments based on real life towing experience. Thank you for spelling it out!

Dealers equip these trailers with overkill Bars just to cover their rears, disregarding the constuction/dynamics of an Airstream trailer in combination with heavy duty tow vehicles.