enter image description here

Say in a P-51 (shown above), when drop tanks (those with external lines) are released, how are the two connections (air and fuel) released?

Do they shear off and fall with the tank?
Are the lines hardened against fluttering and somehow there's a disconnect mechanism for where they attach to the tank?
Something else?

My attempt in finding photos for an answer wasn't useful (the same goes for trying to check flight manuals), because after all some flights take off without tanks, and the photos I found are old and from far away it's hard to see if there are lines still attached.

This stems from my earlier question: How is fuel drawn from drop tanks in WW2 airplanes?

  • 1
    $\begingroup$ For anyone wondering why an American plane is decorated in Nazi symbols, P-51s would often have a swastika decal added to the hull for every Nazi kill. $\endgroup$
    – J...
    Commented May 14, 2022 at 12:34

1 Answer 1


From this site, alternatehistory.com, it appears that it is a simple friction fit with the rubber part of the hose and a regular hose clamp.

Dropping the tank, that rubber hose and hose clamp will NOT be strong enough to retain the tank. Off it comes, and the short part connected to the wing stays.

Alternate description:

From ww2aircraft.net, apparently, it ALL breaks away from the wing.

To answer your original question, yes the plumbing all detached with the tank, leaving just the bomb rack and sway braces as drag producers.

If you are an aircorpslibrary.com member you can go to drawing 109-48181 which is one of the two breakaway fittings installed in each wing and you can see where it is installed on drawing 106-14037 sheet 5. It has two O rings to seal where the pipe slips in. The other, similar, fitting is on the leading edge skin.

No glass tubes used anywhere (another one of those myths that keep rearing their ugly heads).

Since the recent site changes you may be able to view the drawing without being a member.

The fittings show in my Parts Catalog but have no part numbers - they are at the wing skin end of pipes 55 & 56

enter image description here


You must log in to answer this question.