We found this part of an aircraft recently and, in order to improve the safety levels at our airport, we would like to know what possible aircraft model (or models) are compatible with this cover so we can locate it.

image of part (and a pen)

  • 5
    $\begingroup$ Hey, where did the real answer go?!? $\endgroup$
    – dotancohen
    Commented Jul 3, 2017 at 8:21

1 Answer 1


This is a Military Standard fuel cap, part number MS29525-1.

Here is the DOD page for the products: MS29525-1. It is most likely from a military aircraft or some kind of private ex-military warbird.

There really isn't much to say on it, other than it is used by the Air Force and Navy, as well as some British aircraft. It is a universal part used on many different types. It is a serialized part, you could try calling a local airbase and see if you can get records for it, but they will probably not care enough to track it down.

By the way, whoever is missing it, if a private party, paid a dear price for losing it. The cost of these caps in the private market range from \$600 to \$800.

  • 4
    $\begingroup$ $600!! Is it made from gold?!! $\endgroup$ Commented Jul 1, 2017 at 10:30
  • 2
    $\begingroup$ @curious_cat: The certification document is the expensive bit. It's just ink and paper but it cost the company that made that part a lot of money (and still cost them if they keep manufacturing the part). The cost to actually manufacture it is probably around $50 $\endgroup$
    – slebetman
    Commented Jul 2, 2017 at 18:38
  • 2
    $\begingroup$ @mins: Certification, no, tracking yes. For every part, the origin can be traced down to the moment of manufacturing, and often the details of manufacturing as well. I recall an investigation where a defect was traced back to the batch of metal used, which turned out to be a mistake at a foundry. Real experts can probably tell you which parts are important enough that they do get certified individually. (I suspect engines yes, pax seats no) $\endgroup$
    – MSalters
    Commented Jul 3, 2017 at 18:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .