Originally Posted by
trent890
I wonder to what extent that reasoning could be used on other non-US accidents. Even if the AF447 aircraft had Rolls-Royce engines, the placard on the outside of the FDR chassis clearly says "Honeywell". Could the NTSB participate in an accident investigation for the sole reason of being the state of manufacture of the very same recorders that potentially hold the answers to solving the cause of an accident?
Probably not. The concept of "Party to the Investigation" is generally considered to be someone with a major stake in the outcome...ie operator, government of registration, government of the crash site, government of manufacture, airframe mfg, and engine mfg. Since thousands of companies contribute to the construction of an airplane there would not be enough space in the room to include them all so they start with engine and airframe.
But once they determine that a certain sub-component is under suspicion, that mfg. should be invited to the party.
The US NTSB often seems to be invited in an advisory capacity because they have the highest levels of expertise and experience in the world, and better forensic technology than many countries.