French to English Tech/Engineering Aerospace / Aviation / Space Drilling

Hello, this is in a job announcement for an aeronautics company looking for somewhat with a particular type of skill in drilling apparently.

Obviously a one bit of an aircraft that is drilled onto a larger bit (I think we might be talking about the fuselage). I don't have much else to go by I'm afraid, I have found 'coin de malle' several times on Google in French, it is a part of a particular aircraft but I just can't see what it might be in English.

Thanks in advance for any help/ideas.