Was flying with the Dash-8 Q400 and saw the screw sticking out? It's on the wing near the wheel compartment as shown in the picture.

Even if safe, it doesn't look pleasant to the passenger.

Are loose screws on those parts ever appropriate?

Dash-8 Q400 engine nacelle

Full image: https://freeimage.host/i/H4KfDQ4


1 Answer 1


It's not a screw, it's a drain line for the engine tail pipe, for fuel that can collect in the tail pipe during "wet" starts. There are other drains for the various engine and propeller gearbox vents, depicted here.

It's just a pipe with a disc welded to it. The disc is to reduce anything dripping out the opening from being blown back toward the surface of the nacelle, in the air stream.

  • 9
    $\begingroup$ Well it's always been there. There's group of drains with a big flow control disc farther up. I added a link to another post that shows it. $\endgroup$
    – John K
    Commented Jun 4, 2023 at 13:32
  • 21
    $\begingroup$ @EugenSunic Drains must be there someplace, and as the last paragraph describes, need to protrude out away from the nacelle to avoid fluid stains on it from normal drainage. Being at the lowest point of the nacelle, they're easier to see on a Q400 than an A320 (for example), but every engine has one or more. At some point, there's a limit to how far the engineering can go to avoid creating (baseless) fears in nervous fliers. Solution: ask (as you did here) "is that normal?" and get the answer. No more concerns over this drain mast! $\endgroup$
    – Ralph J
    Commented Jun 4, 2023 at 17:24
  • 12
    $\begingroup$ @EugenSunic I think it's rather unlikely that the design will be changed to match passengers' taste of design; even if it's possible. $\endgroup$
    – U. Windl
    Commented Jun 4, 2023 at 21:01
  • 4
    $\begingroup$ @U.Windl Unless said passenger owns the manufacturer, then they can go about trying to justify spending multiple millions on it to get re-certified because "it looks scary". $\endgroup$
    – Nelson
    Commented Jun 5, 2023 at 0:38
  • 4
    $\begingroup$ @AndrewMorton yes, I should write an email to bombardier $\endgroup$ Commented Jun 5, 2023 at 19:56

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