Some PA-28 airplanes have pitot static drain where the pilot pushes 2 buttons to open the system.

But where does the water drip out from the airplane? Is there a hole underneath the airplane? Where?

I mean when you push the buttons where should you look for water coming out?

  • 1
    $\begingroup$ Are you thinking of the alternate static system inside? The static port is usually next to the pitot tube, with the drain underneath on Warriors. I've never seen any buttons in the cockpit - can you provide for info $\endgroup$
    – Dan
    Sep 30, 2019 at 10:23

2 Answers 2


This presentation gives a nice overview of various systems on the Piper Cherokee series. The buttons you describe are shown here:

drain buttons
(slide 9)

The full pitot-static tube including the drain is shown here:

pitot-static tube
(slide 11)

So the drain is incorporated in into the pitot-static tube itself.

The buttons are also acting as a drain themselves, for details see Alexander's answer.



To build on Bianfable's great explanation, the "button" drains in the PA28 series of aircraft are typically the lowest point in the system and where any excess moisture/condensation would gather if it gets past the drain in the pitot-static mast. They are spring loaded and when you press them, any trapped moisture or condensation simply leaks out into the cockpit. It's never a large amount so it's barely noticeable.

Care should be taken, however, as to not drain the system (press the buttons) in the air as it will disrupt the pitot-static instruments.

  • $\begingroup$ Thanks for the addition, I linked to your answer. $\endgroup$
    – Bianfable
    Oct 2, 2019 at 6:33

You must log in to answer this question.

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