Has something failed?

Sep 19, 2026

You scan the panel and see this. Has something failed?

APitot tube

Close, but if the pitot tube were blocked, the airspeed would either read zero or, with the drain blocked too, read higher as you climb. What you can see instead is the airspeed decreasing. If you check the AI, you can see the plane is in a climbing right turn, which fits what the airspeed is doing. The better option is C.

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BVacuum pump

Close, but if the vacuum pump had failed, the AI and DG would be winding down and feeding you bad information. Notice the DG shows a turn to the right, which agrees with the turn coordinator. The TC is electrically driven, so it keeps working even if the engine-driven vacuum pump quits. You can also see the airspeed is decreasing, which agrees with the AI's climbing turn indication. The better option is C.

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CStatic port

You got it -- well done.

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DNothing failed

If you look, you can see the altimeter is frozen and the VSI indicates level flight. But the AI, DG, and TC all indicate a turn to the right, and the AI and airspeed indicator indicate a climb, so the altimeter and VSI must be wrong. They both get their reading from the static port, so option C is the better answer.

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Pick an answer. You can try as many as you like.

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The explanation

C. Static port

Two instruments disagree with the airplane

The attitude indicator, heading indicator and turn coordinator all show a right turn. The attitude indicator and airspeed show a climb, and with the RPM at 2450 and the nose up, a climb is what you'd expect. But the altimeter is frozen and the VSI shows level flight. Both of them read from the static port, so one blockage explains both.

When two instruments fail together

The VSI could fail on its own, but that wouldn't explain the altimeter. When instruments that share a plumbing line go wrong together, the line is a better bet than two coincidences.

The airspeed is wrong too

With the static side blocked and the pitot clear, the airspeed indicator keeps working but under-reads once you climb above the altitude where the port plugged, because the trapped static pressure is higher than the air outside. Early in a climb the error is small, which is why it doesn't jump out. The trap is chasing the low reading by lowering the nose, because descending back through the blockage altitude flips the same needle to reading high.

Why not the pitot tube or vacuum pump

A blocked pitot tube shows up on the airspeed: it reads zero, or with the drain blocked too, reads higher as you climb. A vacuum pump failure takes the attitude indicator and heading indicator down together, and here both agree with the electric turn coordinator.