Definition
Protective covers fitted over the open end of the pitot tube when the airplane is parked, used to prevent insects, dirt, water, or other debris from entering and blocking the tube. They typically include a brightly colored fabric streamer or 'Remove Before Flight' flag so the cover is visible and removed before flight.
Plain English
Small caps or sleeves that go over the little metal tube on the outside of the airplane to keep bugs and dirt out while the airplane is parked. They have a red flag or streamer hanging off them so you can't miss them on your walk-around.
Context Anchor
Seen during postflight securing, preflight inspection, and ramp parking, especially when checking that all covers are installed after flight and removed before flight.
Derivation
Pitot is named after Henri Pitot, an 18th-century French engineer who invented the tube used to measure fluid speed. The 'cover' is simply the protective cap placed over it on the ground.
Why Pilots Care
A blocked pitot tube produces false airspeed readings that have contributed to loss-of-control incidents; covers keep the system clear and reliable.
Grounding Statement
The cover protects the pitot tube on the ground, but it must be removed before the airplane flies.
Intuition Check
Do not think of pitot tube covers as optional cosmetic covers. They protect an important air-sensing opening, and they become a hazard if left on for flight.
Example Sentence 1
After tying the airplane down, the pilot installed the pitot tube cover so insects could not nest inside the tube overnight.
Example Sentence 2
On the preflight walk-around, the student removed the pitot tube covers and verified the tubes were clear of obstructions.