A bee on a Pitot tube. (University of Bristol)

Acoustic methods have been used for detecting blockages in pipes for many years. Researchers set out to discover if similar methods could be used for real aircraft Pitot tubes, which can contain irregular shapes and passages, without needing a very complicated detection method.

Pitot-statics from two different commercial aircraft were X-rayed by a CT scanner, and an acoustic study was carried out to find out the variation between blocked and unblocked reflected acoustic waves. In principle, the method could be adopted to help inform pilots if Pitots are blocked before they take off, or if they subsequently become blocked during a flight.