Detection of pitot tube and static port blockages

[NickN]

I had a question from a friend last night that I can't answer. What procedures are in place to detect pitot tube and static port blockages prior to departure of aircraft in high risk areas? For example if the aircraft overnights in a port where there is high insect movement etc.

[Daniel M]

nil (or minimal) airspeed increase on initial takeoff run...

[NickN]

I was thinking more along the lines of before the aircraft is trying to become airborne.

[Mick F]

Pitot tubes are left covered, however the static vents aren't covered.

The only means of detection pre-flight is to look in the tube with the naked eye. The next mean's of detection, are as Daniel said, rolling down the runway and not noticing an increase in airspeed.

The static vents generally aren't a problem with gathering insects, as the holes are very small. In the time I have been flying, I have never had a blocked static vent as the result of an insect.

Mick

[NickN]

Say you start your take-off roll and one of the airspeed indicators is not moving will the crew reject a take-off or continue in the hope the problem will resolve itself? I assume that by continuing there will be some sort of alarm or warning? Or is it acceptable to only have one airspeed indicator working?

On that note I'd assume it would be dangerous having no second guage to cross-reference against.

[Michael Mak]

I'd say they will reject the take off. The results could be disastrous if they continue the take off and become airborne.

See this accident with Birgenair Flight 301. The cause was a blocked pitot tube and the crew continued the take off.

http://en.wikipedia.org/wiki/Birgenair_Flight_301