Anyone here that can comment on ultrasonic airspeed measurement ?
I did a little googling of this potential alternative (??) to pitot sensing and found out that there are commercial "high grade" products available for
wind sensors as well as for
helicopters. But the limits of its accuracy seems to be around 150 knots top speed.
Any hope of developing this for airliners? (Wikipedia does note that "Another disadvantage is lower accuracy due to precipitation, where rain drops may vary the speed of sound.")
Another potentially usable technology would be the
hot wire mass flow sensor, where the air flowing past cools down an electrically heated wire and the airspeed can be calculated from the wire's electrical resistance which changes according to temperature. But this is not seen on airliners either. Anyone knowing if this is due to inherent drawbacks compared to pitot tubes, or just an aversion to try new technology?
Obviously these technologies must have some drawbacks compared to pitot tubes, otherwise they would already be in widespread use. It would be interesting to know where the problem areas are.
******
Bearfoil
how about a lit probe just out the F/O's side glass?
ATR's used to have exactly such a
device. IIRC it was deployed after the Roselawn crash, but nowadays it's not not so widely used (optional equipment?) as the knowledge of the plane's icing behaviour and how to manage icing conditions is improved. Today they handle icing conditions just fine.