Originally Posted by
Vilters
OK, here we go.
AOA sensors with a vane can be bend, touched by ground equipment, torn off by birdstrikes or other FOD, freeze due to the vane sticking to the fuselage (very little space between vane and fuselage), and so on.
Pressure AOA probes don't have any of these issues.
We are 2019, and even the (in late 70's new F-15 / F-16) are becoming obsolete FAST.
Does the F-22 or F-35 have any of these? No they don't any more and they need a far more accurate AOA input then commercial airframes.
A cobra probe (for example: the Rosemont/Goodrich/UTC/Collins/whoever-they-are-this-week Smartprobe, see page 11:
https://www.faa.gov/air_traffic/sepa...n_for_RVSM.pdf) is also vulnerable to damage from GSE, birdstrike, and FOD. It can still fail due to either freezing external moisture or trapped internal liquid, and some of those failure conditions can be latent and undetectable until the aircraft changes altitude, and your AOA starts behaving as an altimeter.
As noted, this is not a new technology. Here's Rosemont trying to sell them in 1986:
https://www.flightglobal.com/FlightP...20-%202855.PDFBut it does come with it's own set of failure conditions which also need to be assessed. For example, a B-2 bomber equipped with a completely flush-mounted air data system crashed and was destroyed due to water trapped in the static system - so eliminating excrescences like Pitot tubes and AOA vanes is not a panacea for faulty air data.