15

From a safety perspective RAIM is more critical than SBAS. If you are flying using GPS, you always rely on RAIM to keep you safe, sometimes you need SBAS too. Receiver Autonomous Integrity Monitor is a function within an aviation grade GPS receiver that monitors the integrity of the GPS system. Without RAIM, a malfunction in the GPS system can cause large ...


9

The RAIM (Receiver autonomous integrity monitoring) is what allows you to fly using a GPS. If you lose RAIM, by regulations you cannot use the GPS to navigate. So, it should not be a surprise for you to have regulators speak more of RAIM than SBAS. The RAIM basically monitors the accuracy of the navigation. It requires at least five satellites for operation. ...


3

A mechanical blockage inside the airspeed gauge could prevent the needle from dropping all the way back to zero -- assuming the aircraft had exceeded 200 KIAS in the first place. Whether this or the pitot-related failures in the @CamilleGoudeseune answer, the pitot-static unit, airspeed indicator, and altimeter (also connected to the static port) should be ...


1

This would happen if you were flying at 200 knots, encountered enough freezing moisture to completely ice over the pitot tube and the static ports, didn't have pitot heat for some reason, and then (somehow safely) landed and parked, while still iced over. Once iced over, IAS won't change.


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