FAA Aircraft Dispatcher (ADX)Navigation and ATCHard
A flight is being planned to fly an RNAV (GPS) approach at an airport with no other approved means of navigation available as a backup. The aircraft's GPS receiver does not have WAAS capability. What must the dispatcher and pilot verify prior to the flight to comply with FAA guidance?
- AThat the destination airport has DME available
- BThat the aircraft is equipped with an ADF receiver
- CThat the airport has a functioning control tower
- DThat RAIM (Receiver Autonomous Integrity Monitoring) availability is predicted for the estimated time of arrival
Show answer & explanationAnswer & explanation
Correct answer: D. That RAIM (Receiver Autonomous Integrity Monitoring) availability is predicted for the estimated time of arrival
For non-WAAS GPS receivers relying solely on GPS for an RNAV (GPS) approach, RAIM availability must be predicted for the estimated arrival time to ensure the receiver can detect and exclude satellite signal errors sufficient for the intended approach.
Why the other options are wrong
- A. DME availability is not required for a standalone RNAV (GPS) approach using RAIM.
- B. An ADF receiver is unrelated to GPS approach integrity requirements.
- C. A functioning control tower has no bearing on GPS receiver integrity monitoring.
RAIM Prediction Requirement
For non-WAAS GPS equipment used as the sole means of navigation, RAIM availability must be predicted before flight to ensure GPS integrity monitoring capability at the ETA.
- RAIM = Receiver Autonomous Integrity Monitoring
- Required when GPS is sole means of navigation with non-WAAS equipment
- WAAS-equipped aircraft use a different integrity monitoring method, not classic RAIM prediction
- Prediction performed via avionics, FAA tools, or approved software before departure
Memory trick: RAIM checks the sky before you fly