FAA Private Pilot Airplane (PAR)Navigation and Flight PlanningMedium
A pilot is using a GPS receiver for navigation. The flight plan requires an RNAV (GPS) approach. Which of the following is essential for the GPS receiver to provide the required accuracy and integrity for this type of approach?
- AA recent database update for the GPS unit.
- BWAAS (Wide Area Augmentation System) capability.
- CManual input of waypoint coordinates by the pilot.
- DContinuous monitoring by a ground-based VOR system.
Show answer & explanationAnswer & explanation
Correct answer: B. WAAS (Wide Area Augmentation System) capability.
For RNAV (GPS) approaches, especially those with LPV or LNAV/VNAV minimums, WAAS (Wide Area Augmentation System) capability is essential. WAAS provides enhanced accuracy, integrity, and availability for GPS signals, meeting the stringent requirements for precision approaches without ground-based navigation aids.
Why the other options are wrong
- A. A recent database update is important for all GPS navigation but doesn't specifically provide the integrity monitoring for approaches.
- C. Manual input of waypoints is generally not done for approaches and does not ensure the required integrity or accuracy.
- D. GPS is an independent system; it does not rely on VOR systems for its integrity monitoring for approaches.
WAAS (Wide Area Augmentation System)
An air navigation aid developed by the FAA to augment GPS by providing enhanced accuracy, integrity, and availability for aircraft navigation, particularly for precision approaches.
- Consists of ground reference stations, master stations, and geostationary satellites.
- Corrects GPS signal errors and provides integrity messages.
- Enables GPS to be used for all phases of flight, including precision approaches (e.g., LPV).
- Required for GPS approaches to LPV minimums.
Memory trick: WAA-S UP? GPS needs help accuracy and integrity.