A one-hour test of a satellite providing Wide Area Augmentation System (WAAS) signals Monday, May 3, will result in that satellite signal being temporarily unavailable to aviation users. The remaining WAAS satellite will not be affected.
The test is scheduled to start at 4 a.m. Eastern Daylight Time Monday. A notam has been issued to take effect at 3:30 a.m. Eastern time and last for four hours to allow for a few hours of monitoring the signal after the test. The FAA does not expect users to experience any operational impact during the test but has issued a notam to advise pilots in the unlikely event that the WAAS signal is affected. AOPA is remaining in close contact with the FAA to ensure there are no operational impacts and that pilots continue to be updated.
The test is an attempt by the WAAS satellite provider, Intelsat, to shut down the commercial transponders on board the Galaxy 15 satellite, one of two geostationary satellites (GEOs) providing WAAS signals. The satellite experienced a failure April 5 when the satellite provider lost all telemetry, tracking, and control capability with Galaxy 15. The company terminated communications traffic over Galaxy 15 and has relocated its commercial customers to a spare satellite, but there remain active communication transponders on board the satellite that could potentially interfere with other commercial satellites, thus the attempt to shut the transponders down.
Due to the remote risk that this test could impact the WAAS signal currently being broadcast from Galaxy 15, the signal will be made unavailable to aviation users. If there are no issues noted during the monitoring period, the satellite will be placed back into operation.