According to the FAA, the GPS system may be unreliable or unavailable for the next few days due to military test exercises. In order to exercise, the drone jammers must interfere with the GPS signal for several hours during the activity. According to Federal Aviation Administration (FAA) regulations, ADS-B and other GPS-related services may be affected at navigation altitudes of 400 nautical miles and below 400 nautical miles, and a radius of 50 nautical miles is 180 nautical miles.
The upcoming practice dates are as follows: Saturday, January 18, 2020, 12 noon to 7 pm, Thursday, January 23, 7 am to 7 pm, Friday, January 24, 6:30 pm As of 7pm, pilots are encouraged to report anomalies in accordance with paragraphs 1-1-13 and 5-3-3 of the Aeronautical Information Manual (AIM). Reports can be submitted using this online form.
Aircraft owners and pilots' associations reported similar incidents last year, saying it was aware of hundreds of reports of aircraft failures in such incidents, which they found to be very worrying. AOPA reports that an aircraft has lost navigation capabilities and can only recover after landing. Other reports indicate that the aircraft deviated from its course and flew towards active military airspace.