Six practical habits
Expect exposure
Review current NOTAMs, operator intelligence and recent reports for affected regions.
Recognise the pattern
Look for simultaneous GNSS loss, sensor changes and dependent-system messages.
Cross-check position
Use approved independent navigation, raw data and reasonableness checks.
Stabilise workload
Fly the aircraft, confirm modes and separate primary effects from cascading alerts.
State capability
Tell ATC what has failed, what remains available and what assistance is required.
Record and report
Capture useful factual details and submit the required safety report after landing.
Plan for a system-wide effect
Jamming is interference that prevents the receiver from using authentic satellite signals. Because many aircraft systems consume GNSS position or time, one interference event can produce several messages that appear unrelated.
Before departure, identify expected exposure, conventional navigation coverage, procedures dependent on GNSS and suitable alternatives. A threat brief is more useful when it states what the crew will see and do.
Use independent evidence
When indications appear, maintain flight path control and verify the actual position using approved independent sources. Confirm flight modes and avoid repeated resets or selections unless the aircraft procedure directs them.
Distinguish the primary loss of GNSS from secondary effects. A map that freezes, shifts or reverts needs the same disciplined cross-check as an explicit navigation alert.
Communicate the remaining capability
ATC needs operational information: the nature of the degradation, whether RNAV or RNP capability is lost, and what navigation or surveillance capability remains. Request vectors, an alternative procedure or additional separation as appropriate.
After landing, preserve times, locations, indications and crew actions while memories are fresh. Use the operator’s technical and occurrence-reporting channels.
- 01Anticipateaffected area, dependent systems and alternatives
- 02Recognisealerts, sensor changes and inconsistent navigation
- 03Cross-checkindependent position, modes and remaining capability
- 04Recoverapproved procedure, ATC coordination and factual report
Operational summary only. Apply the current approved procedure and see references below.
Final flight-deck prompt
Final flight-deck promptWhich indications are primary, where is the aircraft using independent evidence, and what capability can we still state with confidence?
