Six practical habits
Confirm the specification
Identify the exact RNP requirement and confirm aircraft, crew and operator eligibility.
Verify the procedure
Match the current database procedure with the chart, clearance and intended transition.
Check the RNP value
Confirm the displayed or selected requirement is appropriate for the active segment.
Monitor assurance
Watch navigation performance, position sources, alerts, modes and cross-track behaviour.
Treat alerts as operational
Do not continue on appearance alone when required performance is no longer assured.
Keep a reversion plan
Know the approved alternative navigation and the point at which ATC must be advised.
RNP adds assurance
An RNP navigation specification includes onboard performance monitoring and alerting. That distinction matters because the crew is not only following a computed path; the aircraft must also determine whether its navigation performance remains suitable for the operation.
The number associated with the specification expresses a performance requirement, not a universal clearance or aircraft capability. Eligibility depends on the approved aircraft configuration, operational approval, crew qualification and the particular route or procedure.
Brief what can change
Before the operation, identify the required specification, any special functionality, the expected sensors and the annunciations that show normal performance. Include relevant NOTAMs and known interference areas rather than treating navigation availability as a fixed assumption.
After any runway, transition or direct-to change, repeat the essential path check. Confirm the active leg, waypoint sequence, constraints and what the aeroplane will do next.
Monitor the system, not the magenta line
A plausible map is not proof of valid navigation. Monitor cross-track error, actual navigation performance or estimated uncertainty where displayed, sensor status and any alert that indicates the requirement is not being met.
If capability degrades, apply the approved procedure, use the available alternative and tell ATC promptly. Avoid improvising a continuation that has not been approved for the remaining equipment.
- 01Identifyexact RNP requirement and operational eligibility
- 02Verifychart, clearance, database coding and active value
- 03Monitorperformance, sensors, modes, alerts and aircraft path
- 04Respondapproved reversion, amended clearance and clear ATC report
Operational summary only. Apply the current approved procedure and see references below.
Final flight-deck prompt
Final flight-deck promptWhat RNP performance is required now, how do we know it is being achieved, and what is our approved exit if assurance is lost?
