RNAV Route and Approach Classifications

• RNAV Route to Initial Approach Fix (IAF): RNAV 5
  The RNAV 5 specification applies to en-route navigation and ensures a navigation accuracy of ±5 nautical miles. This standard is typically used for longer-distance routes leading up to the Initial Approach Fix (IAF), which marks the start of the approach phase.
• IAF to Final Approach Fix (FAF): RNAV 1
  RNAV 1 specifies that the aircraft must maintain an accuracy of ±1 nautical mile during the segment from the Initial Approach Fix (IAF) to the Final Approach Fix (FAF). This is the phase where the aircraft is transitioning to the approach phase of flight, requiring more precise navigation.
• FAF to Landing: RNAV 0.3
  The RNAV 0.3 standard applies during the final segment of the approach, from the Final Approach Fix (FAF) to the runway. The accuracy required here is ±0.3 nautical miles, which is needed for precise lateral navigation as the aircraft approaches the runway for landing.
• Missed Approach: RNAV 1
  During the missed approach procedure, the RNAV 1 standard applies, meaning the aircraft must maintain an accuracy of ±1 nautical mile. This ensures safe and accurate navigation when a missed approach procedure is executed, guiding the aircraft to a safe alternative route.

Summary:

• RNAV 5 for en-route (Initial Approach Fix)
• RNAV 1 for approach (IAF to FAF and missed approach)
• RNAV 0.3 for final approach to landing

These standards ensure that the aircraft maintains the appropriate level of accuracy during each phase of flight, allowing for safe and precise navigation in varying conditions.