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ENR: En-Route - Instrument Flight Rules (IFR): From completion of Initial Climb through cruise altitude and completion of controlled descent to the Initial Approach Fix (IAF).
Visual Flight Rules (VFR): From completion of Initial Climb through cruise and controlled descent to the VFR pattern altitude or 1000 feet above runway elevation, whichever comes first.
This phase of flight includes the following sub-phases:
- Climb to Cruise: IFR: From completion of Initial Climb to arrival at initial assigned cruise altitude. VFR: From completion of Initial Climb to initial cruise altitude.
- Cruise: Any level flight segment after arrival at initial cruise altitude until the start of descent to the destination.
- Change of Cruise Level: Any climb or descent during cruise after the initial climb to cruise, but before descent to the destination.
- Descent: IFR: Descent from cruise to either Initial Approach Fix (IAF) or VFR pattern entry. VFR: Descent from cruise to the VFR pattern entry or 1000 feet above the runway elevation, whichever comes first.
- Holding: Execution of a predetermined maneuver (usually an oval race track pattern) which keeps the aircraft within a specified airspace while awaiting further clearance. Descent during holding is also covered in this sub-phase.