6.ifr-flight-plan-filing. Filing an IFR Flight Plan
An IFR flight plan is the formal request a pilot files with Air Traffic Control (ATC) to operate within the National Airspace System under instrument flight rules. Under 14 CFR 91.173, no person may operate an aircraft in controlled airspace under IFR unless that person has filed an IFR flight plan and received an appropriate ATC clearance. The flight plan provides ATC with the information required to issue a clearance, separate the aircraft from other traffic, and initiate search and rescue if the flight becomes overdue.
When and Where to File
IFR flight plans should be filed at least 30 minutes before the proposed departure time to allow processing through the Flight Data Processor and distribution to the appropriate ATC facilities. Pilots may file:
- Electronically through Leidos Flight Service (1800wxbrief.com), ForeFlight, Garmin Pilot, or other DUATS-certified vendors using ICAO format.
- By telephone with Flight Service at 1-800-WX-BRIEF.
- In the air with ARTCC or Flight Service when departing VFR and picking up IFR en route (an "airborne pickup").
- In person at a Flight Service Station, where available.
Since the FAA's transition in 2019, all domestic and international IFR flight plans must be filed in ICAO format (FAA Form 7233-4 / ICAO Doc 4444 layout).
Required ICAO Flight Plan Items
- Item 7 — Aircraft Identification (registration or company callsign).
- Item 8 — Flight Rules (I, V, Y, or Z) and Type of Flight (G for general aviation).
- Item 9 — Number of aircraft, ICAO type designator (e.g., C172), and wake turbulence category (L, M, H, J).
- Item 10 — Equipment and capability codes (e.g., SDFGRY) and surveillance codes (e.g., B1, B2 for ADS-B Out).
- Item 13 — Departure aerodrome (ICAO identifier) and proposed time off (UTC).
- Item 15 — Cruising speed, requested altitude, and full route of flight using fixes, airways, and navaids.
- Item 16 — Destination aerodrome, total estimated time enroute (EET), and at least one alternate when required.
- Item 18 — Other information, including PBN/, NAV/, DOF/, and remarks.
- Item 19 — Supplementary information (fuel endurance, persons on board, survival/emergency equipment, pilot-in-command).
Route Planning
Routes should follow published preferred IFR routes (listed in the Chart Supplement and FAA preferred-routes database) when available, particularly between major terminals, to minimize the chance of a route amendment. When no preferred route exists, file along Victor airways, Jet routes, T-routes, Q-routes, or direct between fixes the aircraft is equipped to navigate. Random RNAV routes require RNAV-capable equipment and use latitude/longitude or named waypoints at intervals not greater than the limits in AIM 5-1-8.
Altitude Selection
The filed altitude must comply with the IFR cruising altitude rules of 14 CFR 91.179: in controlled airspace, fly the altitude assigned by ATC; in uncontrolled airspace below 18,000 feet MSL, eastbound (000°-179° magnetic course) use odd thousands and westbound (180°-359°) use even thousands. Above FL290, RVSM separation applies. Altitude selection must also satisfy minimum IFR altitudes (91.177), terrain and obstacle clearance, equipment limitations, and the aircraft's service ceiling.
Alternate Airport Requirement (1-2-3 Rule)
Under 14 CFR 91.169, an alternate must be filed unless, for at least 1 hour before to 1 hour after the ETA, the destination forecast shows a ceiling of at least 2,000 feet and visibility of at least 3 statute miles. Alternate minimums are typically:
- Precision approach: 600-foot ceiling, 2 SM visibility.
- Nonprecision approach: 800-foot ceiling, 2 SM visibility.
- No instrument approach published: ceiling and visibility allowing descent from MEA, approach, and landing under basic VFR.
Always check the airport's IAP chart for nonstandard alternate minimums (indicated by a triangle with an "A").
Fuel Requirements
14 CFR 91.167 requires enough fuel to fly to the first airport of intended landing, then to the alternate (if required), and then for 45 minutes at normal cruise.
Activation and Closure
Unlike a VFR flight plan, an IFR flight plan is activated automatically when ATC issues the IFR clearance and the aircraft departs. On arrival at a towered airport, the controller closes the flight plan automatically. At a nontowered airport, the pilot must close the flight plan with Flight Service or ATC by radio in the air or by phone after landing — failure to do so within 30 minutes after ETA initiates search and rescue procedures.
Example
A Cessna 172 (C172/L, equipment SDFGRY/B2) filing KAPA to KGJT might submit: route APA V8 HCT V134 GJT, FL120, EET 0215, alternate KMTJ, fuel endurance 0430, 2 souls on board. Filed via ForeFlight 45 minutes before the proposed time off.