Flight Planning
ICAO flight plan format, NOTAM reading, fuel planning, alternates, and pre-flight procedures.
Thorough pre-flight planning is a legal requirement for IFR flights and strongly recommended for all VFR flights. This page covers the key elements: flight plan format, reading NOTAMs, fuel planning, alternate selection, and briefing requirements.
ICAO Flight Plan — Form Items
The ICAO flight plan (ICAO Doc 4444 / ATC Form) uses numbered items filed via AFTN, SITA, or online pre-flight tools. Each item has a specific format and purpose. The most important items for pilots are summarised below.
| Item | Field | Description / Format |
|---|---|---|
| 7 | Aircraft Identification | Callsign or registration (max 7 characters). E.g. BAW123 or G-ABCD |
| 8 | Flight Rules & Type |
Flight rules: I = IFR, V = VFR, Y = IFR then VFR, Z = VFR then IFRType of flight: S = Scheduled, N = Non-scheduled, G = General aviation, M = Military, X = Other
|
| 9 | Number & Type of Aircraft | e.g. 1C172 or B738 — ICAO type designator. Wake turbulence category: L = Light, M = Medium, H = Heavy, J = Super (A380 etc.) |
| 10 | Equipment | Avionics and capabilities codes. First field = COM/NAV/approach aids. Second field (after slash) = surveillance equipment. See equipment code table below. |
| 13 | Departure Aerodrome & Time | ICAO 4-letter code + estimated off-blocks UTC (HHMM). E.g. EGLL 1430 |
| 15 | Route | Speed + level + route. Format: N0450F350 CPT1F CPT UL9 SILVA. Includes SIDs, airways, waypoints, STARs. See route format section below. |
| 16 | Destination & Alternate | Destination ICAO code + total estimated elapsed time (HHMM) + alternate(s). E.g. LFPG 0215 LFPO LFMN |
| 18 | Other Information | Free-text supplementary data. Key indicators: STS/ special handling, PBN/ PBN capability, NAV/ navigation equipment, COM/ communication, DAT/ data link, DEP/ departure point, DEST/ destination, REG/ registration, EET/ estimated elapsed time at FIR boundary, RVR/ required RVR, OPR/ operator, ORGN/ originator, PER/ performance category, ALTN/ alternate, RALT/ en-route alternate, TALT/ take-off alternate, RIF/ re-clearance in flight, RMK/ remarks. Use 0 (zero) if nothing to report. |
| 19 | Supplementary Information | Endurance (HHMM), persons on board (POB), emergency radio type (UHF/VHF/ELT), survival equipment, colour and markings of aircraft. Filed after the double dash – field separator. |
Equipment Codes — Item 10
Item 10 is completed as two fields separated by a forward slash: COM/NAV/approach aid equipment / surveillance equipment. Enter the appropriate letter codes with no spaces between them.
| Code | Capability |
|---|---|
| Group 1 — COM / NAV / Approach Aids | |
| S | Standard (VHF RTF, VOR, ILS) — use if no other capability to list |
| H | HF RTF |
| U | UHF RTF |
| V | VHF RTF |
| C | LORAN C |
| D | DME |
| F | ADF |
| G | GNSS — if PBN approved, also enter R and declare PBN/ in field 18 |
| J | Data link — various capabilities J1–J7 (see ICAO Doc 4444 Appendix 2) |
| K | MLS |
| L | ILS |
| M | Omega/VLF |
| O | VOR |
| R | PBN approved — requires PBN/ indicator in field 18 |
| T | TACAN |
| W | RVSM approved |
| X | MNPS approved |
| Y | VHF with 8.33 kHz channel spacing |
| Group 2 — Surveillance Equipment (after the / slash) | |
| N | No transponder |
| A | Mode A transponder only (4096 codes) |
| C | Mode A + Mode C (altitude reporting) |
| E | Mode S without enhanced surveillance capability |
| H | Mode S with enhanced surveillance — altitude capability |
| I | Mode S with enhanced surveillance — identification capability |
| L | Mode S with all enhanced surveillance capabilities |
| S | Mode S standard (pressure altitude, callsign) |
| P | CPDLC (ATN VDL Mode 2) |
| B1 | ADS-B out on 1090 MHz Extended Squitter |
NOTAM Types and Reading
NOTAMs (Notice to Air Missions/Airmen) are time-critical notices about changes to aeronautical information. Always check NOTAMs for your route, departure, destination, and alternates before flight. Available from official NOTAM offices and national AIP supplements.
NOTAM Classes
| Class | Type | Description |
|---|---|---|
| N | NOTAM N | New NOTAM — original notification of aeronautical information |
| R | NOTAM R | Replace — replaces a previous NOTAM (same series number, new suffix letter) |
| C | NOTAM C | Cancel — cancels a previous NOTAM; the cancelled NOTAM number is referenced |
NOTAM Format (Q-Line and Body)
| Field | Content | Example |
|---|---|---|
| (XXXX/YY) | NOTAM series and year | A0123/24 |
| Q) | Qualifier line — contains FIR, Q-code, traffic, purpose, scope, lower/upper limits, coordinates/radius | Q) EGTT/QFAXX/IV/NBO/AE/000/999/5130N00007W005 |
| A) | FIR(s) affected | EGTT (London FIR) |
| B) | Effective from (UTC) | 2401151200 — 15 Jan 2024 1200Z |
| C) | Effective to (UTC) or PERM or EST | 2401152359 or PERM or 2401152359 EST |
| D) | Schedule (when not continuous) | MON-FRI 0800-1600 |
| E) | Free-text subject of the NOTAM | Full description of the aeronautical change |
| F) | Lower limit (altitude/FL/SFC) | SFC or FL055 |
| G) | Upper limit (altitude/FL/UNL) | FL195 or UNL |
NOTAM Q-Code Second Field — Common Subject Codes
| Code | Subject |
|---|---|
| FA | Aerodrome (general) |
| FD | Runway declared distances |
| LR | Restricted area |
| LF | Free flight zone / danger area activity |
| NA | Air navigation — general |
| NV | VOR — serviceability or change |
| ND | DME — serviceability or change |
| NM | NDB — serviceability or change |
| OB | Obstacle (new, removed, or lighting change) |
Fuel Planning
Fuel Requirements — ICAO (General Guidance)
| Fuel Component | Description | Minimum Requirement |
|---|---|---|
| Taxi fuel | Engine start + taxi to holding point | As determined by operator / actual conditions |
| Trip fuel | From take-off to destination (includes climb, cruise, descent) | Calculated for the planned route and conditions |
| Contingency fuel | For unforeseen deviations from planned route, level, or speed | 5% of planned trip fuel (minimum) |
| Alternate fuel | From destination missed approach to alternate aerodrome | Full trip calculation to alternate (missed approach + route + approach) |
| Final reserve | Fixed absolute minimum upon landing at destination or alternate | 30 min at holding speed at 1500 ft (jet); 45 min (piston) |
| Additional fuel | At commander's discretion for specific conditions or requirements | Discretionary — based on route, conditions, experience |
The final reserve is an absolute minimum and must not be planned to be used. ATC and commanders use specific declarations:
- Minimum fuel: Declare to ATC when remaining fuel allows completion of approach and landing with final reserve intact — but no more. Not an emergency; informs ATC of your situation.
- MAYDAY FUEL: Declare when you calculate that you may land with less than final reserve. This is an emergency — ATC must treat it accordingly.
Alternate Selection
When Is an Alternate Required? (ICAO — General)
A destination alternate is not required when both of the following conditions are met:
- The destination aerodrome has two separate usable runways, at least one with an instrument approach procedure
- The meteorological forecast for the destination for the period ETA ±1 hour shows: ceiling ≥2000 ft and visibility ≥5 km (for IFR flights)
In all other IFR cases, at least one alternate must be filed. Two alternates should be filed when weather at the destination is forecast to be marginal, or the nearest suitable alternate is distant.
Alternate Weather Minima (General Guidance)
| Approach type at alternate | Addition to straight-in published minima |
|---|---|
| CAT I ILS or equivalent precision approach | Add 200 ft to DH / add 1000 m to visibility (or double the published minima, whichever is greater) |
| VOR, NDB, or RNAV (non-precision approach) | Add 200 ft to MDA / add 1000 m to visibility |
| Circling approach | Add 200 ft to circling MDA / add 1000 m to visibility |
Note: Specific alternate minima may differ by operator, national authority (CAA/FAA/EASA), or aircraft type. Always consult your Operations Specifications or applicable national regulations for the exact figures applicable to your operation.
ATC Flight Plan — Route Formats (Item 15)
Item 15 contains the cruise speed, requested level, and the route. Speed and level are entered immediately before the first route element with no space between them.
Pre-Flight Briefing Checklist
Complete this briefing process before every IFR flight, and adapt as appropriate for VFR flights. Items are non-sequential — allow enough time to complete all checks thoroughly before departure.
- ATIS / VOLMET for departure and destination
- METAR + TAF for departure, destination, and alternates (ETA ±1 hour)
- SIGMET and AIRMET for the planned route
- NOTAM check — departure aerodrome, en-route, destination, and alternates
- AIP supplements relevant to the planned route
- Wind and temperature charts for planned flight level
- SNOWTAM / SNOWMAN if winter operations are possible at any aerodrome
- NOTAMs for GPS / GNSS outages if RNAV routes are planned
- Fuel calculation complete with all required reserves
- Weight and balance within approved limits for all phases of flight
- Performance calculations — take-off, climb, en-route, and landing
- Flight plan filed (or VFR flight note lodged with appropriate unit)
Regulatory note: Requirements for flight plan filing, briefing, and fuel minima vary by country, airspace type, aircraft category, and operation type. Always consult the applicable national AIP, Operations Manual, and regulatory authority for legally binding requirements.
Winds and Temperatures Aloft Forecast (FB)
Winds and temperatures aloft forecasts (FB winds) are used for flight planning at specific altitude levels. They are issued for 3,000 ft through FL390 and decoded from compact coded groups.
Standard Decode (6-character group: ddff±TT)
| Coded Group | Decoded |
|---|---|
| 9900 | Light and variable — wind speed <5 kt; temperature not coded at this level |
| 2318+06 | Wind from 230° at 18 kt, temperature +6°C |
| 2318-04 | Wind from 230° at 18 kt, temperature −4°C |
| 0000 | Calm |
Above 24,000 ft all temperatures are assumed negative — the minus sign is omitted. Temperature is omitted entirely at the 3,000 ft level.
High-Speed Wind Encoding (≥100 kt)
When speed ≥100 kt: add 50 to the direction tens and subtract 100 from the speed.
To recognise high-speed encoding: if the first two digits are >36 (i.e. 37–86), subtract 50 for the true direction tens and add 100 to the speed.