Flight plans and associated messages
ATS messages, priority and addressing
Everything an ATS unit sends and receives: what order it gets dealt with, and how it is addressed.
The fixed network aeronautical messages are sent over. Every message carries a priority code and an address, and the priority code is where that order of precedence is actually written down.
- SS
Distress. Distress messages.
Priority1 - DD
Urgency. The safety of the aircraft, or of a person on board.
Priority2 - FF
Flight safety. Movement and control messages, anything from the operating agency of immediate concern to an aircraft, and meteorological messages restricted to SIGMET.
Priority3 - GG
Meteorological, flight regularity and aeronautical information. NOTAM, SNOWTAM, TAF and METAR.
Priority4 - KK
Aeronautical administrative. Everything else the network carries.
Priority5
The five codes run in a strict order of their own: an SS is dealt with ahead of a DD, a DD ahead of an FF, and so on down. They are not the same list as the three categories above. Emergency messages travel as SS or DD, movement and control as FF, and the NOTAM and weather that make up much of flight information as GG. KK is administrative traffic rather than an ATS message at all.
Four for the place, three for who at that place, and one for the department or division inside it. There is usually no department to name, so most addresses end in X. The eight designators on the lesson list are decoded in the tool further down, and printed in full at the end of the note.
When a flight plan has to be filed
Six cases.
What it has to contain
Fifteen things.
1Aircraft identification 2Flight rules and type of flight 3Number and type of aircraft, and wake turbulence category 4Equipment and capability
5Departure aerodrome or operating site 6Estimated off-block date and time 7Cruising speed 8Cruising level 9Route to be followed 10Destination aerodrome and total estimated elapsed time 11Alternate aerodrome
12Fuel or energy endurance 13Persons on board 14Emergency and survival equipment 15Other information
The fifteen are what the plan has to say, in the order and the numbering of SERA.4005(a). The three groupings are this page’s, to make the list learnable. The numbered Items in the tool further down are the boxes on the form, and the two do not line up one for one.
Getting it in
On the ground through IFPS, or in the air as an AFIL.
Run by EUROCONTROL, 24 hours a day. Already met in LAW 006, as the IFR half of the filing pipeline. It will not accept a plan filed more than 120 hours, five days, before the EOBT.
- Checks the details
- Analyses compatibility
- Suggests alternative routes
- Sends a copy of the accepted plan to the local ATC centre
- Checks call sign similarities
- Checks the SAFA blacklist
Goes in Item 13, where the departure aerodrome would otherwise be.
- Who decides. The FISO, on whether there is time to take one.
- What it carries. Call sign, type of aircraft, point of entry, point of exit and level. The competent authority can require more.
- By when. At least 10 minutes before the point of entry into a control area or an advisory area, classes A to F, or the point where it crosses an airway or an advisory route.
AFIL means the flight plan was filed in the air. The course notes also gloss it as the abbreviated flight plan, which is a separate thing: the limited information needed to get a clearance for part of a flight. The two overlap, because a plan filed in the air usually is abbreviated, but they are not the same term.
- SubmitThe pilot gives ATS the information.
- FileATS accepts it. It is a filed flight plan from then on.
- TransmitIt is shared on to everyone who needs it.
The deadlines
The three hours goes with flow management, not with crossing a border and not with IFPS as such. In practice it is the IFR flights that go through IFPS, because every flight operating as general air traffic under IFR in European airspace may be regulated. A VFR flight is not, so for VFR it is the hour. The 120 hours is the IFPS rule above.
The flight plan, field by field
One real flight plan, Copenhagen to Heathrow, as it goes out over the AFTN. Click any part of it: the panel gives that field, and the codes that go in it. The three addresses and the originator come first, then the message itself.
Click a part of the message, or a group below it, to see what it means.
FFMessage envelopeTwo letters at the head of the message. FF is the flight safety level, which is what movement messages travel at, and a flight plan is one.
A real message carries more than the lesson list. Past it here: E2, E3, F, I and R in the COM/NAV field, L and B1 for surveillance, and PBN/, SEL/, OPR/ and PER/ in Item 18. They are decoded anyway, so the message reads whole.
What does not travel: Item 19
Supplementary information, carried for emergencies and for search and rescue. It is not part of the flight plan message, which is why none of it is in the one above, and not something a FISO sees. Worth knowing it exists.
- E/12Fuel or energy endurance, in hours and minutes. E/0430 is four hours thirty.
- P/13Persons on board, passengers and crew. P/001 is one person, P/TBN if it is to be notified later.
- R/14Which radios are, and are not, available.
- S/14Survival equipment.
- J/14Life jackets.
- D/14Dinghies.
- A/Aircraft colour and markings.
- N/Any remark on the equipment carried.
- C/The name of the pilot-in-command.
E/ is number 12 of the fifteen further up, P/ is 13, and R/ through D/ are 14: fuel or energy endurance, persons on board, and emergency and survival equipment. That is the part of what a flight plan has to contain which never travels in the message. Number 15, other information, is Item 18, and that does travel. A/, N/ and C/ are the form’s own, past the fifteen.
Life of a flight plan
From filed to closed, what it is called at each stage, and who sends the two messages that move it.
The plan as it was filed, with none of the later changes in it.
The filed plan plus every change made to it since.
Changing, activating and closing it
Five messages, across six tabs, because ARR comes in two forms. CHG modifies, CNL cancels, DLA delays, DEP activates and ARR closes. Each one names the flight, so the right plan can be found again.
Click a part of the message, or a group below it, to see what it means.
(CHGWhat it doesSent when something in a flight plan that has already gone out has changed. Only the items that changed are repeated, at the end. The bracket opens the message, the same as on a NOTAM.
Adherence to the flight plan
SERA.8020. Three rules, and they bind the flight once it is under way.
The flight is operated in accordance with the current flight plan: the one it was filed as, plus every change since.
A controlled flight needs a clearance from ATC first.
If the weather turns, or VFR is no longer possible, the pilot-in-command takes whatever action the situation needs.
All the codes on one page
Every table in the tool above, in one place. Open the ones you want; Expand all opens the lot, and printing opens them for you. The colours are the groups in the message.
Item 7: three forms, never a mixture3 codes
| Registration | DAGXC, N137DK. Written without the dash. Private aircraft, and small airlines. |
| Agency and flight number | KLM1136. The three-letter designator from LAW 003, then the flight identification. |
| Tactical call sign | BRUNO12, RED1, SWIFT45. Usually military. |
Item 8: flight rules4 codes
| I | IFR. The whole flight under instrument flight rules. |
| V | VFR. The whole flight under visual flight rules. |
| Y | IFR, then VFR. Starts IFR and changes to VFR. |
| Z | VFR, then IFR. Starts VFR and changes to IFR. |
Item 8: type of flight5 codes
| S | Scheduled |
| N | Non-scheduled |
| G | General aviation |
| M | Military |
| X | Anything else: school flights, training and the like |
Item 9: wake turbulence category4 codes
| L | Light. 7 000 kg / 15 500 lb or less. |
| M | Medium. Over 7 000 kg / 15 500 lb, under 136 000 kg / 300 000 lb. |
| H | Heavy. 136 000 kg / 300 000 lb or more. |
| J | Super. The A380-800. |
Item 10: COM/NAV equipment7 codes
| N | None, or unserviceable |
| S | Standard. What counts as standard differs from state to state. |
| D | DME |
| G | GNSS |
| H | HF RTF |
| W | RVSM approved |
| Y | VHF with 8.33 kHz spacing |
Item 10: SSR, surveillance equipment4 codes
| N | None |
| A | Transponder, Mode A. Code only. |
| C | Transponder, Mode A and C. Code and altitude. |
| S | Transponder, Mode A, C and S. Code, altitude and a good deal more. |
Standard squawk codes3 codes
| 7000 | VFR. The conspicuity code, squawked when no discrete code has been assigned. |
| 2000 | IFR. Squawked when no discrete code has been assigned, such as on entering from an adjacent region. |
| 1000 | IFR, Mode S. Squawked where the Mode S environment does not need a discrete code. |
Item 15: how a cruising speed is written3 codes
| K | Kilometres per hour. K0220 is 220 km/h. |
| N | Knots. N0175 is 175 kt. |
| M | Mach. M082 is Mach 0.82, and rarely seen at FIS. |
Item 15: how a cruising level is written5 codes
| F | Flight level. F085 is FL 085. |
| A | Hundreds of feet. A055 is 5 500 ft. |
| S | Standard metric level, in tens of metres. S0150 is 1 500 m. |
| M | Altitude in tens of metres. M0610 is 6 100 m. |
| VFR | Uncontrolled VFR, where the flight is not holding one cruising level. A local training detail or a photo run that climbs and descends throughout is written VFR here instead of a level. |
Item 15: what a route is written from6 codes
| ATS routes | UT851, Y60, KODAR2A |
| Navigation aids | LN, MAY, HADDY |
| Significant points | KEMAX, MOKAM, GOTUR |
| Latitude and longitude | 5602N01520E. Latitude first, with N or S, then longitude, with E or W. |
| Bearing and distance | DUB180040. From DUB, on the 180 bearing, 40 NM out. |
| Direct | DCT |
Item 15: changes along the way, where they are needed2 codes
| Speed or level | LN/N0248A050. At LN, 248 kt and 5 000 ft. |
| Flight rules | LN/N0230A045 VFR. At LN, 230 kt and 4 500 ft, and VFR from there on. |
Item 18: the fields on the lesson list10 codes
| DEP/ | Departure aerodrome, when Item 13 says ZZZZ. |
| DEST/ | Destination aerodrome, when Item 16 says ZZZZ. |
| TYP/ | Aircraft type, when Item 9 says ZZZZ. |
| REG/ | Registration, when it is not the same as the aircraft identification in Item 7. |
| ALTN/ | Alternate aerodrome, when Item 16 says ZZZZ. |
| EET/ | Estimated times of crossing FIR boundaries. |
| DOF/ | Date of flight, as year, month, day. |
| RMK/ | Any other remark, in plain language. |
| STAYINFO/ | What the STAY in Item 15 is for. |
| STS/ | The reason the flight needs special handling by ATS. |
STS: the reasons on the lesson list6 codes
| STS/HOSP | A medical flight. |
| STS/ATFMX | Exempt from air traffic flow management measures. |
| STS/NONRVSM | Not RVSM approved, but going into RVSM airspace. |
| STS/HUM | Humanitarian. |
| STS/FLTCK | Flight check: calibrating navigation aids. |
| STS/SAR | Search and rescue. |
The messages that refer back to this one5 codes
| CHG | Modification. Changes a flight plan already sent. |
| CNL | Cancellation. The flight is not operating. |
| DLA | Delay. Sent when off blocks slips by more than 30 minutes. |
| DEP | Departure. Activates the flight plan. |
| ARR | Arrival. Closes the flight plan. |
Service and organisation designators8 codes
| YFY | AFTN office |
| ZTZ | Control tower |
| ZPZ | ATS reporting office |
| ZQZ | Area control centre |
| YNY | NOTAM office |
| YDY | Airport manager |
| YZY | Meteorological data bank |
| YMY | Local meteorological office |