Introduction

In Europe, all flight plans that have at least one segment under instrument flight rules (IFR) within the Eurocontrol region (IFPZ), are submitted to Eurocontrol and managed through Eurocontrol interfaces which provides a very comfortable and coherent interface that all relevant parties are connected to.

Flight plans that do not match the above criteria, are sent to the relevant parties as text messages via the AFTN (aeronautical fixed telecommunication network), a very old system where there are only messages and no central state or management. autorouter determines automatically if a flight plan is acceptable to Eurocontrol and if not, offers to file it via AFTN.

Flight plan addressing

Flight plans are text messages that have to be distributed to all parties concerned for a particular flight. Each country defines general addressing rules which are published in the AIP section ENR 1.11. On top of that, there can be additional addressing rules published through AIP AMDTs (amendments) and even NOTAMs. Sometimes rules aren’t even spelled out anywhere and require “tribal knowledge” to satisfy all parties. autorouter tries to capture these rules in its database to always perform the correct addressing.

Unfortunately, it is impossible to always address every flight plan correctly. Therefore you get the list of AFTN addresses presented before filing and the chance to include additional addresses. In case you spot an omission or error, please inform us immediately so we can take corrective action.

If a flight plan covers a region that autorouter does not have complete addressing information for, it will show a warning before filing. In this case, you should supply the relevant additional addresses yourself and also inform us so we can expand the database.

ARO addressing issue

Historically, each airport would have an ARO (airport reporting office) where staff would take flight plan forms for flights departing from this aerodrome. They would analyze the route and using information they have, determine the list of AFTN addresses and then submit the flight plan via Telex (which the AFTN was originally based on). Today, most flight plans are filed online, but the key thing here is that the departing airport takes responsibility for the addressing of a flight plan. Several countries officially still stick to this notion and usually have a central function (AIS) that takes AFTN flight plans and handles the complete distribution for both national and international flight plans.

In real life, this does not work very well for international flight plans. Each ARO needs to have complete and correct information about the addressing but this is a far too complex a topic for everybody to get right all the time — especially since it is mostly done manually. Therefore autorouter will not respect the “departure ARO only” rule and performs its own addressing on top. In worst case, flight plans get sent out more than once to receivers but this does not do any harm. We believe that it is much easier for a multinational provider such as autorouter that handles a large volume of flight plans covering dozens of countries, to get the addressing right using modern technologies than it is to rely on individual AROs that often do not have a lot of experience outside “standard routes” (such as to neighboring countries) and handle only a small volume of plans. With the central system and convenience of the Eurocontrol system, AROs in Europe rarely deal with flight plan addressing anymore.

When to file

In the Eurocontrol systems, flight plans usually become available to all parties immediately and while not encouraged, it is virtually possible to click file and take a seat in the cockpit for departure.

AFTN flight plans are messages often processed by humans at human pace. Just like with emails, they can get overlooked if they are too far down in the inbox. Therefore, we recommend to not file AFTN flight plans before the date of flight or the evening before for an early flight. You should give the parties enough time to respond (e.g. “airport is closed” or “no fuel” or “required permission not available, landing denied”) to not find yourself in an unfortunate situation when you’re up in the air.

So this requires a bit of judgement on your side — don’t file too early, don’t file too late!

Bringing flight plans forward

For Eurocontrol flight plans, autorouter offers the option to move the estimated off block time forward, i.e. change it to an earlier time than previously set. This operation does not directly exist for flight plans so what really happens is that the current flight plan gets cancelled and a new flight plan at the earlier time with the same details is instantly filed.

For AFTN flight plans we do not offer this feature although it would be technically possible to do it in the same way. The reason is that in the classic way of dealing with flight plans, many human operators are involved who receive the flight plan messages via email or custom software. If we send out a cancel immediately followed by another file, it is very easy for the human operator to get confused and misunderstand what the intention is.

If you want to bring a flight plan forward, think carefully if you really have to do it and if you want to, cancel it and then file it again using the same route but a new time. This way, there is some time between and the chances of confusing human operators is smaller.

Flight follow up messages

Each AFTN station has the ability to send messages, either standard messages (such as delay or cancel) or free text messages containing arbitrary information such as “flight requires permission number and cannot be accepted”.

Due to the unstructured nature of AFTN messages, it is often not possible to automatically process incoming messages and take the appropriate action. autorouter staff monitor the message flow and forward messages or take action on a best effort basis. Whenever you have an active flight plan, you should monitor your email inbox for messages. It is also recommended to file sufficiently early to give the receivers the opportunity to pass messages that might be important for the operation of the flight.