In this blog we´ve already addressed on more than one occasion how ground communications with aircraft take place constantly and in different ways – for example, through a device called a transponder. The crew must stay informed at all times of any incident or change in plan – which, by the way, does not necessarily have to be a cause for worry. Likewise, everything that concerns the different maneuvers is reported from the aircraft – mainly takeoff and landing. And this is where ATIS and NOTAM advisories come in.
ATIS (Automatic Terminal Information Service)
The work performed by specialised personnel in the control tower requires enormous concentration, especially at an airport where traffic is very dense. ATIS advisories are, in a way, a tool that takes some of the pressure off of them.
It´s a system which transmits – continuously and on a particular frequency – relevant airport-information. Its function is to increase efficiency in especially saturated airports, and in addition, since it uses only one frequency, it frees up the others to offer this same information.
The ATIS imparts data, for example, about the weather affecting the terminal in question; it also advises which runways are operational or of the available approaches. Finally, it issues NOTAMs, which we will talk about below. In short, it conveys information that may cause pilots to have to alter their maneuvers due to weather or traffic saturation.
ATIS Updates and Protocols
This information, essential for approach, takeoff, and landing maneuvers, is updated with a predetermined frequency, unless there is a significant change (to the use of the runway, for example). Each new update receives a letter of the ICAO alphabet (alpha, bravo, etc.) and the pilot, after it, must inform control that he has received it. These messages are issued simultaneously for both departing and arriving aircraft, and must contain certain information and in a certain order:
- Airport name
- Identification of the report (using the aforementioned letters of the ICAO alphabet)
- The time at which the report is issued (in Greenwich Mean Time)
- Wind information (speed, direction, etc.)
- Visibility (expressed in statute miles)
- Weather conditions – rain, snow, hail, storm, fog, etc.
- Sky conditions
- Aproximations (which flights are arriving and on which runways)
- Runways in use
- NOTAM (see below)
After all these updates, the pilot is reminded to notify the control tower with the corresponding designator so that the ground knows that the cockpit crew has the most recent information.
NOTAM (Notices to Air Missions)
Incorporated at the end of the ATIS, NOTMAMs deserve special mention. Concretely, they´re warnings that there are a series of specific situations that could affect the safety of the flight, such as:
- Military manoeuvres causing flight-zone restrictions
- Radio navigation aids which aren´t operational
- Closed runways
- Temporary presence of obstacles near the airport
- Work being done in the area of operations
- Opening or closing of restricted areas
- Change in the maximum speed of a procedure
The NOTAMs follow a pattern established in accordance with the specifications cite in Annex 15 of the that the Convention on International Civil Aviation.
Types of NOTAMs and Ways of Keeping Track of Them
There are four types:
- N – new NOTAM
- E – evento
- R – replacement NOTAM (substituting a previous NOTAM)
- C – Cancellation NOTAM (i.e. cancelling a previous NOTAM)
As we´ve seen, the ATIS incorporate any relevant NOTAMs at the end of each update. There are also other ways for pilots to stay informed about NOTAMs. In Spain, they include:
- Via the Internet portal of the aviation authority which issues them (in Spain it´s called Enaire, whereas in the UK it´s NATS).
- Via Einare´s other website Insignia VFR, which displays NOTAMs on a map, so that entering the name or the coordinate the cockpit crew can determine which ones will affect them at a glance
- Via the Einaire app Ícaro, which requires a security password
Other countries´ aviation authorities operate their own similar portals and utilities.
Finally, a note about the name. NOTAM originally stood for ¨Notice to Airmen¨, but nowadays many cockpit crew are of course not only male; in addition, with the increasing prevalence of drones in the skies, their operators also need this type of information, so the modification covers them, as well.