The IAA have published guidance to general aviation pilots in Ireland about requesting a VFR Clearance. The guidance, which is reproduced below, outlines the steps and processes that happen in the background when you request a VFR clearance.
Introduction
Pilots are often surprised when there is a delay following a request for a VFR clearance. This material explains the internal processes that must occur within air traffic control (ATC) for such a request to be processed.
The processes described here are generalisations and may vary in detail depending on time of day and location. When requesting a clearance from ATC, make your request on the appropriate frequency for the area you are in, unless a particular frequency is specified in AIP IRELAND. ATC will transfer you to the correct frequency if necessary.
Step 1 – Clearance request
“Dublin Approach, Echo India India Alpha Alpha, Cessna 172, approaching Bray, two thousand feet, request entry to the zone routing to Weston.”
Step 2 – Establishing identification
Before any surveillance-based services can be provided, controllers must establish positive identification of the aircraft concerned. VFR aircraft squawking 7000 are shown on ATC air situation displays as relatively inconspicuous grey tracks. Furthermore, there may be more than one VFR track in the relevant area.
In this situation the usual means of establishing identification is to instruct the pilot to squawk a discrete (individual) code. To obtain a discrete code, it is normally necessary for a flight plan (flight notification) to exist within the ATC Eurocat system. However, inactive VFR plans are not always displayed to controllers, so the first question you are likely to get from a controller is “have you got a flight plan in the system?”
Step 3 – Activating flight plans
If a flight plan has been submitted, in most cases it is a relatively simple process for ATC to access and activate it. If not, then the controller will have to take details over the air and create a plan. This is a relatively time-consuming and complex process. Remember: even if your details have changed, it is much easier to amend an existing plan than to create one from scratch.
You can greatly speed up the clearance process, or improve your chances of getting a clearance, by submitting a flight plan before takeoff. If done via the online flight planning tool at www.iaa.ie/generalaviation. It costs nothing and if never activated will self-cancel in due course. However, if needed it will be there waiting for you.
Sometimes due to processing errors, flight plans can be “missing” from the ATC Eurocat system when you call. The more information you provide in your flight plan in relation to your point of departure, intended route, and destination, the easier it will be for ATC staff to initially process your flight plan.
In addition, an accurate departure time and estimated elapsed time will assist the ATCO in activating your flight plan, and the provision of contact information (such as a mobile phone number) in your flight plan will assist in the provision of an Alerting Service.
Step 4 – Linking identification to flight plan
Once ATC has activated the flight plan and instructed you to squawk a discrete code, it will take a few moments for the surveillance system to detect your squawk, couple the flight plan details to it and display the details to the controller. Your aircraft’s track will now have an interactive label attached to it (see above), and there will also be a flight strip giving the controllers access to further information about your flight.
Step 5 – Co-ordination with other controllers
Once the flight plan has coupled to a track, identification has been positively established. The controller talking to you will now need to coordinate with other controllers about your flight before a clearance is approved. For example, at Dublin this will include co-ordination with the Dublin Approach radar controller, Military control and also Weston ATC. Your progress through the control zone can impact on the processing of scheduled IFR traffic at Dublin airport, Baldonnel and Weston airports, depending on the active runway and traffic pattern.
Before you fly…
Each location has preferred routes and/or levels for accepting VFR traffic, which may vary depending on the day of the week, or the time of day. You can often help your chances of obtaining a clearance through busy terminal areas by telephoning the terminal area Station Manager before you flight plan. They will be able to advise on the best routes, levels or times to plan. This is particularly valuable if you want to do something unusual, for example some sightseeing or other air work. The applicable phone numbers are listed below.
Summary
You can see that there are a number of steps that must occur within ATC, not all of them visible to the pilot, before a VFR clearance can be issued. All of this takes time, and the controller will have other aircraft to manage as well. You can improve your chances of obtaining a clearance, reduce delays and minimise the risk of an airspace infringement by:
- telephoning the supervisor at busy locations for advice prior to flight planning
- submitting a flight plan, even if you may not need it
- allowing plenty of time before the CTA boundary when you make your clearance request
- always having an alternative plan and decision point in case a clearance is not available as requested.
Telephone Details
Cork Air Traffic Control Dublin Air Traffic Control Shannon Air Traffic Control
(021) 432 9667 (01) 844 5962 (061) 366 148
