Entering Controlled Airspace
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Entering Controlled Airspace
A significant cause of airspace infringement is that some pilots are not familiar with the correct procedure for entering controlled airspace and do so without clearance. This article deals with international regulations concerning entering controlled airspace.
National regulations may differ in detail but will follow the same general rules.
ICAO Annex 2: Rules of the Air
The Rules of the Air state that clearance must be obtained before an aircraft enters controlled airspace (with the exception of a VFR aircraft entering class "E" airspace). All aircraft wishing to enter controlled airspace must file a flight plan, either on the ground before flight, or in the air, and the air traffic services involved must receive the request at least 10 minutes before the expected time of entry. (See ICAO Annex 2, Chapter 3, Section 3.3)
Getting clearance may take a little time; the controller has other jobs to do and may be dealing with a more urgent task - perhaps on another frequency, and he/she has to check the position and level of other aircraft before giving clearance. That is why the request must be made at least 10 minutes before entry time.
- An aircraft must not enter controlled airspace until clearance has been received.
- It is not sufficient that the pilot has informed the controller of his/her request; entry must await receipt of formal clearance;
- The aircraft must stay clear of controlled airspace while awaiting clearance.
How to Ask for Clearance
The initial call should be made at least 10 minutes before the point of entry, and should consist of the aircraft call sign followed by a brief statement of the request.
- “Zenda Control ABCDE, request crossing of A1 at Benton”.
The controller will reply, saying either:
- “ABCDE, Zenda Control, Standby”, or
- “ABCDE, Zenda Control, pass your message”.
If the reply was “Standby”, then clearance has not been given and the aircraft must wait, keeping out of controlled airspace.
If the reply was “pass your message”, then the following information should be passed:
- aircraft call sign and type,
- present level,
- flight conditions,
- crossing position,
- requested crossing level, and,
- estimated time at the crossing position.
- “Zenda Control ABCDE is a Cessna 172, 25 miles West of Benton heading 100, FL 70 VMC, request crossing clearance of airway A1 at Benton FL 70 at 1023.”
Clearance may not be granted straight away, because the controller has to check the position and levels of other traffic. Until clearance is received, the aircraft must stay clear of controlled airspace.
When the controller passes the crossing clearance, the pilot must read it back so that he/she can check that it has been copied correctly.
The clearance may not be exactly the same as was requested, but it must be obeyed. For example, if the clearance was at a different flight level from that requested, the aircraft must climb or descend to the cleared level before entering controlled airspace.
- ICAO Annex 2: Rules of the Air, Chapter 3, Section 3.3;
EUROCONTROL Airspace Infringement Initiative
- European Action Plan for Airspace Infringement Risk Reduction;
- Airspace Infringement Risk Analysis Part II;
- Airspace Infringement Initiative website;
- Watch your R/T checklist poster
EUROCONTROL Guidance Notes for GA pilots
- Rules for VFR flight;
- Flight preparation;
- Getting aeronautical information before flight;
- Reading and understanding NOTAMS;
- Getting meteorological information before flight;
- Reading and understanding weather reports and forecasts;
- Using meteorological information for planning;
- Visual navigation;
- VOR/DME/ADF Navigation;
- GPS Navigation;
- Getting aeronautical and meteorological information in flight;
- Entering controlled airspace;
- Getting the most out of your transponder;
- Airspace & Safety Initiative
- General Aviation Safety Sense Leaflets
- On Track - A Confidential Airspace Infringement Project;
- CAP 1535: The Skyway Code, September 2017
- IFR / VFR – Air Traffic in Airspace E, Sympathetic Cooperation, by BFU, December 2011