Airspace Infringement and Communication
Airspace Infringement and Communication
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Description
Airspace infringement occurs when an aircraft penetrates an area into which special clearance is required without having such clearance.
A major cause of airspace infringement is breakdown of communications with Air Traffic control.
This may result from:
- lack of knowledge or understanding of procedures for obtaining clearance to enter or cross controlled airspace; or,
- failure to follow correct procedures for crossing or entering controlled airspace.
Effects
The aircraft enters controlled airspace without obtaining clearance, leading to:
- loss of separation from other traffic and, possibly, mid-air collision; and,
- disruption of traffic flow within the airspace; and,
- increased controller workload and distraction from other tasks while the situation is resolved.
Defences
- Communications procedures for obtaining clearance to enter controlled airspace are clearly laid down in internatonal and national regulations.
- Correct use of a transponder will assist TCAS equipped aircraft to avoid collision.
- Short Term Conflict Alert (STCA).
Typical Scenarios
- An aircraft approaching an airway requests crossing clearance; however, the frequency is busy and the controller instructs the pilot to "Stand by". The pilot continues on track and enters the airway without clearance.
- An aircraft approaching an airway requests crossing clearance; the controller acknowledges the call but does not immediately approve the request. The pilot assumes that the acknowledgement constitutes clearance and enters the airway.
- An aircraft (usually military) enters civil airspace but does not contact the ATS unit responsible for that airspace.
Contributory Factors
- Frequency congestion;
- Pilot preoccupation with other tasks.
- Unfavourable attitude of ATC controllers to VFR flights, leading to poor comunication.
Solutions
Greater emphasis on communications procedures during training:
- Pilots should not enter controlled airspace unless a proper clearance has been received.
- Controllers should, whenever possible, remind pilots to remain outside controlled airspace if entry cannot be approved immediately.
A&I Examples
On 26 July 1999, an ATR 72-200 being operated by Mount Cook Airlines on a scheduled passenger flight from Christchurch to Queenstown entered the destination CTR without the required ATC clearance after earlier cancelling IFR and in marginal day VMC due to snow showers, separation was then lost against a Boeing 737-200 being operated IFR by Air New Zealand on a scheduled passenger flight from Auckland to Queenstown which was manoeuvring visually (circling) after making an offset VOR/DME approach in accordance with a valid ATC clearance.
On 27 January 2005, two USAF-operated McDonnell Douglas F15E fighter aircraft, both continued to climb and both passed through the level of an Embraer 145 being operated by British Airways Regional on a scheduled passenger flight from Birmingham to Hannover, one seen at an estimated range of 100 feet.
On 15 October 2008, following participation in a military exercise over East Anglia (UK), a formation of 2 foreign Eurofighters entered busy controlled airspace east north east of London without clearance while in the process of trying to establish the required initial contact with military ATC, resulting in loss of prescribed separation against several civil aircraft.
Further Reading
EUROCONTROL Airspace Infringement Initiative
- European Action Plan for Airspace Infringement Risk Reduction;
- Airspace Infringement Risk Analysis Part II;
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;
HindSight Articles:
European Action Plan for Air-Ground Communications Safety
UK CAA
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