By Joel Morley,
Nav Canada Operational Safety and Human Factors Specialist
Direct Controller-Pilot Communication (DCPC) provides a critical safety link in the Air Traffic Services (ATS) system. We rely on voice communication to form a common understanding between pilots and ATS personnel of what an aircraft will do and what airspace needs to be protected.
The critical nature of this link has led to significant defences being built into the ATS-pilot communications loop to ensure communication errors are avoided or detected before they cause a serious problem. These include standard phraseology and required readbacks of IFR clearances.
Significant data exist which indicate that communication errors are common in aviation. Non-standard phraseology, partial or incomplete readbacks, call sign confusion or omission and other issues happen frequently.
Although such errors are most often inconsequential, they are a leading contributor to some of the most serious incidents including losses of separation, controlled flight into terrain and runway incursions. Consider the following:
• Communication errors are common: One study conducted in the United States found that more than 40% of controller communications and 59% of pilot communication contained at least one communication error! Nav Canada’s normal operations monitoring also noted frequent communications errors by both pilots and controllers.
• Communication errors with consequences are rare: Non-standard phraseology, partial readbacks or omitted call signs rarely result in incidents. The robust nature of the verbal communication system used in aviation is demonstrated in one European study which found that the rate of incidents arising from communication error was 2.44 per million clearances or instructions delivered.
• Communication errors contribute to serious incidents and accidents: The consequences which do result from communication error can be significant. Approximately one third of operating irregularities investigated by Nav Canada in 2005 had communication error as a contributing factor and communication errors have been identified as a significant contributor to runway incursions and approach and landing accidents.
The challenge, as always in a safety system, is to avoid a drift into increasing risk.
Non-standard communications usually happen either because the involved individuals do not see the need to follow procedures exactly or because they perceive some reason not to. For example, "there are only a few aircraft on the frequency – why use my call sign?" Or, "the frequency is quite congested – I can shorten my transmission by eliminating my call sign."
The lack of consequences reinforces this behaviour making it more likely to occur in the future and weakening the defences which are built into the communication system. This cycle recurs until a time when circumstances conspire to combine a communications error with a weakened defence leading to a serious incident or accident.
In the face of this natural tendency to drift, as an industry, we need to find ways to reinforce the need for standard communications and to find ways to strengthen defences against communications error. We need to ensure that everyone understands the role effective communications play in safety.
Ultimately, we need to nurture a culture where good communication practices are the norm and non-standard communication practices are seen as being unacceptable.
Nav Canada has formed the Air Traffic Services - Pilot Communications Working Group to bring partners together from across the industry to address this issue. COPA is one of the partners participating in the working group.
The working group’s mandate is to enhance safety by undertaking initiatives to improve ATS-pilot communication and reduce communication error.
The working group has agreed on five areas of activity to encourage a culture where effective communication practices are employed consistently:
- Raise the bar by focusing on quality assurance and standardization, training and licensing standards for pilots and ATS personnel.
- Raise awareness by developing a communications strategy which will increase awareness of the risks associated with poor communication practices.
- Increase inter-job awareness by building awareness of each other’s jobs.
- Increase data sharing by making data available for safety investigations and learning.
- Capitalize on technology and methodology by considering the potential of technology and procedures to reduce communication errors (reduce the amount of R/T required).
In the coming months, the working group will be developing a communications campaign to increase awareness of the risks associated with non-standard communication and the need for pilots and ATS personnel to work together to reduce communication errors.
Reducing communication error is a goal which will require effort throughout the industry. General Aviation pilots can help by:
1. Examining their communication practices. Are they using standard phraseology? Are full readbacks to clearances and instructions including call sign provided?
2. Looking for ways to encourage good communication practices in others.
For more information on the Air Traffic Services-Pilot Communications Working Group, contact Joel Morley at Nav Canada firstname.lastname@example.org or call 613-563-7618.