BACKGROUND

The tragic events of 11 September 2001 have drastically changed the way in-flight security
incidents are managed. National security authorities are now much more reactive to any
indication that could lead to a security concern. One such indication is the prolonged loss
of radio communication with ATC, also known as COMLOSS.

 In many countries, unnecessary interceptions of aircraft triggered by COMLOSS have
more than doubled, even reaching up to 90% of the total number of interceptions in some
Regions. Interception procedures are costly, they disrupt the Air Traffic Management
(ATM) system, and have the potential to decrease the safety of the flight, the aircraft, and
its occupants.

REASONS FOR COMLOSS

Some instances of COMLOSS in recent years have indeed been associated with a security
threat. However, the vast majority were due to other reasons, including RTF/ground-
based equipment failures, atmospheric conditions, human error, and unintentional crew
actions, such as switching to a wrong radio channel or setting the radio to very low
volume.

 In today’s complex airspace, flight crews and air traffic controllers are facing a high radio
communication workload. They must switch between many congested frequencies and
deal with similar-sounding aircraft call signs, noise interference, simultaneous
transmissions, and varying accents, to name a few issues.

In this very busy environment,
mishearing a frequency assignment, or not receiving it in time, is not unusual.

BACKGROUND USE OF 121.5 MHZ

Pilots would normally tune one radio on the ATC-assigned frequency for primary
communication, and monitor the aeronautical emergency frequency, 121.5 Mhz. on the
other available radio. However, this other radio is also used for secondary communication,
such as contact with the company or handling agent and weather monitoring.

In these situations, it won’t be tuned on 121.5 Mhz. Further, 121.5 MHz is frequently used
for non-emergency purposes in certain Regions, such as testing of operational equipment
(fire services, transmitters, Emergency Locator Transmitters), practice position fixes for
general aviation, or inter-pilot communication. As a result, pilots often turn down the
volume on this frequency to avoid unnecessary cockpit noise and cluttering of their
primary frequency, rendering 121.5 MHz useless as a back-up means of communication.

 IFALPA believes that 121.5 MHz should be monitored at all times, and that this frequency
should only be used for emergency communications.

ATC RESPONSE ICAO Doc 4444, Chapters 8 (ATS Surveillance Services) and 15 (Procedures related to
Emergencies, Communication failure and Contingencies) contain clear guidelines for ATC
actions related to aircraft radio transmitter failure. In particular, if two-way communication
is lost, the controller should determine whether or not the aircraft’s receiver is functioning
by instructing the aircraft on the channel so far used to either: – acknowledge by executing a specified manoeuvre (which would then be observed
on radar); – operate IDENT; – or make SSR code and/or ADS-B transmission changes.

 If unsuccessful, ATC should repeat this process on any other available channel on which
it is believed that the aircraft might be listening. Subsequent actions, if necessary, should include a request for further assistance to other
aircraft on the last assigned frequency and/or to the COMLOSS aircraft’s
dispatch/operations office, using company voice or aircraft datalink communications
channels or satellite phone, if available.

 An interception should only be considered as a
last resort, once all other methods have been attempted and it has been established that
the aircraft represents an actual security threat.

POSITION

 IFALPA is extremely concerned that some States are taking the wrong approach to solving
the extreme complexity of today’s radio communications. Instead of following the above
guidelines, they have begun to hold airlines and flight crews legally and financially
responsible for COMLOSS by accusing them of so-called ‘administrative offenses’ and

sending them fines to compensate for some of the interception costs, without any proper
study of the related COMLOSS event.

 The Federation considers this behaviour to be unacceptable, counterproductive, and
detrimental to flight safety. Blaming airlines, flight crews and/or controllers for COMLOSS
situations will not solve the problem. Whilst COMLOSS can sometimes represent a security concern, most of these situations
are false alarms that do not justify interceptions. They are clearly not security-related but
rather result from other factors, as described above. They should never lead to punitive
measures.

 IFALPA calls for the recognition of the systemic nature of COMLOSS events and strongly
supports a detailed investigation and analysis of each COMLOSS event and actions taken
to establish the contributing factors.

States should also ensure the implementation of a positive safety culture environment
which will encourage individuals to report these events without fear of punishment.

  
This will enable valuable lessons to be learned from these incidents and minimize the chance
of reoccurrence.