Single Person Operations in ATC

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Single Person Operations in ATC

40TH ANNUAL CONFERENCE, Geneva, Switzerland, 19-23 March 2001

WP No. 159

Single Person Operations in ATC


Shrinking federal budgets and commercial pressures from privatisation are producing a global drive for increased efficiencies in the Air Navigation Systems of the world. Consequently, ANS providers are looking to find increased productivity from ATCOs.

Member Associations with staff shortages and those where the Air Navigation System is still developing may find themselves facing similar pressures. As a result, employers are using a number of different labour practices in an effort to increase the number of aircraft movements handled per person and/or reduce number of staff required to run the system.

Because these practices may affect the health and safety of the ATCOs and the safety of the system, IFATCA must monitor their implementation and effect.

This working paper will address one such practice; the use of ATCOs in Single Person Operations (SPO) and will provide appropriate policies.

It should be noted that this Working Paper reflects the realities of the ATCO’s working environment and does not mean that IFATCA endorses the use of SPOs.


Single person operations can be defined as that period of time when an operational ATC unit is providing service with only one person present on staff, that being the ATCO.

Effect on the ATS system

A 1996 study into Air Traffic Control by Transport Canada noted:

“Running an operation at its most efficient staffing levels usually means that very little surplus staff is tolerated. Unfortunately, in a safety-critical working environment, redundancy in system components is a requirement, including the human side of the system”

It is clear that in case of SPO’s, the redundancy of the human element is missing and therefore procedures need to be in place in the event of a failure of that element whether due to illness, fatigue or overloading.

These procedures should limit the levels and duration of traffic to an amount safely handled by a lone ATCO and should also deal with the possibility of the ATCO becoming unable to perform his duties. Procedures should be in place not only for the SPO unit but also for neighbouring units that may be affected.

Because traffic may increase unexpectedly or uncontrollably, back-up staff should be available.

on call-in within reasonable time limits to ensure the safe continuation of service. But it should be noted that in the case of an aircraft emergency, it is unlikely that staff could be called in quickly enough to assist in the increased workload. This is a risk that ANS providers and their customers must be willing to take if they use SPO’s.

SPO’s of longer duration do not allow the taking of normal meal and relief breaks. It should be noted that as a result of their research, the United Kingdom has recently regulated that : “…no operational duty shall exceed a period of two hours without there being taken during or at the end of that period a break or breaks totalling not less than 30 minutes.” IFATCA also has policies on maximum working hours.

Effects on ATCOs

What becomes apparent from the above discussion on the effect to the system is that the SPO also affects the personal wellbeing of the ATCO. As a minimum, he may be unable to take a meal or relief break for extended periods. IFATCA’s policies on nightshifts, working hours and breaks are a good indication that this is an undesirable situation.

Until a recent arbitration, Canada used SPO’s to staff nightshifts of up to 8 hours. The arbitrator ruled that this was an unreasonable length of time for an ATCO to work alone and ordered a minimum of two staff for any duration longer than three hours.

Further, the ATCO has no medical assistance in the event that he falls ill or is injured. Labour law in many jurisdictions requires that there be one employee present at all times who is trained in basic first aid. The use of SPO would require each ATCO have this training and be able to apply first aid on himself.

The ATCO has no assistance should his unit be subject to unlawful interference.

Fatigue may influence the controller’s abilities. The 1996 Transport Canada study noted that:

“…sustained vigilance for prolonged periods of time is demanding… and leads to decreased alertness and low motivation.”

Each of the above factors can increase both the fatigue and the level of stress felt by the ATCO in the course of his shift, both of which have been found to be detrimental to health and well being.

Further information on the resulting effects of SPO’s and current IFATCA policy can be found in the following areas of the IFATCA Manual:

  • Page 4131 Work and Rest Schemes
  • Page 4221 Stress
  • Page 4223 Fatigue
  • Page 4223 Pregnancy


SPOs eliminate redundancy in the human element of the ANS system. This can lead to a failure of the whole system should the traffic demand on the ATCO exceed his abilities or would he fall ill.

SPOs may be detrimental to the well-being of the ATCO by reducing his ability to take normal breaks while at the same time increasing the level of stress and fatigue under which he is operating.

For these reasons, the use of single controller shifts should be strongly discouraged by MAs.

Where providers choose to use SPOs, they, not the ATCO must bear the responsibility for the resulting risk to the system.


It is recommended that the IFATCA Manual page 4112 is amended as follows:

1.6 Single Person Operations

1.6.1 Single Person Operations (SPO) can be defined as operations where an operational ATC unit is providing service with only one person present on duty, that being the ATCO.

1.6.2 Rostering Single Person Operations (SPO) shall be avoided.


Impact of Shift work and Overtime on Air Traffic Controllers: Phase II ; Rhodes & Associates, 1996.

Report of a Committee on Regulation of Air Traffic Controllers’ Hours to the Civil Aviation Authority – United Kingdom, 1990.

Fatigue in Air Traffic Controllers: Literature Review Transport Canada, Transportation development Centre, 2000.

Last Update: September 29, 2020  

March 13, 2020   828   Jean-Francois Lepage    2001    

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