Author: Brent Fishlock
ATC Zero is new term to some so I will say that it is an FAA term and occurs when the FAA is unable to safely provide the published ATC services within the airspace managed by a specific facility. The term is defined in FAA Order JO 1900.47, Air Traffic Control Operational Contingency Plans. It is one of three designations used by the FAA (ATC Alert, ATC Limited, and ATC Zero) to describe degraded operations and invoke operational contingency plans. Information online says that the term ATC Zero came about after the September 11th attacks of 2001 when air traffic facilities shutdown. Much of this article is from the recently released SAFO 20011.
Cases of COVID-19 among ATC facility staff and technicians have led and will likely continue to lead to intermittent, total, or partial closures of ATC facilities. This could occur with little or no warning.
So, what do you do if ATC goes off the air in oceanic airspace?
If you don’t have an oceanic clearance and you are approaching oceanic airspace where the contingency is activated you should land at an appropriate aerodrome or, if possible, request clearance to avoid the affected Oceanic Control Area (OCA).
Flights operating with an oceanic clearance are expected to continue in accordance with the last clearance issued. Due to the uncertainty surrounding the contingency situation, flight crews should, if possible, consider seeking a clearance to reroute around the affected OCA. Flight crews should use extreme caution and use all available means to detect any conflicting traffic.
Flight crews are requested to broadcast traffic information in the blind to other flights/stations on 121.5 and on 123.45 (or 126.9 MHZ in designated International Air Transport Association (IATA) broadcast areas), to exchange position information. A continuous listening watch and regular broadcasts must be maintained.
ATC may invoke the ICAO Traffic Information Broadcast by Aircraft or TIBA procedure.
TIBA is where flight crews broadcast in the following form:
ALL STATIONS (your call sign), FLIGHT LEVEL () (or CLIMBING/DESCENDING TO FLIGHT LEVEL (number)) (direction) (ATS route) (or DIRECT FROM (position) TO (position)) POSITION (position) AT (time) ESTIMATING (next reporting point, or the point of crossing or joining a designated ATS route) AT (time) (call sign) FLIGHT LEVEL (number) (direction)
Basically, it is a normal radio call of who you are, where you are and where you want to go.
TIBA calls should be provided at the following times:
- 10 minutes before entering the designated airspace or, for a flight crew member taking off from an aerodrome located within the lateral limits of the designated airspace, as soon as appropriate after take-off.
- 10 minutes prior to crossing a reporting point.
- 10 minutes prior to crossing or joining an ATS route.
- at 20-minute intervals between distant reporting points.
- 2 to 5 minutes, where possible, before a change in flight level.
- at the time of a change in flight level; and
- at any other time considered necessary by flight crew.
The FAA adds the following comments:
- You should complete a flight level change as soon as possible in accordance with the clearance.
- Mandatory position reports should be accomplished via HF or SAT until directed by ATC.
- Flights equipped with FANS 1/A or equivalent should communicate using HF or SAT while attempting to reestablish CPDLC
- If you can communicate with your operation’s flight dispatch, then they can forward position reports to the relevant OCA.
As always, following your oceanic SOPs is paramount.
You should plan to experience a loss of ATC services at any point in the flight.
A heightened sense of awareness is required for all procedures including:
- adherence to the current clearance
- Mach number or airspeed which may need to be adjusted based on proximate traffic
- Conducting navigation accuracy checks.
- Conducting waypoint and 10-minute post-position checks.
- Using SLOP
Here are some additional recommendations: Consistent with AIP recommendations, should flightcrews encounter situations that are not covered by regulation, they are expected to exercise good judgment in whatever action they elect to take.
Additionally, flightcrews should take the following actions:
- Monitor for traffic visually and by using TCAS or ADS-B In.
- Ensure all appropriate exterior lights are turned on.
- Monitor and use relevant communication channels such as 121.5/123.45 or 126.9 MHz, HF, SATVOICE and data link.
The FAA recommends you review guidance material such as the:
- Aeronautical Information Publications (AIP) for the countries where you operate.
- Regional operational air traffic management contingency plans, such as the Air Traffic Management Operational Contingency Plan for the North Atlantic Region (NAT) Doc 006; and
- Regional Supplements Doc 7030.
Refer to the SAFO itself for more details.