Guidance concerning Air Navigation in and above the NAT MNPSA
CONTINGENCY SITUATIONS AFFECTING ATM PROVISION IN THE NAT REGION
In the anticipation of situations arising which might result in the partial or total disruption of
Air Traffic Services within the NAT Region, NAT ATS Providers have developed arrangements which would, in such events, be put in place to ensure, as far as possible, the continued safety of air navigation. Such arrangements include required actions by pilots and operators of affected flights. These arrangements are detailed in “The North Atlantic Air Traffic Management Operational Contingency Plan – Doc.006” which can be downloaded from the ICAO Paris website at http://www.paris.icao.int/ . Operators and Pilots planning and conducting operations in North Atlantic region should ensure their familiarity with these
arrangements and in particular with the actions expected of pilots in such contingency situations.
The plan is presented in two parts. The first deals with contingency arrangements necessary
when only one NAT ATS unit is affected. While the second addresses events which are likely to affect more than one facility within the NAT region, for example the contamination of the airspace by volcanic ash. Where available, information is also provided outlining the steps taken by ANSPs to deal with any long term unavailability of an ATC facility.
OPERATION OF TRANSPONDERS
All aircraft operating as IFR flights in the NAT Region shall be equipped with a pressure-
altitude reporting SSR transponder. Unless otherwise directed by ATC, pilots flying in the NAT FIRs will operate transponders continuously in Mode A/C Code 2000, except that the last assigned code will be retained for a period of 30 min after entry into NAT airspace. Pilots should note that it is important to change from the last assigned domestic code to the Mode A/C Code 2000 since the original domestic code may not be recognised by the subsequent Domestic Radar Service on exit from the oceanic airspace. It should be noted that this procedure does not affect the use of the special purpose codes (7500, 7600 and 7700) in cases of unlawful interference, radio failure or emergency. However, given the current heightened security environment crews must exercise CAUTION when selecting Codes not to inadvertently cycle through any of these special purpose codes and thereby possibly initiate the launching of an interception.
Reykjavik ACC provides a radar control service in the south-eastern part of its area and
consequently transponder codes issued by Reykjavik ACC must be retained throughout the Reykjavik OCA
until advised by ATC.
AIRBORNE COLLISION AVOIDANCE SYSTEMS (ACAS)
From 1 January 2005, all turbine-engined aeroplanes having a maximum certificated take-off
mass exceeding 5,700 kg or authorized to carry more than 19 passengers have been required to carry and operate ACAS II in the NAT Region. TCAS Version 7.0 meets the technical specifications for ACAS II as contained in ICAO Annex 10 Volume IV. Pilots should report all ACAS/TCAS Resolution Advisories which occur in the NAT Region to the controlling authority for the airspace involved. (See further on this in Chapter 12.)
NAT Doc 007