Guidance concerning Air Navigation in and above the NAT MNPSA
“WHEN ABLE HIGHER” (WAH) REPORTS
Prior advice to ATC of the time or position that a flight will be able to accept the next higher
level can assist ATC in ensuring optimal usage of available altitudes. A WAH Report must be provided by all flights entering the MNPS Airspace portion of the New York OCA and entering the Santa Maria OCA. Due to the higher number of step climb requests on the generally longer NAT route segments that transit New York and Santa Maria OCAs and also because of the greater frequency of crossing traffic situations here, the strategy of issuing “coast-out to coast-in” conflict-free clearances is not always employed by these two oceanic control centres. Here, air traffic control of a more tactical nature is often exercised. The provision of WAH Reports in these circumstances allows the controllers to more effectively utilise their airspace and provide aircraft more fuel efficient profiles. Provision of WAH Reports on entering other NAT OCAs is optional or they may be requested by any OAC.
When required or when otherwise provided, upon entering an oceanic FIR, pilots should
include in the initial position report the time or location that the flight will be able to accept the next higher
altitude. The report may include more than one altitude if that information is available.
”Global Air 543, 40 North 040 West at 1010, Flight Level 350, Estimating 40 North 050 West at 1110, 40 North 060 West Next. Able Flight Level 360 at 1035, Able Flight Level 370 at 1145, Able Flight Level 390 at 1300”
Information thus provided of the aircraft’s future altitude “ability” will not automatically be
interpreted by ATC as an advance “request” for a step climb. It will be used as previously indicated to assist ATC in planning airspace utilisation. However, should the pilot wish to register a request for one or more future step climbs, this may be incorporated in the WAH report by appropriately substituting the word
“Request” for the word “Able”.
“Global Air 543, 42 North 040 West at 1215, Flight Level 330, Estimating 40 North 050 West at 1310, 38 North 060 West Next. Request Flight Level 340 at 1235, Able Flight Level 350 at 1325, Request Flight Level 360 at 1415”
Although optimal use of the WAH reports is in conjunction with a Position Report, a WAH
report can be made or updated separately at any time.
“Global Air 543, Able Flight Level 360 at 1035, Request Flight Level 370 at 1145, Able Flight Level 390 at 1300”
It should be noted that ATC acknowledgement of a WAH report (and any included
requests) is NOT a clearance to change altitude.
In accordance with Amendment 75 to ICAO Annex 3, with effect from 18 November 2010
aircraft are no longer required to provide voice reports of MET observations of wind speed and direction nor
outside air encountered
Nevertheless any turbulence
significant meteorological conditions for the reporting of such observations
should, where appropriate, be by reference to geographical co-ordinates.
When a ground unit establishes an event contract with an aircraft to provide ADS position
reports, it may also establish an additional periodic report contract (e.g. with a 30 mn interval). Such ADS-C
NAT Doc 007