Sir - The article "IFALPA sparks row over use of TCAS logic in RVSM airspace" (Flight International, 12-18 March, P8) is slightly misleading.
The International Federation of Air Line Pilots' Associations (IFALPA) is concerned that the UK Civil Aviation Authority has published guidelines for the North Atlantic (NAT) without submitting them to, or gaining the approval of, the NAT system planning group - and going against the advice of the US Federal Aviation Administration, the developer of traffic-alert and collision-avoidance system (TCAS) logic. The FAA's advice is that "-the pilot's instinctive reaction should always be to respond to RAs [resolution advisories] in the direction and to the degree displayed".
These concerns have been submitted to the UK CAA, which is giving them its attention. IFALPA does not consider, therefore, that it has caused a "row", but rather that it has highlighted its real concerns and worries to the CAA.
EDWARD MURPHY
deputy president
IFALPA, Chertsey, Surrey, UK
Source: Flight International
