Sir - Media attention has focused on the UK Civil Aviation Authority's plans to reduce separation on final approach at Gatwick, Heathrow and Stansted airports in the UK.
This attention followed publication in Transmit, the Journal of the Guild of Air Traffic Control Officers (GATCO), of a report by the commander of a Lufthansa Boeing 737 landing at Heathrow during reduced-separation trials, who was critical of the separation provided and the procedures involved. The attendant hype in some sections of the press has drawn attention away from key issues involved.
GATCO's concerns are that it is unaware of the nature and results of the safety analysis, which it assumes was carried out by the Safety Regulation Group before approval of these trials and approval of reduced separation becoming a permanent procedure; and that flightcrew involved should have been made aware that the trial was in progress on a tactical basis.
GATCO has also drawn attention to the lack of notification by Notices to Airmen or Aviation Information Communication, both in respect of the trials and of the revised vortex-wake spacing introduced permanently at these three airports on 12 May, 1997.
The Guild is also interested to know what methodology was used to determine that vortex-wake spacing is not now needed between certain, recategorised aircraft types, for example the Boeing 737 and Airbus A320, operating at these three airports only, since the 3nm (5km) minimum vortex-wake spacing continues to be mandatory between aircraft of these types during an instrument approach at all other UK airports.
GATCO has not said that these new procedures and criteria are unsafe, despite being invited to do so on several occasions. Its position is that objective and informed comment is not possible since details of the associated safety analysis have not been made available.
Until this information is provided and has been examined, the Guild, and specifically its members at the air-traffic-services units involved, remains justifiably concerned.
Michael L Burlyn
Editor,
Transmit, Midhurst, Sussex
Source: Flight International
