THE US NATIONAL Transportation Safety Board (NTSB) is urging the Federal Aviation Administration to allow the immediate commissioning of the Westinghouse Norden Systems ASDE-3 surface-movement radar installed at 23 US airports.
It also wants the FAA to speed up development of the associated Airport Movement Area Safety System (AMASS).
The recommendations arise from the Board's probe into the 22 November, 1994 runway collision involving a McDonnell Douglas MD-80 operated by Trans World Airlines (TWA) and a Cessna 441 Conquest at Lambert St Louis International Airport, Missouri.
The Conquest was cleared to hold on Runway 31, a commuter runway. Instead, it held on Runway 30R, where the TWA airliner was already into its take-off roll. The pilot and passenger aboard the Cessna 441 were killed and there were eight injuries to passengers on the airliner.
An ASDE-3 was installed, but not commissioned, at Lambert International at the time of the accident. To date, ASDE-3 systems are operational at only seven US airports because of technical problems.
The NTSB believes that the fatal runway collision could have been avoided had the ASDE-3/AMASS been in use.
Multi-path problems, creating false targets on the radar display, have delayed ASDE-3 commissioning, but FAA officials say that potential solutions are in development. The NTSB, however, claims that this is no longer a problem.
The NTSB is urging that all ASDE-3 radar now installed be commissioned because "...almost all problems have been corrected or resolved in some manner, although it is acknowledged that the system is not perfect".
The Board believes that the ASDE-3s should be operational between sunset and sunrise, regardless of weather, and should be operated round-the-clock once the AMASS is developed.
NTSB criticism of the FAA, over its handling of the AMASS project, centres on its being "effectively paralysed as a result of a succession of changes, in operational specifications, it would appear that factions within [the FAA] are attempting to require, that AMASS become something it was never intended to be".
The AMASS was to have become operational by 1992. The FAA has spent over $20 million on the system.
Source: Flight International
