FAA Orders Tests of Transmitter It Closed at Airport

Responding to Orange County protests, Federal Aviation Administration chief Donald D. Engen has ordered immediate testing of a navigational radio transmitter that his agency shut down last month because its signal allegedly was interrupted by a new office complex near John Wayne Airport.

David Prebish, Orange County Airport Commission chairman, said Wednesday that he learned of the order in a memo from George A. Rebella, manager of the county airport, who could not be reached for comment.

FAA spokesman Russell Park said the FAA plans to fly one of its own planes through the area today or Friday to test for transmitter interference.

If no interference is found, the FAA may return the transmitter to service immediately, Park said, or the agency may wait for a meeting with Orange County officials to discuss the controversy involving building interference.

Last month, the FAA shut down John Wayne Airport’s Vor (very high frequency omnidirectional range) transmitter because, according to the FAA, its signal was being blocked by a high-rise office building under construction at Hutton Center on MacArthur Boulevard in Santa Ana.

Signals from the transmitter help pilots using navigational instruments determine where they are in relation to the airport.

Although airport and FAA officials agree that the absence of the Vor is not dangerous, shutting it down forces most aircraft to use the same instrument landing approach that jetliners follow when they fly into John Wayne Airport. The path takes aircraft over Tustin, where residents are angry about aircraft noise and worried about air traffic safety, instead of spreading them out over other cities.

With the Vor in service, pilots can turn toward their landings when they’re much closer to the airport before they get as far east as Tustin.

One of the county’s complaints, airport officials said, is that they believe the FAA shut down the Vor transmitter without actually testing for signal problems.

The FAA has complained that the same MacArthur Boulevard office complex has been responsible for a series of Vor transmission problems since early 1984.

FAA officials said earlier this month that they intend to resume using the Vor transmitter if tests prove that it works after the new office tower in the complex has been completed.

The accuracy of the Vor signals is affected by various kinds of building surfaces. Reflective coatings on glass surfaces cause the worst problem, according to the FAA.

Attempts to relocate the Vor transmitter have failed, according to airport officials, because the FAA wants a guarantee that the new location will be protected from urban encroachment.