Feb. 15--The Federal Aviation Administration yesterday abruptly canceled plans to test and calibrate a new computer upgrade to Logan International Airport's ground radar system.
The upgrade is critical to fixing problems that led to a spate of runway incidents at the airport last year.
The tests, which would have involved two propeller aircraft repeatedly taking off and landing on intersecting runways while airlines were also using the airport, had been scheduled to begin next week.
But yesterday, federal aviation safety officials said they would conduct the tests at another airport, which has not been named.
Jim Peters, a spokesman for the FAA, declined to comment when asked whether officials were concerned about the safety of conducting the tests on Logan's intersecting runways while the airport was operating during a busy school vacation week.
Logan was the first airport in the nation to have received the software upgrade, part of an effort by the FAA and the Massachusetts Port Authority, which owns and operates the airport, to prevent runway incidents. Logan led the nation last year in occasions in which a plane or vehicle entered or crossed a runway being used by another aircraft.
Wherever and whenever the tests are rescheduled, two FAA aircraft, a King Air and a Convair 580 with onboard equipment, will be used to conduct testing.
The testing had been scheduled to take place between 10 a.m. and 1 p.m. next Tuesday through Friday.
Testers said they need two full days of daylight and clear conditions, so that air traffic controllers testing the system do not have to rely solely on the upgraded radar system during the tests.
The proposed schedule included extra days in case the weather interfered with the testing, officials said.
Before the tests were canceled, FAA and Massport officials had notified nearby residents about the tests. The officials told the residents that they may see aircraft flying in the airport pattern or over parts of the city at low altitude on days on which the tests are conducted.
In addition, officials had planned to warn Logan passengers and flight crews to be aware of the tests.
"We don't want to do the test at Logan," Peters said. "We recommended that the test be done at another airport with intersecting runways and where they have [a similar ground radar system]."
Peters said FAA officials would recommend that the tests be done at an airport with similar geographical and procedural constraints as Logan.
"The test was scheduled at a busy time at Logan, and we felt that it would be more appropriate to do it at another airport," he added. "Basically, Logan is a busy airport, and we need to devote all our resources to the daily operation."
Logan reported its 17th runway episode in 14 months in December, the most of any US airport for that period.
Logan was put on a short list for an advanced ground-radar system that works better at night and in bad weather. Massport officials had pledged to spend almost $9 million to speed the new system.
