The pilot of the medevac helicopter that crashed in Prince George's County last month asked an air traffic controller for turn-by-turn landing instructions before he went down, but the controller couldn't provide such directions because she was not trained to use the base's precision radar equipment, according to a preliminary federal report released yesterday.
The controller, in the tower at Andrews Air Force Base, was not required to be trained on the radar system, which is the responsibility of regional controllers in Northern Virginia, a spokeswoman for the Federal Aviation Administration said. The helicopter disappeared soon after the pilot asked for help, and it was unclear from yesterday's report whether radar guidance might have prevented the crash.
The report on the Sept. 28 crash, released yesterday by the National Transportation Safety Board, stopped short of naming a probable cause. But it offered new details about the final minutes before the aircraft disappeared in a park near Andrews, killing the pilot, a Maryland State Police paramedic, a civilian medic and one of two patients on board.
After picking up two victims of a car accident in Waldorf, pilot Stephen H. Bunker turned back from his approach to Prince George's Hospital Center because of bad weather and told regional air traffic controllers he intended to land at Andrews, the helicopter's home base. He then contacted the controller at the base.
Shortly before midnight, Bunker said he was "not receiving the glide slope," referring to a radio signal that would allow him to guide the helicopter using its onboard instruments. The Andrews controller responded that the equipment was "green," or functioning properly.
Bunker then requested an "Airport Surveillance Radar approach," or precise radar-based landing instructions.
"The controller responded she was not current and qualified to provide that service," the report said. "There were no further transmissions received."
FAA spokeswoman Laura Brown said a tower controller is not the person a pilot would typically ask for radar guidance.
"ASR approach is considered a secondary duty at Andrews, and controllers are not required to be current on it," Brown said. "Towers don't generally provide a lot of radar services."
The helicopter was reported missing within a half-hour, and a second State Police helicopter launched to search for it but turned back because of low clouds, the report said. The second helicopter's crew then set off on foot and located the crash site at about 1:30 a.m. One patient on board survived.
