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.
The crash, one of 26 fatal medevac crashes in the United States in the past six years, fueled a national debate over the medical merits of transporting patients by helicopter, because the two patients on board were selected to fly based on the condition of their wrecked car rather than any apparent injuries. State officials appointed a seven-person panel last week to explore whether Maryland uses medical helicopters appropriately, including a doctor whose research has raised doubts about whether helicopters are helpful in treating trauma patients.
Yesterday's report added detail to another question the panel will consider - whether helicopters deliver patients to a hospital faster than ground ambulances.
Maryland's trauma triage guidelines say patients should be driven to a hospital unless the drive will take more than 30 minutes. The 32-mile drive from the scene of the Sept. 28 car accident to Prince George's Hospital Center takes 42 minutes, according to a Mapquest search. The helicopter waited 30 minutes at the scene before taking off with the two patients on board, according to the NTSB report.
State police spokesman Greg Shipley said numerous factors could cause such a delay, including difficulty removing victims from the crash and preparing them for flight, but he did not know enough details about the Sept. 28 incident to comment.