Published October 8, 2009 (AP)

WASHINGTON — A medical helicopter that crashed in South Carolina last month, killing three crew members, lacked safety features recommended by experts, a federal official said Thursday.

National Transportation Safety Board spokesman Peter Knudson told The Washington Post for a story posted on its Web site that the helicopter did not have night-vision equipment or a system to warn the crew that it was flying too close to obstacles or the ground. The NTSB has urged medical helicopter programs to adopt each of those features, saying they could have prevented some accidents.

Neither a call nor e-mail placed by The Associated Press to Knudson was immediately returned.

The helicopter had just dropped off a patient at a Charleston hospital on Sept. 25 and was flying to Conway, about 90 miles to the northeast, when it crashed in Georgetown County.

NTSB board member Robert Sumwalt had said the helicopter had flown between two intense thunderstorms and it was raining when it crashed. He could not say if the conditions were a factor and no cause has been determined.

In addition, the weather station at the Georgetown County Airport was not working because of a lightning strike Sept. 4 “that completely fried the equipment” and was awaiting repairs, said Jamey Kempson, an airport engineer with the South Carolina Aeronautics Commission.

Prior to the crash, the Federal Aviation Administration said the pilot last radioed air traffic control at 11:05 p.m., saying the crew was about four miles from an airport near Charleston and had it in sight. It crashed about 25 minutes later.

Crew members killed were pilot Patrick Walters, 45, of Murrells Inlet; flight nurse Diana Conner, 42, of Florence; and paramedic Randolph Claxton Dove, 39, of Bladenboro, N.C.