FREDERICK, Md. -- Authorities recovered a wealth of data that should help them determine why a plane and a helicopter collided in the air near a municipal airport, killing three people on the chopper, a federal investigator said Friday.
The plane was intact to the point that investigators can retrieve data about air speed, altitude and pitch, said Brian Rayner of the National Transportation Safety Board.
"Right now it's sort of a confusing blend of dots" that will take time to sort out, Rayner said. A final report on the cause is probably a year away.
The two men aboard the small plane, a Cirrus SR22, survived after the pilot deployed a parachute to slow its descent. The plane landed in some trees. The helicopter was demolished.
Rayner did not provide details about the crash, including the altitude at the point of collision. He said investigators were talking to air traffic controllers at Frederick Municipal Airport. Thus far, there was no information that either pilot signaled any kind of distress, Rayner said.
A transcript of the control tower conversation provided by LiveATC.net indicated the tower was working with two airplanes and three helicopters shortly before the crash.
"I have three helicopters below you in the traffic pattern," the controller tells an inbound airplane.
"I have two of 'em in sight," the pilot responds.
The controller then gave the airplane clearance to land. In the next second, the audio is overtaken by someone screaming, "Oh, God! Oh, God!"
The dead were identified as Christopher Parsons, 29, of Westminster, Breandan McFawn, 35, of Cumberland; and William Jenkins, 47, of Morrison, Colorado.
The plane's pilot, Scott Graeves, 55, of Brookeville, and his passenger, Gilbert Porter, 75, of Sandy Spring, were treated at a hospital and released, according to state police.
Messages left at their homes were not immediately returned.
The helicopter was leased to Advanced Helicopter Concepts, a flight school at the airport. Chris Hollingshead, an employee, said Parsons was an experienced flight instructor and Jenkins was on board to see if everything was in order for it to be rented out. Hollingshead said McFawn was a passenger but did not make clear whether Parsons or Jenkins was flying the helicopter. He did not answer questions.
Rayner said Friday that he did not know who was piloting the helicopter, either.
Parsons decided to become a helicopter pilot during his service in the Marines, and was looking forward to helping students begin their own careers, the company's website said.
"This is a horrible day," Hollingshead said.
A helicopter of the same make and model, also operated by Advanced Helicopter, crashed in 2009 on Interstate 70 about 15 miles west of Frederick, killing all four people aboard. The NTSB ruled that crash an accident due to poor nighttime visibility on a fog-shrouded mountain. The weather Thursday was cloudy and breezy, and Rayner said it did not seem to be a factor.
Jesse Ault Jr. saw the airplane "spiraling out of control" before the crash.
"The pilot had blood up above his nose and on his face," Ault said. "You could tell he was visibly shaken."