Originally Published: August 20, 2009 10:58 p.m.
PRESCOTT - It will be six months to a year before the public knows what caused pilot Thomas Armor, 66, to crash a Piper Comanche airplane Monday at Prescott Airport, killing himself and passenger Marvin Loper, 74 (see story, "Airplane crash at Prescott Airport kills 2").
"It could be any number of things," said Bob Fiegl, chairman of the aeronautical science department at Embry-Riddle Aeronautical University. "It could be a mechanical malfunction, a problem with the instruments, the pilot could have felt a vibration or a physiological (medical) problem with the pilot."
The National Transportation Safety Board (NTSB) sent a "go team" Monday to investigate the accident.
"They (NTSB) own the airplane and the ground around it until they release it back to us," said Ben Vardiman, Prescott Airport manager. "They released the ground back to us Wednesday afternoon. We're going to take soil samples to make sure there is not any unburned fuel left on the ground."
"The Federal Aviation Administration is the regulatory body, and the NTSB is the investigative body," Fiegl said.
However, the FAA releases a preliminary report within hours of a mishap and identifies it as an "accident" or an "incident."
The NTSB defines an accident as "an occurrence" that results in a person dying or suffering serious injury, or when an aircraft "receives substantial damage." An incident is any occurrence that does not qualify as an accident.
The FAA's preliminary report for Monday's Piper crash, tail number N6304P, reads, "Aircraft was attempting to return to the airport shortly after takeoff and crashed near the approach end of runway 30, Love Field Airport, Prescott, AZ."
Vardiman said it has been at least three years since anyone died in a plane crash at the Prescott Airport.
"In a textbook example, a pilot would declare an emergency and the tower would offer an emergency runway," Fiegl said. "But in the real world, you have very few options at takeoff. In aviation we have an axiom: aviate, navigate, communicate."
Between Aug. 6 and Aug. 19, the FAA wrote 129 aircraft accident or incident preliminary reports. So far in 2009, the NTSB reported 1,649 civilian aviation accidents involving 495 fatalities.
An NTSB investigation is time-consuming and thorough, Fiegl said.
"They'll investigate the wreckage, look for abnormalities, send out the engine to take apart, look at the propeller pitch, position of the controls and gauges," he explained.
The investigation also includes the control tower operation at the time of the crash, weather, the structure of the airframe and the pilot's history a few days prior to the crash.
"Big accidents could take years to write the final report," Fiegl added.
An eyewitness to Monday's crash said that the plane appeared to stall while it was turning around. But Fiegl and other aviation experts said that any explanation is speculation until the NTSB's final report.
"An accident is usually the result of an unbroken chain of events," Fiegl said. "It rarely is the result of just one thing. It's a chain of events that culminate in an accident."