The NTSB’s first investigation of an unmanned aircraft accident highlighted a problem that many have worried about and that the FAA has yet to address: the different standards applied to manned aircraft versus unmanned aircraft (UA) operations. It has long been the case that accidents that result in the deaths of many people gain far more attention than accidents involving fewer fatalities. The different standards, either overt or unacknowledged, between passenger and cargo operations illustrate how the safety approach varies depending on whether the cargo is people or freight. The growing popularity of UAs with military and government agencies has resulted in a dichotomy in the application of safety standards, according to the NTSB.
A U.S. Customs and Border Protection turboprop General Atomics Predator B on an IFR flight plan crashed on April 25, 2006, in a residential area near Nogales, Ariz., after the pilot’s console locked up and the switch to a backup console failed due to improperly performed emergency procedures. Probable cause of the accident, according to the NTSB, “was the pilot’s failure to use checklist procedures when switching operational control from a console that had become inoperable due to a ‘lock-up’ condition, which resulted in the fuel valve inadvertently being shut off and the subsequent total loss of engine power, and a lack of a flight instructor in the ground control station.”
Standardizing the Rules
Safety Board chairman Mark Rosenker asked why standards are different for manned and unmanned aircraft, citing the example of repetitive console lock-ups as a key issue. “Why,” he asked, “were numerous unresolved lock-ups of the pilot’s control console even possible while such conditions would never be tolerated in the cockpit of a manned aircraft?”
The NTSB also expressed concern about the pilot’s lack of proficiency in emergency procedures. “The pilot is still the pilot, whether he is at a remote console or on the flight deck,” said Rosenker.
The pilot admitted that during the accident flight he did not use the required checklist when switching control from his console (PPO-1) to the other console (PPO-2), which is normally used to operate the UA’s camera. Before switching control, both sets of controls on the two consoles must be matched, but the pilot told the NTSB that “he was in a ‘hurry’ and that he failed to do this.
The condition lever on PPO-2 was in the fuel cutoff position when control was transferred from PPO-1 to PPO-2. As a result, the fuel was cut off to the UA engine when control moved to PPO-2.” The condition lever on the second console is used to control the camera’s iris so it wouldn’t necessarily match the position of the condition lever on PPO-1.
The NTSB issued 22 safety recommendations as a result of its investigation. To the FAA, it suggested that all communications between UA pilots, ATC, other UA pilots and support personnel be recorded and retained; that procedures used for manned aircraft emergencies be applied to UAs; and that all UA operators report all incidents and malfunctions that affect safety to the FAA, which should analyze this data “to determine whether programs and procedures remain effective in mitigating safety risks.”