Frustration's Ill Effects
Frustration. Webster's defines it as a deep, chronic sense or state of insecurity and dissatisfaction arising from unresolved problems or unfulfilled needs. It is not a word often associated with helicopter accidents. When pilots make errors, we normally hear words like judgment, experience and risk. However, consider what happened to this pilot.
According to the National Transportation Safety Board, early on July 21, 2001 the pilot of a Sikorsky S-76A had completed a nighttime air taxi flight. After deplaning his passengers and returning to the cockpit, the pilot was preparing to depart an elevated helipad to reposition the helicopter to the operator's base when he noticed a "door unsecured" indication on the instrument panel for the left cabin door. The passengers had deplaned through the right-hand door and the left door annunciation had not been on during the inbound flight. He thought one of the passengers might have released the left door latch inadvertently while preparing to deplane. He idled the engines and exited the cockpit to check the door. He re-closed the door and returned to the cockpit. However, the door open annunciation came on again. He recalled leaving the cockpit two or three times to deal with the door. He did not recall retarding the engine power control levers to ground idle before leaving the cockpit the final time.
The wheel-equipped helicopter started to move this time as the pilot was returning to the cockpit. He stated it was moving toward the edge of the helipad. He returned to the cockpit, but before he could regain control--at 0049 local time--there was a confusing sequence of events. The next thing he knew the helicopter was on its side. The pilot reported there were no mechanical discrepancies with the helicopter up to the time of the event. He remarked that it was very lightweight with no one else on board. On the deck of the helipad, there was a tire skid pattern consistent with a dynamic rollover event. The engine power control levers were found in the fly position.
After the events ceased, the pilot recalled he was loose inside the cockpit, unrestrained by his seat belts. He was disoriented in the darkness and had trouble finding the fuel shutoff levers, and didn't know how he got out of the helicopter. He recalled trying to kick out the windshield and being concerned that the helicopter would either catch fire or roll off the elevated helipad. The certificated airline transport pilot, the sole occupant, received minor injuries and the helicopter was substantially damaged.
The NTSB determined the probable cause of this accident was the failure of the pilot to reduce the engine power control levers to ground idle prior to leaving the helicopter, resulting in the unmanned helicopter moving on the helipad and performing a dynamic rollover.
During an interview in the hospital emergency room about 3 hr. after the accident, the pilot said he was "frustrated with it." He also stated he was not fatigued, had rested well the night of July 19 and awoke at 0830 or 0900 on July 20. According to duty time records provided by the operator, the pilot had worked each of the eight preceding days. His duty time was 8-13 hr. each day. His total flight time for the eight-day period was 14.6 hr. The pilot reported for duty on July 20 at 1330, after resting for more 17 hr.
Just what caused this experienced pilot to allow the situation to deteriorate so badly? According to the pilot's own admission and the Federal Aviation Regulations regarding rest and duty time, fatigue doesn't seem to be the smoking gun. However, fixation, distractibility, neglect of secondary tasks and irritability are all characteristics that seem to have played a role in this accident. Interestingly enough, these are also the mental deficits that are apparent to others before an individual notices any physical signs of fatigue. In fact, a summary of effects of fatigue on performance published by the University of Denver states that human beings are not very good at estimating their current level of alertness. Also noted was an article by David Dinges of the University of Pennsylvania that states the longer someone is awake beyond 14-16 hr., the greater the occurrence of fatigue lapses.
Something as simple and frustrating as a persistent door light might just be enough to trigger the effects of fatigue in a person who has been awake 16 hr. but who otherwise feels alert. The effects of fatigue on the human mind are complex and hard to quantify. Unlike drugs and alcohol, there are no tests to determine what, if any, role fatigue plays in a specific accident. Anytime that feeling of frustration starts, it should be a sign to slow down and reassess the situation. As we have seen here, the consequences of not quickly recognizing and correcting this emotion can be enormous.