The pilot had worked a 10-hour shift the day of the accident and had been off duty for about two hours when the chief pilot called him around midnight to transport a patient. The pilot accepted the flight, and about two hours later he was conducting an instrument approach to Atqasuk airport to pick up the patient. The pilot reported receiving his clearance for a GPS Runway 6 approach about 35 miles from the airport. He remained above 2,200 feet–just above the cloud tops–in the descent, most likely to remain clear of the ice. Before the initial approach fix he did descend to 2,000 feet, putting the aircraft in the clouds.
He turned on all of the anti-ice and de-ice systems, and these appeared to be shedding ice almost completely, the pilot reported. He extended the flaps and lowered the landing gear to descend and added power. The airspeed continued to decrease, however, as the airplane descended. The pilot raised the flaps and landing gear and applied full climb power. The airplane shuddered as it climbed and the airspeed continued dropping. When the stall warning activated, the pilot lowered the nose to increase the airspeed, but the aircraft continued descending until it struck the level, snow-covered terrain. The pilot did not indicate any mechanical issues with the airplane.
The aircraft satellite tracking and engine and flight control monitoring were used in the investigation. The minimum safe operating speed for the airplane in continuous icing conditions is listed as 140 kias. The King Air’s IAS fell below 140 knots four minutes before impact. During the last minute of flight, the IAS varied from a high of 124.5 knots to a low of 64.6 knots and the vertical speed varied from +1,965 fpm to -2,464 fpm. The last data recorded showed the airplane at 68 kias, descending at 1,651 fpm with the nose pitched up 20 degrees.
The chief pilot reported pilots were on call 14 consecutive 24-hour periods before receiving two weeks off. He said the accident pilot had worked the previous day, but stated he was rested enough to accept the mission. The chief pilot indicated he was aware that sleep cycles and circadian rhythms are disturbed by varied and prolonged activity.
The operator’s management said it does not prioritize patient transportation with regard to medical condition but bases transport decisions on medical staff requests and the availability of a pilot, aircraft and suitable weather. The NTSB said that given the long duty day and the early-morning departure time of the flight, it is likely the pilot experienced significant fatigue that substantially degraded his ability to monitor the airplane during a dark night instrument flight in icing conditions.
One of the NTSB’s safety recommendations (A-06-13) stemming from the crash addresses the importance of conducting a thorough risk assessment before accepting a flight. The safety recommendation asks the FAA to “require all emergency medical services (EMS) operators develop and implement flight risk evaluation programs that include training all employees involved in the operation and procedures that support the systematic evaluation of flight risks, and consultation with others trained in EMS flight operations if the risks reach a predefined level.” Had such a thorough risk assessment been performed, the decision to launch a fatigued pilot into icing conditions late at night might have been different or additional precautions might have been taken to alleviate the risk.
The NTSB is also concerned that the pressure to conduct EMS operations safely and quickly in various environmental conditions elevates the risk of accidents when compared with other methods of patient transport. However, guidelines vary greatly for determining the mode of and need for transportation. Thus, the NTSB recommends in A-09-103 that the Federal Interagency Committee on Emergency Medical Services (Ficems) “develop national guidelines for the selection of appropriate emergency transportation modes for urgent care.” The most recent correspondence from Ficems indicated that the guidelines are close to being finalized and distributed to members. Such guidance will help hospitals and physicians assess the appropriate mode of transport for patients.
This material is based on the NTSB’s report (preliminary, factual or final) of each accident or, in the case of recent accidents, on information obtained from the FAA or local authorities. It is not intended to judge or evaluate the ability of any person, living or dead, and is presented here for informational purposes.
