Barrow

The pilot had worked a 10-hour shift the day of the accident and had been off duty about 2 hours when the chief pilot called him around midnight to transport a patient. The pilot accepted the flight and, about 2 hours later, was on an instrument approach to the airport to pick up the patient. While on the instrument approach, all of the anti-ice and deice systems were turned on. The pilot said that the deice boots seemed to be shedding the ice almost completely. He extended the flaps and lowered the landing gear to descend; he then added power, but the airspeed continued to decrease. The airplane continued to descend, and he raised the flaps and landing gear and applied full climb power. The airplane shuddered as it climbed, and the airspeed continued to decrease. The stall warning horn came on, and the pilot lowered the nose to increase the airspeed. The airplane descended until it impacted level, snow-covered terrain. The airplane was equipped with satellite tracking and engine and flight control monitoring. The minimum safe operating speed for the airplane in continuous icing conditions is 140 knots indicated airspeed. The airplane's IAS dropped below 140 knots 4 minutes prior to impact. During the last 1 minute of flight, the indicated airspeed varied from a high of 124.5 knots to a low of 64.6 knots, and the vertical speed varied from 1,965 feet per minute to -2,464 feet per minute. The last data recorded prior to the impact showed that the airplane was at an indicated airspeed of 68 knots, descending at 1,651 feet per minute, and the nose was pitched up at 20 degrees. The pilot did not indicate that there were any mechanical issues with the airplane. The chief pilot reported that pilots are on call for 14 consecutive 24-hour periods before receiving two weeks off. He said that the accident pilot had worked the previous day but that the pilot stated that 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. An NTSB study found that pilots with more than 12 hours of time since waking made significantly more procedural and tactical decision errors than pilots with less than 12 hours of time since waking. A 2000 FAA study found accidents to be more prevalent among pilots who had been on duty for more than 10 hours, and a study by the U.S. Naval Safety Center found that pilots who were on duty for more than 10 of the last 24 hours were more likely to be involved in pilot-at-fault accidents than pilots who had less duty time. The operator’s management stated that they do not prioritize patient transportation with regard to their medical condition but base their decision to transport on a request from medical staff and availability of a pilot and aircraft, and suitable weather. The morning of the accident, the patient subsequently took a commercial flight to another hospital to receive medical treatment for his non-critical injury/illness. Given the long duty day and the early morning departure time of the flight, it is likely the pilot experienced significant levels of fatigue that substantially degraded his ability to monitor the airplane during a dark night instrument flight in icing conditions. The NTSB has issued numerous recommendations to improve emergency medical services aviation operations. One safety recommendation (A-06-13) addresses the importance of conducting a thorough risk assessment before accepting a flight. The safety recommendation asked the Federal Aviation Administration to "require all emergency medical services (EMS) operators to develop and implement flight risk evaluation programs that include training all employees involved in the operation, 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 may have been different or additional precautions may 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 (for example, in inclement weather and at night) increases the risk of accidents when compared to other types of patient transport methods, including ground ambulances or commercial flights. However, guidelines vary greatly for determining the mode of and need for transportation. Thus, the NTSB recommended, in safety recommendation 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.

The certificated airline transport pilot, with one non-revenue passenger, departed in the twin engine turboprop airplane from a rural airport on a CFR Part 135, VFR cargo flight over ocean waters. The flight did not reach its destination, and was reported overdue. Search personnel searched along the airplane's anticipated route of flight, over ocean waters. Shortly after initiation of the search, airborne search personnel reported sighting floating debris, consisting of what appeared to be aircraft seats, cardboard boxes, and small portions of aircraft wreckage, about 30.5 miles southwest of the flight's departure airport, and about 10 miles from shore. The airplane is presumed to have sunk in ocean waters estimated to be between 50 and 70 feet deep. Underwater search and recovery efforts were unsuccessful, and the airplane, pilot, and passenger remain missing. A review of archived radar data disclosed that as the accident airplane approached an area about 30.5 miles southwest of the departure airport, it descended to 500 feet msl, and then entered a right turn. As the turn progressed, the airplane continued to descend to 400 feet msl, with a radar-derived ground speed of 180 knots. The last radar return was recorded with the same radar-derived groundspeed, on an approximate heading of 200 degrees. A pilot who is familiar with geographical locations in the area reported that migrating whales are commonly sighted in the area where the radar depicted a descending right turn.

The aircraft was engaged in an expedition over the Arctic and was completing a flight from Longyearbyen (Spitzberg Islands) to Barrow, Alaska, with another Cessna 185. The crew of the Cessna landed first to check the ice thickness. When the AN-2 landed, the ice started to crack. The pilot attempted to takeoff but the undercarriage went through the ice and the aircraft came to rest partially submerged in water. All five occupants escaped uninjured while the aircraft was damaged beyond repair.

The pilot, who was also the station manager, arrived at the airport earlier than other company employees to prepare for a scheduled commuter flight, transporting seven passengers and cargo to another village during hours of arctic, predawn darkness. Heavy frost was described on vehicles and airplanes the morning of the accident, and the lineman who serviced the airplane described a thin glaze of ice on the upper surface of the left wing. The pilot was not observed deicing the airplane prior to flight, and was described by the other employees as in a hurry to depart on time. The pilot directed the lineman to place fuel in the left wing only, which resulted in a fuel imbalance between 450 and 991 pounds (left wing heavy). The first turn after takeoff was into the heavy left wing. The airplane was observed climbing past the end of the runway, and descending vertically into the water. No preimpact mechanical anomalies were found with the airplane or powerplant. The aileron trim indicator was found in the full right wing down position. Postaccident flight tests with left wing heavy lateral fuel imbalances, disclosed that approximately one-half of right wing down aileron control deflection was used to maintain level flight, thus leaving only one-half right wing down aileron control efficacy. Research has shown that frost on airfoils can result in reduced stall angles of attack (often below that required to activate stall warning devices), increases in stall speeds between 20% and 40%, asymmetric stalls resulting in large rolling moments, and differing stall angles of attack for wings with upward and downward deflected ailerons (as when recovering from turns).

The pilot had contacted the FSS 11 times on the day of the accident to obtain weather briefings. The conditions were below VFR minimums, which were required to conduct the passenger carrying commercial flight in a single-engine airplane. The conditions later improved and the pilot departed under a special VFR clearance. The pilot performed two approaches at the destination airport in IMC that were consistent with the two GPS approaches that were available there. Weather data and witnesses indicate that daylight conditions, low clouds and poor visibility prevailed, with cloud tops at 1,000 feet. After the second approach, the pilot radioed that he was heading back to the departure airport because he could not see the airport. No distress calls or unusual engine noises were heard. The airplane subsequently flew north of the airport and away from the departure airport at an altitude beneath the minimum radar coverage of 2,200 feet. It impacted the frozen Arctic Ocean in a right bank and at a 60-degree nose-down attitude about three miles away from the location of the pilot's last radio transmission. An examination of the airplane (before it sank through cracking ice) revealed no pre-impact mechanical malfunctions. An examination of the propeller revealed that it was under a power setting consistent with a maneuvering airspeed at the time of impact. An examination of the autopilot annunciator filament revealed that the autopilot was not engaged at impact. The airplane was nearly full of fuel and over its published maximum gross weight at impact. Small pieces of clear ice, about 1/4-inch thick, were found on portions of the tail surfaces. Interviews with operator employees and the pilot's wife revealed that the pilot may have felt pressure from himself and passengers to complete the flight.

While cruising in poor weather conditions on a cargo flight from Barrow to Fairbanks, the twin engine airplane struck trees and crashed in a wooded and hilly terrain located near a pipeline, in the region of Livengood. The pilot, sole on board, was killed.

On final approach to Kotzebue-Ralph Wien Memorial Airport in good weather conditions, the pilot failed to realize his altitude was too low. The twin engine airplane struck the water surface and crashed short of runway threshold. All six occupants were rescued.

The twin engine airplane was completing a taxi flight from Anaktuvuk Pass to Barrow. On final approach to Barrow Airport in icing conditions, the airplane stalled and crashed in flames short of runway. The aircraft was destroyed, the pilot was killed and the passenger was seriously injured.

On final approach to Barrow, the crew failed to realize the configuration was wrong. Few dozen yards short of runway threshold, the airplane struck a snowbank, lost its undercarriage and its left wing before bursting into flames. All three crew members were injured and the aircraft was destroyed.

On final approach to Barrow, an engine failed. The crew reduced his altitude and attempted an emergency landing. The airplane crash landed and slid for dozen yards before coming to rest few hundred yards short of runway threshold. All 10 occupants evacuated safely while the aircraft was damaged beyond repair.