Alaska

The commercial pilot departed with five passengers on an on-demand air taxi flight between two remote Alaskan villages separated by mountainous terrain. When the airplane did not reach its destination, the operator reported the airplane overdue. After an extensive search, the airplane's wreckage was discovered in an area of steep, tree-covered terrain, about 1,720 feet msl, along the pilot's anticipated flight path. The flight was conducted under visual flight rules, but weather conditions in the area were reported as low ceilings and reduced visibility due to rain, fog, and mist. There is no record that the pilot obtained a weather briefing before departing. According to a passenger who was seated in the front, right seat, next to the pilot, about 20 minutes after departure, as the flight progressed into mountainous terrain, low clouds, rain and fog restricted the visibility. At one point, the pilot told the passenger, in part: "This is getting pretty bad." The pilot then descended and flew the airplane very close to the ground, then climbed the airplane, and then descended again. Moments later, the airplane entered "whiteout conditions," according to the passenger. The next thing the passenger recalled was looking out the front windscreen and, just before impact, seeing the mountainside suddenly appear out of the fog. A postaccident examination did not reveal any evidence of a mechanical malfunction. A weather study identified instrument meteorological conditions in the area at the time of the accident. Given the lack of mechanical deficiencies with the airplane and the passenger's account of the accident, it is likely that the pilot flew into instrument meteorological conditions while en route to his destination, and subsequently collided with mountainous terrain.

According to the captain, while on approach to land, he distracted the crew by pointing out a boat dock. He said that after touchdown, he realized that the landing gear was not extended, and the airplane slid on its belly, sustaining substantial damage to the underside of the fuselage. He said that the crew did not hear the landing gear retracted warning horn, and the accident could have been prevented if he had not distracted the crew. The captain reported that there were no mechanical malfunctions with the airplane that would have precluded normal operation.

The pilot indicated that, prior to the accident flight, the wing flaps had failed, but he decided to proceed with the flight contrary to the Airplane Flight Manual guidance. While conducting a no-flap approach to the airport, he decided that his airspeed was too fast to land, and he initiated a go-around. During the go-around, the airplane continued to descend, and the fuselage struck the runway. The pilot was able to complete the go-around, and realized that he had not extended the landing gear. He lowered the landing gear, and landed the airplane uneventfully. He elected to remain overnight at the airport due to fatigue. The next day, he decided to test fly the airplane. During the takeoff roll, the airplane had a severe vibration, and he aborted the takeoff. During a subsequent inspection, an aviation mechanic discovered that the center wing carry-through cracked when the belly skid pad deflected up into a stringer during the gear-up landing.

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 pilot reported that the runway at the destination airport was ice-covered, and that upon touchdown the surface was slicker than he had anticipated. He aborted the landing by applying full power to take off. The airplane was unable to out-climb the rising terrain at the end of the runway, and it collided with terrain, sustaining substantial damage to the fuselage and both wings. The pilot indicated that there were no mechanical issues with the airplane that precluded its normal operation.

Shortly after take off from runway 20, aircraft hit tree tops, stalled and crashed in a wooded area near the airport. Both passenger were slightly injured while the pilot was seriously injured. Aircraft was damaged beyond repair. The director of operations for the operator stated that soft field conditions and standing water on the runway slowed the airplane during the takeoff roll. The airplane did not lift off in time to clear trees at the end of the runway and sustained substantial damage to both wings and the fuselage when it collided with the trees. The pilot reported that he used partial power at the beginning of the takeoff roll to avoid hitting standing water on the runway with full power. After passing most of the water, he applied full power, but the airplane did not accelerate like he thought it would. He recalled the airplane being in a nose-high attitude and the main wheels bouncing several times before the airplane impacted the trees at the end of the runway.

The commercial pilot departed a remote, oceanside lagoon in a float-equipped airplane with three passengers on an on-demand air taxi flight in reduced visibility and heavy rain. When the airplane did not reach its destination, the operator reported the airplane overdue. Extensive search-and-rescue efforts along the coast and inland failed to find the wreckage. After the search ended, small portions of the fragmented airplane washed ashore about 28 miles northeast of the departure lagoon. The remainder of wreckage has not been located despite sonar searches of the ocean near where the wreckage was found. A stowed tent and duffel bag, which were reported to be aboard the airplane, were also found ashore near the wreckage location. The tent and duffel bag exhibited evidence of exposure to a high temperature environment, such as a fire. However, there was no evidence indicating that the fire occurred in flight. The lack of soot on the undamaged areas of the items, as well as the very abrupt demarcation line between the damaged portion and the undamaged material, is consistent with these items floating in the water and being exposed to a fuel fire on the surface of the water, rather than having been exposed to a fire in the airplane’s cargo compartment. Due to the fragmentation of the recovered wreckage, it is likely that the airplane collided with ocean’s surface while in flight; however, because the engine and a majority of the wreckage have not been found, the sequence of events leading to the accident could not be determined.

On August 9, 2010, about 1442 Alaska daylight time, a single-engine, turbine-powered, amphibious float-equipped de Havilland DHC-3T airplane, N455A, impacted mountainous, tree-covered terrain about 10 nautical miles (nm) northeast of Aleknagik, Alaska. The airline transport pilot and four passengers received fatal injuries, and four passengers received serious injuries. The airplane sustained substantial damage, including deformation and breaching of the fuselage. The flight was operated by GCI Communication Corp. (GCI), of Anchorage, Alaska, under the provisions of 14 Code of Federal Regulations (CFR) Part 91. About the time of the accident, meteorological conditions that met the criteria for marginal visual flight rules (MVFR) were reported at Dillingham Airport (DLG), Dillingham, Alaska, about 18 nm south of the accident site. No flight plan was filed. The flight departed about 1427 from a GCI-owned private lodge on the shore of Lake Nerka and was en route to a remote sport fishing camp about 52 nm southeast on the Nushagak River. According to GCI lodge personnel, the purpose of the flight was to transport the lodge guests to the fishing camp for an afternoon of fishing. The GCI lodge manager stated that the accident pilot had flown previously that morning in the accident airplane to DLG, where he dropped off another GCI pilot and then returned to the lodge. Sky Connect tracking system data for the accident airplane showed that, on that previous trip, the accident pilot departed the lodge for DLG about 0902 and returned about 1120. A review of DLG flight service station (FSS) recordings revealed that, about 1105, during the return flight from DLG to the lodge, the accident pilot filed a pilot report (PIREP) in which he reported ceilings at 500 feet, visibility of 2 to 3 miles in light rain, and “extremely irritating…continuous light chop” turbulence that he described as “kind of that shove-around type stuff rather than just bumps.” According to GCI lodge personnel, when the pilot returned to the lodge, he stated that the weather was not conducive for a flight to the fishing camp because of the turbulence and low ceilings. Passengers from the accident flight and GCI personnel indicated during postaccident interviews that, by the time that they had lunch about 1300, the weather had improved, and the group discussed with the pilot the option of going to the fishing camp. One passenger characterized the conversation as casual and stated that no pressure was placed on the pilot to make the flight or to depart by a certain time. The GCI lodge manager and some passengers stated that they thought that the pilot checked the weather on the computer during lunch, and the guest party co-host (one of GCI’s senior vice presidents) stated that the pilot informed him about 1400 that he was comfortable taking the group to the fishing camp if the group wanted to go. The GCI lodge manager stated that, before the airplane departed, he sent an e-mail to the fishing camp to indicate that the guests were coming, and personnel there informed him that the pilot had already contacted them. The lodge manager stated that he went down to the dock to help push the airplane off and that, when the flight departed, he could see all of Jackknife Mountain across the lake. (The mountain’s highest peak, which is about 3 nm from the dock, is depicted as 2,326 feet above mean sea level [msl] on an aviation sectional chart, and the elevation of Lake Nerka is depicted as about 40 feet msl on a topographical map.) He stated that the weather included broken ceilings about 2,000 feet above ground level (agl) with some blue patches in the sky and good visibility. The flight route from the lodge to the fishing camp traversed Class G airspace; 14 CFR 91.155 specifies that, for daytime flights below 1,200 feet agl, the flight must be flown clear of clouds and in conditions that allow at least 1 mile flight visibility. During a postaccident interview, the passenger who was in the right cockpit seat stated that, when the airplane departed, the visibility was “fine.” He stated that the pilot went a different direction during takeoff (compared to the passenger’s experiences during previous flights to the fishing camp) and that the pilot said it was to avoid “wind and weather.” The passenger described the weather as cloudy above with light turbulence. He stated that the airplane stayed below the clouds and that he noticed water “running across” the outside of the windshield before he fell asleep about 10 minutes into the flight. Another passenger, who was seated in the second seat behind the pilot on the left side of the airplane, stated that some fog was present beneath the airplane but that he did not think that the airplane flew into any clouds. He estimated that he fell asleep about 3 to 4 minutes after departure. The passenger who was in the first seat behind the pilot on the left side of the airplane stated in an initial interview that he could not see well out his side window and that he had no indication of the weather; however, in a subsequent interview, he stated that, once the airplane was airborne, he could not see the ground and could see only “white-out” conditions outside the airplane. He stated in the subsequent interview that he did not know if the airplane had climbed into clouds initially or if it had entered clouds at some point along the way. The passenger who was in the third seat behind the pilot on the left side of the airplane stated that the pilot kept the airplane below the cloud ceiling and flew along the tree line, followed streams, and maneuvered to avoid terrain. The passenger stated that the airplane banked into a left turn (he said that the bank angle was not unusual) and then immediately impacted terrain. Neither he nor the other passenger who was awake at the time of impact recalled noticing any unusual maneuvering, unusual bank or pitch angles, or change in engine noises that would indicate any problem before the airplane impacted terrain. The wreckage was found at an elevation of about 950 feet msl in steep, wooded terrain in the Muklung Hills, about 16 nm southeast of the GCI lodge. Figure 1 shows the accident site (view looking north-northwest).

The pilot, co-pilot and the passenger departed on a day VFR cross country flight in a large, 1950's era former military transportb category airplane to deliver cargo. The pilot did not file a flight plan, and had no communication with any air traffic control facility during the flight. While en route, witnesses saw the airplane fly slowly across a valley near the entrance of a national park, which was not the intended route of flight. The airplane suddenly pitched up, stalled, and dived into wooded terrain within the park. Two pilot-rated witnesses said the engines were operating at the time of the accident, and the landing gear was retracted. An on-scene examination of the burned airplane structure and engines revealed no evidence of any preaccident mechanical deficiencies, or any evidence that the cargo had shifted during the flight. A former military pilot who had experience in the accident type airplane, stated that the airplane was considered unrecoverable from a stall, and for that reason, pilots did not typically practice stalls in it. He also indicated that if a problem was encountered with one of the two piston engines on the airplane, the auxiliary jet engine on the affected side should be started to provide additional thrust. Given the lack of mechanical deficiencies discovered during postaccident inspection, the absence of any distress communications, and the fact that neither of the two auxiliary jet engines had been started to assist in the event of a piston engine malfunction, it is likely the pilot allowed the airplane to lose airspeed and enter a low altitude stall from which he was unable to recover.

The crew was engaged in a training exercise in preparation to the 'Thunder Air Show' taking part at Elmendorf-Richardson AFB on 31JUL2010. Shortly after take off from runway 06, the pilot-in-command initiated a first turn to the left then a steep turn to the right when the aircraft entered an uncontrolled descent and crashed in a huge explosion in a wooded area located some 3 km northwest of the airbase. The aircraft was totally destroyed by impact forces and a post crash fire and all four crew members were killed.