Alaska

On October 17, 2019, a Saab SA-2000 airplane, operated by Peninsula Aviation Services Inc. d.b.a. PenAir flight 3296, overran the end of runway 13 at Unalaska Airport (DUT), Unalaska, Alaska. The flight crew executed a go-around during the first approach to runway 13; the airplane then entered the traffic pattern for a second landing attempt on the same runway. Shortly before landing, the flight crew learned that the wind at midfield was from 300° at 24 knots, indicating that a significant tailwind would be present during the landing. Because an airplane requires more runway length to decelerate and stop when a tailwind is present during landing, a landing in the opposite direction (on runway 31) would have favored the wind at the time. However, the flight crew continued with the plan to land on runway 13. Our postaccident calculations showed that, when the airplane touched down on the runway, the tailwind was 15 knots. The captain reported after the accident that the initial braking action after touchdown was normal but that, as the airplane traveled down the runway, the airplane had “zero braking” despite the application of maximum brakes. The airplane subsequently overran the end of the runway and the adjacent 300-ft runway safety area (RSA), which was designed to reduce airplane damage during an overrun, and came to rest beyond the airport property. The airplane was substantially damaged during the runway overrun; as a result, of the 3 crewmembers and 39 passengers aboard, 1 passenger sustained fatal injuries, and 1 passenger sustained serious injuries. Eight passengers sustained minor injuries, most of which occurred during the evacuation. The crewmembers and 29 passengers were not injured.

The flight crew was landing the transport-category airplane at a remote, gravel-covered runway. According to the captain, the terrain on the approach to the runway sloped down toward the approach end, which positioned the airplane close to terrain during the final stages of the approach. A video recorded by a bystander showed that while the airplane was on short final approach, it flew low on the glidepath and dragged its landing gear through vegetation near the approach end of the runway. The video showed that, just before the main landing gear wheels reached the runway threshold, the right main landing wheel impacted a dirt and rock berm. The captain said that to keep the airplane from veering to the right, he placed the No. 1 and No. 2 engine propellers in reverse pitch. The flight engineer applied asymmetric reverse thrust to help correct for the right turning tendency, and the airplane tracked straight for about 2,000 ft. The video then showed that the right main landing gear assembly separated, and the airplane continued straight down the runway before veering to the right, exiting the runway, and spinning about 180°, resulting in substantial damage to the fuselage. On-site examination of the runway revealed several 4-ft piles of rocks and dirt at the runway threshold, which is likely what the right main landing wheel impacted. Given that the airplane landing gear struck vegetation and rocks on the approach to the runway, it is likely that they were below the proper glidepath for the approach. The crew stated there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.

The pilot stated that, during takeoff in the float-equipped airplane, he saw the left float begin to move into his peripheral vision from the left cockpit window and the airplane began to yaw to the left. The left wing subsequently impacted the water and the airplane nosed over, separating the right wing from the fuselage. The passengers consistently reported choppy water conditions at the time of the accident; one passenger reported that white caps were visible on the ocean waves in the distance. The passengers said that, during the takeoff, the airplane impacted a swell or wave and nosed over abruptly, and the cabin rapidly filled with water. Examination of the float assembly revealed fractures in the left front flying wire attachment fitting and the right rear flying wire attachment strap and hole elongation in the left rear flying wire attachment fitting. Additionally, the bolts attaching the two left flying wire attachment fittings to the left float were bent, and the two flying wires that had been attached to the fractured attachment fitting and attachment strap were buckled. While some areas of corrosion were observed on the fractured left forward fitting, the total area of corrosion was a small percentage of the total cross-section, and the remainder of the fracture and associated deformation of the lug was consistent with ductile overstress fracture. Similar areas of corrosion were also observed on each of the intact flying wire attachment fittings. Post-accident testing completed by the float manufacturer revealed that buckling of flying wires similar to that observed on the accident airplane was only reproduced at strap and fitting failure loads above 9,000 pounds force; the design specification load was 3,453 pounds of force. This indicates that the small amount of corrosion present on the fractured flying wire attachment fitting did not reduce its loadcarrying capability below the design specification load of 3,453 pounds of force, and that both the flying wire attachment fitting and flying wire attachment strap fractured due to overload. Therefore, it is likely that the accident airplane floats were subject to forces that exceeded their design limitations, resulting in overload of the flying wires attached to the left float. It is also likely that, given the lack of damage on either float, the force was due to impact with an ocean wave or swell and not by striking an object.

The commercial pilot was conducting a visual flight rules scheduled passenger flight with five passengers. During the return leg to the company’s base airport, the pilot requested, and was given clearance to, a short gravel runway of 1,858 ft that terminated at parallel cross-runways and had inbound airplanes. The wind was reported as variable at 3 knots, and the outside air temperature was 88°F which was 25° warmer than usual. The pilot stated that he conducted a steeper than normal approach and performed a normal 30° flap landing flare; however, the airplane floated halfway down the runway. He initiated a go-around by advancing the throttle to takeoff power and retracting the flaps to 20° as the main landing gear briefly touched down. Automatic dependent surveillance-broadcast (ADS-B) data indicated that the airplane arrived 0.1 mile from the runway threshold at 149 ft above ground level (agl) and 110 knots of ground speed, which was 32 knots faster than the short field landing approach speed listed in the pilot operating handbook. A witness in the air traffic control tower (the ground controller) stated that the airplane “bled off a lot of airspeed,” during the landing attempt and climbed out in a very flat profile. The tower local controller stated that after liftoff, the airplane’s right wing dropped and the airplane appeared to be turning right into conflicting landing traffic, so he twice instructed the airplane to “left turn out immediately.” The pilot stated that he attempted to comply with the tower controller’s instruction, but when he applied left aileron, the airplane appeared to stall, rolled rapidly right, and descended in a right-wing-low attitude. It subsequently impacted the surface between runways. A postimpact fire ensued, and the pilot helped the passengers egress. The airplane was destroyed by postimpact fire. Given the evidence, it is likely that the pilot decided to land on the short runway to expedite the arrival and did not perform an appropriate short field landing approach, which resulted in excessive airspeed and altitude over the runway threshold, a long landing flare, rapid deceleration, and a self-initiated go-around from a slow airspeed. Had the pilot initiated the go-around as he approached the runway with indications of an unstable visual approach, the airspeed would have been well above stall speed, which would have allowed for the desired positive climb out on runway heading. The pilot likely attempted to comply with the tower local controller’s urgent commands to turn while the airplane was near the limit of performance (the temperature was about 25 degrees warmer than average, which would have resulted in a higher density altitude than the pilot was accustomed to and degraded aircraft and engine performance). The pilot’s maneuvering resulted in the exceedance of the critical angle-of-attack of the high wing (right wing) during the left turn, and an aerodynamic stall.

The commercial pilot was conducting his first scheduled commuter flight from the company’s seaplane base to a nearby island seaplane base with one passenger and cargo onboard. According to company pilots, the destination harbor was prone to challenging downdrafts and changing wind conditions due to surrounding terrain. Multiple witnesses at the destination stated that the airplane made a westerly approach, and the wind was from the southeast with light chop on the water. Two witnesses reported the wings rocking left and right before touchdown. One witness stated that a wind gust pushed the tail up before the airplane landed. A different witness reported that the airplane was drifting right during the touchdown, and another witness saw the right (downwind) float submerge under water after touchdown, and the airplane nosed over as it pivoted around the right wingtip, which impacted the water. Flight track and performance data from the cockpit display units revealed that, as the airplane descended on the final approach, the wind changed from a right headwind of 6 knots to a left quartering tailwind of 8 knots before touchdown. The crosswind and tailwind components were within the airplane’s operational limitations. Examination of the airframe, engine, and associated systems revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation or egress. During the final approach and descent, the pilot had various wind information available to him; the sea surface wind waves and signatures, the nearest airport observation winds, the cockpit display calculated wind, and the visual relative ground speed. Had the pilot recognized that the winds had shifted to a quartering tailwind and the airplane’s ground speed was faster than normal, he could have aborted the landing and performed another approach into the wind. Although crosswind landings were practiced during flight training, tailwind landings were not because new pilots were not expected to perform them. Although the crosswind component was well within the airplane’s limits, it is possible that combined with the higher ground speed, the inexperienced pilot was unable to counteract the lateral drift during touchdown in a rapidly shifting wind. The pilot was hired the previous month with 5 hours of seaplane experience, and he completed company-required training and competency checks less than 2 weeks before the accident. According to the chief pilot (CP), company policy was to assign newly hired pilots to tour flights while they gained experience before assigning them to commuter flights later in the season. The previous year, the CP distributed a list of each pilot’s clearances for specific types of flights and destinations; however, an updated list had not been generated for the season at the time of the accident, and the flight coordinators, who were delegated operational control for assigning pilots to flights, and station manager were unaware of the pilot’s assignment limitations. Before the flight, the flight coordinator on duty completed a company flight risk assessment that included numerical values based on flight experience levels. The total risk value for the flight was in the caution area, which required management notification before releasing the flight, due to the pilot’s lack of experience in the accident airplane make and model and with the company, and his unfamiliarity with the geographical area; however, the flight coordinator did not notify management before release because the CP had approved a tour flight with the same risk value earlier in the day. Had the CP been notified, he may not have approved of the pilot's assignment to the accident flight. The pilot's minimal operational experience in seaplane operations likely affected his situational awareness in rapidly changing wind conditions and his ability to compensate adequately for a quartering tailwind at a higher-than-normal ground speed, which resulted in a loss of control during the water landing and a subsequent nose-over.

On May 13, 2019, about 1221 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, N952DB, and a float-equipped de Havilland DHC-3 (Otter) airplane, N959PA, collided in midair about 8 miles northeast of Ketchikan, Alaska. The DHC-2 pilot and four passengers sustained fatal injuries. The DHC-3 pilot sustained minor injuries, nine passengers sustained serious injuries, and one passenger sustained fatal injuries. The DHC-2 was destroyed, and the DHC-3 sustained substantial damage. The DHC-2 was registered to and operated by Mountain Air Service LLC, Ketchikan, Alaska, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 135 as an on-demand sightseeing flight. The DHC-3 was registered to Pantechnicon Aviation LTD, Minden, Nevada, and operated by Venture Travel, LLC, dba Taquan Air, Ketchikan, Alaska, under the provisions of Part 135 as an on-demand sightseeing flight. Visual meteorological conditions prevailed in the area at the time of the accident. According to information provided by the operators, both airplanes had been conducting sightseeing flights to the Misty Fjords National Monument area. They were both converging on a scenic waterfall in the Mahoney Lakes area on Revillagigedo Island before returning to the Ketchikan Harbor Seaplane Base (5KE), Ketchikan, Alaska, when the accident occurred. According to recorded avionics data recovered from the DHC-3, it departed from an inlet (Rudyerd Bay) in the Misty Fjords National Monument area about 1203 and followed the inlet westward toward Point Eva and Manzanita Island. At 1209, at an altitude between 1,900 and 2,200 ft, the DHC-3 crossed the Behm Canal then turned to the southwest about 1212 in the vicinity of Lake Grace. Automatic dependent surveillance-broadcast (ADS-B) tracking data for both airplanes, which were provided by the Federal Aviation Administration (FAA), began at 1213:08 for the DHC-3, and at 1213:55 for the DHC-2. At 1217:15, the DHC-3 was about level at 4,000 ft mean sea level (msl) over Carroll Inlet on a track of 225°. The DHC-2 was 4.2 nautical miles (nm) south of the DHC-3, climbing through 2,800 ft, on a track of 255°. The DHC-3 pilot stated that, about this time, he checked his traffic display and “there were two groups of blue triangles, but not on my line. They were to the left of where I was going.” He stated that he did not observe the DHC-2 on his traffic display before the collision. The ADS-B data indicated that, about 1219, the DHC-3 started a descent from 4,000 ft, and the DHC-2 was climbing from 3,175 ft. During the next 1 minute 21 seconds, the DHC-3 continued to descend on a track between 224° and 237°, and the DHC-2 leveled out at 3,350 ft on a track of about 255°. Between 1220:21 and 1221:14, the DHC-3 made a shallow left turn to a track of 210°, then a shallow right turn back to a track of 226°. The airplanes collided at 1221:14 at an altitude of 3,350 ft, 7.4 nm northeast of 5KE. The ADS-B data for both airplanes end about the time of the collision. The DHC-2 was fractured into multiple pieces and impacted the water and terrain northeast of Mahoney Lake. Recorded avionics data for the DHC-3 indicate that at 1221:14, the DHC-3 experienced a brief upset in vertical load factor and soon after entered a right bank, reaching an attitude about 50° right wing down at 1221:19 and 27° nose down at 1221:22. The DHC-3 began descending and completed a 180° turn before impacting George Inlet at 1222:15 along a northeast track.

On May 13, 2019, about 1221 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, N952DB, and a float-equipped de Havilland DHC-3 (Otter) airplane, N959PA, collided in midair about 8 miles northeast of Ketchikan, Alaska. The DHC-2 pilot and four passengers sustained fatal injuries. The DHC-3 pilot sustained minor injuries, nine passengers sustained serious injuries, and one passenger sustained fatal injuries. The DHC-2 was destroyed, and the DHC-3 sustained substantial damage. The DHC-2 was registered to and operated by Mountain Air Service LLC, Ketchikan, Alaska, under the provisions of Title 14 Code of Federal Regulations (CFR) Part 135 as an on-demand sightseeing flight. The DHC-3 was registered to Pantechnicon Aviation LTD, Minden, Nevada, and operated by Venture Travel, LLC, dba Taquan Air, Ketchikan, Alaska, under the provisions of Part 135 as an on-demand sightseeing flight. Visual meteorological conditions prevailed in the area at the time of the accident. According to information provided by the operators, both airplanes had been conducting sightseeing flights to the Misty Fjords National Monument area. They were both converging on a scenic waterfall in the Mahoney Lakes area on Revillagigedo Island before returning to the Ketchikan Harbor Seaplane Base (5KE), Ketchikan, Alaska, when the accident occurred. According to recorded avionics data recovered from the DHC-3, it departed from an inlet (Rudyerd Bay) in the Misty Fjords National Monument area about 1203 and followed the inlet westward toward Point Eva and Manzanita Island. At 1209, at an altitude between 1,900 and 2,200 ft, the DHC-3 crossed the Behm Canal then turned to the southwest about 1212 in the vicinity of Lake Grace. Automatic dependent surveillance-broadcast (ADS-B) tracking data for both airplanes, which were provided by the Federal Aviation Administration (FAA), began at 1213:08 for the DHC-3, and at 1213:55 for the DHC-2. At 1217:15, the DHC-3 was about level at 4,000 ft mean sea level (msl) over Carroll Inlet on a track of 225°. The DHC-2 was 4.2 nautical miles (nm) south of the DHC-3, climbing through 2,800 ft, on a track of 255°. The DHC-3 pilot stated that, about this time, he checked his traffic display and “there were two groups of blue triangles, but not on my line. They were to the left of where I was going.” He stated that he did not observe the DHC-2 on his traffic display before the collision. The ADS-B data indicated that, about 1219, the DHC-3 started a descent from 4,000 ft, and the DHC-2 was climbing from 3,175 ft. During the next 1 minute 21 seconds, the DHC-3 continued to descend on a track between 224° and 237°, and the DHC-2 leveled out at 3,350 ft on a track of about 255°. Between 1220:21 and 1221:14, the DHC-3 made a shallow left turn to a track of 210°, then a shallow right turn back to a track of 226°. The airplanes collided at 1221:14 at an altitude of 3,350 ft, 7.4 nm northeast of 5KE. The ADS-B data for both airplanes end about the time of the collision. The DHC-2 was fractured into multiple pieces and impacted the water and terrain northeast of Mahoney Lake. Recorded avionics data for the DHC-3 indicate that at 1221:14, the DHC-3 experienced a brief upset in vertical load factor and soon after entered a right bank, reaching an attitude about 50° right wing down at 1221:19 and 27° nose down at 1221:22. The DHC-3 began descending and completed a 180° turn before impacting George Inlet at 1222:15 along a northeast track.

The pilot of the medical transport flight had been cleared by the air traffic controller for the instrument approach and told by ATC to change to the advisory frequency, which the pilot acknowledged. After crossing the initial approach fix on the RNAV approach, the airplane began a gradual descent and continued northeast towards the intermediate fix. Before reaching the intermediate fix, the airplane entered a right turn and began a rapid descent, losing about 2,575 ft of altitude in 14 seconds; radar returns were then lost. A witness at the destination airport, who was scheduled to meet the accident airplane, observed the pilot-controlled runway lights illuminate. When the airplane failed to arrive, she contacted the company to inquire about the overdue airplane. The following day, debris was found floating on the surface of the ocean. About 48 days later, after an extensive underwater search, the heavily fragmented wreckage was located on the ocean floor at a depth of about 500 ft. A postaccident examination of the engines revealed contact signatures consistent with the engines developing power at the time of impact and no evidence of mechanical malfunctions or failures that would have precluded normal operation. A postaccident examination of the airframe revealed about a 10° asymmetric flap condition; however, significant impact damage was present to the flap actuator flex drive cables and flap actuators, indicating the flap actuator measurements were likely not a reliable source of preimpact flap settings. In addition, it is unlikely that a 10° asymmetric flap condition would result in a loss of control. The airplane was equipped with a total of 5 seats and 5 restraints. Of the three restraints recovered, none were buckled. The unbuckled restraints could suggest an emergency that required crewmembers to be up and moving about the cabin; however, the reason for the unbuckled restraints could not be confirmed. While the known circumstances of the accident are consistent with a loss of control event, the factual information available was limited because the wreckage in its entirety was not recovered, the CVR recording did not contain the accident flight, no non-volatile memory was recovered from the accident airplane, and no autopsy or toxicology of the pilot could be performed; therefore, the reason for the loss of control could not be determined. Due to the limited factual information that was available, without a working CVR there is little we know about this accident.

The pilot of the float-equipped airplane reported that, during the initial climb after a water takeoff, about 200 feet, he turned right, and the engine lost power. He immediately switched fuel tanks and attempted to restart the engine to no avail. The airplane descended and struck trees, and the right wing impacted terrain. The airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot reported to the Federal Aviation Administration inspector that, during the initial climb and after the engine lost power, he noticed that the center tank, which was selected for takeoff, was empty. He added that passengers stated that the engine did regain power after switching tanks, but the airplane had already struck trees. The pilot reported as a recommendation to more closely follow checklists.

The commercial pilot was conducting a 1-hour commercial air tour flight over Denali National Park and Preserve with four passengers on board. About 48 minutes after departure, the Alaska Rescue Coordination Center received an alert from the airplane's emergency locator transmitter. About 7 minutes later, company personnel received a call from the pilot, who reported that the airplane had run "into the side of a mountain." Although a search was initiated almost immediately, due to poor weather conditions in the area, the wreckage was not located until almost 36 hours later in a crevasse on a glacier about 10,920 ft mean sea level. Due to the unique challenges posed by the steepness of terrain, the crevasse, avalanche hazard, and the condition of the airplane, neither the occupants nor the wreckage were recovered from the accident site. A weather model sounding for the area of the accident site estimated broken cloud bases at 700 ft above ground level (agl) with overcast clouds at 1,000 ft agl and cloud tops to 21,000 ft agl and higher clouds above. The freezing level was at 9,866 ft and supported light-to-moderate rime type icing in clouds and precipitation. The on-scene assessment indicated that the right wing impacted snow while the airplane was flying in a wings-level attitude; the right wing had separated from the remainder of the wreckage. Based upon available weather data and forecast models and the impact evidence, it is likely that the pilot entered an area of reduced visibility and was unable to see the terrain before the airplane's right wing impacted the snow. The company's organizational structure was such that one group of management personnel oversaw operations in both Anchorage and Talkeetna. Interviews with company management revealed that they were not always aware of the exact routing a pilot would take for a tour; the route was pilot's discretion based upon the weather at the time of the flight to provide the best tour experience. Regarding risk mitigation, the company did not utilize a formal risk assessment process, but rather relied on conversations between pilots and flight followers. This could lead to an oversight of actual risk associated with a particular flight route and weather conditions. About 8 months after the accident, an assessment flight conducted by the National Park Service determined that during the winter, the hazardous hanging glacier at the accident site calved, releasing an estimated 4,000 to 6,000 tons of ice and debris. There was no evidence of the airplane wreckage near the crash site, in the steep fall line, or on the glacier surface over 3,600 ft below. Although the known circumstances of the accident are consistent with a controlled flight into terrain event, the factual information available was limited because the wreckage was not recovered and no autopsy or toxicology of the pilot could be performed; therefore, whether other circumstances may have contributed to the accident could not be determined.