Primary finding
Probable cause
An inadvertent aerodynamic stall resulting from the pilot's poor decision-making and inadequate planning and execution when he took off toward nearby rising terrain, in strong winds, under circumstances where his options for maneuvering were severely limited and where his safety margin was, thus, insufficient.
Investigator assessment
Analysis narrative
The float-equipped airplane was departing from a remote bay 20 miles north of Ketchikan, Alaska, to return air taxi passengers to Ketchikan after a ground tour. The accident pilot, who reported that he had 17,000 flight hours and 7,000 hours in the make and model of the accident airplane, said that southeasterly winds had begun to increase while he was waiting at the bay for the passengers to return from the tour. He said that, unlike when he had landed about 2.5 hours earlier, it was no longer "nice and calm" when the passengers returned. The pilot noticed choppy waves in parts of a nearby cove. To avoid some of the wind and waves, the pilot elected to take off toward the interior of the bay, in the direction of rising terrain. The pilot said that he had never taken off in that direction before. The pilot also said that he had intended to make a shallow, right-climbing turn toward the mouth of the bay and away from the terrain, but shortly after takeoff, he saw numerous choppy waves concentrated along his proposed departure flightpath, which he said indicated to him that strong winds were likely along that path. The pilot decided to change his plan and continue flying straight temporarily, away from the waves, and to make a left, 180-degree turn inside the bay, which was surrounded by high terrain. The pilot indicated that when the turn was initiated, the airplane was about 400 feet above the water, and he did not recall the indicated airspeed. The attempted 180-degree turn was within the airplane’s performance capabilities but placed it closer to rising terrain. While attempting this turn, the pilot encountered a downdraft, was unable to climb above the terrain, and stalled the airplane about 60 feet above the ground. The downdraft likely made it more difficult to avoid descending into the rising terrain. A weather study by the National Transportation Safety Board confirmed that there was a gust front in the area and an abrupt wind change about the time of the accident. Pilots flying nearby also reported low-level windshear, strong winds, and turbulence. No mechanical anomalies were discovered during postaccident inspections by the Safety Board.
Source record
Factual narrative
HISTORY OF FLIGHT On August 16, 2007, about 1730 Alaska daylight time, a float-equipped de Havilland DHC-2 (Beaver) airplane, N345KA, was destroyed by impact and a postimpact fire when it collided with tree-covered terrain, about 20 miles north of Ketchikan, Alaska. The airplane was being operated as a visual flight rules (VFR) sightseeing flight under the provisions of 14 Code of Federal Regulations (CFR) Part 135, when the accident occurred. The airplane was owned and operated by Seawind Aviation, Inc., Ketchikan, Alaska. Of the nine people aboard, the airline transport pilot and three passengers sustained serious injuries, and five passengers died at the scene. A sixth passenger died of her injuries 48 days after the accident. Visual meteorological conditions prevailed, and company flight following procedures were in effect. At the time of the accident, the flight was returning to the operator's base at the Ketchikan Harbor Seaplane Base, Ketchikan. The flight was a sightseeing flight for cruise ship passengers. The passenger's cruise ship was docked in Ketchikan, and the accident flight was the last flight of the day following a bear viewing tour in an area known as Traitor's Cove. During an initial emergency room interview with an Alaska State Trooper on August 16, a passenger stated that at the completion of the 2-hour long bear-viewing tour, the group retuned to the airplane for the flight to Ketchikan. The passenger reported strong and gusty winds prior to beginning the takeoff run. She said that the airplane started its takeoff run directly into the strong winds, and shortly after becoming airborne, it made a steep turn to the left. The passenger indicated that as the airplane turned left, it abruptly descended, and collided with a tall stand of trees along the shoreline of the bay. During the impact, the right wing was severed, and the airplane's fuselage came to rest on its right side. The passenger said that a postaccident fire ensued about 30 seconds after the collision, which consumed the airplane's cabin area and fuselage. Pilots flying in the area about the time of the accident reported strong southeasterly winds, ranging between 30 and 40 knots, with significant downdraft activity. As a result of the accident, the pilot sustained serious burn injuries, and was flown from Ketchikan by air ambulance to a hospital in Seattle, Washington. On September 5 and 6, 2007, once the pilot's condition had improved, the National Transportation Safety Board's (NTSB) operations group chairman, and an NTSB human factors investigator, interviewed the pilot in his hospital room. The pilot reported the arrival at Traitors Cove was normal, and that he waited at the airplane while the passengers took the bear-viewing ground tour. He noted that the weather was beautiful, with hardly any wind, but that while he was waiting for his passengers, the weather changed. He said that he could tell that the wind at higher altitudes was getting blustery, and could tell the direction of the wind, but not the magnitude. There was no rain or convective activity, and the only change he noted was that it "just wasn't as nice and flat calm anymore." He said he took off into the southeasterly wind, with the intent of making a shallow, right climbing turn toward the mouth of the bay, away from rising terrain. However, during the takeoff run, he indicated that there were numerous 3-foot choppy waves concentrated along his proposed departure flight path, and he decided to continue straight ahead, toward the mouth of the bay, and then make a left, 180-degree turn inside the bay. He said he had never seen the wind "blowing that hard out of the lake like that." About 400 feet agl, and about 90 degrees into his intended 180-degree left turn, the pilot said, in part, "the bottom started to fall out fast." He indicated that the left bank was "not much, less than 30, 25 degrees." He said that he added engine power and more flaps while holding back elevator, but the airplane continued to descend. He said that the airplane stalled about 60 feet above the ground, just before contacting the tops of the trees. The airplane collided with trees and descended to the ground. The engine was torn off the fuselage, and a fire began immediately near the front of the airplane. The pilot stated that there were no preaccident mechanical anomalies with the accident airplane. PERSONNEL INFORMATION Pilot Information The pilot held an airline transport pilot certificate with airplane multiengine land and sea ratings. In addition, he held commercial pilot privileges with airplane single-engine land and sea ratings. His most recent second-class medical certificate was issued March 8, 2007, and contained the limitation that he must wear correcting lenses. He reported that his flight experience was about 17,000 total flight hours, of which about 7,000 hours were in the accident airplane make and model. In the 30 days before the accident, he flew about 180 hours. His flight time in the previous 90 days was 467 hours, and about 580 hours in the previous year. His most recent CFR Part 135.293 check ride was on April 17, 2007. A Federal Aviation Administration (FAA) operations inspector from the Juneau Flight Standards District Office (FSDO) administered the check ride in the accident airplane. Flight and duty records for the pilot revealed that his annual/quarterly record keeping began in January 2007. From January 2007, through March 2007, the pilot flew a total of 11 days, with the remainder as days off. From April 2007, through June 2007, the pilot flew 57 days, and had 35 days off. Beginning on May 12, he flew every day for the next 63 days, until his most recent day off from flying on July 14. He then flew every day for the next 33 days until the accident. Company Information The pilot was the owner of the company, and held a Part 135 single-pilot operator air taxi certificate. He was responsible for operational control of the company's only airplane. The pilot's wife assisted him in the company's day-to-day business needs. As a single-pilot operator, the company was not required to have an operating manual, a formal training program, a director of maintenance, director of operations, or a chief pilot. The company operations specifications, issued by the FAA's Juneau FSDO, specified that all weather reports and forecasts would be obtained from the National Weather Service (NWS), a source approved by the NWS, or other sources approved by the FAA. For VFR operations, the pilot's own observations, or those of another competent observer, could be used when approved sources were not available. AIRPLANE INFORMATION The airplane was equipped with a Pratt & Whitney R-985 radial engine that was rated at 450 horsepower. Originally, the airplane's maximum gross weight was 5,090 pounds, but it had been modified to 5,500 pounds. The airplane was equipped with Edo 4930 floats. The airplane was not equipped with a cockpit voice recorder, or a flight data recorder, nor was it required to be. Maintenance records revealed that the last recorded inspection event of the engine and airframe was a 100-hour inspection, completed on August 14, 2007, 2 days before the accident. At that time, the airplane had a total 22,409 service hours, and the engine had 1,070 service hours since the last major overhaul. The most recent annual inspection of the engine and airframe was on March 9, 2007, at which the airplane had 21,974 service hours, and the engine had 635 service hours since a major overhaul. An engine overhaul was done by Tulsa Aircraft Engines, Inc., on October 17, 2005. The engine was installed on the accident airplane on March 23, 2006, and it remained there until the accident. The airplane had a stall warning system, which incorporated a horn and a red light mounted on the instrument panel that war