HISTORY OF FLIGHT On July 7, 2005, about 1100 Alaska daylight time, a float-equipped Maule M-7-235 airplane, N5661J, sustained substantial damage when it impacted water and sank, following an in-flight loss of control during final approach at Johnstone Lake, about 25 miles southeast of Seward, Alaska. The airplane was being operated by Glacier Air Adventures, of Anchorage, Alaska, as a visual flight rules (VFR) business flight under Title 14, CFR Part 91, when the accident occurred. The commercial certificated pilot/lodge operator and three passengers received minor injuries, a fourth passenger received fatal injuries. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight originated at Bear Lake, 6 miles northeast of Seward, about 1030. During an interview with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on July 7, the pilot said the flight from Bear Lake to Johnstone Lake was to transport passengers for a kayaking adventure on Johnstone Lake at the foot of the Excelsior Glacier. He said the flight was uneventful until, about 25-50 feet above Johnstone Lake, during the final approach for landing on the lake, the airplane "quit flying." He said the airplane impacted the lake in a near-level attitude, with a high rate of descent. He and the four passengers exited the airplane, and stood on top of the wings and fuselage. He said the float's supporting structure had collapsed, and the wings were resting on the top of the floats on the water. He stated the airplane was more than a mile from shore, surrounded by icebergs, and slowly sinking. In an attempt to move from the sinking airplane to a large iceberg, the pilot said one of the passengers, who was not wearing a personal flotation device, drown. The pilot said that prior to the impact there were no known mechanical anomalies with the airplane, and the engine was running normally. INJURIES TO PERSONS The pilot and three passengers received minor injuries. The fourth passenger drown while trying to swim back to the floating airplane wreckage from an iceberg, and was not recovered from the lake. DAMAGE TO AIRCRAFT According to statements by the pilot and passengers, the airplane received substantial structural damage to the wings and fuselage during the accident. The airplane subsequently sank in water estimated to be 600-800 feet deep, and has not been recovered. PERSONNEL INFORMATION According to FAA records the pilot held a commercial pilot certificate with ratings for single-engine land, single-engine sea, and instrument airplane. According to an estimate by the pilot, he had accumulated about 1,738 total hours of flying experience, with 370 of those hours in the same make and model as the accident airplane. The pilot was issued an FAA class 2 medical certificate in December, 2004. The pilot did not present evidence of a current biennial flight review; however, he received an additional aeronautical rating April 21, 2005. AIRCRAFT INFORMATION The airplane was a model year 1997 Maule M-7-235, single-engine, float equipped airplane. The airplane had accumulated about 1,140 service hours on the airframe at the time of the last annual inspection, which was completed on June 27, 2004. The airplane did not have a current annual inspection at the time of the accident. The engine had accumulated 1,140 total service hours at the time of the annual inspection. An airframe log book entry indicated the floats were removed in November 2004. According to the mechanic who installed the floats in the spring of 2005, the installation was not completed under his signature because the pilot failed to provide the fuselage-mounted ventral fin necessary to complete the installation. According to the airplane and float manufacturers, the ventral fin provides additional in-flight yaw axis stability. The fifth seat configuration for the accident airplane requires a supplemental type certificate (STC) for the fifth seat installation in the aft baggage area. The manufacturer reported that their records disclosed that the airplane was delivered without the fifth seat. Federal Aviation Administration records do not record a fifth seat STC being issued for the accident airplane. METEOROLOGICAL INFORMATION According to the pilot, visual meteorological conditions prevailed, and weather was not a factor in the accident. WRECKAGE AND IMPACT INFORMATION The accident occurred on Johnstone Lake, Alaska. Johnstone Lake is a freshwater lake whose long axis is oriented approximately north-south, about 1 mile from the Gulf of Alaska, and is about 3.5 miles long, and averages about 1 mile wide. The south end of the lake is separated from the Gulf of Alaska by a rocky beach, about 1 mile wide, with a fresh water (stream-like) outlet. The north end of the lake is dominated by the Excelsior Glacier. The lake water is filled with glacial silt, is gray colored, and is reported to be 600-800 feet deep. The lake is populated with various-sized floating ice chunks, and large icebergs. According to the pilot and survivors, the airplane descended rapidly from about 25-50 feet above the surface, and impacted the lake in a level attitude. They reported that the floats spread apart, and collapsed against the underside of the wings. They said the floats maintained their longitudinal position with respect to the fuselage. The fuselage lay submerged, supported by the floats under the wings, until it subsequently sank. The airplane has not been recovered. MEDICAL AND PATHOLOGICAL INFORMATION The pilot and surviving passengers received minor impact and subsequent minor exposure injuries. The fatal passenger has not been recovered from the lake. SURVIVAL ASPECTS The accident occurred while the four seat (pilot and three passenger), float-equipped airplane was on final approach to a glacier-fed, fresh water lake. The lake is estimated to be 600-800 feet deep with a surface temperature of 38-42 degrees F. The lake is populated by large icebergs, and smaller cakes of ice. The day of the accident was clear with relatively calm winds, and long hours of midsummer daylight. Prior to the flight the pilot gave each passenger a personal flotation device (PFD), and briefed them on its use. The fourth/fatal passenger was seated in the aft cargo compartment atop kayak spray-skirts and gloves. The pilot and all four passengers survived the water impact with a few minor injuries. After the impact, the five survivors climbed onto the fuselage top and wings. The pilot and fatal passenger exited the airplane, leaving their PFD's behind. The other three passengers were wearing their PFD's when the accident occurred, and exited the airplane wearing them. The airplane was sinking, and all the survivors swam to a large, nearby iceberg, but were unable to climb out of the water onto the iceberg. The pilot, and the three passengers wearing PFD's, swam back to the airplane, and climbed out of the water onto the airplane. The pilot borrowed a PFD from one of the passengers, and swam back to the remaining passenger, but was unable to render aid because he'd lost all feeling in his hands due to the cold water. The remaining passenger, without aid of a PFD, slipped below the surface of the lake, and was not seen again. The survivors were able to cut through the fabric fuselage skin to retrieve extra clothing from the baggage compartment, which they gave to the pilot who, according to them, was showing signs of hypothermia. During the accident scenario, two of the passengers were dressed in layered clothing, including fleece, as suggested by the pilot. The other two passengers and the pilot were dressed in cotton levis and cotton shirts. As the airplane continued to slowly sink, two of the passengers swam to a smaller ice cake, which they were able to climb on, and the remaining passenger followed. Prior to the airplane sinking, using an inflated dry-bag, the pilot joined the others on the iceberg. The flight used "company flight following" instead of an FAA flight plan. When the airplane did not return as scheduled, the person responsible for tracking the progress of the flight elected to contact other pilots in the area rather than report the airplane missing. After seeing several airplanes orbit the lake, presumably looking for the now submerged airplane, and then leave without seeing them, the survivors decided they had to make their own way to shore. The survivors were on an iceberg near the center of the lake, about a mile from shore. Two of the survivors boarded a cake of ice, and using makeshift paddles, paddled toward the shore where they knew there was a camp with kayaks and supplies. After paddling for about 2 hours, and within 100 yards of the shore, a State Trooper helicopter appeared, headed for the same camp as the paddlers. The helicopter recovered the paddlers, and the two remaining survivors on the iceberg. All four survivors were taken to the hospital, and treated for minor impact and exposure related injuries.