HISTORY OF FLIGHT On July 30, 2004, about 1815 Alaska daylight time, a wheel-equipped Cessna 170B airplane, N2269D, sustained substantial damage during a collision with terrain following an in-flight loss of control, about 26 miles northeast of Kenai, Alaska. The airplane was being operated by the pilot as a visual flight rules (VFR) personal cross-country flight under Title 14, CFR Part 91 when the accident occurred. The private pilot and the three passengers received fatal injuries. Visual meteorological conditions prevailed, and no flight plan was filed. The flight departed the Kenai Airport, Kenai, about 1800. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on August 4, the Alaska State Trooper who responded to the site, said a witness reported the airplane made two passes in opposite directions over the landing area, about two feet above the ground. The witness reported that on the second pass the airplane had a tailwind, and that during the initial climb after the pass, the airplane started a turn to the right, and the "wing stalled." The witness said the airplane rolled over and dove to the ground nose first, in a near vertical descent. During a telephone conversation with the NTSB IIC on July 31, the owner of the airplane said the pilot had borrowed the airplane to transport friends to the Kustatan River, about 26 miles northeast of Kenai, to go fishing. He said there were no known mechanical anomalies with the airplane prior to the accident. INJURIES TO PERSONS The pilot and the three passengers received fatal injuries. DAMAGE TO AIRCRAFT The airplane sustained substantial structural damage to the wings and fuselage. PERSONNEL INFORMATION According to FAA documents and pilot logbook information, the pilot held a private pilot certificate with ratings for single-engine land airplane. He had accumulated about 1,052 total hours of flying experience. The pilot was issued an FAA class 3 medical certificate on September 19, 2003, and successfully completed a biennial flight review on September 23, 2003. AIRCRAFT INFORMATION The airplane was a model year 1952 Cessna 170B, single-engine, fixed-gear airplane. The airplane had accumulated 3,355 service hours on the airframe, and passed an annual inspection on October 10, 2003. The engine had accumulated 1,263 total service hours, and was overhauled 288 service hours prior to the accident. METEOROLOGICAL INFORMATION According to a pilot who witnessed the accident, and a trooper pilot who responded to the accident, visual meteorological conditions prevailed at the accident site at the time of the accident. They reported clear skies below 12,000 feet, visibility greater than 10 miles, and light winds out of the south. AIDS TO NAVIGATION No aids to navigation were involved with the accident. COMMUNICATIONS There were no direct communications with the accident airplane. Pilots in the area heard the accident pilot make position reports in the vicinity of the remote airstrip on the common traffic advisory frequency (CTAF). They said the position reports sounded appropriate, and without concern. WRECKAGE AND IMPACT INFORMATION The accident site is a grassy coastal plain cut by several rivers and streams. There are no trees or obstacles in the area. The landing airstrip sits atop a riverbank, about 8 feet above the river. The grass-covered airstrip is flat, about 1,800 feet long, and oriented approximately 140/320 degrees magnetic. On July 31, an on-site investigation was conducted by the IIC, accompanied by an FAA aviation safety inspector. The airplane impacted level terrain, about 250 yards off the northwest end of the airstrip, approximately 60 degrees nose down. All of the airframe components were located at the impact site, and control continuity was confirmed to all the flight control surfaces. The vertical speed indicator indicated 2,000 feet per minute down. The key (magnetos) was found in the "both" position, and the fuel selector was missing (broken off). The airplane was upright, resting on the nose and tail section with the middle of the fuselage broken sharply downward, forming an inverted "V". The airplane impacted on a heading of approximately 053 degrees magnetic. The engine and propeller were buried in the impact crater to the firewall. The wings were flexed forward with the tips touching the ground. The aft section of the fuselage had forward crushing behind the baggage compartment, and had collapsed downward, about 30 inches aft of the passenger cabin with the rudder's trailing edge touching the ground. Both main landing gear were flexed aft. Both wing tanks contained usable amounts of fuel, and the gascolator also contained fuel. The mechanical flap handle was observed in the upper most detent position (40 degrees extended), and the left inboard section of the left flap had a span-wise crease, about 3" aft of the flap's leading edge. On August 17, after recovery, the airplane was reexamined by the IIC accompanied by representatives from the airplane and engine manufacturers. No preaccident mechanical anomalies were found. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was conducted under the authority of the Alaska State Medical Examiner, 4500 South Boniface Parkway, Anchorage, Alaska, on June 26, 2004. The examination revealed the cause of death of the pilot was multiple blunt force trauma. Toxicology tests were performed for legal and illegal drugs at the FAA laboratory in Okalahoma City, Oklahoma, with negative results. Ethanol, Acetaldehyde, N-Butanol, and N-Propanol were detected in blood, muscle, and urine, but all were attributed to postmortem production. TESTS AND RESEARCH An approximate weight and balance was calculated using listed weights (driver's licenses) of the pilot and passengers, and estimated weights of the baggage and fuel onboard. The calculations indicate that the airplane was loaded at or near the maximum gross weight of the airplane, and the center of gravity was at or near the aft center or gravity limit. ADDITIONAL INFORMATION A video tape of the accident flight was made by the right front seat passenger, and recovered from the wreckage. The tape was sent to the NTSB laboratory and repaired. The tape showed that the right front engine cowl came open during the flight to the remote airstrip, and remained unsecured for the rest of the flight. The pilot and passenger made recorded comments about the cowling, but did not seem concerned. The tape shows the two passes over the intended landing strip, but stops as the airplane breaks to the right during the final climb. The original tape and a digital copy were returned to the family of the front seat passenger. A witness said he saw the right engine cowl was loose as the airplane made a pass over the airstrip. The unsecured cowl was confirmed by the passenger's video. The cowl latches were examined, and found to be excessively worn. No pieces, parts, or equipment from the airplane was taken or retained by the NTSB. The wreckage has been released to the owner's insurance company.