On August 28, 2005, about 2129 Alaska daylight time, a Cessna 441 turboprop airplane, N77SA, sustained substantial damage following an unintentional gear-up landing and postcrash fire during landing on runway 7R at the Ted Stevens Anchorage International Airport, Anchorage, Alaska. The airplane was being operated as an instrument flight rules (IFR) cross-country personal flight under Title 14, CFR Part 91, when the accident occurred. The airplane was owned by Security Aviation, Inc., Anchorage, Alaska. The airline transport pilot, and the sole passenger, were not injured. The flight originated at the Merle K. (Mudhole) Smith Airport, Cordova, Alaska, about 2045. Visual meteorological conditions prevailed at the flight's destination airport, and an instrument flight rules (IFR) flight plan was in effect at the time of the accident. According to the accident pilot, he obtained an IFR clearance after departing from Cordova, en route to Anchorage. During an on scene conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on August 28, about 2200, the pilot reported that he was the director of operations for Security Aviation, and that he was using the airplane for a personal flight between Anchorage and Cordova. He said that the purpose of the flight was to transport some building materials to Cordova, and that he was returning to Anchorage at the time of the accident. He noted that upon arrival in the Anchorage area, dark night VFR conditions prevailed as the flight was cleared for the ILS runway 7R approach. He stated that the Anchorage air traffic control tower (ATCT) specialist on duty asked him to "keep his speed up" during the approach in order to accommodate arriving traffic that was sequenced behind him for landing. According to the pilot, as the airplane continued on the ILS 7R approach, he selected 10 degrees of wing flaps, and then selected the landing gear selector switch to the down position, which was followed by "three greens" indicting the landing gear was down, locked, and safe for landing. The pilot said that after landing touchdown, during the initial landing roll, the landing gear retracted, and the airplane slid on the underside of the fuselage. The airplane veered to the right of the runway centerline, and the right wing collided with numerous runway edge lights. A postcrash fire ensued when the right wing's fuel tank was breached. The airplane received structural damage to the underside of the fuselage, and the right wing was destroyed. During the NTSB IIC's on scene investigation, propeller strike marks on the runway were discovered in the vicinity of the accident airplane's touchdown point, and extended along the crash path approximately 2,200 feet to the airplane's final resting point. Runway 7R is a 10,900 foot long, by 150 foot wide paved runway. According to the operator's president, when the airplane was lifted off the runway during recovery, the cockpit mounted emergency landing gear extension T-handle was pulled in order to extend the landing gear. He said that once the T-handle was pulled, the landing gear extended, and locked in the down position. A postaccident inspection of the airplane by the IIC and another NTSB air safety investigator on September 1, disclosed no evidence of any preaccident mechanical malfunction of the landing gear assembly or its associated operating systems. There were no significant side scuff marks or damage on any of the landing gear tires or rims. The bottom of the landing gear doors had near uniform damage from runway contact, with no damage noted to their edges or extension mechanism. On October 27, 2005, under the direction of the NTSB IIC and another NTSB air safety investigator, the airplane was placed on jack stands and hydraulic pressure was supplied to the airplane's hydraulic system using a hydraulic ground power unit. The airplane's landing gear retraction system was cycled, numerous times, with no mechanical anomalies noted. Each time the landing gear was lowered, three green landing gear safe lights were observed by an NTSB investigator positioned in the airplane's cockpit area. The accident airplane was equipped with a landing gear warning horn system that is designed to alert the flight crew if the landing gear is not extended prior to landing. According to an air safety representative from Cessna Aircraft, the landing gear warning horn system is not armed with only 10 degrees of flaps set, which avoids an erroneous warning horn activation during approach.