20020313004909A

(.19) On March 13, 2002, about 1940 hours pacific standard time (PST), a Beech E-90, N948CC, experienced an in-flight loss of control and descended into an unoccupied commercial building during a nighttime instrument approach to the Reno/Tahoe International Airport, Reno, Nevada. The airplane was operated by pilot services corporation, doing business as regent air service, inc., truckee, California. The airplane was destroyed. The airline transport certificated pilot and five passengers sustained minor injuries. Instrument meteorological conditions prevailed, and an instrument flight rules (IFR) flight plan was filed. The flight was operated under 14 CFR part 135 as an on-demand round trip air taxi flight from truckee. The first flight of the day began upon the pilot's departure from truckee about 0518 PST. The pilot indicated that after taking off he proceeded nonstop to durango, Colorado, and landed about 0850 mountain standard time (0750 PST). Thereafter, the pilot had lunch and he retired at the prearranged crew-rest hotel. The pilot further indicated that the airplane was refueled, and he did not observe any discrepancies with the airplane during his preflight inspection. The pilot departed durango at 1625 mountain standard time (1525 PST) for the return flight to truckee. According to the pilot, the flight was uneventful until he attempted to land. At 1905 PST, the pilot received a clearance to perform an instrument approach to the truckee-Tahoe airport. The pilot stated that he initiated the approach, but he could not land because the weather conditions were inadequate. He executed a missed approach. The pilot then requested and received a radar vector to proceed to Reno. Snow showers existed at both truckee and Reno, and the pilot reported that he had activated the airplane's antiicing and deicing equipment. The pressurized turboprop airplane was certificated for flight into known icing conditions. Approaching Reno, accumulated ice was observed dislodging from the wings when the deice boots were inflated. (The deice boots on the vertical and horizontal stabilizers cannot be seen from the cockpit. There is no annunciator light or indicator gauge to indicate these component's functionality.) At 1925:27, the pilot was cleared to perform a localizer, distance measuring equipment, back course instrument approach to runway 34L. At the time, the pilot was inbound to the airport and approximately 6 nautical miles from the final approach fix. The pilot acknowledged the clearance to the air traffic controller. During the national transportation safety board investigator's subsequent interview with the pilot, he indicated it was his belief that, upon reaching the final approach fix, the airport's reported weather was at or above his landing minimums. At 1936:44, the pilot made his last recorded radio transmission during which he acknowledged being cleared to land. The pilot also reported to safety board investigators that the airplane's approach was initially stabilized upon reaching the authorized minimum descent altitude of 5,060 feet mean sea level (653 feet above ground level). Some ice was visible on the wing's leading edge stall strip, but it was "way less than 1/4-inch" in depth. The ice did not extend beyond the aft portion of the wing's deicing boot. The pilot reported that initially the airplane was flying at 140 knots, the recommended approach speed for icing conditions. But, a few miles from the airport, the airspeed decreased to between 111 and 115 knots. Thereafter, he felt a vibration in the control yoke and the airplane began yawing. When the airplane started shaking he applied full engine power and decreased the pitch attitude. The airplane's stall warning light illuminated and the airplane descended. The airplane's last recorded radar position was at 1940:08. At this time the airplane's mode c reporting transponder altitude was 4,600 feet. Runway 34L'S touchdown zone's elevation is 4,407 feet mean sea level. The accident site was located about 0.96 nautical miles and 162 degrees (magnetic) from the landing threshold. Minutes earlier, at 1921, Reno fire department personnel had responded to a medical call (about 1/4-mile from the crash site). The personnel noted that at the time it was snowing lightly. However, by 1931 it was snowing heavily, the wind speed had increased, and the conditions appeared like a "squall blowing into the area with white-out conditions." In pertinent part, at 1939, Reno reported that its surface wind was from 300 degrees at 10 knots, and the visibility was 1/2-mile. There was moderate snow and freezing fog. A broken ceiling existed at 700 feet above ground level, and temperature/dew points were, respectively, minus 2 and minus 3 degrees celsius. The safety board's examination of the initial point of impact revealed a white paint transfer signature and impact damage in the block wall structure of a rectangular shaped two-story building located at approximate global positioning satellite coordinates of 39 degrees 28.222 minutes north latitude by 119 degrees 46.112 minutes west longitude. The angle of the paint signature was measured about 70 degrees. (A 90-degree angle would be perpendicular to the horizon.) The airplane's separated white colored left wing was located beneath the wall outside the building. The wing's leading edge was observed crushed in an aft direction. The remainder of the airplane was observed to have penetrated the building's roof and come to rest on its left side in an approximate 70-degree left bank attitude. The airplane was recovered from the accident site and was examined. All flight control surfaces were found with the airplane and no evidence of any preimpact separation was noted. The continuity of the flight control system was confirmed. Fuel was noted in the right wing's fuel tank. The left wing tank was destroyed. The engines' fuel controls were found set to the maximum power position. The air inlet screens were coveredwith building-related debris, the compressors were observed having ingested debris, and debris was noted having exited the bleed valve assemblies. The propeller blades were noted torsionally twisted, leading edge gouged, chordwise scratched, and several tips were broken. With the exception of the majority of the left wing's destroyed deice boot and the totally destroyed left horizontal stabilizer's deice boot, all of the boots were tested to ascertain their ability to pressurize utilizing an external air supply source. The air supply was initially directed into the airplane's pneumatic air supply lines at attachment points next to the inboard portion of each respective boot assembly at the wing roots, and from the rear of the aft pressure bulkhead. Using pressurized air at these locations, all of the testable boots inflated. In one area of the airplane, a blockage was noted to the pneumatic air supply line during its integrity examination. The blockage was located in the bottom of the airplane, between 1 and 3 feet forward of the aft pressure bulkhead, beneath the lavatory area. At this location, the pneumatic line is located inches away from an environmental heat duct which supplies hot air to the cabin. The preliminary examination revealed that the pneumatic line near this heat duct had collapsed, and it had the appearance of being subjected to elevated temperatures in this region. The blockage to this pneumatic line in this area precluded the deice boots on all tail surfaces from inflating during the post impact examination when the pressurized air source was connected to the pneumatic line from a location forward of the aft pressure bulkhead. (-23) pilot had attempted a GPS 19 approach to truckee/Tahoe airport and diverted to Reno/Tahoe International Airport. He reported that all anti-ice systems on the aircraft were on just prior to intercepting the rno LOC DME back course runway 34L approach and during the stepdown he needed more than 20 degrees of left wind correction. Tower radar was lost approximately 1/2 to 1 mile from the approach end of the runway threshold. In blowing snow the aircraft struck a two story building while in a left bank. The left wing and stabilizer were torn from the aircraft and fell into a street. The aircraft continued over the wall, went through the roof and came to rest on the floor of the second floor offices with the right wing protruding through the open hole in the roof. The right engine assembly tore loose and continued into the north west corner of the building. When everything stopped moving the pilot walked through the cabin and opened the door and all six occupants exited the aircraft and the building. Minor injuries. No post crash fire.