NTSB Eyes Procedures In King Air Mishap
The NTSB's investigation of a King Air B200 that landed safely last Friday after suffering serious structural damage is likely to focus on cockpit checklists and procedures, along with radar data collection. N777AJ was headed from Rogers, Ark., for Stanton, Va., when it encountered complications after suffering a shattered (but not blown out) windshield at 27,000 feet and ultimately rained parts down on an aeromedical helicopter flying below. The helicopter was not struck by debris, and the King Air landed at Cape Giraradeau, Mo., with buckled wing skins and empennage and much of the horizontal stabilizer and elevator missing. The King Air's pilot, Sheldon Stone, said in early reports that the aircraft suffered a shattered left windshield at altitude and he then depressurized the cabin to prevent a blowout. According to the King Air pilot operating manual, the "abnormal checklist" for a cracked windshield specifies a descent to 10,000 feet or other methods to reduce the pressure differential to less than 3 PSI within 10 minutes. After depressurizing the cabin, Stone and his copilot then donned their oxygen masks and turned on the valve, but no oxygen appeared to be forthcoming. The sole-occupant pilots then passed out. Stone, a 4,200 hour ATP-rated pilot, said he awoke at 7,000 feet and recovered the aircraft.
According to the aircraft's flight track as provided by FlightAware, the aircraft reached 27,000 feet just after 7:00 a.m. It cruised at that altitude until 7:17 when it went to 25,900. At 7:18 the aircraft was at 25,400 but a minute later was back at 27,000 and had slowed from 417 to 104 knots ground speed, further slowing to 44 knots at 7:20, according to FlightAware. At 7:22, the position report showed holding 27,000 feet and 102 knots. One minute later, the radar indicates 125 knots at 7,800. Aberrations earlier in the minute-by-minute reporting (from 6:49 to 6:50, the aircraft is shown to jump from 17,000 to 27,000 then back down) suggest the data may not be entirely accurate. But the data seem to follow roughly with the pilot's initial comments and damage suffered by the aircraft.