What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Disappeared from radar fast of fca in mountain terrain. Became missing. (-23) on April 11, 1998 at 0221 MDT a Piper NA-46-350P malibu N9247W registered to cm systems of polson, MT and being flown by an airline transport pilot disappeared from radar 20NM east-southeast of Glacier Park International Airport (fca) Kalispell, MT. The aircraft is missing and pilot and passenger are presumed to have sustained fatal injuries. The flight was presumed to be personal from madison, WI to polson, MT. (.4)the aircraft disappeared from air traffic control (ATC) radar immediately after being cleared to descend from 12,000 feet to 10,000 feet. ATC radar data showed the aircraft at 11,900 to 12,000 feet for approximately the last 6 minutes prior to the disappearance, with the last mode c altitude (at 0221:03) reported as 11,900 feet. Subsequent attempts by the controller to contact the aircraft were unsuccessful. A 7,000- to 7,500-foot overcast was reported at the destination, along with lower clouds and precipitation. The aircraft impacted approximately straight-and-level into a northwest-facing 60-degree mountain slope at approximately the 5,600-foot level, and was not located for approximately two months. Post-accident examinations of the aircraft's bendix/king KEA-130A (united instruments 5035PB-P57) encoding altimeter revealed needle capture and needle impressions on the indicator face and pointers consistent with an altitude indication of 12,620 feet at impact. The aircraft was also equipped with a copilot's altimeter; examination of an altimeter face forwarded by the accident pilot's father, which the pilot's father reported had been recovered from the accident site, re vealed needle impressions on that alimeter face consistent with an altitude indication of 5,560 feet at impact. The pilot's 4-DAY activity history showed that he was returned from a demanding 3-DAY work assignment, that his recent sleeping schedule was irregular, and that he had been awake about 20 hours at the time of the accidnet.
As the FAA filed it
DISAPPEARED FROM RADAR FAST OF FCA IN MOUNTAIN TERRAIN. BECAME MISSING. (-23) ON APRIL 11, 1998 AT 0221 MDT A PIPER NA-46-350P MALIBU N9247W REGISTERED TO CM SYSTEMS OF POLSON, MT AND BEING FLOWN BY AN AIRLINE TRANSPORT PILOT DISAPPEARED FROM RADAR 20NM EAST-SOUTHEAST OF GLACIER PARK INTERNATIONAL AIRPORT (FCA) KALISPELL, MT. THE AIRCRAFT IS MISSING AND PILOT AND PASSENGER ARE PRESUMED TO HAVE SUSTAINED FATAL INJURIES. THE FLIGHT WAS PRESUMED TO BE PERSONAL FROM MADISON, WI TO POLSON, MT. (.4)THE AIRCRAFT DISAPPEARED FROM AIR TRAFFIC CONTROL (ATC) RADAR IMMEDIATELY AFTER BEING CLEARED TO DESCEND FROM 12,000 FEET TO 10,000 FEET. ATC RADAR DATA SHOWED THE AIRCRAFT AT 11,900 TO 12,000 FEET FOR APPROXIMATELY THE LAST 6 MINUTES PRIOR TO THE DISAPPEARANCE, WITH THE LAST MODE C ALTITUDE (AT 0221:03) REPORTED AS 11,900 FEET. SUBSEQUENT ATTEMPTS BY THE CONTROLLER TO CONTACT THE AIRCRAFT WERE UNSUCCESSFUL. A 7,000- TO 7,500-FOOT OVERCAST WAS REPORTED AT THE DESTINATION, ALONG WITH LOWER CLOUDS AND PRECIPITATION. THE AIRCRAFT IMPACTED APPROXIMATELY STRAIGHT-AND-LEVEL INTO A NORTHWEST-FACING 60-DEGREE MOUNTAIN SLOPE AT APPROXIMATELY THE 5,600-FOOT LEVEL, AND WAS NOT LOCATED FOR APPROXIMATELY TWO MONTHS. POST-ACCIDENT EXAMINATIONS OF THE AIRCRAFT'S BENDIX/KING KEA-130A (UNITED INSTRUMENTS 5035PB-P57) ENCODING ALTIMETER REVEALED NEEDLE CAPTURE AND NEEDLE IMPRESSIONS ON THE INDICATOR FACE AND POINTERS CONSISTENT WITH AN ALTITUDE INDICATION OF 12,620 FEET AT IMPACT. THE AIRCRAFT WAS ALSO EQUIPPED WITH A COPILOT'S ALTIMETER; EXAMINATION OF AN ALTIMETER FACE FORWARDED BY THE ACCIDENT PILOT'S FATHER, WHICH THE PILOT'S FATHER REPORTED HAD BEEN RECOVERED FROM THE ACCIDENT SITE, RE VEALED NEEDLE IMPRESSIONS ON THAT ALIMETER FACE CONSISTENT WITH AN ALTITUDE INDICATION OF 5,560 FEET AT IMPACT. THE PILOT'S 4-DAY ACTIVITY HISTORY SHOWED THAT HE WAS RETURNED FROM A DEMANDING 3-DAY WORK ASSIGNMENT, THAT HIS RECENT SLEEPING SCHEDULE WAS IRREGULAR, AND THAT HE HAD BEEN AWAKE ABOUT 20 HOURS AT THE TIME OF THE ACCIDNET.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.