LINCOLN, MT, USA
N88JH
Cessna 340
During preflight weather briefing, the pilot was briefed to expect rain showers and thunderstorms up to Level 6 (extreme) intensity along his route of flight. The pilot, whose aircraft was equipped with radar and Stormscope equipment, filed an instrument flight rules (IFR) flight plan and departed under IFR. Upon radar contact, ATC cleared the pilot direct to his destination. 21 minutes later, while flying on the direct (northwesterly) track to the destination, the aircraft entered a Level 4 thunderstorm cell. The pilot told air traffic control (ATC), '...[I] hit a pretty heavy cell here [I've] got lightning all around and picking up some hard ice.' The crew of another aircraft deviating to the north of the storm suggested the aircraft turn north to exit the weather. ATC relayed this suggestion, and the pilot replied he was turning to the north. The aircraft then entered a right turn; radar contact was lost after approximately 90 degrees of turn. 6 seconds after the time at the last radar position, the pilot radioed, '...[I'm] in a tremendous downdraft [I'm] losing altitude six thousand'. This was the last transmission received from the accident aircraft. A search for the aircraft was initiated; the aircraft wreckage was found approximately 11 1/2 hours later, approximately 1 1/2 miles south of the last radar position. Logbooks recovered from the wreckage indicated the pilot was not current for IFR flight.
HISTORY OF FLIGHT On June 18, 1998, approximately 2207 mountain daylight time, radio and radar contact was lost with N88JH, a Cessna 340 registered to America West Communications of Ritzville, Washington, while on a 14 CFR 91 business flight from Gallatin Field, Bozeman, Montana, to Glacier Park International Airport, Kalispell, Montana. The flight was on an instrument flight rules (IFR) flight plan from Bozeman to Kalispell at the time of the disappearance. The wreckage of N88JH was located by search and rescue forces on the morning of June 19, 1998, approximately 8 nautical miles southeast of Lincoln, Montana. The aircraft was found to be destroyed, and the private pilot-in-command, who owned America West Communications and was the airplane's sole occupant, was found to have received fatal injuries. Visual meteorological conditions were reported at Helena, Montana (approximately 30 miles southeast of the accident site) at 2156 on June 18; however, the pilot reported to air traffic controllers that he had encountered a thunderstorm just prior to the loss of contact. Air traffic control (ATC) information furnished by the FAA indicated that the pilot contacted the FAA automated flight service station (AFSS) in Great Falls, Montana, by telephone from Bozeman approximately 2051 and again approximately 2114 on the evening of the accident. In the first contact, the pilot requested the current weather in Kalispell and eastern Washington between Moses Lake and Spokane (NOTE: Ritzville, where the pilot indicated the aircraft was based when he filed his IFR flight plan for the accident flight, is located approximately midway between Moses Lake and Spokane.) The briefer gave hourly observations for Bozeman and Kalispell in Montana and Moses Lake, Ephrata, Wenatchee and Spokane in Washington; all stations were reporting visual flight rules (VFR) conditions, with cumulonimbus distant in all quadrants at Kalispell. The pilot then asked if "this low front or this little front that was coming across" would be dissipating by morning; the briefer replied that marginal VFR conditions were forecast for the flight area, with no improvement forecast until late Friday (June 19) or early Saturday (June 20), approximately 24 to 36 hours after the time of the call. The pilot then asked for any pilot reports (PIREPs) or information on tops between Bozeman and Spokane; he was provided forecast cumulonimbus tops ranging from flight level (FL) 180 to FL 320 with associated shower activity and turbulence, and bases of a scattered to broken layer at 13,000 feet (with top of the layer at 14,000 feet) in Montana and Idaho. The pilot then asked, "but right now [K]alispell's open whats youre saying [sic]". He was told that it was open "right now" and was given the radar picture showing most echo activity south of Missoula and northwest of Great Falls, with significant light to moderate (but possibly heavy to very heavy) cells or precipitation through Missoula, Montana. The pilot replied, "ok well [I'm] in a three forty [I] may [I] may [sic] elect to go to [K]alispell [IFR] tonight". The briefer reiterated that the flight would cross significant shower activity and described Doppler radar decibel levels as reaching up to 57, level 6 and above in intensity, extreme. The pilot stated, "[I] know". The pilot then asked if the weather was predicted to "hang through tomorrow", and was told again to expect it through Saturday morning with an improving trend for a few days after that. The pilot then stated he would think it over and call back if he wanted to file a flight plan, and the briefer told the pilot again to expect the shower activity to continue for the next 24 to 36 hours. In the 2114 telephone contact with Great Falls AFSS, the pilot stated he was at Bozeman and wanted to go IFR to Kalispell in about 15 minutes. The Great Falls AFSS briefer confirmed the pilot's destination as Glacier Park International, and his intention to fly IFR. The pilot said he had called a few minutes ago and that "they said it was fairly clear up there." The briefer told the pilot that Kalispell was reporting cumulonimbus and showers distant northwest through northeast, and that the biggest areas of precipitation en route would be south of Missoula. The pilot replied that he was going direct from Bozeman to Kalispell, and that he could see "from here to [G]reat [F]alls". The briefer stated: yeah its uh its not bad at all going in that direction like [I] say just south and a little southeast of [M]issoula theres some light to moderate precipitation echoes uh you might keep your eyes open for that um other than that uh there is some uh cumulonimbus pretty much over the entire route but nothing too terribly bad [I] dont believe there are any convective sigmets not at this time and no sigmets... The briefer then gave the Kalispell terminal forecast, which was for VFR conditions with occasional light rain showers and occasional ceiling of 4,000 feet broken. The pilot then filed an IFR flight plan from Bozeman to Kalispell, giving the following data: cruise altitude 14,000 feet, proposed time of departure approximately 2130, 1 hour estimated time enroute at a true airspeed of 180 knots, and 5 hours fuel on board. At 2128, the pilot called the Salt Lake City, Utah, Air Route Traffic Control Center (ARTCC) by radio while on the ground at Bozeman, and requested and received his IFR clearance to Kalispell. The clearance was to Glacier Park International via the V343 Federal airway to the Drummond VOR, then direct, at 14,000 feet. At 2142, the pilot called Salt Lake ARTCC about 20 miles northwest of Bozeman at 14,000 feet (Gallatin Field, the departure airport, is non-towered), and radar contact with the aircraft was established. ATC then cleared the flight direct to Glacier Park International. Approximately 2144, the pilot requested and received a clearance to climb to 16,000 feet. At 2153, the pilot called Salt Lake ARTCC asking how his track looked to Kalispell, and was told that it looked good. The transcript of the pilot's communications with ATC indicated that at 2205:20, the pilot told the Salt Lake ARTCC controller, "...[I] hit a pretty heavy cell here [I]'ve got lightning all around and picking up some hard ice." The Salt Lake ARTCC controller then told the pilot that another aircraft approximately 10 to 12 miles north of his position, Alpine 5013, was going around the north end of the cell at 11,000 feet. The crew of Alpine 5013 then told the Salt Lake controller to tell N88JH to divert directly north in order to exit the weather. The Salt Lake controller told N88JH, "...suggestion is to uh turn to the north to avoid the weather." The pilot replied, "uh give me a steer", and the controller said, "uh heading three six zero", at 2206:14. The pilot replied, "roger turning three six zero" at 2206:17. The crew of Alpine 5013 subsequently described the storm as "heavy to extreme" on the sector frequency, reporting that "there's a lot of lightning out here just to the left of us." ATC radar data showed N88JH on a generally northwesterly course at approximately 16,000 feet at an average ground speed of 200 knots until the last secondary radar return at 2206:35 at 15,900 feet. Two correlated primary radar positions indicating a right turn of approximately 90 degrees were then depicted, the first at 2206:47 and the second at 2206:59, before loss of radar contact. At 2207:05, the pilot told Salt Lake ARTCC, "[I]'m in a tremendous downdraft [I]'m losing altitude six thousand." This was the last reported transmission from the accident aircraft. The controller cleared the pilot to descend at pilot's discretion to 12,000 feet at 2207:18, without response. The crash site was approximately 1 1/2 nautical miles south of the last (2206:59) radar position. The accident occurred at the end of evening civil twilight, during dark night conditions, at 46 degrees 52.5 minutes North and 112 degrees 31.6 minutes West. PERSONNEL INFORMATION According to FAA records, the pilot possessed a private pilot certificate with airplane single-engine land, airplane multiengine land, and instrument airplane ratings. He passed his FAA multiengine practical test on July 2, 1997, and he indicated that he had 2,400 hours total pilot time on his last FAA medical certificate application in March 1997. Documents (including a pilot logbook) recovered from the aircraft wreckage indicated that the pilot had approximately 237 hours of Cessna 340 time (all logged since May 1997), that he had undergone Cessna 340 initial training in July 1997 and that his last instrument competency check was completed on July 11, 1997. The pilot logbook recovered from the wreckage contained 22.0 hours of night time, with the most recent night time (1.5 hours of a 2.5-hour flight, with 3 landings) logged on March 20, 1998. The last pure night flight logged was March 13, 1998, a 2.2-hour flight with 2 landings. The logbook contained 18.2 hours of actual instrument time and 13.0 hours of simulated instrument time, including 8.5 hours of actual instrument time and 3 instrument approaches in the 6 calendar months preceding the accident. The most recent instrument time logged was 0.7 hours of actual instrument time on February 16, 1998. AIRCRAFT INFORMATION The aircraft records indicated that the accident aircraft (a 1972 Cessna 340, serial number 340-0007) was equipped with two Teledyne Continental Motors TSIO-520-J engines. The aircraft logbooks indicated that an annual inspection had been accomplished on the aircraft at Sunbird Aviation in Bozeman on June 18, 1998, and that both engines had undergone a turbocharger intercooler modification per FAA Supplemental Type Certificate (STC) SA4158NM (held by American Aviation of Spokane, Washington) coincident with the annual inspection at Sunbird Aviation. (NOTE: The log entries in both engine logbooks documenting the STC intercooler modification incorrectly gave the STC number as SA4148NM.) The STC intercooler modification (consisting of replacing the factory-installed intercooler with a more efficient heat exchanger, and attachment of an external cowling to the existing aircraft cowling to channel high-velocity air from the propeller through the intercooler) provided an increase in maximum manifold pressure from 33 inches Hg to 35.3 inches Hg, and an increase in engine power from 285 horsepower (HP) each engine (for an unmodified aircraft equipped with TSIO-520-K engines) to 310 HP each engine. A new turbocharger and exhaust wye were also installed on the right engine at the annual inspection, according to the right engine log. The engine logbooks indicated that both engines had 1,761 hours since major overhaul at the time of the annual inspection signoff. Teledyne Continental Motors service data give the recommended time between overhauls for TSIO-520 series engines as 1,400 hours. The aircraft records indicated that the aircraft was equipped with dual flight instrumentation, autopilot, deicing equipment, RCA AVQ-47 weather radar, a 3M WX-8 Stormscope weather mapping system, a King KN-74 area navigation (RNAV) system, and a Foster Airdata LRN500 LORAN-C receiver. The aircraft records indicated that the RNAV and LORAN systems were certified for VFR operations only, although the #1 and #2 VOR receivers were certified for IFR if not used with RNAV. A telephone inquiry to Sunbird Aviation's director of maintenance disclosed that, to the Sunbird maintenance director's recollection, all of the accident aircraft's installed equipment (to include radar, Stormscope, autopilot, navigation systems and deicing systems) was operational at the time of the annual inspection. The Sunbird maintenance director stated that no non-operational systems of these types were brought to Sunbird Aviation's attention by the aircraft owner, and he did not recall any of those systems being placarded as inoperative. The Sunbird Aviation director of maintenance reported that the accident flight was bound for Kalispell in order to have avionics work done on the aircraft at Rocky Mountain Avionics, an avionics shop at Glacier Park International Airport. A telephone inquiry to Rocky Mountain Avionics disclosed that scheduled work on the aircraft for that visit comprised installation of some radios, installation of an IFR-certified Global Positioning System (GPS), and pitot-static system tests. Rocky Mountain Avionics reported that the pilot had not requested any work to be done on the aircraft's weather radar or Stormscope systems. METEOROLOGICAL INFORMATION A meteorological study of the accident was conducted by the NTSB's Operational Factors Division in Washington, D.C. Review of Doppler weather radar data from the WSR-88D site at Missoula revealed that the flight entered an area of Digital Video Integrated Processor (DVIP) Level 4 echo activity approximately 1 minute and 40 seconds prior to the loss of radar contact. Review of Geostationary Operational Environment Satellite number 9 (GOES-9) infrared imagery recorded at 2200 on the night of the accident placed the accident site within a large, generally west-to-east oriented cluster of cumulonimbus clouds which lay across the flight's route from Bozeman to Kalispell. The meteorological study revealed that, based on an upper air sounding obtained from Great Falls, GOES-9 radiative temperatures at the location of the last ATC radar contact equated to cloud tops of approximately 27,000 feet at the last radar position, with a range of 20,000 to 31,000 feet in the immediate vicinity. The National Weather Service (NWS) Area Forecast included scattered rain showers and widely scattered thunderstorm activity with tops to 32,000 feet for the route of flight. No in-flight weather advisories were current at the time of the accident based upon the NWS issuance criteria definitions and none were required. The NTSB meteorological study disclosed no evidence that the NWS forecast the weather conditions inaccurately, that the FAA AFSS preflight weather briefer inadequately advised the pilot of current or forecast weather conditions for the flight, or that the NWS failed to issue any required hazardous weather advisories. U.S. Naval Observatory astronomical data indicated that the end of evening civil twilight at the location of the last ATC radar position occurred at 2207, coincident with the time radar contact with the aircraft was lost. There was no moon at the time radar contact was lost. WRECKAGE Investigators from the NTSB, FAA, and Cessna Aircraft Corporation performed an on-site examination of the aircraft wreckage on June 20, 1998. The aircraft was found to be totally disintegrated at the crash site. The largest section of airframe found was a section of the left side fuselage, approximately 6 to 7 feet long, that bore the accident aircraft's registration number N88JH. The impact was into a moderately to heavily wooded, north-south oriented draw. A series of three major ground scars, aligned on a north-south line roughly parallel to the draw, was observed on the west slope of the draw, which coursed downhill on approximately a 20-degree slope toward the south at that point. The centers of the first and third major ground scars were each spaced 17 feet from the center of the center major ground scar. A freshly broken treetop was observed to the north of the three major ground scars, with a vertical inclination angle of 59 degrees above horizontal measured from the nearest point of ground scarring to the treetop, and 34 degrees above horizontal measured from the center major ground scar to the treetop. The aircraft wreckage was scattered down the draw to the south of these three major ground scars for approximately 200 yards. There were several freshly downed and broken trees interspersed with the aircraft wreckage. Both engines were located approximately 200 feet south-southeast of the three major ground scars, one on the west slope of the draw and the other on the east slope of the draw. Both engines were missing their data plates, and investigators were unable to positively match the engines to their originally installed sides. Investigators designated the engine on the west slo
The pilot's improper or inadequate use of the aircraft's weather avoidance equipment, resulting in penetration of a Level 4 thunderstorm and subsequent loss of aircraft control from which the pilot did not recover. Factors included a thunderstorm and the pilot's lack of instrument currency.
Source: NTSB Aviation Accident Database
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