NTSB Factual Report

HISTORY OF FLIGHT

On September 9, 1983, approximately 1250 mountain daylight time, a Cessna 182N, N92368, collided with the terrain about 13 miles east of Kalispell, Montana. Although search and rescue teams and local law enforcement officials conducted a multi-day search, the aircraft could not be located by the time the official search was terminated. Although numerous searches were conducted in the area over the following 19 years, the aircraft was not located until August 9, 2002. On that day, two hikers came across the wreckage in an area of heavily wooded mountainous terrain. There were no clear signs of the private pilot and his passenger at the site, but due to the severity of the impact and the intensity of the post-crash fire, they are assumed to have sustained fatal injuries during the accident sequence. The aircraft, which was owned and operated by the pilot, was destroyed. A review of NTSB missing aircraft records revealed that the aircraft departed Glacier Park International Airport, Kalispell, Montana, at 1226 mountain daylight time on September 9, 1983. The pilot had been on an IFR flight plan en route to Billings, Montana, but had reversed course in order to return to Kalispell. During the attempted return, radio and radar contact were lost.

Just prior to takeoff, the flight had been cleared to climb to 12,000 feet, and six minutes after departure Salt Lake Center advised the pilot they had radar contact four miles northwest of Kalispell VOR. At that time the pilot requested a 360 degree right turn in order to climb high enough to clear the hills prior to proceeding on course. At 1237 the pilot advised Center that he was passing 9,500 feet and proceeding on course. Center acknowledged that transmission and requested that the pilot advise them when he reached 12,000 feet. About four minutes later the center controller asked the pilot what his altitude was then, and the pilot responded that it was 11,000 feet. About two minutes after that, the pilot advised Center that he would like to stay at 11,000 because he was "...having difficulty climbing." The center then advised the pilot that he would have to maintain his own terrain clearance at that altitude because the "minimum en routes" in that area was 10,900 feet. The controller also advised the pilot that he would have to be at 12,000 for the Center to provide vectors. At that time (1243:50) the pilot responded with "We'll try for twelve." A little less than one minute later (1244:38), the pilot advised Center that he was turning back toward Kalispell, and that he would like vectors. Center advised him that they could only clear him to 11,000 feet until he got a little closer to Kalispell, but the pilot responded that he was already down to 10,500. The controller then advised him that there was no traffic and that his present altitude "…should be no problem." About three minutes later, the controller asked the pilot what his altitude was then, and he replied that he was down to 8,800 feet. Because of his low altitude, the controller asked the pilot if he could see the ground, but the pilot stated that he could not yet see it. The controller then suggested that the pilot turn left to a heading of 230 degrees so that he would be heading toward lower terrain. The pilot advised the controller he was turning to the suggested heading, and at the request of the controller, responded that he would advise as soon as he could see the ground. At 1249:36 the controller asked the pilot if he was "still with me," but the responding transmission from N92368 was garbled and unreadable. The controller therefore asked another aircraft operating in the same area as N92368 to relay to the pilot the fact that the "minimum en route" in that area was about 8,500 to 9,000 feet. The aircraft relaying the message reported back to the controller that the pilot of N92368 had made a transmission that sounded like he either said that he was at 200 feet, or more likely he said 6,200 feet. The last audible transmission from N92368 occurred about 1250.

METEOROLOGICAL INFORMATION

On the morning of the flight, the pilot called Great Falls Flight Service Station for two separate weather briefings. The first was at 1000, and the second at 1150. During the first briefing, the pilot stated that his desire was to fly to Jackson, Wyoming, via Missoula, Drummond, Coppertown, and Dubois. He said that his second choice was to fly to Billings and drive on down to Jackson. During the briefing, the briefer advised the pilot that he would probably be in "better conditions" if he took the route to Jackson instead of to Billings, but he also mentioned the possibility of thunderstorms, mountain obscuration, and occasional moderate turbulence below 16,000 feet. He also mentioned to the pilot that the terrain along that route was "…a little bit tougher." At that point the pilot asked the briefer to confirm that he would have "smoother terrain" once he got past Great Falls if he flew to Billings instead. The briefer responded with "…for the most part yes." Then the pilot explained that he was "out of nice flat country, New Jersey," and that he only got out there every three or four years, and that "I don't want obscured mountains or turbulence." The pilot talked further with the briefer about the terrain and minimum en route altitudes (MEA's) on the route to Billings. Ultimately the pilot told the briefer that he had decided to go to Billings, but before the briefing terminated, the briefer advised the pilot that he would have to watch out for the possibility of some icing along that route. He further told the pilot that along that route there had been some light icing, and a few pockets of moisture where more than light icing had occurred, but that "…for the most part just occasional light mixed icing in the clouds above the freezing level." The pilot said "now we can watch for that," and then told the briefer he would call him from the airport for an update about a half hour before he was ready to depart.

After getting to the airport, the pilot called for the second briefing, this time for a route from Kalispell to Billings, via Great Falls and Lewiston. During that briefing, he was advised that along that route there would be occasional moderate turbulence, mountain obscuration, layered clouds from 4,500 feet to 14,500 feet, and some rain showers. The controller also said that the freezing level around Glacier Park (located about 20 miles east of Kalispell) would be about 8,000 feet, with a freezing level of about 10,000 to 11,000 feet in the Billings area. After being advised of the freezing levels en route, the pilot told the controller, "You got me worried about that freezing level. Is there any report of icing in that?" The briefer responded with, "… we haven't had any reports of any ice at Glacier Park yet." Then, after the briefer reiterated that pilot reports indicated that the tops of the clouds around the mountains were about 14,500 feet, the pilot filed an IFR flight plan to Billings.

The weather observation taken at 1257 at Kalispell indicated a sky condition of 3,800 feet scattered, estimated 6,000 broken, 25,000 overcast, visibility 30 miles, temperature 52 degrees Fahrenheit, dew point 36 degrees, wind from 230 at 13 knots gusting to 17 knots, altimeter of 30.09, with breaks in the overcast, and showers over the mountains.

A pilot flying another Cessna 182 in the same general area at about the same time stated, "I observed heavy dark clouds with moderate rain showers on Victor 536 (an airway) just east of the FCA (Kalispell) VOR. The bases were about 6,300 MSL (Mean sea level), and the ridge just east of the VOR was obscured." The same pilot said, "Had I known he was leaving IFR, I would have warned him about the possibility of ice over the range east of the VOR, and of severe mountain wave on the leeward side of the range. In the conditions that existed that day, the wave can have 2,000 feet per minute vertical down air under 14,000 feet just east of the crest of that range and in the area that ATC lost 92368 on radar."

Although there were no icing reports at the time the pilot received his briefings, instrument meteorological condition and airframe icing was reported by other pilots flying in the general area about the same time the pilot reported he was returning to his point of departure.

WRECKAGE AND IMPACT INFORMATION

The aircraft wreckage was located at N 48 degrees, 07.366 minutes, and W 113 degrees 53.309 minutes. The accident site elevation was approximately 5,500 feet. The wreckage was located near the bottom of a deep valley approximately 50 feet upslope on the northeast side. The valley ran approximately north/south with a down slope to the north. The terrain rose steeply to about 6,800 feet on the northeast side and about 6,000 feet on the southwest side. The terrain was densely covered with 100 foot plus deciduous trees with a thick brush ground cover underneath.

The wreckage was contained in generally one location on an approximate 20-degree slope. The fuselage was pointing 310 degrees magnetic. A large tree had fallen over the top of the wreckage and covered the engine and cockpit area. The wreckage underneath this tree was burned extensively, however the tree was not fire damaged, indicating that it fell sometime after the accident. Two trees located approximately 30 feet down slope on a magnetic bearing of 230 degrees from the wreckage were broken near their tops approximately 50 feet from their base. A wing tip cap remained snagged in the limbs of one of the trees near its broken top. No other trees appeared to be broken. An eight-foot section of the right wing was on the upslope side and the left wing was on the down-slope side. Both wing sections were severely deformed and twisted. Sections of flap and aileron remained attached to their hinge points. Both wing lift struts were located near their respective wing sections. Both wings displayed evidence of minor heat distress. A two-foot section of the left wing at the wing root displayed a circular indentation measuring 13 inches in diameter. A 29-inch section of the flap remained attached at one hinge point. The cockpit was destroyed by fire, and no cockpit readings were preserved. The fuselage was destroyed by fire. A small section of the right horizontal stabilizer with a small section of elevator attached was found about 10 feet uphill from the main wreckage.

The engine was positioned approximately 80 degrees nose down in the soil and was mostly buried. The accessories were destroyed by fire. The vacuum pump remained attached to its mount. An internal inspection of the pump revealed that the rotor remained intact and two of the vanes displayed surface gouging. The internal walls of the pump housing were not scored. The bearing rotated freely, however, the gear shaft would not rotate. There was no evidence of corrosion. Due to the position of the engine in the ground, only the topside spark plugs were inspected. Plugs from cylinders 1,2,4 and 5 were removed. Although corrosion was noted, the electrodes displayed normal operating signatures. All cylinders appeared intact. The engine was an O-470-R, s/n: 203061-9-R. Both magnetos were broken from their mounts, the alternator was crushed, and the oil cooler was bent in a "U" shape. The engine case and cylinders were intact with only minimal external damage. The propeller, throttle and mixture controls were all forward. The propeller assembly separated from the crankshaft at the flange and was located near the engine. Blade A displayed "S" bending and twisting about 20 to 30 degrees and bowed forward about 10 to 20 degrees. The blade tip was wrinkled and bowed forward another 45 degrees. Blade "B" displayed a more pronounced "S" bending and twisting than blade "A". There was a deep gouge approximately mid range along the leading edge of this blade. The blade tip was twisted. The spinner, which remained attached to its mounting bulkhead, was crushed aft and displayed evidence of significant heat distress and melting.

ADDITIIONAL DATA NAD INFORMATION

No autopsy or toxicology tests could be performed due to insufficient human remains.

Due to the remoteness of the terrain and the extent to which the remaining wreckage had been covered by the natural overgrowth, local officials made the decision not to try to remove any portion of the aircraft.

NTSB Probable Cause

The pilot's failure to maintain clearance from the terrain while attempting to maneuver back to the departure airport after encountering icing conditions. Factors include icing conditions, mountainous terrain, and low ceilings.