Aviation Accident Summaries

Aviation Accident Summary ANC95GA048

BUMPING LAKE, WA, USA

Aircraft #1

N97843

Cessna 182Q

Analysis

The private pilot, a civil air patrol (CAP) volunteer, was on a CAP flight for proficiency training and to conduct business. The VFR cross-country flight was planned over mountainous terrain. The pilot obtained a weather briefing that included information about icing conditions along the planned route. During the flight, no communication was received from the pilot other than activation of his flight plan after departing the airport. The airplane was reported overdue, but a search was hampered due to IFR conditions and snow. No transponder code was issued to the airplane, and no discrete radar data was located in stored radar data to assist in locating the airplane. By 0900 on 4/15/95, analysis of the primary target radar returns helped in locating the accident airplane. Also, only an intermittent signal was transmitted from the airplane's emergency locator transmitter (ELT). The wreckage was located 3 days later, where the airplane had crash landed on snow covered mountainous terrain. Investigation revealed the pilot initially survived the accident, but succumbed to hypothermia. He was wearing a flight suit over dress clothes, a flight jacket, and dress shoes. No survival equipment was required to be carried in the airplane. The pilot had a personal survival kit, but had left it in his vehicle at the departure airport. A note found in the wreckage indicated that the engine lost power. After recovery, the engine operated normally. The transponder switch was found in the "standby" position; inspection of the ELT revealed a faulty tuning crystal. The pilot had received training in survival skills and was a CAP survival skills instructor.

Factual Information

HISTORY OF FLIGHT On April 12, 1995, about 0615 Pacific daylight time, a Cessna 182Q, N97843, crashed during an emergency landing, about 4 miles east of Bumping Lake, Washington. The airplane, registered to the Civil Air Patrol (CAP), Maxwell Air Force Base, Alabama, and operated by the Washington Wing of the CAP (WACAP), sustained substantial damage. The airplane was being operated as a visual flight rules (VFR), cross-country flight to Boise, Idaho. The pilot's itinerary included a proposed business meeting. The CAP indicated the flight was a military auxiliary proficiency training flight. The Yakima County Coroner reported the pilot received minor injuries during the accident but later succumbed to hypothermia. The certificated private pilot, the sole occupant, filed a VFR flight plan to Yakima, Washington. A primary radar target was located departing the Auburn Municipal airport, Auburn, Washington, at 0502. At 0409, the pilot obtained a weather briefing from the Federal Aviation Administration (FAA), Seattle Automated Flight Service Station (AFSS). The pilot indicated the route of flight was from Auburn, to Yakima, Washington, with a continuation to Boise, Idaho, via Pendleton, and Baker City, Oregon. The briefing included a local field Notice to Airmen (NOTAM) that the unicom radio facility at the Auburn airport was out of service. The pilot then filed his VFR flight plan to Yakima, Washington. After departure, the pilot opened his flight plan with the Seattle AFSS at 0519. A review of primary radar data located a target at 0519 that was about 20 miles southeast of Auburn. No further communication was received from the pilot. When the pilot failed to close his flight plan, the FAA began a telephone and airport search for the airplane. About 0850, the airplane was declared overdue and an alert notice (ALNOT) was issued. The FAA notified State of Washington, Department of Aeronautics (WADOA) personnel of the missing airplane. An aerial and ground search was initiated for the missing airplane. Poor weather conditions in the area, including low ceilings, snow, and thunderstorms, hampered search efforts. Emergency locator transmitter (ELT) signals in the area of the search were intermittent throughout the search. Search personnel did not locate any discreet transponder radar data from the airplane. On April 15, 1995, about 1115 hours, the airplane was located about 32 miles northwest of Yakima, Washington. The location was about 4.5 miles southeast of Bumping Lake Dam in the William O. Douglas Wilderness Area on the northwest ridge of Nelson Butte. The accident occurred during the hours of daylight at latitude 46 degrees, 49.37 minutes north, and longitude 121 degrees, 12.49 minutes west, about 7,100 feet mean sea level. CREW INFORMATION The pilot held a private pilot certificate with an airplane single engine land rating. The most recent third class medical certificate was issued to the pilot on July 5, 1994, and listed no limitations. According to the WACAP, the pilot's total aeronautical experience consisted of about 266 hours, of which 96 were accrued in the accident airplane make and model. In the preceding 90 and 30 days prior to the accident, the pilot accrued a total of 31 and 11 hours respectively. On July 12, 1994, the pilot received a CAP Form 101T (training) authorization for search and rescue mission pilot that was signed by his unit commander. The pilot qualified to fly a CAP Cessna 182 on July 22, 1994, by completion of a check ride (CAP Form 5). The pilot received a CAP Form 101 authorization for transport mission pilot on September 21, 1994. The pilot had not completed a search and rescue mission pilot check ride (CAP Form 91). AIRCRAFT INFORMATION The airplane had accumulated a total time in service of 1,583 flight hours. The most recent annual inspection was accomplished on March 31, 1995, 3 flight hours before the accident. The engine had accrued a total time in service of 25 hours of operation since being installed as a remanufactured engine. An annual inspection was accomplished on March 31, 1995. METEOROLOGICAL INFORMATION The closest official weather observation station at Stampede Pass, Washington, is located 28 miles north of the accident site at an elevation of 3,800 feet msl. At 0533, a special observation was reporting, in part: Sky condition and ceiling, measured ceiling 2,600 feet broken, 5,000 feet overcast; visibility, 4 miles in light snow; temperature 34 degrees F; dew point, 25 degrees F; wind, 100 degrees at 13 knots, gusts to 21 knots; altimeter, 29.87 inHg; remarks, snow began at 0527. A 0556 special observation at Stampede Pass was reporting, in part: Sky condition and ceiling, measured ceiling 1,800 feet overcast; visibility, 2 1/2 miles in light snow; temperature, 34 degrees F; dew point, 26 degrees; wind, 110 degrees at 10 knots, gusts to 19 knots; altimeter, 29.87 inHg. A 0550 observation from Yakima, Washington, elevation 1,100 feet msl, located 32 miles southeast of the accident site, was reporting, in part: Sky condition and ceiling, measured ceiling, 7,000 feet overcast; visibility, 20 miles; temperature, 45 degrees F; dew point, 31 degrees F; wind, 010 degrees at 4 knots; altimeter, 29.95 inHg. A 0650 observation from Yakima was reporting, in part: Sky condition and ceiling, measured ceiling 5,000 feet overcast; visibility, 30 miles in light rain; temperature, 43 degrees F; dew point, 33 degrees F; wind, 150 degrees at 3 knots; altimeter, 29.95 inHg. Examination of meteorological data from the area of the accident was conducted by a National Transportation Safety Board meteorologist. In the area of the accident, radar data indicated weak radar echoes. Upper air data indicated that the winds aloft were southerly about 25 knots near 10,000 feet. Cloud tops were decreasing and were moving to the northeast. The transcribed weather broadcast for the Seattle, Stampede Pass, and Ellensburg, Washington areas stated, in part: "All heights are mean sea level except ceilings. Cascades/ Passes partly obscured by clouds. West of the Cascades, 3,000 to 5,000 feet scattered clouds, cirrus clouds above. Between 0500 and 0800, isolated visibilities 3 to 5 miles in fog. At 0900, 4,000 feet scattered clouds, 8,000 feet scattered to broken clouds, 12,000 feet scattered to broken clouds, cirrus clouds above. East of the Cascades, 6,000 to 8,000 feet scattered clouds, thin cirrus clouds above. At 1000, 6,000 feet scattered to broken clouds, 12,000 feet scattered to broken clouds, cirrus above. No amendments available for Stampede Pass or Ellensburg." Airmet Zulu, issued for icing and freezing levels and valid until 0700, stated in part: "Icing...Washington, Oregon, California and coastal waters, Idaho, Montana, and Nevada. From 120 miles west of Hoquiam, Washington to Missoula, Montana to Salmon, Idaho to 40 miles southeast of Rome, Oregon to 150 miles west of Salinas, California to 120 miles west of Fortuna, California to 120 miles west of Hoquiam. Occasional moderate rime/mixed icing in clouds and precipitation between 6,000 and 16,000 feet. Conditions spreading into eastern portion of the area and continuing beyond 1000 through 1300. Freezing level...Washington, 4,000 feet in northwestern Washington, sloping to 6,000 feet southeastern..." COMMUNICATIONS During the weather briefing, the AFSS specialist advised the pilot of potential hazardous weather conditions by providing information about an AIRMET. The specialist stated, in part:"...they're showing an AIRMET from Hoquiam to just north of Yakima and south of that line, occasional moderate icing, rime or mixed, and that's from six thousand to sixteen thousand and that's the only airmet that we do have that's on your route and you're on the northern edge of that, synoptic-wise..." The specialist included a route forecast, stating, in part:"...on the route forecast that goes across Stampede pass, ah looks like they're calling for west of the Cascades, three to five thousand scattered, cirrus above that and that's up until sixteen hundred zulu (0900), and with some isolated visibilities three to five miles in fog, and they, looks like there might be some fog developing for a little while this morning east of the Cascades, six to eight thousand, scattered thin cirrus above and that's up to about ten a.m., so it looks good goin over there..." A complete transcript of telephone communications between the pilot and the Seattle AFSS is attached to this report. A review of FAA National Track and Analysis Program (NTAP) radar data from the Seattle Air Route Traffic Control Center (ARTCC) did not reveal any discrete transponder codes associated with the accident airplane. ARTCC personnel located primary radar hits from a review of NTAP data and were assisted by California Civil Air Patrol (CACAP) Pacific Region personnel in Oakland, California. An enclosed NTSB graphical representation of radar data depicts NTAP points as diamonds. Straight lines between data points are for continuity of data points and may not necessarily reflect the aircraft position at anytime between the points. WRECKAGE AND IMPACT INFORMATION A Safety Board investigator examined the airplane wreckage at the accident site on April 18, 1995. The wreckage was located approximately 4.5 miles from the Bumping Lake Dam on a 130 degree magnetic bearing, approximately 205 feet west of the northwest ridge of Nelson Butte. From the top of the ridge to a spot about 50 feet uphill from the wreckage, the terrain slopped down about 23 degrees. From that spot to the wreckage, the steepness of the slope was reduced to about 10 degrees. Just downhill from the airplane, the angle of slope increased to about 40 degrees. The nose of the airplane was oriented on a 015 degree magnetic heading, which was approximately parallel with the top of the ridge directly uphill from the wreckage. The airplane was sitting in snow that was estimated to be five to ten feet deep. From the top of the ridge to just below the wreckage, there were widely scattered groups of small coniferous trees. Most of the trees were between three and eight feet high. Downhill from the wreckage, the trees became much more dense. The fuselage, from the engine cowling back to the first bulkhead aft of the rear window, was laying in a nose down attitude of about 28 degrees. The lower engine cowling and most of the engine compartment was embedded in the snow, with about one-half of one propeller blade exposed above the surface. The lower portion of the windshield was broken out, and the left cabin door was found separated from the fuselage. The flaps were extended to the 30 degree position. The trailing edge of the elevator trim tab was displaced 3/8 inch up from the elevator. The airplane manufacturer reported that the displacement corresponded to a five degree tab up setting. The top portion of the fuselage was split open at the rear window bulkhead and there was a "V" shaped gap, about two and one-half feet wide at the top, running around approximately three-quarters of the structure. From that point aft, the fuselage was hanging toward the ground and twisted counter-clockwise, with the trailing portion of the empennage sitting in the snow. Except for the gap in the fuselage and some bent/torn skin about half the span of the left wing, most of the impact damage was limited to an area forward of the cabin door posts. The airplane's battery was still mounted to the airplane floor and both cables were still connected to their respective terminals. Initial testing of the battery found that it contained no charge. The inside of the cabin was relatively intact, with all seats remaining attached to their railings. The instrument panel was also intact, but displayed some distortion/twisting, and the left hand grip of the pilot's control yoke had been torn off. The airplane's transponder was found in the "standby" position. After the wreckage was removed from the accident site, the airplane's electrical system was connected to a military power cart generating 28 volts DC. The VHF communications radios were turned to the "on" position. Although the faces of the radios illuminated, and selection of different channels were possible, an attempt to transmit to the on-field control tower, both with a headset microphone and the hand-held microphone, was not successful. Both microphones were later shown to function properly. The reason for the failure to transmit was not determined. A WACAP FM radio that was installed in the airplane was removed and during later tests, functioned properly. The ELT had been removed by rescue personnel, but the coaxial cable leading from the ELT to its externally mounted antenna was still attached to the antenna jack. The cable had an eight inch diameter loop about half-way between the antenna base and the ELT. This loop was clamped tightly with a plastic tie-wrap, limiting the overall length of the antenna cable to 19 inches. Without the tie-wrap in place, the cable was about 41 inches in length. The end of the cable which had been attached to the ELT had a sharp bend in it, and both the plastic covering and the wire shielding mesh were kinked and distorted. After the airplane was recovered, the ELT was remounted in the fuselage. When the cable from the antenna to the ELT was held in place at the ELT connection, the cable was noted to be under extreme tension at its tie-wrap limited length of 19 inches. According to rescue personnel, the end of the cable which attaches to the ELT had pulled almost totally away from its jack. It was reported to be still laying in contact with the jack when initially found, but when rescue personnel reached into the fuselage to remove the ELT, the cable fell off the jack when brushed lightly by the rescuer's arm. When the wreckage was lifted out of the snow, it was noted that the carburetor heat box was bent, dented, and distorted. The tubing from the engine heat manifold to the male fitting on the carburetor heat box was disconnected. The fitting itself was dented and misshapen, and the metal hose clamp which had held the tubing to the fitting was lying in the snow under the lower cowling, undamaged. The propeller did not display any leading edge indentations, chord-wise scarring, or longitudinal twisting. The engine crankcase, cylinders, and accessories were not damaged. MEDICAL AND PATHOLOGICAL INFORMATION A postmortem examination of the pilot was conducted by the Yakima County Coroner's Office, 128 N. Second Street, Yakima, Washington, 98901, on April 17, 1995. The examination revealed that the pilot sustained injuries that included abrasions, lacerations, and contusions. The cause of death for the pilot was attributed to hypothermia. The corner noted that the pilot was wearing a flight suit over dress clothes, flight jacket, and dress shoes. The coroner did not state a date and time of death. A toxicological examination was conducted by the FAA's Civil Aeromedical Institute (CAMI) on December 1, 1995. The examination revealed that 59.00 mg/dl of acetone was detected in the urine and 24.00 mg/dl of acetone was detected in the blood. Medical personnel at CAMI indicated that the level of acetone could be attributed to the pilot being a diabetic or to fasting. The pilot was not a known diabetic. SURVIVAL ASPECTS The State of Washington mandates survival kits to be carried on airplanes used for compensation and in any rented or leased airplane. Airplanes owned by and exclusively used in the service of the U.S. government are exempt. The accident airplane, operated by the WACAP, was exempt from the requirement. The pilot had received training in survival skills and was a CAP survival skills instructor. CAP personnel reported that he usually carried a personal survival kit in the airplane. A kit was located in the pilot's personal vehicle at the departure airport. Several CAP aircraft have some type of survival items stored in each airplane; however, no consistent policy mandates an aircraft survival kit. After the accident, the crash site was subjected to low temperatures and snow. Ground searc

Probable Cause and Findings

A loss of engine power for an undetermined reason. Factors relating to the accident were: lack of suitable terrain for a forced landing in mountains, low ambient temperatures that contributed to hypothermia, the lack of survival equipment, an erratic ELT signal due to a faulty tuning crystal, and the lack of discrete transponder data to assist in the search.

 

Source: NTSB Aviation Accident Database

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