Aviation Accident Summaries

Aviation Accident Summary SEA97FA097

BULLFROG, UT, USA

Aircraft #1

N732QB

Cessna T210M

Analysis

A witness at the airport observed the aircraft arrive and reported it as being 'slower and lower' than other aircraft he had seen arriving. He also reported that 'at the north end he (the aircraft) made a sharp left turn - he seemed vertical to the ground.' A witness in a different location confirmed seeing the aircraft at a high angle of bank. The aircraft impacted the ground approximately 40 degrees nose low and 90 degrees left wing down. The pilot was experienced in the accident aircraft and familiar with the airport. The aircraft's weight at the time of the accident was estimated to be between 3,350 to 3,800 pounds (the latter weight being maximum gross takeoff weight). No evidence of control or power plant malfunction was found. The flaps were fully extended as were the landing gear. The fire damaged remains of an assortment of tools, construction material, personal effects as well as a cooler of beer, all totaled to weigh an estimated 200 pounds minimally, were found in the cabin area. The pilot-in-command's toxicology was negative, however the rear left seat passenger screened positive for ethanol (0.14 gm/dl blood (heart) and 0.15 gm/dl vitreous).

Factual Information

HISTORY OF FLIGHT On May 3, 1997, approximately 0958 mountain daylight time, a Cessna T210M, N732QB, registered to High Country Flying Club, and being flown by a private pilot, collided with terrain following a loss of control in flight while turning on final approach to runway 19 at the Bullfrog Basin airport, Bullfrog, Utah. The pilot and three passengers were fatally injured, and the aircraft was destroyed by impact and a post crash fire. Visual meteorological conditions prevailed at the time and no flight plan had been filed. The flight, which was personal, was to have been operated under 14CFR91, and originated from Gunnison, Colorado, approximately 0845 on the morning of the accident. Shortly before the accident a radio call to the Bullfrog Basin UNICOM on frequency 122.8 mHz was received from N732QB. The radio call was handled by an employee of Arrowmark who provided the UNICOM service for the airport. She reported that the pilot reported inbound and inquired about conditions at the airport and she advised him that the wind was 2 knots at 190 degrees with no reported traffic in the area. No further contact occurred with the aircraft. Several witnesses reported observing the aircraft. One witness, on horseback located east of the airport reported that "the aircraft was flying westbound just north of the north end of the runway" and that "the left wing was straight down (and) the right one was straight up." This witness reported that when he looked back at the plane he saw a column of smoke. A second witness located several miles south of the airport, and who reported flying experience in the Cessna 210 aircraft, reported seeing the aircraft in flight although he did not see the descent to the crash site. He reported that he "did not notice anything unusual about the aircraft. It sounded normal. Its speed, altitude, and attitude appeared normal for being on the down wind leg of a standard left hand traffic pattern for runway 19." He could not recall whether the landing gear were extended. A third witness waiting at the airport for the accident aircraft to arrive reported observing the aircraft come in "from the south slower and lower than most I've seen land at the airstrip." He reported that "the engine sound(ed) smooth as he went by" and that "at the north end he made a sharp left turn - he seemed vertical to the ground and was east of (the) runway." The witness then looked down and when he looked back up the aircraft had impacted the terrain. PERSONNEL INFORMATION Three personal logbooks maintained by the pilot were reviewed by the investigator and the following information was noted: Logbook number one was opened on February 7, 1972, with the commencement of instructional flights. The last recorded entry was May 11, 1977, and the total flight time logged was approximately 375 hours. No Cessna 210 time was logged. Logbook number two was opened on May 13, 1977. The last recorded entry was December 20, 1984, and the total flight time logged was approximately 463 hours. Aside from a single log entry on July 7, 1978, showing 9.8 hours of Cessna 210 flight time (N6844R), no Cessna 210 time was logged until December 3, 1980. This entry was entered as aircraft N732QB and all remaining Cessna 210 flights logged were in this aircraft. A total of approximately 318 hours of 210 time was logged in this logbook. Logbook number three was opened on January 10, 1985. The last recorded entry was January 22, 1997, and the total flight time logged was approximately 406 hours (401 pilot-in-command). All but three of the entries within this logbook were Cessna 210 flights conducted in N732QB. A total of approximately 403 hours of 210 time was logged in this logbook. The last flight recorded in this logbooks was a bi-annual flight review conducted in the accident aircraft. No records were available for the pilot beyond the January 22, 1997, time period. The pilot's brother reported that he had made a number of trips into the Bullfrog Basin airport and that the trip on May 3, 1997, was intended for the purposes of maintenance on the pilot's houseboat at Lake Powell. A review of the pilot's three logbooks revealed the following entries: DATE: ACFT: DESTINATION: 09/21/75 C-182 Bullfrog 09/24/78 C-206 Lake Powell 10/06/83 C-210 Bullfrog 05/27/85 C-210 Bullfrog 05/16/87 C-210 Bullfrog 08/12/90 C-210 Bullfrog 08/08/91 C-210 Bullfrog 05/26/93 C-210 Bullfrog 03/18/94 C-210 Powell 10/21/95 C-210 Powell 05/09/96 C-210 Powell 05/19/96 C-210 Powell 06/09/96 C-210 Powell 03/30/97 C-210 Bullfrog (from ATTACHMENT RL-I) AIRCRAFT INFORMATION The airframe logbook for N732QB showed an annual inspection conducted on January 10, 1997, at a total time (tach) of 2,999 hours. The last entry in the engine logbook showed an oil change on April 31, 1997, at a tach time of 3,023 hours. The time accrued between this date and the date of the accident was unknown and the times entered in NTSB Form 6120.4 are based upon the information up to April 31, 1997, as well as information found on ATTACHMENT RL-1 (discussed further). Records showed that the aircraft was fueled with 30 gallons of 100 low lead grade aviation fuel by Gunnison Valley Aviation on the morning of May 3, 1997. The fueler could not verify whether this topped the aircraft's fuel tanks or not. The aircraft's fuel capacity was 90 gallons. It's maximum gross takeoff weight (MGTOW) was 3,800 pounds and, according to the most recent weight entry within the airframe log, its empty weight was 2436.4 pounds. A projected fuel load based on the weights of the occupants, estimated baggage/cargo weight and aircraft empty weight subtracted from the MGTOW was derived as follows: Aircraft MGTOW: 3800# Aircraft empty weight: -2436# Pilot weight (note 1): -207# Passenger #1 (note 2): -195# Passenger #2 (note 2): -160# Passenger #3 (note 2): -155# Bags & Cargo (note 3): -200# Total [NO FUEL] WT : = 3353# Maximum allowable fuel weight for takeoff from Gunnison: 3800# - 3353# = 447# (=74.5 gallons) Note 1: weight derived from FAA medical records Note 2: weights derived from driver's license records Note 3: weight estimated and discussed further METEOROLOGICAL INFORMATION A witness located at the Bullfrog Basin airport at the time of the accident reported that the "windsock was flat down" and that it was "bright and sunny." A second witness located several miles south of the accident site estimated the winds as "steady out of 200 degrees (approx) at 7-9 knots." AERODROME INFORMATION The Bullfrog Basin airport is serviced by a single 3,500 foot long asphalt runway (01/19) measuring 40 feet in width. The airport elevation is 4,167 feet above sea level (ASL). The geography of the runway is such that the runway slopes gradually uphill from its approximate midpoint toward each end. There is no VASI nor any other visual system providing vertical guidance to landing pilots. The airport is unattended and has no fueling facilities. WRECKAGE AND IMPACT INFORMATION The ground impact site was established at 37 degrees 33.22 minutes north and 110 degrees 42.61 minutes west latitude and longitude respectively using a hand held global positioning unit. The elevation of the ground impact site was approximately 4,175 feet above mean sea level. The terrain at the site was characterized by gently sloping hard packed dirt mixed with small rock aggregate. The crash site was located approximately 700 feet north northeast of the approach end of runway 19 at the Bullfrog Basin airport (refer to CHART I). The first evidence of ground impact was a ground scar oriented along a 219 degree magnetic bearing line. The ground scar measured approximately 40 feet in length with its southwest end terminating in a crater approximately one foot deep. The main wreckage of the aircraft was observed at a point approximately 60 feet southwest of this crater. The left wingtip cap was observed slightly east of this bearing line approximately midway in the 40 foot scar. All three propeller blades were observed lying on the ground slightly east of the bearing line and just south of the final impact crater (refer to photograph 1 and page 3 of Supplement I). The northeast end of the scar, characterized by a small crater, contained fragments of broken red glass from the aircraft's left wingtip navigation light (refer to photograph 2). The engine, located at the southwest end of the 100 foot ground track, was observed inverted as was the cockpit, cabin and empennage, all oriented along an approximate 240 degree magnetic bearing line (tail west). The entire wing assembly was observed lying upright on the ground with its lateral axis oriented along an approximate 258 degree magnetic bearing line (left wingtip west). An extensive post crash fire had consumed the cockpit and cabin area of the aircraft (refer to photographs 3 through 5, and 10). The three propeller blades, which had been ejected from the hub assembly, were observed lying on the ground within several feet of one another and with their blade axes relatively parallel to one another (the blades were reported to have been left in place (undisturbed) during the rescue operation). Fragments of shattered windscreen were observed on the ground in this area (refer to photograph 6). All three blades displayed extensive leading edge polishing, paint abrasion, chordwise scratching and blade twist and bending deformation (refer to photographs 7 through 9). The right wing sustained leading edge fire damage, however, the right plastic wingtip cap remained attached to the wing (refer to photograph 11). The fuel cap was observed in place. The empennage, including the horizontal and vertical control surfaces sustained some impact and fire damage. The outboard portion of the right horizontal stabilizer, elevator and trim tab were observed to be crushed and deformed upward with little fire damage. The left horizontal stabilizer and elevator were observed to be relatively undamaged aside from some fire damage at the leading edge of the stabilizer. The vertical stabilizer and rudder were observed to be relatively undamaged with the exception of some damage at the top forward portion of the stabilizer leading edge (refer to photographs 12 and 13). The left wing was observed to be broken along its chord line at a point forward of the flap/aileron seam and this outboard portion of the left wing was folded over on top of the inboard portion (refer to photograph 13). The outboard portion of the wing was repositioned into its normal location and a substantial impact crush was noted at the outboard tip and leading edge area (refer to photograph 14). A crush angle of approximately 40 degrees was measured relative to the wing's lateral axis (refer to photograph 15). Both left and right main landing gear struts were observed to be in an extended orientation. The right wheel was observed to have been destroyed by fire whereas the left wheel remained attached to its strut and displayed some fire damage (refer to photographs 16 and 17). The nose landing gear strut was observed to be extended and displayed minimal bending deformation. Its wheel, although fire damaged, remained attached to the nose gear fork unit (refer to photograph 18). The flap jackscrew unit was examined and found in a position consistent with 30 degrees of extension or flaps full down (refer to photograph 19). There were no missing control surfaces at the accident site and control continuity from the cockpit area to the three main control surfaces was verified on site. Additionally, the elevator trim extension was found to be 1.25 inches, corresponding to a neutral position. The engine, which had been subjected to the post crash fire, was examined and there was no observed evidence of any pre-impact breach of the engine case (refer to photograph 20). The propeller hub was observed to have been broken off the forward portion of the engine. The engine turbo-charger impeller was found to rotate freely with some direct/sand within the compressor area. The crankshaft was rotated slightly with concurrent rotation of the accessory drive gears observed. The throttle body was observed to be substantially melted with only the butterfly valve remaining. Both magnetos were fire damaged. The spark plugs were observed to exhibit normal wear. Within the remains of the cockpit/cabin area were numerous tools, boxes of sockets and wrenches, power tools (saw, battery operated screwdriver and drill), an assortment of nuts, bolts and screws, an unknown amount of lumber (two by four remains), personal effects, a single water ski and the remains of an ice chest with numerous cans labeled "Budweiser" (refer to photograph 21). There was no evidence observed within the remains of a cargo net or cargo retention webbing at the site. Cockpit instrumentation had been destroyed by fire. However, a clock from the aircraft's instrument panel was observed to have stopped operating. Although the face was burned off the clock, the hour and minute hands were oriented approximately to 9:58. Two pages torn from a spiral bound notebook were recovered from the accident site by emergency response personnel. One page was partially burned. Both pages displayed entries arranged in columnar format with a date column at the left followed by three columns of numbers, an open fifth column of "notes" and a sixth column containing initials. The entry at the top of the burned page opened on "1-6-96" with the second column reading 2999.3, the third column reading 3001.0, the fourth reading 1.7, followed by an entry in the fifth column reading "maintenance." There were no initials in the sixth column. The number 2999.3 noted on 01/06/96 appears to be consistent with the tach time reading of 2999 hours from the airframe logbook dated 01/10/96. The last sequential entry on these two sheets was dated "4-18" and showed a closing entry of 3026.6 (third column) and the initials (sixth column) of GS (refer to ATTACHMENT RL-I). MEDICAL AND PATHOLOGICAL INFORMATION Post-mortem examination of the pilot and three passengers was conducted by Maureen J. Frikke, M.D., at the facilities of the State of Utah, Office of the Medical Examiner, 48 North Medical Drive, Salt Lake City, Utah, 84113, on May 4/5, 1997. Toxicological evaluation of samples from the pilot was conducted by the FAA's Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma. All tests were negative with the exception of a finding of ethanol detected in Kidney tissue. The report stated that "Ethanol found in this case is most likely from post-mortem ethanol production" (refer to attached Toxicology report). Additionally, a drug screen test was conducted by the Utah Office of the Medical Examiner and all results were reported as negative. A drug screen evaluation of samples from the three passengers was conducted by the Utah Office of the Medical Examiner and all results were reported as follows: One passenger (seat 1A) screened entirely negative, one passenger (seat 2B) screen positive for Naproxen (an anti-inflammatory analgesic), and the third passenger (seat 2A) screened positive for ethanol (0.14 gm/dl blood {heart} and 0.15 gm/dl vitreous). ADDITIONAL INFORMATION On-site examination of the wreckage was conducted on May 4, 1997, after which the wreckage was verbally released to the insurance representative. Written wreckage release was initiated on May 7, 1997, as documented on NTSB Form 6120.15 (attached). Pilot logs 1, 2 and 3 were returned via Federal Express to Mr. Kenneth R. Bergen, 36128 W. Hwy 50, Gunnison, CO, 81230, on March 19, 1998. Aircraft logs and records retained were returned via Federal Express to Mr. Ernest DeSpain at the address documented on NTSB Form 6120.15 on March 19, 1998.

Probable Cause and Findings

The pilot-in-command's failure to maintain adequate flying airspeed, for reason(s) unknown, resulting in a subsequent stall.

 

Source: NTSB Aviation Accident Database

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