Aviation Accident Summaries

Aviation Accident Summary SEA94FA225

LARAMIE, WY, USA

Aircraft #1

N79444

CESSNA 172K

Analysis

THE AIRCRAFT IMPACTED TERRAIN ABOUT 500 FEET BELOW RIDGELINE WHILE MANEUVERING IN A BOWL OR CANYON, DURING A CROSS COUNTRY FLIGHT TO ROCK SPRINGS, WYOMING. SURFACE WINDS AT THE NEAREST REPORTING FACILITY WERE FIFTEEN KNOTS, APROXIMATELY PERPENDICULAR TO THE RIDGELINE. THE AIRCRAFT WAS ON THE LEE SIDE OF THE RIDGELINE AT THE TIME OF IMPACT. POST-CRASH FIRE CONSUMED ABOUT 10 ACRES OF FOREST.

Factual Information

HISTORY OF FLIGHT On August 26, 1994, approximately 1710 mountain daylight time, a Cessna 172K, N79444, was destroyed by impact damage and post- crash fire while maneuvering below ridgeline in a canyon southwest of Laramie, Wyoming. The private pilot and his passenger were fatally injured. No flight plan was filed for the flight, which originated from a private airstrip near Erie, Colorado, at about 1500, and was reported to be en route to Rock Springs, Wyoming. Visual meteorological conditions prevailed at the time of the accident. The ELT was consumed by post-crash fire. The aircraft impacted the terrain in a steep mountainous area on the eastern face of the Medicine Bow mountain range, about 500 feet below ridgeline. Post-crash fire consumed about ten acres of forest. PERSONNEL INFORMATION The pilot's log books and flight records were not recovered or located. No record of a biannual flight review was located. AIRCRAFT INFORMATION The aircraft log books were not recovered or located. METEOROLOGICAL INFORMATION Winds at the nearest reporting station were 230 degrees at 15 knots, approximately perpendicular to the ridgeline. The wreckage was located on the lee side of the ridgeline. WRECKAGE AND IMPACT INFORMATION A watch, which had stopped at 5:10, was found in the wreckage. The aircraft data plate was found in the burned wreckage. The aircraft was found near the bottom of a bowl, about 500 feet below a Hells Canyon ridgeline on the eastern face of the Medicine Bow mountain range south of Centennial. A ten acre forest fire was associated with the crash. The wreckage distribution path, which included several uprooted and topped trees, was on an approximate 150 degree magnetic heading, on a slope measured at 42 degrees. The first observed point of contact was a 100-120 foot tree, which had been topped, about 200 feet from the main wreckage. The first component between the tree and the main wreckage was the right wing tip. Other components, as indicated on the attached wreckage diagram, were located on both sides of a courseline between the tree and the main wreckage. A tree of about 20-24 inch diameter at the base had been toppled and was on a 150 degree line, parallel to the wreckage distribution path. The engine was extensively damaged and melted from fire damage. The accessory section was melted. The carburetor base was melted. The carburetor throat was inspected and the butterfly valve was found to be partially open. The right side cylinder heads were separated from the cylinder barrels. The propeller blades were bent aft in smooth arcs, and portions of their leading edges and tips showed evidence of melting. Two accessible spark plugs were removed and found to have light sooty deposits, with one having a worn center electrode. No mechanical discrepancies were noted. Control cable continuity was established through the tail cone. Aileron cables were separated due to apparent tensile overload. The wing flaps were determined to be in the retracted position. Throttle, propeller, and mixture control positions could not be determined. MEDICAL AND PATHOLOGICAL INFORMATION The Albany County coroner stated that an autopsy could not be conducted and toxicological samples were not available due to consumption of the pilot's remains by the extensive fire at the accident scene. ADDITIONAL INFORMATION The wreckage was released to the pilot's daughter on August 31, 1994, and it was transported for storage at Beagle Aircraft, Greeley, Colorado by the insurance adjuster.

Probable Cause and Findings

THE PILOT'S FAILURE TO MAINTAIN CLEARANCE FROM TERRAIN. DOWNDRAFT WIND ON THE LEE SIDE OF THE RIDGELINE WAS A FACTOR.

 

Source: NTSB Aviation Accident Database

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