Aviation Accident Summaries

Aviation Accident Summary LAX94FA007

SEDONA, AZ, USA

Aircraft #1

N5365D

CESSNA 172N

Analysis

The pilot was returning from a day long charter flight. About 2000 hours, the pilot dropped his passengers in Flagstaff, Arizona, and departed for Sedona, located 21 miles to the south. At a point 13.6 miles south of Flagstaff, the airplane collided with a sheer rock wall about 1,000 feet below the top of the mountainous terrain. Based on weather data and witness statements, low clouds existed in the accident area around the time of the accident. A witness reported seeing the airplane's lights flash on the clouds while the aircraft appeared to be reversing course. The witnesses heard normal engine sounds until the impact. No system discrepancies were noted during the examination of the aircraft. Based on fuel calculations, the airplane had about 5.5 gallons of fuel on board or about 40 minutes of flight time remaining.

Factual Information

HISTORY OF FLIGHT On October 7, 1993, at 2038 hours mountain standard time, a Cessna 172N, N5365D, operated by Aerovision, Inc., of Sedona, Arizona, collided with a shear rock wall in mountainous terrain near Sedona, Arizona. The airplane was destroyed and the pilot received fatal injuries. Visual meteorological conditions prevailed at the departure and destination points and a VFR flight plan was filed. The accident occurred during the hours of darkness. The pilot had just completed a 14 CFR Part 135 charter flight from Flagstaff Arizona, to Farmington, New Mexico, and back to Flagstaff where his passengers deplaned. The pilot was returning the aircraft to its Sedona base when the accident occurred. Two witnesses, a husband and wife, were located about 2 miles north of the accident site at the time of the accident. They observed a low flying aircraft. The wife stated that her attention was first drawn to the area of the aircraft by what she first thought was lightning and then she realized that it was a bright, flashing white light reflecting off the clouds. She stated that the airplane made an abrupt turn southbound; she observed both red and white flashing lights, and reported that the engine sounded normal. Upon hearing an impact, she notified the Sedona Police. PERSONNEL INFORMATION According to the pilot's logbook, he had accumulated about 13,205 hours of flight time with about 60 hours as a pilot examiner. The day before the accident the pilot successfully passed a 14 CFR Part 135 proficiency check ride with a Federal Aviation Administration (FAA) inspector from the Scottsdale Flight Standards District Office. AIRCRAFT INFORMATION The airplane was manufactured in 1979 and had accumulated 4,325 hours at the time of the last annual inspection. The last documented annual inspection was accomplished on September 21, 1993, at a recording tachometer time of 259.5 hours. According to the records, the engine had accumulated 296.9 hours of operation since a major overhaul was performed. The recording tachometer recovered at the postcrash examination revealed a reading of 275.0 hours. Airport fueling records at the Flagstaff and surrounding airports disclosed no evidence that N5365D was refueled on the day of the accident. The last documented fueling for the aircraft was at Farmington, New Mexico, where 10 gallons of 100LL aviation gasoline was added to the tanks. National Transportation Safety Board investigators performed fuel consumption calculations using the known flight times, since the morning departure from Sedona to the accident site, at an average consumption rate for 75 percent power. The calculations revealed that at the time of the accident the aircraft had about 5.5 total gallons of usable fuel on board. The calculations are attached to this report. METEOROLOGICAL INFORMATION The closest surface weather observation to the accident site was the Flagstaff, Arizona, Automated Meteorological Observing Station (AMOS). The 2009 hour weather observation was reporting in part: temperature 46 degrees Fahrenheit, dew point 41 degrees; wind 240 degrees at 1 knot; altimeter 30.12; remarks -- peak wind 5 knots. A pilot witness stated that just prior to the accident time he noted some scattered clouds in the accident area with tops around 5,000 feet msl. According to a National Transportation Safety Board meteorologist report, infrared satellite images taken around the time of the accident show patchy lighter shades of grey in the vicinity of Flagstaff and Sedona. These lighter colors imply temperatures consistent with colder cloud top temperatures. In addition, these features drifted to the northeast. WRECKAGE AND IMPACT INFORMATION The wreckage was located in the Coconino National Forest. According to Arizona Department of Public Safety helicopter pilots who responded to the accident site, the airplane collided with a sheer rock wall at 5,980 feet msl, 13.6 nautical miles from the Flagstaff VOR along the 182 degree radial. An aerial view revealed the impact site was about 1,000 below the top of the 6,900 foot mountain. There was an imprint of the aircraft on the rock wall. The majority of the wreckage was located at the base of the wall about 5,800 feet msl. Examination of one of the propeller blades indicated chordwise scratches and leading edge gouges with spanwise twisting. The dry air vacuum pump drive and vanes were found intact. MEDICAL AND PATHOLOGICAL INFORMATION On October 10, 1993, the Coconino County Medical Examiner in Flagstaff, Arizona, performed the autopsy on the pilot. Samples were obtained from the pilot for toxicological analysis by the FAA Civil Aeromedical Institute in Oklahoma City, Oklahoma. The results of the toxicological analysis were negative for all screened drug substances and alcohol. ADDITIONAL INFORMATION Postcrash examination of the aircraft radios revealed that the ADF was tuned to 780 KHz which is the frequency of a local radio station located about 3.0 miles west of the Sedona Airport. The Sedona nondirectional radio beacon was NOTAMed out of service October 11, 1991. The other recovered radio frequency from a navigation receiver was determined by an approved radio shop to be set on 108.2 MHz, which is the Flagstaff VOR frequency. The aircraft wreckage was released to Mr. Bill Bertles, an insurance representative, on May 24, 1994.

Probable Cause and Findings

the pilot's decision to continue VFR at an improper altitude into mountainous terrain at night and the inadvertent encounter with clouds along the route. Self-induced pressure due to a low fuel state contributed to the accident.

 

Source: NTSB Aviation Accident Database

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