Aviation Accident Summaries

Aviation Accident Summary FTW94FA057

VAN HORN, TX, USA

Aircraft #1

N1527H

CESSNA 177RG

Analysis

A NON-INSTRUMENT RATED PRIVATE PILOT ON A DAY VFR CROSS COUNTRY FLIGHT ATTEMPTED TO CONTINUE TO HIS DESTINATION AIRPORT AFTER ENCOUNTERING LOW CEILINGS, FOG, AND TURBULENCE OVER THE MOUNTAINS WITHIN 100 MILES OF HIS DESTINATION. CONTROL WAS LOST AND THE AIRPLANE DESCENDED OUT OF CONTROL, BREAKING UP IN FLIGHT PRIOR TO IMPACTING THE MOUNTAINOUS TERRAIN. THE WRECKAGE WAS SPREAD OVER 2,263 FEET ON A HEADING OF 030 DEGREES. A WEATHER BRIEFING RECEIVED ABOUT 5 HOURS BEFORE THE ACCIDENT DID NOT INCLUDE THE CONDITIONS ENCOUNTERED. AT APPROXIMATELY 1400 THE PILOT WAS INFORMED OF WEATHER CONDITIONS AT THE VAN HORN AIRPORT VIA UNICOM.

Factual Information

HISTORY OF FLIGHT On December 29, 1993, at approximately 1430 central standard time, a Cessna 177RG, N1527H, was destroyed upon impact with terrain following a loss of control while in cruise flight near Van Horn, Texas. The non-instrument rated private pilot and his two passengers were fatally injured. Instrument meteorological conditions prevailed throughout the area for the personal flight. The flight originated at the Mexia-Limestone County Airport (TX06), with the El Paso International Airport (ELP) as its destination. An intermediate stop was planned at the San Angelo, Texas, Airport (SJT) for fuel. The tower at San Angelo reported that the airplane departed at 1226. The last contact with the airplane was made at 1400 by the UNICOM at the airport at Van Horn, Texas, when he was provided with the weather. The UNICOM operator estimated, based on the clarity of the radio transmissions, that the airplane "was most likely within a 20 mile radius from the airport." The airplane was reported missing on December 30, 1993, and later located by units of the Civil Air Patrol in rolling terrain within the Delaware Mountains, approximately 46 miles north of Van Horn, Texas. There were no reported eye witnesses to the accident. AIRCRAFT INFORMATION The airplane was topped off with 15 gallons of 100LL aviation fuel at his intermediate stop at San Angelo, Texas. A review of the airframe and engine records by the Federal Aviation Administration (FAA) inspector did not reveal any anomalies or uncorrected maintenance defects prior to the flight. The pilot was reported to own one-fourth interest in the airplane. METEOROLOGICAL INFORMATION According to the National Weather Service, the southwest was under the influence of a weather system which produced marginal VFR and icing conditions in clouds, as well as occasional low ceilings, mountain obscuration, freezing precipitation, and low level turbulence. Observations within 60 to 100 miles from the accident site verify the existence of low ceilings, gusty winds, light precipitation, and freezing temperatures. Prior to his departure from Mexia, Texas, the pilot obtained a weather briefing at 0947. The weather briefing did not forecast that the weather would deteriorate to the point that VFR flight would not be recommended. The forecast for the El Paso area was amended twice, once at 0909 and again at 1418, to reflect the deteriorating conditions encountered. An updated forecast was available to the pilot when he stopped for fuel at San Angelo, Texas; however, the pilot did not call or visit the Flight Service Station (FSS) for an update on his weather briefing. At approximately 1400, the pilot contacted the UNICOM at The Culberson County Airport, near Van Horn, Texas, asking for the current weather at Van Horn. He was given a report of 500 feet overcast with freezing drizzle, fog, and wind from the northeast gusting to 20 knots. The temperature was estimated at 34 to 36 degrees. A ranch worker in the vicinity of the property owner's house, approximately 15 miles from the accident site, stated that the weather for that entire afternoon was "cold, foggy, and very windy." Detailed weather reports and forecasts for the area are enclosed in this report. COMMUNICATIONS The transcripts from all pertinent communications between the airplane and the ATC facilities are enclosed in this report. WRECKAGE AND IMPACT INFORMATION Airframe components were retrieved from 2,180 feet short of the resting place of the main wreckage. The farthest pieces that were found were fragments of the windshield, interior trim, and wing tip fairing. Following these pieces, were various fragments of several of the control surfaces, followed by increasingly large segments of both wings, followed by the ground scars at the initial point of ground impact. See the enclosed wreckage diagram for wreckage distribution pattern. Both propeller blades were found separated from the hub and exhibited "S" type bending and chordwise gouging. The propeller hub assembly was found separated at the crankshaft flange. Examination of the airplane and engine at the accident site did not disclose any pre-impact discrepancies or mechanical defects. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy and toxicological tests were ordered and performed. The autopsy was performed by Juan U. Contin, M.D., Medical Examiner, County of El Paso. Toxicology tests were found positive for Fluoxerine and Norfluoxetine (Prozac). In the opinion of Dr. Canfield, of the Civil Aero Medical Institute (CAMI), "the 4.9 mg/kg Fluoxetine (Prozac) detected in the lung and 56 mg/kg Norfluoxetine (metabolite of Prozac), detected in the lung are within therapeutic levels. The pilot should not have been taking Prozac for two reasons: (1) Definitely for the medication should not have been taken while performing pilot duties, (2) Possibly for the underlying condition that was being treated (psychiatric, severe depression) are disqualifying conditions." TEST AND RESEARCH The leading edge of the vertical stabilizer was found crushed, and showed evidence of white paint transfer. Those paint transfers were matched to those of the left wing. Physical evidence demonstrated that the right horizontal stabilator separated in an upward and aft direction. The left wing exhibited evidence of having separated in an upward and aft direction. No pre-impact discrepancies were observed with the airframe or aircraft systems. ADDITIONAL INFORMATION The wreckage was released to the owner's representative.

Probable Cause and Findings

THE PILOT EXCEEDED THE DESIGN STRESS LIMITS OF THE AIRCRAFT AFTER A LOSS OF CONTROL WHICH RESULTED FROM VFR FLIGHT INTO INSTRUMENT METEOROLOGICAL CONDITIONS. FACTORS WERE THE WEATHER, THE PILOT'S LACK OF INSTRUMENT TRAINING AND EXPERIENCE, AND HIS FAILURE TO UPDATE HIS WEATHER BRIEFING.

 

Source: NTSB Aviation Accident Database

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