1 fatality

27 Nov 2012: CESSNA 421C (N67SR) — Wells, TX

Wells, TX, United States

On 27 Nov 2012, a CESSNA 421C (registration N67SR) was involved in an aviation accident near Wells, TX. One person was killed. Investigators recorded the probable cause as: The pilot’s decision to continue the flight into an area of extreme weather, which led to the in-flight encounter with a thunderstorm and structural failure of the wings and tail. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

On November 26, 2012, a Cessna 421C, N67SR, was substantially damaged after an in-flight weather encounter, structural separation, and impact near Wells, Texas. The private pilot was fatally injured. The flight operated on an IFR flight plan from Houston to Tulsa.

History of Flight

On November 26, 2012, at approximately 2124 central standard time, a Cessna 421C airplane, registration N67SR, experienced an in-flight encounter with weather, separation of airframe components, and subsequent impact with terrain near Wells, Texas. The aircraft was substantially damaged. The private pilot, the sole occupant, sustained fatal injuries. The airplane, registered to H-S Air LP, was operated by the pilot under 14 CFR Part 91 as a business flight. Instrument meteorological conditions prevailed, and the flight operated on an instrument flight rules (IFR) flight plan. The flight departed West Houston Airport (IWS) at about 2040, destined for Richard Lloyd Jones Jr. Airport (RVS) in Tulsa, Oklahoma.

Witnesses near the accident site reported hearing an explosion and observing a fireball descending through clouds to the ground. Radar track data for the final portion of the flight indicated the airplane was squawking code 7720. The track initially showed a heading of about 20 degrees at 23,000 feet. At 2120:03.73, the airplane began a right turn, maintaining altitude for about 30 seconds until the heading changed to about 90 degrees. After 2120:45.86, the track depicted an erratic steep descent until the last data point at 2122:15.53 at an altitude of 2,800 feet. The accident site was 0.86 miles at 94 degrees from the last radar position.

Pilot Information

The pilot held a private pilot certificate with ratings for airplane single-engine land, multiengine land, and instrument airplane. He was issued a third-class medical certificate on May 8, 2012, with a restriction for corrective lenses. According to FAA records, the pilot reported 2,500 total flight hours, with 75 hours in the six months preceding his medical exam. His flight logbook was not recovered.

Aircraft Information

The Cessna 421C, serial number 421C-0257, was a twin-engine, propeller-driven monoplane with retractable tricycle landing gear and a pressurized fuselage. It could seat up to eight occupants, though the exact configuration at the time of the accident could not be determined due to fire damage. Two Continental GTSIO-520-L engines, each rated at 375 horsepower, were mounted on the wings. Maintenance records showed the airplane had 6,736.2 total hours as of its last annual inspection on October 13, 2012. The left and right engines had accumulated 1,039.1 and 1,215.1 hours since overhaul, respectively.

Meteorological Information

No record of a weather briefing from Flight Service Station or DUATS was found for the accident flight, but it could not be determined if the pilot obtained weather information from other sources. An Area Forecast issued at 2045 for the region forecast ceiling broken at 3,000 feet msl with cloud tops to 8,000 feet, broken cirrus, isolated thunderstorms, and light rain with cumulonimbus tops to 38,000 feet. No AIRMET advisories covered the accident site at the most recent issuance, though an AIRMET for IFR conditions was active nearby. Convective SIGMETs issued at 1955 and 2055 were valid for a line of thunderstorms in eastern Texas, with boundaries near the accident site. The most recent SIGMET (5C) described a 35-mile wide line of thunderstorms from 30 miles south-southeast of the BELCHER VORTAC to 40 miles east of the CENTEX VORTAC, with cloud tops to 45,000 feet. The accident site lay within the SIGMET boundaries.

Surface analysis at 2100 showed a low-pressure center near the northwestern Louisiana border with Texas, associated with a cold front stretching southwestward through the accident region. Station models indicated northerly winds behind the cold front at 10-20 knots, with southerly winds ahead. Most stations in eastern Texas reported clear skies. Regional NEXRAD radar at 2120 showed a broken line of high reflectivity (>50 dBZ) from central east Texas to northwestern Louisiana, coincident with the accident location. Level-II radar data from Shreveport indicated the aircraft penetrated the highest reflectivity values (>50 dBZ) just before its rapid descent. An algorithm estimated potential hail up to 1.25 inches and a probability of severe hail (POSH) as high as 84.6 percent.

Communications

At 2033, the pilot contacted Houston Intercontinental TRACON and received an IFR clearance from IWS to RVS. Departure occurred at 2040. The pilot communicated with Houston ARTCC starting at 2057, requesting a climb to 23,000 feet. The controller provided information about weather deviations and convective SIGMETs. At 2113, the pilot requested a 10-degree deviation to the right, which was approved. At 2120:28, the Fort Worth controller asked if the aircraft had onboard weather radar; the pilot confirmed. The controller reported moderate to heavy precipitation ten miles ahead. The pilot acknowledged with "yes sir," the final transmission.

Wreckage and Impact

The airplane came to rest inverted in a wooded area near Wells, Texas, oriented at 220 degrees. The fuselage and both wings suffered extensive fire damage; the lower fuselage was nearly consumed. A baggage door was found 0.6 miles southeast. The vertical stabilizer impacted a tree and remained attached, while the rudder was mostly missing. The horizontal stabilizer and elevators separated and were found 0.25 miles south-southwest, showing no fire damage but with hail dents on the left stabilizer. The right stabilizer had missing structure with tearing. The outboard right wing was heavily fire-damaged and inverted; the inboard wing spars showed overload failure downward. A portion of the outboard left wing lay atop the left engine nacelle; large parts of the left wing were missing. Control cable continuity was examined; several separations occurred due to overload or fire. The left engine could not be rotated due to internal fractures but showed no preimpact anomalies. The right engine rotated successfully with compression and normal spark plug signatures.

Medical and Pathological Information

An autopsy performed on November 28, 2012, attributed the pilot's death to injuries from the accident. Toxicology testing detected Atorvastatin (a cholesterol-lowering statin) in the liver; no other substances were found.

Contributing factors

Causes

PilotEffect on equipmentDecision related to conditionEffect on operation

Other contributing factors

Wing structure — FailureEmpennage structure — Failure