N67SR

HISTORY OF FLIGHT

On November 26, 2012, about 2124 central standard time, a Cessna 421C airplane, N67SR, was substantially damaged during an in-flight encounter with weather, in-flight separation of airframe components, and subsequent impact with the ground near Wells, Texas. The private pilot, who was the sole occupant, was fatally injured. The airplane sustained impact and fire damage to all major airframe components. The aircraft was registered to H-S Air LP and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a business flight. Instrument meteorological conditions prevailed for the flight, which operated on an instrument flight rules (IFR) flight plan. The flight originated from the West Houston Airport (IWS), Houston, Texas, about 2040 and was bound for the Richard Lloyd Jones Jr. Airport (RVS), Tulsa, Oklahoma.

Witnesses near the accident site reported hearing an explosion and then seeing a fireball descending through the clouds to the ground.

Radar track data for the last portion of the flight depicted the airplane on a 7720 transponder code. The track showed the airplane initially on a heading of about 20 degrees at 23,000 feet. The track continued in this direction until 2120:03.73 when the airplane began a right turn. The right turn continued for about 30 seconds during which time the altitude remained constant and the heading changed to about 90 degrees. After 2120:45.86, the track showed an erratic steep descent that continued to the end of the data. The final data location was received at 2122:15.53 at an altitude of 2,800 feet. The accident location was 0.86 miles and 94 degrees from the last recorded radar position.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with airplane single-engine land, airplane multiengine land, and instrument airplane ratings. He was issued a third-class airman medical certificate, with a restriction for corrective lenses, on May 8, 2012. According to Federal Aviation Administration (FAA) records, the pilot reported having 2,500 hours total flight experience with 75 hours in the six months preceding his most recent medical examination. The pilot's flight logbook was not recovered during the investigation.

AIRCRAFT INFORMATION

The airplane was a Cessna model 421C, bearing serial number 421C-0257. It was a twin-engine propeller driven monoplane with a retractable tricycle landing gear. Different seating arrangements could be employed with the capability of seating 8 occupants including the 2 flight crew seats. The exact seating configuration of the accident airplane could not be determined due to the extensive impact and fire damage. The airplane was constructed mainly of aluminum alloy materials and had a cantilever main wing arrangement and a pressurized fuselage. Two Continental GTSIO-520-L engines, serial numbers 825011-R and 292480-R, were mounted on each wing and were each capable of producing 375 horsepower.

Maintenance records for the airplane showed that it had accumulated 6736.2 hours total time in service as of its most recent annual inspection dated October 13, 2012. The left and right engines had accumulated 1,039.1 hours, and 1215.1 hours respectively since overhaul as of the date of the annual inspection.

METEOROLOGICAL INFORMATION

No record of the pilot having obtained a Flight Service Station (FSS), or Direct User Access Terminal System (DUATS), weather briefing was found for the accident flight. However, no determination could be made as to whether the pilot obtained weather information from other sources prior to the flight.

An Area Forecast (FA) that included Texas was issued at 2045. The portion of the FA directed toward the southeastern quarter of the northeastern portion of Texas forecasted for times until 0100 the next day: ceiling broken at 3,000 feet msl with cloud tops to 8,000 feet msl and broken cirrus, isolated thunderstorms and light rain with cumulonimbus tops to 38,000 feet. No thunderstorms were forecast for other portions of northeastern Texas.

No Airmen's Meteorological Information (AIRMET) advisories were issued for the accident location at the most recent AIRMET issuance times prior to the accident. The accident site was, however, close to an active AIRMET for IFR conditions issued at 2045.

The Aviation Weather Center in Kansas City, Missouri, issued several Convective Significant Meteorological Information (SIGMET) advisories at 1955 and 2055 that were valid until 2155 and 2255 respectively. These SIGMETs were active for a line of thunderstorms in eastern Texas. The boundaries of the SIGMETs were all near to the accident site. The most recent SIGMET (5C) boundary depicted a 35 mile wide line of thunderstorms that stretched from 30 miles south-southeast of the BELCHER Very High Frequency Omni-Directional Radio Range Tactical Air Navigation Aid (VORTAC), near Shreveport, Louisiana, to 40 miles east of the CENTEX VORTAC near Austin, Texas. The thunderstorm had cloud tops to 45,000 feet and was moving eastward at 20 knots. The accident site was within the boundaries described in the SIGMET.

The National Weather Service (NWS) Surface Analysis Chart for 2100 depicted a low-pressure center at the northwestern Louisiana border with Texas. Associated with the low-pressure center was a cold front that stretched southwestward through the accident region to Mexico, a warm front that stretched southeastward to the Mississippi Gulf coast, and a stationary front that stretched east-northeast.

Station models depicted the wind as northerly behind the cold front in northeast Texas with magnitudes ranging from approximately 10 to 20 knots. Ahead of the cold front the wind was generally southerly with magnitudes near 5 knots. Most station models across eastern Texas depicted clear skies. Temperatures near to and immediately ahead of the cold front were near 70° Fahrenheit (F) with dew point depressions as low as 2°F.

A regional Next-Generation Radar (NEXRAD) mosaic obtained from the National Climatic Data Center (NCDC) for 2120 CST identified a broken line of high (>50 dBZ) values of reflectivity that stretched from central east Texas to northwestern Louisiana. A part of this line was coincident with the accident location.

WSR-88D Level-II base reflectivity weather radar data from Shreveport, Louisiana was obtained. Three-dimensional presentations of base reflectivity isosurfaces from the volume scan initiated at 2116:35 indicated that the accident aircraft penetrated the highest values of reflectivity (> 50 dBZ) during the final portion of its flight and just before its rapid descent. The eastern portion of the 50 dBZ isosurface that rose to a higher altitude was consistent with a convective updraft that may have contained hail. An algorithm utilized by the program GR2Alanlyst (a Nexrad Level II analysis application) to estimate hail stone diameter indicated the potential for 1.25 inch hail in that portion of the storm, and GR2Analyst identified the probability of severe hail (POSH) as high as 84.6 percent.

COMMUNICATIONS

Summaries and transcripts of communications between the airplane and various controlling facilities were obtained from the FAA.

At 2033, the pilot contacted the Houston Intercontinental Airport (IAH) Terminal Radar Approach Control (TRACON), Satellite Clearance Delivery position using his airplane's radio and was issued an IFR clearance from IWS to RVS. The airplane subsequently departed IWS at 2040. The pilot maintained communications with the IAH TRACON until 0257 when he was handed off to the Houston Air Route Traffic Control Center (ARTCC).

At 2057, the pilot checked in with the Houston ARTCC. After establishing communications, the controller cleared the pilot to climb and maintain 23,000 feet. The pilot inquired regarding reports of the cloud tops for the weather he was approaching. The controller advised the pilot that other aircraft were deviating around the weather and that he was working on a route for the airplane to avoid the weather. At 2058, the controller advised the pilot that there were no cloud top reports and then cleared the airplane direct to Longview, Texas, and then direct to Tulsa, Oklahoma. At 2059, the controller disseminated convective SIGMETs 5C and 6C. At 2102, the controller advised the pilot that 23,000 feet would be his final altitude. At 2107, the controller advised the pilot of moderate, heavy, and extreme precipitation 40 miles ahead of the airplane and moving east, and that if the pilot needed to deviate further to the right to let him know. The pilot responded that he was looking at the weather and would let the controller know if he needed to deviate further to the right. Subsequently, at 2113, the pilot requested a 10 degree deviation to the right, which the controller approved. At 2119, the pilot was provided a frequency and advised to contact the Fort Worth ARTCC.

At 2120:28, the Fort Worth controller established communication with N67SR and queried the pilot as to whether the airplane was equipped with a weather radar system on-board. The pilot confirmed having weather radar. The controller then advised the pilot of moderate to heavy precipitation ten miles directly ahead of the airplane's flight path. The pilot acknowledged saying "yes sir", which was the final transmission received from the airplane.

WRECKAGE AND IMPACT INFORMATION

The airplane came to rest in a wooded area near Wells, Texas, in an inverted position with the fuselage oriented in a 220 degree direction. The fuselage and both wings suffered extensive fire damage. The lower fuselage was almost completely consumed by fire. The upper fuselage was recognizable but also had significant fire damage. The landing gear was observed in the retracted position. A baggage door from the nose of the airplane was located about 0.6 miles southeast of the main wreckage.

The vertical stabilizer had impacted a tree on its lower leading edge. It remained attached to...