N729MS

HISTORY OF FLIGHT

On October 26, 2009, approximately 1143 central daylight time, a Beech B100 King Air, N729MS, registered to Mazak Properties, Incorporated, and operated by a private pilot, impacted terrain after encountering severe weather near Benavides, Texas. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91 and an instrument flight rules (IFR) flight plan was filed. Instrument meteorological conditions prevailed. The private pilot and three passengers received fatal injuries and the airplane was destroyed. The flight departed Garner Field Airport (KUVA) Uvalde, Texas, and was destined for Leesburg International Airport (KLEE), Leesburg, Florida.

Prior to departure, the pilot received three separate weather briefings from an Automated Flight Service Station (AFSS). A review of these communications revealed that the pilot was provided information regarding the severe weather conditions along his planned route of flight. The pilot expressed his concern about these conditions and altered his route of flight further south so he could maneuver around and through “holes” in the weather.

A review of air traffic control (ATC) communications revealed that the accident airplane departed from Uvalde, Texas, about 1058. The pilot contacted Houston Air Route Traffic Control Center (ARTCC) sector 59 at 1105:08, and reported that he was at an altitude of 10,200 feet and climbing to 23,000 feet. He also continued to say, "All right if you don't mind helping us we're looking at the radar – it might be better for us to go down toward Laredo <unintelligible> route…looks like a squall line." The controller responded, "Niner mike sierra yes there is a very significant squall line between you and your destination. Not sure how you'll get through, but we'll work on it somehow." The pilot responded, "All right – I sure appreciate the help."

At 1107:44, the pilot requested to proceed direct to Laredo. The controller responded, "…direct Laredo, direct Corpus, direct Leeville, rest of route unchanged." The pilot read back the route, and the controller cleared the accident airplane to climb to 25,000 feet, which was the pilot's requested final altitude.

At 1122:23, the pilot stated that he had a request, and the controller acknowledged. The pilot continued, "uh, we're looking at a hole um going towards Corpus is it possible we could get about a one five zero degree heading try and work through that way <unintelligible>. The controller replied, "November niner mike sierra fly heading of one two zero when able proceed direct Corpus Christi rest of route unchanged." The pilot responded, "…sounds great one two zero and when able direct Corpus for mike sierra thank you."

At 1140:43, the controller transmitted, "November niner mike sierra verify you're level flight level two five zero." The pilot replied, "No sir, we had dropped down to – we'd gotten into some pretty good turbulence we're at two four zero." The controller responded, "November niner mike sierra you've got to tell me these things…I've got a MOA below you at flight level two three zero and below so november niner mike sierra when able maintain flight level two five zero." The pilot transmitted, "Yes sir um I'm sorry sir.'" The controller then asked,"…and uh any injuries or uh damage?" The pilot did not reply and there were no further communications with him.

At 1142:07, an expletive and propeller noise were heard on the same frequency used by the pilot, and for the next 35 seconds there was sound similar to that made by a stuck microphone conflicting with other transmissions. In response, the controller transmitted, "All right now everybody use caution – we had a stuck mic there for a while, that's very bad now."

A review of recorded radar data revealed that after departing Uvalde, the airplane traveled on a southeasterly heading before it made a turn to the south at 1108. The airplane then traveled on this southerly heading for approximately 15 minutes before it turned back to a southeasterly heading toward Benavides, Texas. At 1140, when the airplane was approximately 6 ½ miles north of Benavides at an altitude of 25,000 feet, it entered a right turn toward the northwest and started to descend. The last radar return was received at 1141:46 at an altitude of 22,200 feet. The radar track went into "coast" status at 1142:55, indicating that the radar data processing system had lost track of the aircraft.

A review of the National Weather Service (NWS) Corpus Christi, Texas, Weather Surveillance Radar-1988, Doppler (WSR-88D) weather and radar track data revealed that the airplane entered a line of echoes in the range of 40 to 54 dBZ (very heavy to intense) before it began to lose altitude and reverse course. The Federal Aviation Administration (FAA) defines reflectivity of 50 dBZ and greater as “extreme” intensity with severe turbulence, lightning, hail likely, and organized surface wind gusts. Stronger echoes with maximum reflectivies to 63 dBZ or “extreme” intensity were located in the immediate vicinity along the intended route of flight.

PERSONNEL INFORMATION

The pilot held a private pilot certificate for airplane single and multi-engine land, and instrument airplane. His last Federal Aviation Administration (FAA) second class medical was issued on January 10, 2008. At that time, he reported a total of 550 flight hours. The pilot’s logbook was never located.

METEOROLOGICAL INFORMATION

The closest weather reporting facility to the accident was from Jim Hogg County Airport (KHBV), Hebbronville, Texas, located approximately 24 miles southwest of the accident site at an elevation of 663 feet. The airport had an Automated Weather Observation System (AWOS-3) and reported the following conditions surrounding the time of the accident:

At 1103, the weather was reported as wind from 210 degrees at 8 knots, visibility 7 miles, scattered clouds at 1,600 feet, ceilings broken at 2,200 feet, overcast at 7,000 feet, temperature 26 degrees Celsius, dew point 22 degrees Celsius, and a barometric pressure setting of 29.91 inches of Mercury. Remarks: automated observation system, lightning distant north, northeast, and southwest, temperature 25.9 degrees Celsius, dew point 21.5 degrees Celsius.

At 1125, the weather was reported as wind from 310 degrees at 18 knots gusting to 26 knots, visibility 5 miles in moderate rain, scattered clouds at 1,000 feet, ceiling broken at 1,500 feet, overcast at 2,800 feet, temperature 20 degrees Celsius, dew point 18 degrees Celsius, and a barometric pressure setting of 29.95 inches of Mercury. Remarks: automated observation system, lightning distant northeast, hourly precipitation 0.19 inches, temperature 19.7 degrees Celsius, dew point 17.6 degrees Celsius.

At 1143, the weather was reported as wind from 330 degrees at 21 knots gusting to 31 knots, visibility 4 miles in thunderstorms and heavy rain, scattered clouds at 800 feet, ceiling broken at 2,300 feet, overcast at 3,000 feet, temperature 18 degrees Celsius, dew point 17 degrees Celsius,

and a barometric pressure setting of 29.94 inches of Mercury. Remarks: automated observation system, lightning distant north east and east, hourly precipitation 0.24 inches, temperature 17.7 degrees Celsius, dew point 16.5 degrees Celsius.

At 1203, the weather was reported as wind from 350 degrees at 22 knots gusting to 32 knots, visibility 10 miles, scattered clouds at 800 feet, scattered at 2,300 feet, ceiling overcast at 3,000 feet, temperature 18 degrees Celsius, dew point 16 degrees Celsius, and a barometric pressure setting of 29.95 inches of Mercury. Remarks: automated observation system, lightning distant northeast through southeast,temperature 17.6 degrees Celsius, dew point 16.4 degrees Celsius.

The NWS Corpus Chisti (KCRP) upper air sounding for 0700 indicated an unstable atmosphere with a Lifted Index of -6.8 and a K-Index of 31.6, which supported thunderstorm development across the region. The degree of instability and vertical wind profile also supported a moderate to strong risk of multicellular type thunderstorms in lines and clusters, with the potential for strong updrafts and downdrafts. The tropopause was identified at 54,000 feet.

At the airplane's cruising altitude, the WSR-88D 2.4° elevation scan documented echoes of 40 to 49 dBZ along the flight track when the pilot lost altitude and reported encountering turbulence, and turned back into an area of 40 dBZ when the upset occurred. Echo tops of 18 dBZ or higher

were detected between 30,000 to 34,000 feet over the accident site, with tops to 45,000 feet approximately 10 miles south-southeast of the accident site.

The National Lightning Detection Network (NLDN) detected 140 cloud-to-ground lightning strikes between 1122 and 1202 within 15 miles of the accident site, and confirmed that active thunderstorms were occurring in the vicinity of the accident site.

The NWS had Convective SIGMET 38C current over the area for an area of thunderstorms moving southeast at 20 knots, with tops to 37,000 feet. The advisory implied severe to extreme turbulence, severe icing, and low-level wind shear associated with the thunderstorms.

The NWS also had AIRMET Zulu current for moderate icing conditions from the freezing level identified at 13,500 feet to 25,000 feet over the area.

WRECKAGE AND IMPACT INFORMATION

The National Transportation Safety Board’s on-scene investigation was conducted on October 27-29, 2009.

A hand held global position receiver (GPS) was used to identify the position of the main wreckage as 27.6663 degrees north latitude, 98.4613 degrees west longitude. The main wreckage was located approximately 6 1/2-miles north of Benavides, Texas, on a remote cattle ranch. The associated debris was located in two general areas, situated about 0.8 nautical miles from each other. The overall wreckage distribution was consistent with an in-flight bre...