History of Flight
On September 17, 2012, at about 1400 central daylight time, a Mooney M20M, N1085A, was substantially damaged when it struck terrain in Crane Hill, Alabama. The private pilot and passenger were fatally injured. Instrument meteorological conditions (IMC) prevailed, and the airplane was operating on an instrument flight rules flight plan from Destin-Fort Walton Beach Airport (DTS), Destin, Florida, to Sumner County Regional Airport (M33), Gallatin, Tennessee. The personal flight was conducted under 14 CFR Part 91.
According to air traffic control information from the Federal Aviation Administration (FAA), the airplane departed DTS at 1245 and was issued a heading of 330 degrees and a climb to 10,000 feet. At 1247, the pilot contacted the next sector controller, who issued an advisory for weather in the flight path. At 1253, the pilot was told to switch to Jacksonville Center and expect vectors around a weather cell. At 1254, the pilot reported climbing from 7,000 to 10,000 feet; the controller advised of "extreme" precipitation and asked intentions. The pilot stated he was looking at "ADS-B" weather, described what he saw, and told the controller his plans. At 1255, the controller approved deviations left or right and cleared the pilot direct to destination when able.
At 1300, the controller asked for flight conditions; the pilot reported cloudy and smooth with light rain becoming heavy and a "little bit bouncy" ride. At 1303, a convective SIGMET broadcast was made. At 1306, the pilot contacted Atlanta Center. At 1317, while at 13,000 feet, the pilot inquired about icing ahead at 15,000 feet; the controller reported no icing reports but clouds and precipitation ahead. The pilot requested 15,000 feet "to see if I can see things better," which was approved.
At 1325, the controller advised of moderate to extreme precipitation for about 90 miles ahead. The pilot noted looking at "a-s-d-n" and requested deviation to 358 degrees. At 1334, the controller reported precipitation at 12 o'clock about 12 miles ahead; the pilot requested another 10 degrees left deviation, approved. At 1336, the pilot turned to 320 degrees. At 1354, the controller issued a frequency change; the pilot responded, "Unable, we're battling some pretty bad (end of transmission)."
Radar data showed at 1357:39 the airplane was northbound at 15,300 feet. By 1358:11, it turned 90 degrees right (east) and descended to 14,600 feet. By 1358:20, it turned another 90 degrees right (south) to 14,100 feet, then made a sharp left turn climbing to 15,500 feet by 1358:34, followed by another sharp left turn and descent northwest. At 1359:02, the controller contacted the pilot; at 1359:06, the pilot responded with "mayday." At 1359:13, he said, "may (unintelligible) eight five alpha mayday mayday." Further descents continued with a calculated rate over 15,000 feet per minute. At 1401, the handling controller stated, "he declared, he said mayday on the frequency and he won't respond to me; he got into that weather and he started losing altitude."
A witness reported heavy rain but no thunder; he heard an engine sound "like he had power" then a "thud." Upon arrival, the cabin was on fire.
Personnel Information
The pilot, age 61, held a private pilot certificate with single-engine land and instrument ratings. His logbook was not recovered; his last FAA medical application (November 1, 2010) indicated 1,000 hours total and 50 hours in make and model. He had failed color vision testing, specifically red-green discrimination, and was issued a Statement of Demonstrated Ability (SODA) on July 14, 1998, after passing a signal light test. No other significant medical issues were noted.
Aircraft Information
The 1989 Mooney M20M was powered by a Lycoming TIO-540 engine. Its last annual inspection was completed on April 4, 2012, at 1,590 total hours.
Meteorological Information
Weather recorded at Walker County Airport-Bevill Field (JFX), 11 nautical miles west-southwest of the accident site, at 1355 included wind from 170 degrees true at 3 knots, visibility 8 statute miles, rain, few clouds at 2,500 feet agl, altimeter 29.82 inches Hg, and distant lightning east and southwest.
At 1009, the pilot received a weather briefing from a Lockheed Martin flight service station. The briefer noted a line of thunderstorms, another area of rain with lower IMC, and a convective SIGMET with small clusters of convection moving north. Embedded convective activity from the Alabama-Tennessee border to the destination was not expected to dissipate soon. The briefer suggested routing but noted the convective area would expand. The pilot asked about icing (airplane not approved for known icing); the briefer advised an AIRMET for icing between 13,000 and 25,000 feet. At 1225, the pilot filed a flight plan for 1245 departure, direct to M33, at 13,000 feet, with 3 hours of fuel.
An NTSB Weather Study identified a low-pressure system and stationary front. A NAM model sounding at 1300 indicated unstable lower atmosphere and conditional instability below about 14,000 feet, with the freezing level at about 13,300 feet. RAOB calculations showed potential for light to moderate rime icing between 14,000 and 25,000 feet. A vertical radar cross section at 1359 showed the airplane in moderate reflectivity, then entering heavier moderate reflectivity, reversing course, descending into moderate to heavy reflectivity, briefly climbing, then rapidly descending.
The study compared NOAA radar imagery with expected FIS-B depictions; FIS-B data were time-delayed, resulting in "significant differences in depiction of hazardous reflectivity values." The FIS-B product showed the airplane clear of moderate or greater reflectivity during turns, but actual radar showed proximity to heavy values.
Wreckage and Impact Information
The airplane first impacted rolling pastureland at 33° 58.58' N, 087° 07.04' W, elevation about 560 feet. A ground imprint of the tail began about 5 feet beyond an undamaged fence post, consistent with a flat, upright impact with gear up. Fragments were found along a 225-foot debris path heading about 010 degrees magnetic; the cabin with engine was near the end. Both wings and tail separated, unburned, with no soot indicating in-flight fire. The aft fuselage was crushed downward; cabin roof and sidewalls missing, charred forward of the oxygen bottle (which was itself charred). Flight control surfaces accounted for but continuity could not be confirmed due to fractures and fire.
One propeller blade separated at impact; the hub with two remaining blades was found 75 feet beyond. Blades exhibited curling, torsional bending, leading edge burnishing, and chordwise scratching. The engine could not be examined due to fire and impact damage; the starter ring showed rotational fracturing. No recording devices were found.
Medical and Pathological Information
An autopsy listed cause of death as blunt force injuries. Toxicology testing detected bupropion, citalopram, and N-Desmethylcitalopram in muscle and kidney. These are antidepressants according to the National Institute of Health.
Additional Information
An NTSB Safety Alert on in-cockpit NEXRAD noted that actual data age can differ significantly from displayed age, up to 15-20 minutes. The AIM states that FIS-B weather products are not appropriate for tactical avoidance of severe weather but support strategic decision making.