LAX02FA278

The airplane departed from controlled flight after encountering forecast conditions including moderate turbulence and icing during a cross-country instrument flight and collided with the ground in a near vertical spinning descent. The airplane was equipped with a Stormscope, but not weather radar. The pilot received a preflight weather briefing that included advisories for icing conditions, scattered thunderstorms, and moderate to severe turbulence. The briefer advised that radar indicated a large area of echoes extended over the route of flight with light to moderate intensities and that cloud tops were up to 24,000 feet with scattered thunderstorms and a high likelihood of icing conditions between 15,000 and 24,000 feet. The pilot filed his IFR flight plan with a cruising altitude of 17,000 feet. After takeoff and achieving 17,000 feet, the pilot asked the center controller for a clearance to a higher altitude of 19,000 feet, which was approved. Within the next 3 minutes the pilot made a request to deviate to the left and then to climb higher to 21,000 feet, which were all approved. Shortly thereafter, the pilot advised he "really went through some bad turbulence here," and the controller inquired about his heading and altitude. The pilot advised he wanted to climb back to altitude but he was still in IMC conditions. That was the last communication from the flight. According to the controller's memory of the radar display, the airplane was getting into some weather and had deviated north, made a u-turn and had gone down to 19,000 feet, and had started getting back on course when it disappeared. The requests from the pilot to climb to higher altitude was likely made to climb out of icing conditions and an attempt to climb over some of the towering cumulus clouds tops. A limited overlay of weather echoes that would have been available to the controller. The controller provided no weather deviations or support even after the flight encountered some weather, lost altitude, and reported encountering significant turbulence. The weather data showed a shear level was at 19,800 feet, with a 11.1 knot per 1,000 feet change in wind speed. This shear layer had a high probability of severe turbulence. The data also showed a 92 percent probability of rime icing at 20,000 feet.

History of flight

On September 8, 2002, about 1135 mountain standard time, a Beech A36, N8261J, descended from cruise altitude and collided with terrain about 20 miles west of Grand Canyon, Arizona. The private pilot/owner operated the airplane under the provisions of 14 CFR Part 91. The pilot was fatally injured, and the airplane was substantially damaged. The personal flight originated at Bullhead City, Arizona, at 1047, and was destined for Liberal, Kansas. Visual meteorological conditions prevailed at the departure point, and an instrument flight rules (IFR) flight plan had been filed.

The pilot contacted the Prescott Automated Flight Service Station (AFSS) between 0941 and 1008 on September 8, 2002, to file an IFR flight plan and to obtain a standard weather briefing. The briefer provided a synopsis of current conditions, a description of the weather radar, the in-flight advisory for icing conditions, the route forecast, and winds aloft data. The transcript of that briefing is included in the docket for this accident.

The AFSS briefer advised the pilot that "the worst of your flight, as far as the weather is going to be right through Arizona and the western section of New Mexico." Regarding the current radar image the briefer advised the pilot that "north of Kingman and north of Winslow, right now there is a fairly sizable echo return of precip17 its been a kind of broken band of precipitation all day long, like I say extending from the southwest to the northeast section of the state." The pilot acknowledged that and the briefer advised, "..you'll probably have to go through that at some point, right now it looks like light to occasionally moderate precip in that area and then there's another fairly sizeable return that is just to the east of Farmington." The pilot acknowledged. The briefer then advised "...you can count on having some precip whether it's the one I'm discussing with you or something else moving in (over the northern Arizona)." The briefer gave the pilot the current AIRMETs in effect and stated, "...also of a concern is one for icing and they're calling for light to occasional moderate rime in clouds from 15,000 to 24,000 (feet)..." The pilot acknowledged and the briefing continued with the other en route and destination forecast and ended at 0957 after the pilot filed his IFR flight plan with a cruising altitude of 17,000 feet.

The Federal Aviation Administration (FAA) Los Angeles (ZLA) Air Route Traffic Control Center (ARTCC) transcripts of radio communications from 1046 through 1137 between the facility and the accident airplane were reviewed.

At 1046, N8261J contacted ZLA Sector-6 (R-6) after departure from Bullhead City and requested an IFR clearance to Liberal, Kansas, which the controller issued. The pilot then reported climbing through 11,000 feet at 1051. Three minutes later the pilot requested higher altitude and was cleared to 15,000 feet.

At 1101, the R-8 sector controller broadcasted Convective SIGMETs 30 for western Utah and Nevada, SIGMET 31 for western Arizona, and SIGMET 32 for western New Mexico and Arizona.

The flight was cleared to climb to 17,000 feet at 1104 and the pilot subsequently requested 19,000 feet at 1110, and the controller cleared the flight to the higher altitude.

At 1112, the pilot requested left deviation. The controller approved left deviation and cleared the flight direct to Liberal, Kansas, when the pilot was able. One minute later the pilot requested 21,000 feet and the controller approved the higher altitude.

The controller called N8261J at 1124, and the pilot reported "I really went through some bad turbulence here." The controller acknowledged the communication and then asked the pilot what his heading was and he advised "...270 (degrees) right now, I'll get back on course here in a minute." The controller then called traffic out to the airplane and asked the pilot if he was still descending or going back up. The pilot advised, "I'd like to go back up...but I'm still in the soup here." The controller advised the pilot that if he needed to change altitude and heading in the future, to let them know before he did it. There was no response. The recorded radar data showed the onboard transponder signal then went into a coast mode followed by a primary target only. Subsequently, an emergency locator transmitter (ELT) beacon signal was received. The wreckage was located on the Grand Canyon Vortac 265-degree radial at 21 nautical miles.

Review of the recordings disclosed that at 1145, during a position relief briefing, the R-8 controller advised the relieving controller that N8261J was getting into some weather, and had deviated north, made a U-turn and gone down to about 19,000 feet. The controller stated that N8261J had started going back on course and then disappeared.

Personnel information

According to the private pilot's logbook, he had accumulated about 2,124 total flight hours, with about 557 hours in the Prop-Jet Bonanza. The log showed 415 hours of instrument flight time and documented a flight review in compliance with the requirements of 14 CFR 61.56, occurring on October 2, 2000. His most recent second-class flight physical occurred on July 9, 2002.

Aircraft information

According to airframe logbook information, the most recent annual inspection occurred on December 5, 2001, at 1,036 total airframe flight hours.

The airplane had been modified by replacing the Continental TSIO-520 engine with a Allison 250-B17 turboprop engine. The airplane was also equipped with a WX1000 Stormscope, thunderstorm avoidance system.

Meteorological information

A National Transportation Safety Board staff meteorologist conducted a study of the weather conditions as forecast and existing at the time of the accident. The study is included in the docket for this accident. In summary, the meteorologist found the following.

The closest upper air or rawinsonde observation was from the Flagstaff NWS Office, located approximately 50 miles southeast of the accident site. The 1200Z sounding on September 8, 2002, along with the observed and derived stability parameters indicated a moist low-level environment through 500-mb, with the relatively humidity exceeding 90 percent several times between the surface and cruising level of the accident airplane at 21,000 feet. The freezing level was identified at 611-mb or approximately 14,000 feet and had a relative humidity of 88 percent.

The wind profile indicated a surface wind from the southwest veering to the southwest and increasing in wind speed with height. The rawinsonde wind information was lost above 300-mb or approximately 30,000 feet with wind speeds of 69 knots. The accident airplane was last observed at 21,000 feet and the sounding indicated wind at that level was from 200 degrees at 41 knots, with a temperature of -11.7 degrees C. Immediately below this level at 488-mb or approximately 19,800 feet, a strong shear layer was noted with a 11.1 knot per 1,000 feet change in wind speed with a Richardson number (Ri) of 0.4, which indicated a probability of severe clear air turbulence (CAT). This layer also had a high relative humidity of 92 percent and a threat of light rime type icing with a liquid water content (LWC) of 0.64 grams per cubic meter.

The GOES-10 infrared image at 1830Z depicted a large area of low to middle layer clouds covering most of Arizona with four areas of convective clouds depicted by the enhanced colors. The largest area of convective clouds identified as cumulonimbus clouds was located over the southern portions of the image, located south of Phoenix (KPHX). The second area was over eastern Arizona, east of Winslow (KINW) and north of Show Low (KSOW). The third largest area was associated with a line of towering cumulus and cumulonimbus clouds extending from southern Nevada near Bryce Canyon (KBCE) s