Anaheim Hills, CA, USA
N6268P
Piper PA-24-250
The airplane sustained an in-flight breakup following an encounter with weather. The flight was in instrument conditions on an IFR clearance and being radar vectored to the ILS final approach course at 3,000 feet when the breakup occurred. The left wing tip and the outboard 1/2 of the left and right horizontal stabilators were the first pieces of wreckage in the 1/4-mile long debris path. The horizontal stabilators exhibited permanent down deformation at the separation points. The wings exhibited both up and down permanent deformation of the spars and other structural elements. The fracture surfaces at the separation points for the wings and stabilators were consistent with structural overload. There is no record that the pilot requested or received a preflight weather briefing. The National Weather Service (NWS) issued SIGMETs and AIRMETs for occasional severe turbulence, strong gusty winds, low level wind shear, and for occasional severe rime to mixed icing in clouds. The SIGMETs and AIRMETS were valid prior to the pilot's departure and covered the timeline of the flight. The NWS weather radar depicted moderate intensity echoes extending over the accident site. While en route at 1219, the pilot requested the current destination weather from the center controller, who provided the METAR report of 10 miles visibility and broken layers at 4,000 and 20,000 feet. Shortly after the pilot was given this observation, the destination conditions rapidly deteriorated to include lowering ceilings, strong and gusty winds, and moderate to heavy rain showers. The destination weather 30 minutes prior to the accident included winds gusting to 21 knots with scattered clouds at 3,800 feet, and a broken layer at 10,000 feet. A special observation issued about 5 minutes prior to the accident indicated that winds were gusting 14 to 19 knots, visibility was 2 miles in moderate rain and mist, a broken ceiling was at 2,800 feet, and the sky was overcast at 5,000 feet. It noted that rain began about 15 minutes earlier than the observation time. Five minutes after the accident, another observation reported that the winds were gusting to 21 knots, visibility was 1 1/2 miles with moderate rain, and broken and overcast ceilings at 2,100 feet and 4,700 feet respectively. The crew of a Boeing 757 making the approach 10 minutes after the accident reported a 45-knot crosswind shear at 100 feet, and light to moderate turbulence throughout the approach. An analysis of the weather conditions at the time of the accident, including radar and satellite sensor imagery, disclosed that strong weather echoes existed near the accident site with embedded areas of intense to extreme echoes. The tops were in excess of 33,000 feet. The analysis indicated that several low level wind shear layers were present with moderate to severe turbulence.
HISTORY OF FLIGHT On December 16, 2002, about 1430 Pacific standard time (PST), a Piper PA-24-250, N6268P, collided with terrain and several homes in Anaheim Hills, California, following the in-flight separation of the left wing and portions of the horizontal stabilizers. The private pilot/owner was operating the airplane under the provisions of 14 CFR Part 91. The pilot and one passenger sustained fatal injuries; the airplane was destroyed. The personal cross-country flight departed Prescott (PRC), Arizona, at 1129 PST, en route to John Wayne/Orange County Airport (SNA), California. Instrument meteorological conditions prevailed at Orange County. An instrument flight rules (IFR) flight plan had been filed in flight near Palm Springs, California. The primary wreckage was at 33 degrees 50 minutes north latitude and 117 degrees 46 minutes west longitude. A ground witness reported that he heard an airplane coming down. He looked up and saw the airplane with the wings vertical. He said that the engine was producing power. He saw the airplane hit the ground and skid into the house. He ran across the street to try and assist the occupants. He heard a hissing sound, and then the garage and airplane exploded. The National Transportation Safety Board investigator-in-charge (IIC) reviewed a transcript of recorded radio transmissions. The airplane departed Prescott, and the pilot obtained flight following from Albuquerque Air Route Traffic Control Center (ARTCC) for the initial part of the trip. The pilot told them that he was level at 10,500 feet. His route of flight would be direct Parker, California; direct Thermal, California; and then direct Santa Ana. Albuquerque passed control to Los Angeles ARTCC (ZLA) at 1207 PST. At 1216, the pilot advised ZLA that he might need an instrument approach into Orange County, and the controller said that he would keep the pilot advised of the weather. At 1219, ZLA gave the Orange County weather: wind 170 degrees at 12 knots; visibility 10; and few clouds at 2,500 feet, broken layers at 4,000 feet and 20,000 feet. The controller added that the weather was not too bad, but he believed that weather was moving in. At 1353, ZLA instructed the pilot to contact Southern California (SOCAL) Terminal Radar Approach Control (TRACON) on frequency 134.0, the Banning Radar sector (BANR). The pilot checked in with BANR, and reported descending through 9,000 feet. He said that he would try to maintain 10,500, but he had gotten pushed down to this altitude. He informed BANR that he might need an instrument landing system (ILS) approach. BANR amended his flight plan to IFR, and told him to expect his clearance in 10 miles. BANR issued an IFR clearance at 1400; it was direct to Orange County via direct Seal Beach VOR (very high frequency omni-directional radio range), maintain 8,000 feet. About 1407, BANR issued a heading of 240 degrees, vectors to the Orange County final approach course. At 1414, BANR handed the pilot off to SOCAL on frequency 124.1, the Shore Radar sector (SHRR). The pilot checked in to SHRR with Orange County automatic terminal information service (ATIS) information Tango. At 1421:47, SHRR instructed the pilot to descend and maintain 6,000 feet. About 30 seconds later, SHRR instructed him to turn right to a heading of 270 degrees. About 2 minutes later they instructed him to turn right to 290 degrees, and descend to 5,000 feet. About 50 seconds later, SHRR instructed him to turn to 330 degrees, and contact SOCAL on 121.3, the Tustin Radar sector (TUSR). The pilot checked in with TUSR, and TUSR issued a heading change to 350 degrees. Twenty-five seconds later, TUSR instructed him to descend and maintain 4,000 feet. Twenty-nine seconds later TUSR instructed him to turn left to 310 degrees. About 1 minute later, TUSR instructed him to turn left to 230 degrees. TUSR added descend and maintain 3,000 feet if he had not already been instructed to do so. At 1427:44, TUSR stated that the target was 5 miles from Lemon (intersection/outer marker), and said to continue the left turn to a heading of 220 degrees. TUSR also instructed the pilot to maintain 3,000 feet until established on the localizer (course 194 degrees). TUSR cleared him for the ILS runway 19R approach. Nine seconds later, at 1427:53, the pilot acknowledged the instructions. There were no other transmissions from the pilot. TUSR asked the pilot to say his heading, but received no response. TUSR lost radar contact and asked the Orange County air traffic control tower if they had contact. The tower did not. The controllers discussed the situation and both remarked that the radar target appeared to have made a right turn prior to the lost contact. PERSONNEL INFORMATION A review of Federal Aviation Administration (FAA) airman records revealed that the pilot held a private pilot certificate with airplane single engine land and instrument ratings. The pilot held a third-class medical certificate issued on June 4, 2002. It had the limitations that the pilot must wear corrective lenses. The pilot's charred logbook was in the wreckage. The IIC estimated that the pilot had a total flight time of 890 hours. He logged 25 hours in the last 90 days, which included three round trips between Orange County and Prescott. Two of the return trips to Orange County terminated with an ILS approach. He logged 5 hours in the last 30 days. He had an estimated 740 hours in this airplane; the first flight occurred in April 1992. AIRCRAFT INFORMATION The airplane was a Piper PA-24-250, serial number 24-1376. A review of the airplane's logbooks revealed a total airframe time of 4,421 hours at the last annual inspection. An entry on January 13, 2002 recorded an annual inspection. The tachometer read 2,962.1 at the last inspection. Witnesses familiar with the airplane reported that several years earlier they observed damage to the stabilator. One witness observed the pilot/owner making repairs. The pilot said that he had flown through turbulence severe enough to damage the horizontal stabilator. One witness said that the owner had installed another stabilator. FAA records did not indicate that the owner held an airframe mechanic certificate. The airframe logbooks did not contain an entry for repairs, and the owner did not notify the Safety Board of the damage. A certified copy of the airplane records from the FAA Aircraft Registration Branch did not contain a record of a major repair or alteration. The engine was a Textron Lycoming O-540-A1D5 engine, serial number L-3608-40. At the last annual inspection, total time on the engine was 3,798.1 hours; time since major overhaul was 615 hours. Technicians installed six new cylinders at the annual inspection. METEOROLOGICAL INFORMATION There was no record of the pilot of N6268P having contacted any Direct User Access Terminal (DUAT) venders or an Automated Flight Service Station (AFSS) for a formal preflight weather briefing. A staff meteorologist prepared a factual report on the prevailing weather conditions. The following paragraphs summarize his findings; the full report is part of the public docket. All the weather data used in this report was from official National Weather Service (NWS) sources including the National Climatic Data Center (NCDC). The IIC converted all times to PST. The NWS Surface Analysis Chart for the southwestern United States depicted the primary synoptic conditions at the surface at 1600 on December 16, 2002, immediately after the accident. The main features included a cold front moving across southern California. The station models across southern California depicted overcast skies with continuous rain. Wind direction surrounding the accident site varied. The wind was from the south and southeast at 15 to 20 knots immediately in the vicinity of the accident site and Orange County Airport. East of the site it was west-southwest at 30 knots. Northwest of the site it was northwesterly at 10 to 15 knots. The NWS Weather Depiction Chart for the southwestern United States at 1400 depicted an area of IFR conditions by a shaded contour line over southern California. An area of marginal visual flight rules (MVFR) conditions, indicated by an unshaded contour line, surrounded the IFR area. Visual flight rules (VFR) conditions extended over southeast California and Arizona. The accident site was within the area identified under IFR conditions. The station models on the chart depicted visibilities from 1/2 to 1 3/4 miles in moderate to heavy rain. They depicted overcast skies with ceilings from 200 to 1,200 feet in the vicinity of the accident site. The NWS Radar Summary Chart for 1415 on December 16, 2002, depicted the conditions prior to the accident. The chart depicted a large area of echoes over Arizona, Nevada, California, and extending over the route of flight. The echo intensities were light to moderate over Arizona, Nevada, and southeastern California. The echoes increased to strong to very strong echoes over southwestern California, with an embedded area of intense to extreme echoes near the coast identified as rain showers. Echo tops ranged from 24,000 to 27,000 feet in the vicinity of the accident site. The pilot received Orange County weather while en route from Los Angeles Center at 1219. About 1414, the pilot reported that he had Orange County information Tango. Recorded radio transmissions contained no other references to weather reports. The closest weather reporting station was Orange County Airport; the planned destination that was 11 miles southwest at an elevation of 56 feet. The airport had an Automated Surface Observation System augmented by certified NWS observers. The reported conditions surrounding the time of the accident were: KSNA weather observation at 1353: wind from 140 degrees at 13 knots gusting to 21 knots; visibility 10 statute miles; a few clouds at 2,700 feet, scattered clouds at 3,800 feet, ceiling broken at 10,000 feet, and overcast at 20,000 feet; temperature 16 degrees Celsius (C), dew point 12 degrees C; and altimeter 29.89 inches of mercury (inHg). Remarks: automated observation system, peak wind from 140 degrees at 26 knots recorded at 1339; rain ended at 1315; sea level pressure 1012.0-hPa; precipitation since last hour less than 0.01 of an inch; temperature 16.1 degrees C; dew point 11.7 degrees C. KSNA special weather observation at 1424: wind from 160 degrees at 14 knots gusting to 19 knots; visibility 2 miles in moderate rain and mist; a few clouds at 2,100 feet, ceiling broken at 2,800 feet, overcast at 5,000 feet; temperature 15 degrees C; dew point 13 degrees C; and altimeter 29.85 inHg. Remarks: automated observation system, rain began at 1410, pressure falling rapidly, precipitation since last hour 0.05 inches. KSNA special weather observation at 1433; wind from 150 degrees at 15 knots gusting to 21 knots; visibility 1 1/2 miles in moderate rain and mist; a few clouds at 2,100 feet, ceiling broken at 2,700 feet, overcast at 4,700 feet; temperature 15 degrees C; dew point 13 degrees C; and altimeter 29.85 inHg. Remarks: automated observation system, tower visibility 2 miles; rain began at 1410; precipitation since 1353 at 0.10 inches. KSNA weather observation at 1453: wind from 170 degrees at 14 knots; visibility 2 miles in moderate rain and mist; scattered clouds at 2,000 feet, ceiling broken at 2,500 feet, overcast at 3,300 feet; temperature 15 degrees C; dew point 13 degrees C; and altimeter 29.84 inHg. Remarks: automated observation system, rain began at 1410; sea level pressure 1010.4-hPa; precipitation since last hour 0.18 inches; temperature 15.0 degrees C; dew point 13.3 degrees C. KSNA special weather observation at 1502: wind from 160 degrees at 16 knots gusting to 21 knots; visibility 1 3/4 miles in heavy rain and mist; a few clouds at 1,300 feet, ceiling broken at 1,900 feet, overcast at 3,300 feet; temperature 15 degrees C; dew point 14 degrees C; and altimeter 29.83 inHg. Remarks: automated observation system, tower visibility 2 miles; precipitation last observation 0.04 inches. The closest upper air sounding or rawinsonde was from NWS San Diego Regional Forecast Office (KMYF), station number 72283, located 70 miles southeast of the accident site. The sounding indicated a moist low-level environment with a relative humidity greater than 75 percent from the surface to 833-mb or 5,369 feet, and there was a temperature inversion from 816-mb or 5,515 feet to 6,000 feet. Another moist layer was above 500-mb or approximately 18,000 feet. The Lifted Condensation Level (LCL) or base layer of the clouds was 944-mb or 1,576 feet, with the Level of Free Convection (LFC) at 932-mb or 1,910 feet. The freezing level was at 675-mb or at 10,544 feet. The sounding indicated the following stability parameters, a Lifted Index (LI) of 5.7 and a K-Index of 1.9. The wind profile indicated surface winds from the south-southeast at 18 knots veering to the west and the northwest with altitude. It identified a low-level wind maximum at 2,000 feet with winds of 35 knots. Winds decreased above this level and then increased to a maximum located at 31,000 feet with winds at 111 knots. The estimated mean wind from the surface to approximately 18,000 feet was from 260 degrees at 57 knots. The surface to 2,000 feet mean wind was from 180 degrees at 22 knots. The staff meteorologist obtained Geostationary Operations Environmental Satellite number 10 (GOES-10) data from the Safety Board's Man-computer Interactive Data Access System (McIDAS) workstation. He obtained both visible and infrared imagery surrounding the time of the accident, and documented relevant images. The GOES-10 4X magnification infrared satellite image at 1430 depicted a large band of enhanced clouds extending over southern California and bordering over the accident site. The radiative temperature over the site was 230.0 degrees K or -43.16 degrees C, which corresponded to cloud tops in the range of 33,000 feet. The GOES-10 2X magnification visible image for 1430 depicted a large band of stratiform type clouds consistent with nimbostratus extending over the destination and the accident site. The image depicted several small north-to-south transverse bands of higher clouds. The closest NWS Weather Surveillance Radar-1988, Doppler (WSR-88D) was at Santa Ana Mountains (KSOX), approximately 8 miles east. The radar produces three basic types of products: reflectivity, radial velocity, and spectral width. FAA Advisory Circular AC 00-24B titled "Thunderstorms" dated January 2, 1983, also defines the echo intensity levels and potential weather phenomena associated with those levels. If the maximum VIP (Video and Integrator Processor) Levels are 1 "weak" and 2 "moderate," then light to moderate turbulence is possible with lightning. VIP Level 3 is "strong" and severe turbulence is possible with lightning. VIP Level 4 is "very heavy" and severe turbulence is likely with lightning. VIP Level 5 is "intense" with severe turbulence, lightning, hail likely, and organized surface wind gusts. VIP Level 6 is "extreme" with severe turbulence, lightning, large hail, extensive surface wind gusts and turbulence. The Aeronautical Information Manual (AIM) also references these levels in the Pilot/Controller Glossary under radar weather echo intensity levels. The KSOX image depicted a large area of echoes over the accident site with reflectivities in the range of 30 to 40 dBZ or VIP Level 2 "moderate" intensity echoes. The radial velocity wind pattern indicated winds from the south at the surface and veering to the southwest with height with winds from the south-southwest and approximately 30 knots within 5 miles of the accident site. Immediately north and east of the radar site, rapid changes in wind velocity occurred with wind speeds of 44 to 60 knots. The specialist identified no rotational couplets within 5 miles of the accident site. A sergeant with the Anaheim Police air unit was in his office. He noted that heavy rain began about 1415. About 1430, he heard a report of an airplane crash in Anaheim Hills on the police radio. He immediately access
the pilot's encounter with forecast severe turbulence during an inadvertent penetration of an intense weather cell, which resulted in the pilot exceeding the design structural limits of the airplane. A factor in the accident was the pilot's inadequate preflight planning and preparation, and his failure to obtain a complete weather briefing.
Source: NTSB Aviation Accident Database
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