Factual Report: Icing eyed in caravan crash

 - January 31, 2007, 9:25 AM

CESSNA 208, PARKS, ARIZ., NOV. 8, 2002–At approximately 10:20 a.m. (MST) a Cessna 208B (N514DB), operated by Brown County Financial Services, LLC, of Snyder, Texas, was destroyed when it crashed approximately three miles south of Parks, Ariz., about 16 nm northwest of Flagstaff. The commercial pilot, a private-pilot-rated passenger and two other passengers were killed. The FAR Part 91 flight had departed Las Vegas, Nev., at 9:19 a.m. (MST) for Midland, Texas.

At 8:44 a.m., the pilot contacted the Fort Worth, Texas, Automated Flight Service Station to file an IFR flight plan. The pilot told the briefer that he planned to leave Las Vegas at 9 a.m. and cruise at 12,000 feet. The route of flight was to proceed via Peach Springs, Flagstaff and Winslow, Ariz.; Zuni, Albuquerque, Corona and Roswell/Chisum, N.M.; and end at Midland. The pilot told the briefer he planned for four hours en route and had six hours of fuel on board.

As the briefer was entering the flight plan, he asked the pilot if he had got his weather. The pilot replied, “just a second ago.” The pilot then asked about an Airmet for icing. The briefer told the pilot an Airmet was in effect for the route of flight that included moderate mixed and rime icing from the freezing level up to 24,000 feet. The briefer added that the freezing level was forecast to be at 12,500 feet in Arizona and that it was dropping down to 10,500 feet farther east. The briefer also gave the pilot advisories for scattered rain cells in New Mexico, advised him of a Sigmet for severe turbulence north of his planned route and cautioned that he might experience some turbulence. The pilot said he was expecting it.

According to the NTSB the airplane departed at approximately 9:19 a.m., received routine clearances and climbed to 13,000 feet. At 10:05 the pilot contacted ATC and reported that he was level at 13,000 feet and four minutes later requested a climb to 15,000 feet; it was approved.

At 10:13 the pilot contacted the Albuquerque automated flight service station. He reported to the Flight Watch specialist that he was approximately 23 miles west of Flagstaff at 15,000 feet, and that about 20 miles west of his position, at 13,000 feet, he had encountered light mixed icing. The pilot requested any pireps from the specialist. Flight Watch reported that the only pirep for icing was from an airplane climbing out of ABQ westbound, whose pilot reported a trace of rime icing at 12,000 feet. The pilot acknowledged and asked about the weather across New Mexico. The specialist advised the pilot to stand by while he gathered the reports.

At 10:15 the pilot called Albuquerque Center (ZAB) and reported “getting…
mixed…right…now.” and requested a climb to 17,000 feet. The transmission was partially blocked by other aircraft. A few seconds later the pilot repeated the request and was cleared to 17,000 feet. The pilot acknowledged.

During the conversation between the pilot and ZAB, the Flight Watch specialist transmitted the weather reports for northern New Mexico and western Texas, advising that light rain was reported at Gallup, N.M., layered clouds near Roswell, New Mexico, and good VFR weather near Midland, Texas. At 10:16, the specialist repeated the report of trace icing near ABQ and concluded the report with “mostly just aircraft getting light chop, over.” The pilot did not reply. At the same time Flight Watch was sending the weather reports, radar showed the airplane climb to 15,200 feet, then rapidly descend.

At 10:17 Flight Watch advised the pilot to “check back when you get a chance, Flagstaff altimeter 30.11.” At 1017:08, Flight Watch received a broken transmission, “four delta bravo.” The specialist said, “you[r transmission] broke up.” There were no further transmissions from the airplane. Radar contact was lost at 1017:20. At 10:19, the ZAB controller attempted to contact N514DB with no results. The controller then requested another aircraft to monitor for an ELT signal but none was heard.

A retired airline pilot who was near the accident site said he heard engine noises that sounded similar to an airplane doing “aerobatics.” Shortly thereafter, he saw the Caravan emerge from the clouds pointed straight down and in a spin. The airplane disappeared behind trees and the witness said he heard it hit the ground. A second witness, who was flying an air ambulance Cessna 208 in the vicinity, said he heard N514DB ask ZAB for clearance to 17,000 feet because he was “getting mixed ice.” The witness reported that the person making the radio call from N514DB sounded “stressed,” and that the transmissions were “garbled.” A third witness, a mechanic on the air-ambulance Cessna 208, said that he heard N514DB report that they were “getting ice.” The witness said the “pilot sounded scared.” The witness also said that his pilot told him “the Cessna 208 is very susceptible to icing.”

The wreckage of N514DB was located at approximately 1030. The NTSB was on the scene at 8:05 the next morning. The accident site was located in a wooded area approximately three nautical miles south of Parks, Ariz. The investigator detected an odor of aviation fuel at the site but there were no signs of a post-impact fire. The wreckage rested predominantly upright and the engine and propeller hub rested in the impact crater. A debris field surrounded the main wreckage and extended outward for approximately 90 to 100 feet in all directions. An examination of the airplane’s systems showed no pre-impact anomalies.

According to FAA records, the pilot held a commercial certificate with airplane single-engine land, and multi-engine land ratings, dated Aug. 28, 2000. The pilot also held a flight instructor certificate with an airplane single-engine land rating, dated July 23, 2000. His first-class medical was current.” The Coconino County medical examiner conducted an autopsy on the pilot on Nov. 9, 2002, at Flagstaff, Ariz. FAA toxicology of samples taken from the pilot were negative for all tests conducted.

According to his logbook, as of Oct. 10, 2002, the pilot had a total flight time of 1,880.2 hours in all aircraft. It indicated he had 1,187.1 hours as pilot-in-command, 428.7 hours as a flight instructor, 125.0 hours of actual instrument (3.0 hours in the last 30 days), and 76.9 hours in make and model (6.9 hours in the last 30 days). In June 2002, the pilot attended FlightSafety International for Cessna 208 training, during which he received 7.5 hours of simulator time, including a 1.5-hour flight review. An accurate account of flight time from Oct. 10, 2002, to the date of the accident was not determined.

According to FAA records, the pilot-rated passenger held a private pilot certificate with an airplane single-engine land rating, dated Nov. 22, 1987. As of July 31, 2002, he had accumulated a total flight time of 650 hours in all aircraft. According to his records, he also attended FlightSafety International for Cessna 208 training in June 2002, when he received 7.5 hours of simulator time. He held a current third-class medical certificate.

At 9:56 the reported weather conditions at Flagstaff Pulliam Airport (FLG), Flagstaff, Ariz., 16nm from the accident site were wind 230 degrees at 22 knots, gusting to 27 knots; visibility 10 statute miles; sky condition broken at 3,300 feet, overcast at 4,400 feet; temperature 43 degrees F, dew point 27 degrees F; and an altimeter setting of 30.11. At 10:56 FLG reported basically the same weather conditions.

Pilots flying in the vicinity of Grand Canyon, Flagstaff and Prescott, Arizona, reported broken and overcast skies with light rime to moderate rime icing between 7,500 and 17,000 feet. According to the National Weather Service, in-flight weather advisories for occasional moderate icing and occasional moderate turbulence were in effect for the accident area.

The Caravan’s de-ice system valves were examined by Cessna. According to a laboratory engineer, the three de-ice valves showed no significant external damage. Examination of the valves showed no external pre-impact anomalies that could have precluded their proper operation in flight.

The airplane’s engine was examined at the Pratt & Whitney Canada Service Investigation Facility in St. Hubert, Quebec. It showed contact signatures to the engine’s internal components characteristic of the engine developing significant power at the time of impact. The engine displayed no anomalies that would have precluded normal operation before impact. Other tests conducted on instruments and systems that were not destroyed in the accident did not reveal any pre-crash problems.