Midway, UT, USA
N2256J
Yakovlev YAK 52
The purpose of the flight was for one pilot to familiarize the other pilot with the YAK 52. Both were retired military pilots and airline captains. The fixed base operator's (FBO) receptionist heard a voice on the Unicom frequency say, "We're crashing, we're going in," or words to that effect. Witnesses saw the airplane descend vertically and impact an open field in a residential area. They said the engine was developing full power. During wreckage examination, a brass nut was found in the crushed skin of the empennage. The nut was identified as coming from an air hose assembly. Many of the airplane's systems were pneumatically operated (i.e., engine start, flaps/landing gear extension/retraction). On one end of the assembly was a brass adapter that consisted of a nut and fitting. According to a partner of Squadron 52 LLC, the adapter portion of the assembly was always connected to, and was an integral part of, the hose assembly. Although not normally carried in the airplane, an air hose assembly was usually carried on cross-country trips in the event the air tank developed a leak and there was insufficient pressure to start the engine. The hose assembly could be attached to an FBO's air bottle and the engine could be "jump started." The nut exhibited numerous gouges. The nut was placed between the elevator bellcrank and housing. When the bellcrank was moved by hand, full up and down elevator control could not be achieved because to the impeding nut. The gouges on the nut were consistent with elevator bellcrank contact. Scrape marks were also noted on the underside of the bellcrank housing. It could not be determined how or when the adapter assembly separated from the hose, or how the nut got into the empennage. This report was modified on July 29, 2004.
HISTORY OF FLIGHT On January 16, 2003, at 1157 mountain standard time, a Yakovlev YAK 52, N2256J, registered to and operated by Squadron 52 LLC of Park City, Utah, was destroyed when it impacted terrain, exploded, and burned at Midway, Utah. The two airline transport certificated pilots were fatally injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The local flight originated at Heber City, Utah, approximately 1100. According to one of the partners, an owner-pilot and two third-parties arrived at the airport to go flying. The owner-pilot and one of the third-parties boarded the airplane and took off. The other third-party was supposed to fly with the owner-pilot after completion of this flight. The receptionist at Wasatch Aero Services and another pilot who was waiting for take off at the Heber City airport said they heard a voice on the Unicom frequency say, "We're crashing, we're going in," or words to that effect. She said the volume was low and the voice was calm. She said she knew the pilot personally, and was familiar with his voice. She said it was not his voice. Witnesses said they saw the airplane in a vertical or near-vertical attitude just prior to impact, and the engine sounded like it was developing full power. None of the witnesses reported seeing the airplane performing aerobatic maneuvers. The partner said the pilot-in-command was "adamant about using a minimum of 2,500 feet agl for completing any aerobatic maneuvers." The first 9-1-1 call was received by the sheriff's office at 1157. The accident occurred during the hours of daylight at a location of 40 degrees, 35'48" north latitude, and 111 degrees, 27'18" west longitude. PERSONNEL INFORMATION Both the pilot-in-command and second pilot were former military pilots and retired airline captains. The pilot-in-command, who was seated in the front seat, held an airline transport pilot certificate for airplanes, multiengine, land; type ratings in the Boeing 757/767, Douglas DC-9, and Cessna 500, and commercial privileges in airplanes, single-engine, land, dated August 17, 1998. He also held a flight engineer certificate with a turbojet rating, dated December 23, 1969. His most recent second class airman medical certificate, dated June 18, 2002, contained the restriction, "Holder shall possess glasses for near and intermediate vision." On his application for medical certification, he reported 19,650 total hours of flight experience. According to American Airlines, his last recurrency check was taken in the Boeing 767 on March 21, 1999. In late May 2002, he took a 3-day flight proficiency course through the Cessna Pilots Association in Santa Monica, California. At the completion of the course, he passed a flight review in his Cessna 210 on June 2, 2002. His partner said he had flown the YAK 52 regularly for the past 8 years. The second pilot, who was seated in the rear seat, held an airline transport pilot certificate for airplanes, multiengine, land; type ratings in the Boeing 727/757/767/777, Douglas DC-9, and McDonnell-Douglas MD-11 with the restriction, "Circling approaches VMC only," and commercial privileges in airplanes, single-engine, land. It was dated October 28, 2000. He also held a flight engineer certificate with a turbojet rating, dated March 28, 1973. His most recent first class airman medical certificate, dated May 17, 2002, contained the restriction, "Must have glasses for near vision." On his application for medical certification, he reported 23,700 total hours of flight experience. According to American Airlines, his transition qualification was taken in the Boeing 777 on October 28, 2000. AIRCRAFT INFORMATION N2256J (s/n 833709), a YAK 52, was manufactured by Yakolev in 1983, and certificated by FAA in the experimental category in 1995. The single engine, propeller driven, two seat airplane was equipped with a Ivchenko M-14P reciprocating engine, and a 2-blade, wooden, constant-speed propeller (m/n B530TA). The last conditional inspection was performed on August 1, 2002, at a tachometer time of 255.3 hours. Airframe total time was computed to be 840.6 flight hours. METEOROLOGICAL INFORMATION At 1156, the weather conditions at Salt Lake City, Utah (elevation 4,227 feet), 115 degrees, 28 nautical miles (nm) from the accident site were as follows: wind 150 at 4 knots; visibility 10 sm; cloud condition few at 1,500 feet; temperature 3 degrees Celsius; dew point -6 degrees Celsius; altimeter setting 30.55 inches. WRECKAGE AND IMPACT INFORMATION FAA's Flight Standards District Office in Salt Lake City was asked to conduct the on-scene investigation. Because one of its inspectors had once been a co-owner of the airplane, and to avoid any conflict of interest, the investigation was transferred to FAA's Flight Standards District Office in Boise, Idaho. According to the Boise inspector, the accident site was in an open field in a residential area of Midway, Utah. The burning wreckage was contained in a large, 4-1/2 foot deep crater. The airplane's wooden propeller was shattered, and the engine had all cylinders broken and bent backwards. The leading edge of both wings showed even crushing from the wing root out to the wing tip. All of the major aircraft components were recovered. Elevator and rudder control continuity were partially established. Both pilots wore parachutes, but there was no evidence that either tried to jump. NTSB examined the wreckage layout on March 12, 2003. A brass nut was found in the crushed skin of the empennage. The airplane owners identified the nut as part of an air hose. Many of the YAK 52 systems are pneumatically operated (i.e., engine start, flaps/landing gear extension/retraction). Although not normally carried in the airplane, the air hose was usually carried on cross-country trips in the event the air tank developed a leak and there was insufficient pressure to start the engine. The air hose could be attached to an FBO's (fixed base operator) air bottle and the engine could be "jump started." The nut exhibited numerous gouge marks. The nut was placed between the elevator bellcrank and housing. When the bellcrank was moved by hand, full up and down elevator control could not be achieved due to the impeding nut. The gouges on the nut were consistent with elevator bellcrank contact. Scrape marks were also noted on the underside of the bellcrank housing. The owners said the air hose was stored in the FBO community hanger where the airplane was also kept. The last time it was known to have been used was when it was strapped to the rear seat and the airplane was ferried to its last conditional inspection in August 2002, and used to lubricate the pneumatic system seals. It could not be determined how or when the adapter assembly separated from the hose, or how the nut got into the empennage. MEDICAL AND PATHOLOGICAL INFORMATION The Utah State Medical Examiner's Office performed gross examinations on the two pilots on January 17, 2003. Toxicological tests could not be performed. TESTS AND RESEARCH There have been several accidents involving the YAK 52 around the world. The first accident occurred in Smolensk, USSR, in 1998. According to the http://www.skytrace.co.uk/ website, the pilot had made "two vertical figures" and was "transitioning from diving to climbing flight." The airplane made a slow right and impacted the ground at an 80-degree angle. The pilot was killed. An investigation revealed a camera lens cap had "jammed in the fastening lever of the elevator balancing load." The camera lens cap had been lost by a cameraman on a previous flight. According to a United Kingdom YAK importer-distributor (whose company provides YAK 52 flight training and maintenance), there were two similar, but nonfatal, accidents in Lithuania in 2002 (http://www.yakuk.com). The first occurred in Kaunas. The pilot was forced to parachute to safety when a flight recorder frame (the recorder had been removed) jammed the elevator controls. In the second, the pilot rolled inverted and discovered the elevator control was inoperable. He rolled the airplane upright and the elevator control worked freely. The item that caused the control to jam was not given. According to the owner of AirCare Systems, a YAK 52 importer-distributor in Lamar, Colorado, there was an incident in Atlanta, Georgia (date not given). A YAK 52 pilot was doing aerobatics when a radio cap came off and jammed the elevator control. He managed to land safely. The AirCare Systems owner added that during a recent preflight of his personal YAK 52, he removed the inspection panels and found a checklist and radio knob that he had lost several months previously. In addition to the current accident under investigation, NTSB's website (http://www.ntsb.gov/) lists two other YAK 52 accidents. In Aledo, Texas, on August 6, 2002, witnesses saw N5C performing "barrel rolls, side rolls, flips, turning side to side, circles, upside down, spirals, a half-loops, and loops." The airplane was seen to make a loop and go straight down. The ATP pilot and passenger were killed. On June 18, 2002, in Antioch, California, witnesses saw N644LL perform a loop before impacting the ground nose first, killing the ATP pilot. Another accident occurred in Northamptonshire, England, near Towcester, on December 29, 2002. According to the BBC News website, a witness saw the airplane make "an apparent near-vertical dive, then [the pilot] tried to level out." Another report said the pilot was performing "a stall turn." The airplane struck a high voltage power line. Although the final report had not been released as of this writing, preliminary information indicates a screwdriver was found lodged in the elevator bellcrank. The pilot and his brother, who were from Surrey, were killed. One of the owners of N2256J said that the design of the YAK 52 made it susceptible to foreign objects interfering with the flight controls. As its accident history indicates, the design of the elevator bellcrank and its close proximity to the housing makes it susceptible to being jammed by small articles, particularly when the airplane is subjected to near-zero or negative "G" flight maneuvers or inverted flight. As one operator observed, "In a North American T-6 or Waco, the fuselage is bigger and the control tube is about a foot off the fuselage floor. In the YAK, the control tube is closer to the fuselage and more prone to FOD." The owner also said the opening behind the rear seat, which is hidden from view, allows any objects dropped in the rear cockpit to readily migrate into the rear empennage where the bellcrank is located. As an example, one of his partners placed a sick bag in the rear cockpit side storage pocket in November 2002. During the March 12, 2003, NTSB post-accident examination, the sick bag was found entangled in the control cables in the rear empennage. He also said Russian design philosophy -- building cheaper parts that require regular replacement prior to failure, significantly lowering initial aircraft production costs -- differed from that of the Western world -- building more expensive parts that last much longer, with fewer failures and replacements, resulting in higher aircraft prices. The United Kingdom YAK importer-distributor also noted the lack of technical support for Russian aircraft once they are exported to Western countries when he wrote in his e-mail: "[The] Russians just do not seem to care about what happens to these machines." ADDITIONAL INFORMATION Other than the Federal Aviation Administration, there were no other parties to the investigation. The wreckage was released to the insurance company on March 12, 2003.
The malfunction of the elevator control as a result of a jammed elevator control bell crank, rendering control of the airplane impossible. A contributing factor was the foreign object (nut) damage.
Source: NTSB Aviation Accident Database
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