N914ESCampbell Earl S Jr RV-6A

On July 29, 2013, at 1446 central daylight time (all times cdt), an amateur-built Campbell RV-6A, N914ES, was destroyed when it collided with terrain during a landing approach to runway 36 (4,401 feet by 75 feet, asphalt), at the Starke County Airport (OXI), Knox, Indiana. The private pilot was fatally injured. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91, as a personal flight. Visual meteorological conditions prevailed in the vicinity of the accident site and no flight plan had been filed. The personal flight originated from Richard Downing Airport (I40), Coshocton, Ohio at 1250. The intended destination was OXI.

The airplane was in a group of four other airplanes that originally departed the Fredericksburg, Virginia, area. According to the pilots of the other airplanes in the group, the intention was to land at OXI, stay overnight near Knox, Indiana, and then continue the trip the following day to the annual Experimental Aircraft Association Airventure fly-in. The pilots reported that the accident airplane was the fourth airplane in the group and three other airplanes had already landed at OXI. The three pilots that had already landed reported seeing the airplane fly over the airport on a left crosswind portion of the landing pattern. They reported that their attention was diverted and they did not watch the remainder of the landing approach. When the fifth airplane of the group landed, the first three pilots to land then realized that the accident airplane had not landed. The pilot and passenger of the fifth airplane in the group commented that they saw the accident airplane enter the traffic pattern at OXI, and heard his radio transmissions on the common traffic advisory (CTAF) frequency. They commented that the transmission from the accident pilot seemed out of the ordinary and that he was fumbling for words. They said that this was not common for the accident pilot and that he was usually very precise in his radio transmissions. The pilot and passenger of the fifth airplane did not see the accident happen and only learned of it after they themselves had landed.

A witness to the accident reported seeing the airplane when it was in the airport traffic pattern. He stated that the airplane was flying level and then it rolled to the left and dove into the ground.

The pilot's wife reported that the pilot had complained that he was not feeling well and had chest pain two days before the accident flight. Reportedly the pilot thought the chest pain was from a pulled muscle. The wife reported that the chest pain had resolved and the pilot was feeling better by the time of the flight, but he had not seen a physician.

Flight track data was downloaded from a handheld GPS recovered from the accident airplane. The track data for the day of the accident showed that the airplane departed from the Shannon Airport (KEZF), Fredericksburg, Virginia, at 0955, and traveled to I40. The airplane remained on the ground at I40 for about 20 minutes. The other pilots in the group reported that all five airplanes were fueled at I40, including the accident airplane. The data showed that the airplane then departed I40 at 1246 and continued to OXI. The data showed the airplane traveled in a westerly direction when it passed over the airport at about 1,300 feet mean sea level (msl). The airplane then made a left turn to the south and began descending. When the airplane was about 0.36 nautical miles southwest of the approach end of runway 36, it began a descending left turn back toward the runway. The left turn continued until the end of the data. The last recorded position was 0.3 nautical miles and 193 degrees from the approach end of runway 36. The altitude recorded at the last data point was 806 feet msl. The last recorded GPS location coincided with the location where the wreckage was found. The final few seconds of recorded data indicated that the airplane was in a descending left turn, the rate of turn had increased to about 900 degrees per minute, the descent rate had increased to about 1,300 feet per minute, and the groundspeed had decreased to about 54 knots.

The pilot held a private pilot certificate with a single-engine land airplane rating. He was issued a third-class airman medical certificate, with a restriction for corrective lenses, on November 21, 2012. An incomplete copy of his flight logbook showed that he had accumulated 1,826 total flight hours as of the last entry dated April 25, 2013. His most recent flight review was completed on February 1, 2012.

The accident airplane was an amateur-built RV-6A airplane that was constructed from a kit. It was a low-wing monoplane of predominately aluminum construction. It was a two-place, low wing, single engine airplane, with a tricycle landing gear configuration. The airplane was issued an FAA experimental airworthiness certificate on August 4, 1994. The airplane was powered by a 150-horsepower Lycoming O-320-E2G four-cylinder, reciprocating engine, serial number L-47414-27A. The engine was manufactured in July 1977.

Weather conditions recorded by the OXI Automated Weather Observing System (AWOS), at 1455 were: wind from 30 degrees at 3 knots, visibility 10 miles, scattered clouds at 4,100 feet above ground level (agl), broken clouds at 4,800 feet agl, temperature 22 degrees Celsius, dew point 13 degrees Celsius, and altimeter 30.14 inches of mercury.

The airplane impacted a corn field about 0.30 nautical miles south-southwest of the approach end of runway 36 at OXI. The airplane was upright and was facing about 120 degrees. The path through the corn and the crushing of the forward fuselage and wing indicated that the airplane impacted the ground in a near wings level attitude with the nose pitched downward about 60 degrees. The forward fuselage was crushed rearward and upward, and the engine and firewall were partially separated from the remainder of the fuselage. The wing leading edges were crushed rearward and upward with flattening of the leading edge wings skins at an angle coinciding with an approximate 60 degree nose down attitude. The wings, aft fuselage, and tail surfaces remained attached to the fuselage. The aft fuselage and tail surfaces exhibited little damage.

Examination of the airplane's flight controls revealed elevator and rudder continuity from the cockpit controls to the respective control surfaces. Right aileron continuity was confirmed from the right control stick to the aileron. Left aileron control continuity was confirmed from the left control stick to the aileron. A broken rod end was found on the push rod that connected the right and left control sticks. The break in the rod end was consistent with damage incurred during the impact. The linkages from the flap torque tube to the flaps were found broken on both right and left flaps. The breaks were consistent with damage incurred during the impact.

The airplane's engine rotated freely by hand. Suction and compression were confirmed on all cylinders. Valve train continuity was confirmed and valve action was noted at the number two cylinder. The left magneto was broken loose from its mount. It was equipped with an impulse coupling, and produced spark on all four ignition leads when rotated by hand. The right magneto remained attached to the engine. The right magneto was not equipped with an impulse coupling. After removal from the engine, the magneto was rotated using an electric drill and spark was noted on all four ignition leads. The carburetor was fragmented and only the upper portion remained attached to the engine's induction system.

Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.

The pilot was in apparent good health except for a history of chest pain due to an unknown cause two days prior to the accident that had resolved prior to the accident flight. According to witness reports, the pilot was "fumbling for words" during radio transmissions prior to the crash. The pathologist that performed the autopsy identified hypertrophy of the left ventricular wall, moderate to severe coronary artery disease involving the left anterior descending coronary artery, and small areas of myocardial fibrosis. However, autopsy did not identify evidence of recent ischemia (heart attack) or other acute natural disease.

During his last medical certification examination on November 21, 2012, the pilot reported no recent medical concerns and was issued a third class medical certificate with the following limitation: Must wear corrective lenses.

The pathologist that performed the autopsy determined the cause of death was multiple blunt force trauma and the manner of death was accident. In addition to significant traumatic injuries the autopsy identified atherosclerotic cardiovascular disease of coronary arteries and aorta, emphysema, and surgical absence of the right kidney but no natural disease in the remaining left kidney.

Examination of the cardiovascular system identified a 310 gram heart (average for a man of his weight is 383 grams with a range from 290 to 506 grams).The left ventricular wall was 1.5 cm (normal is 1.23 cm with a range from 1.07 to 1.39 cm). The pathologist on gross examination identified coronary artery atherosclerosis with 50% stenosis of the left main and 50% stenosis of the left anterior descending coronary artery. The circumflex and right coronary arteries were not narrowed by plaque.

Microscopic examination of the left anterior descending coronary artery revealed moderate to severe arteriosclerosis. The pathologist evaluated ten additional blocks of heart tissue. These slides show severe calcific coronary arteriosclerosis, myofibrillar hypertrophy, and occasional foci of interstitial fibrosis. The specific vessel(s) and areas of the heart involved in the microscopic evaluation of heart tissue were not identified.

An addendum to the autopsy stated, "While no acute ischemic changes are found, the interstitial fibrosis is consistent with prior ischemia, and cardiac hypertrophy is associated with arrhythmias. Indeed, microscopic evidence of ischemia may not been [be] seen in myocardial infarcts of less than 12 hours' duration. Thus, it appears possible, given the information that decedent's radio transmissions on the CTAF prior to the accident indicated he was fumbling for words, that he suffered a cardiac arrhythmia prior to the accident."

Toxicology testing was performed by the FAA's Civil Aerospace Medical Institute. The analysis detected no carbon monoxide, medications or drugs in the blood and no ethanol in the vitreous.

On October 26, 2008, about 1000 eastern daylight time, an experimental amateur-built Vans RV-8A, N88FG, was substantially damaged when it was struck by an experimental amateur-built RV-6A, N914ES, while standing at Cambridge-Dorchester Airport (CGE), Cambridge, Maryland. The certificated commercial pilot of the RV-8A, and the certificated private pilot of the RV-6A, were not injured. Visual meteorological conditions prevailed at the time of the accident, and neither airplane was operating on a flight plan. The personal flights, which both departed from Eastern West Virginia Regional Airport (MRB), Martinsburg, West Virginia, were conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

Both pilots provided written statements that recounted a similar series of events. According to the pilots, after landing at CGE, both airplanes taxied to the parking area. The RV-8A parked first, and the pilot of the RV-6A planned to park his airplane immediately to the right of the RV-8A. As the RV-6A approached the stationary RV-8A from the right and perpendicular to the RV-8A, the RV-6A pilot applied right brake in order to turn the airplane into the intended parking spot. The brake "failed totally," and the pilot then pumped the brake several times, with no response. The pilot then applied left brake to avoid hitting the RV-8A, but the right wing of the RV-6A struck the right wing of the other airplane. The RV-6A turned to the right, and the propeller of the RV-6A struck the right horizontal stabilizer of the RV-8A, substantially damaging it.

A Federal Aviation Administration (FAA) inspector examined both airplanes, and noted the presence of brake fluid both on the exterior of the right brake and on the ground around the right wheel of the RV-6A. According to the inspector, the right wing tips of both aircraft were damaged as well as the horizontal stabilizer of the parked airplanes.

According to the pilot/builder of the RV-6A, a post-accident disassembly of the right brake revealed that the o-ring between the main brake housing (cylinder assembly) and the piston had "deteriorated."

The RV-6A's most recent conditional inspection was completed on September 23, 2008, and the airplane had accumulated 718 total hours of operation on that date.

The National Transportation Safety Board subsequently retained the o-ring, and shipped it to the brake assembly manufacturer for further testing under the supervision of FAA inspectors. An acceptance test was performed utilizing a new brake assembly, with the accident o-ring installed. Once the o-ring was in place, pressure was applied using a test stand, and hydraulic fluid immediately leaked from the brake assembly piston area. The accident o-ring was removed and a new o-ring installed to verify the condition of the test brake assembly. The brake assembly passed the inspection with no leaks noted using the new o-ring.

The manufacturer subsequently performed an analysis of the o-ring for material type, hardness, and dimensions. A Fourier Transform Infrared Spectroscope (FTIR) analysis showed that both the accident o-ring and a new (control) o-ring were composed of a nitrile rubber compound, conforming to the o-ring material requirements set by the manufacturer's engineering drawing; however, the FTIR spectrum of the accident o-ring indicated the presence of an unknown substance on its outside diameter surfaces.

Dimensional measurements showed that the accident o-ring was smaller in size that the control o-ring, with a compression set of about 8 percent on contacting surfaces in radial dimensions. Hardness testing revealed that the accident o-ring exhibited a greater hardness than the control o-ring. The testing concluded that the abnormalities observed were consistent with the accident o-ring having experienced excessive heat.