ERA13FA424

The pilot's improper aerobatic maneuver that resulted in a loss of control, exceedance of the airplane's design limitations, and a subsequent in-flight breakup of the airplane.

After taking off, the pilot climbed the experimental amateur-built airplane to 6,500 feet mean sea level in visual meteorological conditions; the airplane remained in level flight for about 13 minutes and was traveling about 130 knots indicated airspeed. The airplane then suddenly lost about 3500 feet in altitude, accelerated to about 220 knots, and reversed direction within a 10 second period. Moments later, the airplane was observed traveling in a northwesterly direction at a low altitude, almost completely upside down at one point, with pieces of the airplane falling to the ground. Recorded radar data revealed that the airplane had entered a steep descending and accelerating left turn, and portions of the empennage separated from the airplane. The airplane continued on a descending, turning flight path until it impacted terrain. A postimpact fire ensued. The wreckage path was about ½-mile long and contained three distinct areas of debris. The first area contained the lower half of the rudder. The second area contained the vertical stabilizer, the rudder balance weight, the left horizontal stabilizer, the left elevator, the left wingtip, the left elevator balance weight, and the cockpit canopy—all of which had separated from their mounting locations. The third area contained the main wreckage (the fuselage, engine, and wings), which struck the top of a tree, fell to the ground, and came to rest inverted. Examination of the wreckage revealed no evidence of an inflight fire, explosion, flight control failure, bird strike, or any preexisting structural anomaly. Review of the airplane's design revealed that at an aerobatic gross weight of 1,600 pounds, the airplane complied with the +6/-3G standards of the FAA's aerobatic category. It had a maximum maneuvering speed of 124 knots and a never exceed speed of 200 knots. At the time of the inflight breakup, the airplane was traveling 20 knots above the published never exceed speed. A friend of the pilot noted that he had seen the pilot recover after falling out of a maneuver at low altitude before, and that it was not uncommon for the pilot to sometimes fall out of a maneuver (loop and/or roll). Review of a video taken by his friend revealed that, during that flight, the pilot performed a left roll. During that maneuver, the pilot allowed the nose to drop and the airplane lost approximately 1,000 feet of altitude. The accident airplane's abrupt and sudden maneuvering, which exceeded its design limitations, is consistent with the pilot's loss of control after attempting an aerobatic maneuver.

HISTORY OF FLIGHTOn September 20, 2013, about 1651 eastern daylight time, an experimental amateur built Vans RV-7A, N174BK, was destroyed during an inflight breakup and impact with terrain after a rapid loss of altitude and increase in airspeed near the Township of Hamilton, New Jersey. The private pilot was fatally injured. Visual meteorological conditions prevailed for the local personal flight conducted under Title 14 Code of Federal Regulations (CFR) Part 91, which departed Cross Keys Airport (17N), Cross Keys, New Jersey about 1640. According to radar data provided by the Federal Aviation Administration (FAA), the airplane departed 17N at approximately 1640. Turn to an approximate magnetic heading of 120 degrees and climb to an altitude of 6,500 feet above mean sea level (msl). Approximately 13 minutes later, the airplane turned right to a southeasterly heading. It then rapidly lost altitude while reversing direction before descending through 300 feet msl where it was lost from radar as it descended below the floor of radar coverage. According to witnesses, moments later the airplane was observed traveling in a northwesterly direction at low altitude, almost completely upside down at one point, and "pieces" of the airplane were observed falling to the ground. It then impacted in a wooded area and a fire ensued PERSONNEL INFORMATION According to NTSB records, the pilot had been involved in a previous accident in the Township of Hamilton, New Jersey (NYC08CA042) on November 21, 2007, while flying a Cessna 172N, N172MG when the engine sputtered while in cruise flight and stopped producing power. The pilot then performed a forced landing to trees, resulting in substantial damage. Neither he nor his two passengers were injured. Examination of the fuel tanks by a FAA inspector revealed they were intact, and no evidence of fuel, fuel spillage, or fuel odor was identified at the scene. The pilot stated that he departed his home airport with full tanks earlier in the day and recorded 3.2 hours on the Hobbs meter. Several stops were made during the day, which involved six takeoffs and climbs to altitude. The Safety Board determined that the probable cause of that accident was the pilot's inadequate fuel consumption calculations which resulted in fuel exhaustion. According to FAA records, the pilot held a private pilot certificate with ratings for airplane single-engine land. His most recent FAA second-class medical certificate was issued on July 11, 2013. He reported that he had accrued approximately 400 hours of total flight experience on that date, 85 hours of which was in the previous six months. AIRCRAFT INFORMATION The accident aircraft was a tricycle landing gear equipped, two seat, low wing airplane of conventional metal construction. It was equipped with a Superior Air Parts IO-360-B1AA3, horizontally opposed, 4-cylinder, air cooled engine which produced 180 horsepower, and a MTV-A5-B, three bladed constant speed MT-Propeller. The airplane had not been built by the pilot but had been built by a previous owner. At an aerobatic gross weight of 1,600 pounds, the airplane complied with the +6/-3G standards of the FAA's aerobatic category. It had a maximum maneuvering speed of 142 mph (124 knots), and a never exceed speed of 230 mph (200 knots). The maximum maneuvering speed of 142 mph (124 knots) was the maximum permissible speed at which full and abrupt control inputs could be applied. Any speed in excess of the maximum maneuvering speed with full control application could result in G-loads in excess of design limits. The never exceed speed of 230 mph (200 knots) was the maximum permissible speed under any condition. Any speed in excess of this could result in structural damage. Full control application at the never exceed speed would produce a load of approximately +15.0 G. According to FAA and maintenance records, the airplane had received its special airworthiness certificate on June 6, 2006. The airplane was purchased by the pilot on March 27, 2011. The airplane's most recent conditional inspection was completed on March 15, 2013. Shortly afterwards, the rudder on the airplane was damaged while the airplane was tied down on a parking ramp when the rudder came into contact with a rudder stop which punctured the right lower, side of the rudder. The damaged rudder was removed by the owner and reskinned in accordance with FAA Advisory Circular 43.13-1B and Van's Aircraft design drawings, and was returned to service on April 18, 2013. At the time of the accident, the airplane had accrued approximately 461 total hours of operation. METEOROLOGICAL INFORMATION The recorded weather at Atlantic City International Airport (ACY), Atlantic City, New Jersey, located approximately 6 nautical miles southeast of the accident site, at 1654, included: winds 200 degrees at 9 knots, visibility 10 miles; clear skies, temperature 22 degrees C, dew point 14 degrees C, and an altimeter setting of 30.05 inches of mercury. Visual meteorological conditions prevailed along the route of flight and atmospheric data for use in determining the upper air profile in the area of the accident site was gathered on behalf of the NTSB by the United States Army Aberdeen Test Center from a high resolution weather forecast model (4DWx), developed by the National Center for Atmospheric Research (NCAR) that the Army Test and Evaluation Center (ATEC) Meteorology Teams use on a daily basis. The model continuously merges data gathered from the Army's ranges as well as from sources such as FAA aircraft reports, air traffic control radar, satellites, National Weather Service weather radar, and upper-air and surface observations. Since data continues to be assimilated, when a new forecast is being developed, 4DWx "compares" its previous forecast with the observations and adjusts or "nudges" its forecast towards the observations. So, although the data provided by the program was model data, it included observations to produce and interpolate the upper air profile over a given point. This data was generated from an altitude of 10,504 feet msl down to 66 feet msl at a point above the geographic location of the accident site. This data along with recorded radar data, and airplane characteristics, was later used to develop an airplane performance history for the accident and indicated that at 1700, at the airplanes initial maneuvering altitude of 6,500 feet, the weather conditions included: winds 125 degrees at 3 knots, temperature 10 degrees C, and a barometric pressure of 23.64 inches of mercury. WRECKAGE AND IMPACT INFORMATION Examination of the wreckage path revealed that it was approximately 1/2 mile long and contained three distinct areas of debris. The first area contained the lower half of the rudder. The second area contained numerous pieces all of which were separated from their mounting locations. This included the vertical stabilizer (which was found in the top of a tree), the rudder balance weight, the left horizontal stabilizer, the left elevator, the left wingtip, the left elevator balance weight, and the cockpit canopy. The third area contained the main wreckage (the fuselage, engine, and wings), which had remained attached to each other until striking the top of a tree, falling to the forest floor and coming to rest inverted, where they were further damaged by exposure to a postcrash fire. Examination of the debris fields and main wreckage revealed no evidence of an inflight fire, explosion, or bird strike, and all of the major components of the airplane were recovered. After collection and examination of the flight control system components, control continuity was established from the flight controls in the cockpit to the breaks in the system which displayed evidence of tensile overload and from the breaks in the system to the flight control surfaces. Examination of the cockpit revealed that both m