WPR11FA225

The pilot's continued operation of the aircraft with deteriorated wing fabric and his aggressive maneuvering at low altitude, which resulted in the right wing fabric’s failure during flight. Contributing to the accident was the pilot's loading of the aircraft in excess of the maximum gross weight limit.

The sport pilot flight instructor was giving an introductory instructional flight in a light sport weight-shift-control aircraft. Review of video recorded by two video cameras attached to the aircraft indicated that the takeoff and departure were uneventful with no observed difficulties with the aircraft’s airframe, wing, or engine. About 30 minutes into the flight, the video documented the instructor maneuvering the aircraft in the vicinity of the accident site. The video documentation stopped about 15 seconds before the accident due to data buffering time. However, witnesses observed the aircraft low over the water flying directly toward a scallop-shaped sandy beach surrounded on three sides by high rocky cliffs. The pilot was observed to fly the aircraft within 50 to 100 feet of the cliffs in a steep-bank, 180-degree turn. The witnesses said that the aircraft's bank angle increased to nearly 90 degrees, and the aircraft began to descend rapidly in a side-slip. As the aircraft completed its turn about 200 feet above ground level, and with its nose pointed steeply downward, the pilot was observed to push aggressively forward on the flight controls, and a loud “pop” was heard. One witness observed the right wing's fabric go slack, and the aircraft performed a complete barrel roll to the right. Moments later the aircraft impacted the ocean. Postaccident examination of the wreckage found numerous holes torn in the wing fabric and several repair patches were identified on the fabric. Testing with a Bettsometer fabric tester determined that the fabric had deteriorated due to exposure to sunlight and that its strength was below the manufacturer’s recommendations for flight. A manufacturer’s representative stated that the pilot had contacted him several weeks before the accident and ordered a new replacement wing, which indicates that the pilot was aware of the fabric’s deteriorated condition. The maximum takeoff gross weight for the aircraft was 903 pounds. An estimate of the aircraft's weight at takeoff indicated that it was about 121 pounds overweight. This excess weight increased the load on the aircraft’s wing and likely contributed to the failure of the fabric.

HISTORY OF FLIGHT On May 17, 2011, about 1043 Hawaiian standard time, a P&M Aviation LTD Pegasus Quik 912S, light sport weight-shift-control (WSC) aircraft, N705PM, sustained substantial damage during impact with the ocean near Honopu Beach in Na Pali Coast State Park, Hanalei, Hawaii. The sport pilot instructor and his student sustained fatal injuries. Kauai Aerosports was operating the aircraft under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed for the local instructional flight, which had originated from Port Allen Airport, Hanapepe, Hawaii, about 30 minutes before the accident. A flight plan had not been filed. Two video cameras on the WSC aircraft documented an uneventful takeoff/departure and pre-accident portion of the flight; the video documentation stopped approximately 15 seconds before impact, due to data buffering time. Witnesses on Honopu Beach and on a boat immediately off-shore observed the aircraft flying southwest along the shoreline towards Honopu Arch about 400 feet above the ground (agl). It flew over the rock arch, back towards the ocean, and around a rock pinnacle. As the aircraft headed back towards Honopu beach in level flight, its altitude was about 150 to 200 feet agl, and its airspeed had slowed to about 40 knots. One witness said that, as the aircraft flew over the sandy beach heading inland, the pilot applied full power and entered an abrupt, steep climb. All the witnesses said that it looked like the pilot was attempting to clear the 450-foot rock cliff to reach Honopu valley. At about 300 feet agl, the WSC aircraft initiated a steep left-hand turn, paralleling the 800-foot-high concave cliff and clearing the cliff face laterally by about 50 to 100 feet. As the aircraft approached 180 degrees of turn, the witnesses observed that the aircraft’s bank angle increased until the left wing looked like it was pointing straight down. One witness said that, during this steep turn, the aircraft began to side-slip downwards at about 500 to 600 feet per minute. As the turn was completed and the wings were rolled level, the aircraft’s altitude was about 200 feet agl with its nose low and descending. The witnesses observed the pilot fully extending his arms, pushing full forward on the flight controls in an effort to stop the aircraft from descending. One witness reported that the aircraft’s wing started buffeting, he heard a loud “pop,” and the right wing fabric went slack. Several witnesses then observed the aircraft abruptly roll to the right and perform a complete barrel roll. The aircraft was last observed in about a 15-degree left bank, nose low, and at an airspeed of about 70 knots as it entered the water. PERSONNEL INFORMATION The 49-year-old pilot held a commercial sport pilot certificate and a sport pilot flight instructor certificate for WSC aircraft; additionally he held a repairman certificate for light sport airplanes in the WSC category. He also held a commercial lighter-than-air balloon pilot certificate and a private pilot certificate for single-engine land aircraft. His most recent second-class Federal Aviation Administration (FAA) medical certificate was issued on August 25, 2008. The pilot’s flight logbook was not recovered, but he reported having 1,800 hours of flight experience on his last FAA medical application. AIRCRAFT INFORMATION The single-engine (pusher), propeller-driven, two seat tandem WSC aircraft was manufactured by P&M Aviation LTD, Manton, Marlborough, United Kingdom, on February 16, 2007. Its maximum takeoff gross weight was 903 pounds. Maintenance records indicate that at the time of manufacture, the aircraft's weight was 464 pounds. These records further indicate that in March 2008, a Ballistic Recovery System and several other pieces of equipment were added to the aircraft. Their estimated total weight was 38.5 pounds. Medical records from both occupants indicated that their total weight came to approximately 420 pounds. The aircraft held 17 gallons of fuel, which was located in a single Polyethylene tank mounted beneath the seats; when full, it weighed about 102 pounds. With a full fuel tank at takeoff, the aircraft would have weighed about 1,024.5 pounds, or it was over the manufacturer's maximum gross takeoff weight by 121 pounds. It was powered by a Rotax 912 ULS four-stroke engine, which had a maximum output of 100 horsepower. It used between 2.9 and 4.0 gallons per hour. The engine was equipped with a three-bladed composite propeller. The aircraft had a pilot-passenger “pod” suspended by a triangular frame, hinged below the wing, which permitted weight shift control of pitch and roll. It was equipped with dual flight controls. The occupants in the aircraft were provided with a headset with noise canceling capabilities, which provided for communication between the two occupants. Each occupant was provided with an automatic inflatable personal flotation device. The aircraft’s wing was 27.4 feet from tip to tip, and it had 114 square feet of surface area. The wing’s fabric sailcloth was a Polyester material called Dimension Polyant TNF210 with Aramid X-05 reinforcement bands. The aircraft manufacturer’s maintenance manual included a warning that stated, “Check your sail for ultra violet [UV] damage regularly. Flying with a damaged sail could cause structural failure, injury or death.” The manual indicated that the sailcloth fabric should be tested annually or every 100 hours of flight time for strength degradation due to UV light damage. According to the maintenance manual, if a Bettsometer tester can rip the fabric at less than 1,360 grams of force, then the wing’s fabric must be replaced. The aircraft’s maintenance manual also states that small holes (up to 10 mm, or 3/8 inch), cuts (up to 15 mm, or 5/8 inch), and rips (up to 25 mm, or about 1 inch) in the wing’s sailcloth fabric can be repaired in the field. Anything larger must be repaired at a P&M Aviation approved workshop. The aircraft manufacturer’s operating instructions limited normal flight operations to a maximum of 60 degrees of bank and a maximum of 45 degrees pitch nose up or nose down from the horizontal. Additionally, the operating instructions stated that the aircraft must be flown with positive acceleration forces at all times, i.e., a maximum of plus 4 gs and no less than 0 gs. The aircraft’s maintenance logbook indicated that the most recent 100-hour inspection was completed on May 1, 2010, at 380 hours of total flight time. The logbook entry for this 100-hour inspection did not include any information about a Bettsometer test. The logbook entry for the previous 100-hour inspection on December 23, 2009, at 286 hours of total flight time indicated that the wing’s sailcloth fabric was tested. A manufacturer’s representative stated that approximately 2 weeks before the accident, the pilot had contacted him to purchase a new wing. The representative stated that the pilot told him that the aircraft had accumulated about 500 hours of total flight time. METEOROLOGICAL INFORMATION At 1053, the reported weather conditions at Lihue Airport (LIH; elevation 153 feet), were: wind 080 degrees at 9 knots; visibility 10 statute miles; cloud condition clear; temperature 79 degrees Fahrenheit; dew point 66 degrees Fahrenheit; altimeter setting 30.13 inches of mercury. WRECKAGE AND IMPACT INFORMATION The WSC aircraft was found in approximately 30 feet of water and about 400 feet from shore. The recovery divers noted that the emergency ballistic recovery system had not been activated. On May 18, 2011, salvage divers attached lift bags to the wreckage and raised it to the surface, and a helicopter recovered it to a hangar at Lihue Airport, Lihue, Hawaii. On May 19, 2011, two FAA inspectors and the NTSB investigator-in-charge examined the wreckage in the hangar. Crushing and