ERA20FA086

According to a previous owner of the experimental, amateur-built airplane, the pilot had flown aerobatic maneuvers in the airplane about 1 week before the accident, during which he exceeded the airplane’s never exceed speed of 230 mph by between about 20 to 25 mph. Additionally, two videos provided by a witness showed the airplane making two high-speed, low passes over the airport earlier on the day of the accident. The airplane owner stated that, after the pilot departed for the accident flight, the pilot flew over the local area for about 15 minutes and then performed a barrel roll. Video evidence revealed six rolls. Shortly thereafter, the canopy and vertical stabilizer separated, and the airplane subsequently descended nose down and impacted terrain. During the descent and just before impact, the outboard section of the right horizontal stabilizer separated. Examination of the canopy frame revealed that it had separated due to overstress and that it did not have reinforcing gussets installed per a kit manufacturer canopy frame revision issued in 1984. Metallurgical examination of the vertical stabilizer revealed ratchet marks along the internal edge of the aft doubler rib consistent with stress and multiple fatigue cracks. Based on the evidence, it is likely that the pilot previously exceeded the airplane’s structural limits, which led to the in-flight separation of the vertical stabilizer and canopy.

The airplane’s never exceed airspeed was 230 mph. According to the owner, after he purchased the airplane 1 week before the accident, he had the pilot conduct a flight with the previous owner because the pilot had more experience in the make and model airplane than he did. The previous owner stated that, during that flight, the pilot performed maneuvers and reached indicated airspeeds of between 270 and 275 mph. The current owner added that the airspeed indicator indicated about 20 mph too fast, that the pilot was a good friend, and that he allowed him to use the airplane whenever he wanted. The kit manufacturer had issued a canopy frame revision in 1984 that stated, in part, that gussets should be installed in the aft corner junctions of the frame to strengthen the canopy framework. The kit manufacturer listed the airplane as fully aerobatic to +6/-4.5G’s. The airplane was owned by another person from 2007 to 2018. The previous owner reported that, when he purchased the airplane in 2007, the red line marking on the airspeed indicator was near 87 mph, rather than the VNE of 230 mph. He added that he left the marking there as a reminder to not fly slower than 90 mph indicated airspeed during approach because the airplane tended to “drop a wing” at speeds below that. On January 25, 2020, about 1712 eastern standard time, an experimental, amateur-built Mustang II airplane was destroyed when it impacted terrain near Big 'T' Airport (64GA), Senoia, Georgia. The pilot and passenger were fatally injured. The flight was being conducted as a Title 14 Code of Federal Regulations Part 91 personal flight. Two videos provided by a witness showed the airplane make two high-speed, low passes over the airport earlier on the day of the accident. The airplane owner stated that, after the pilot departed for the accident flight, he flew over the local area for about 15 minutes and then performed a barrel roll. Shortly thereafter, the canopy and vertical stabilizer separated, and the airplane subsequently descended nose down and impacted terrain. During the descent and just before impact, the outboard section of the right horizontal stabilizer also separated. Video also revealed that the airplane performed six rolls prior to the accident. An autopsy was performed of the pilot by the Georgia Bureau of Investigation, Division of Forensic Sciences. The cause of death was multiple blunt impact injuries. Toxicology testing of the pilot’s tissue specimens was performed by the Federal Aviation Administration’s Bioaeronautical Sciences Laboratory. The results were negative for drugs and alcohol. The pilot’s logbook was not recovered. The airplane came to rest nose down in a wooded area about .5 mile south of 64GA. All of the airplane’s major components were accounted for at the accident site, except for the canopy and vertical stabilizer, which were located about .25 mile north of the main wreckage. The vertical stabilizer came to rest first along the debris path, followedby the canopy and then the main wreckage. The outboard section of the right horizontal stabilizer was found near the main wreckage. The propeller had separated from the engine, but both blades remained in the hub. One propeller blade exhibited tip curling, chordwise scratching, and leading-edge gouging. The other propeller blade exhibited s-bending near the tip. Examination of the canopy revealed that the canopy latch remained secured and that it was operational. The canopy frame was separated near the left aft corner junction and through the horizontal tube near the rear of the frame, and the fracture features were consistent with overstress. No gussets were found installed in the canopy frame. During examination of the vertical stabilizer, a flat area was observed on the fracture surface at the corner of the doubler. Magnification of the flat area revealed that there was a thumbnail-shaped pattern on it, which was consistent with fatigue cracking emanating from the internal corner of the doubler. Ratchet marks consistent with stress and multiple initiation fatigue cracks were observed along the internal edge of the aft doubler rib. Although damage obscured the fatigue initiation site, the orientation of the thumbnail-shaped pattern and the location of the ratchet marks indicated that the fatigue cracking likely started at the internal corner of the aft doubler rib.