Extreme weather, turbulence, wind shear and a decision to "fly under a thunderstorm" on final approach to East Hampton Airport likely caused a fatal crash in the Atlantic Ocean that killed four people off Amagansett in June 2018, the National Transportation Safety Board said in its final accident report released Tuesday.
The crash of that twin-engine Piper Navajo on June 2, 2018, killed East Hampton luxury developers Ben and Bonnie Krupinski, both 70, their grandson William Maerov, 22, also of East Hampton, and the pilot, Jon Dollard, 47, of Hampton Bays. East Hampton Town police completed the recovery of the occupants when the partial skeletal remains of Maerov washed ashore in Amagansett in January, with the Suffolk County Medical Examiner positively identifying those remains using DNA.
Laura Krupinski, the former Vogue cover model whose son and parents died in the crash, herself died suddenly in February. She was 53.
The NTSB report said that while "the reason for the pilot's loss of control could not be determined" based on available information, the probable cause of the fatal crash was "the pilot's decision to fly under a thunderstorm and a subsequent encounter with turbulence and restricted visibility in heavy rain, which resulted in a loss of control."
The report said a post-accident examination of the plane "revealed no preimpact anomalies with the airplane or engines that would have precluded normal operation."
The flight was one of two planes that departed Newport State Airport in Rhode Island en route to East Hampton Airport, the NTSB said, noting that the pilot of the second airplane said he had changed his travel route due to information gleaned from a preflight weather report.
Two inflght weather advisories issued for the route and destination area 42 minutes and just 15 minutes before the fatal flight departed Rhode Island "warned of heavy to extreme precipitation associated with thunderstorms," the NTSB report stated, adding: "It could not be determined whether the accident pilot received these advisories."
The NTSB said a local resident about a half-mile from the crash site took "several photos" of the approaching storm, which documented "a shelf cloud and cumulus mammatus clouds" — in layman's terms, an anvil-type thunderhead — along the leading edge, which had "extreme" intensity echoes topping at about 48,000 feet.
"Imagery also depicted heavy to extreme intensity radar echoes over the accident site extending to the destination airport," the report said.
In a preliminary finding last July, the NTSB said that the Piper Navajo was about six miles south of East Hampton Airport when it dropped to 152 feet from 512 feet, then climbed back to 532 feet before again dropping to 152 feet. Its last indication on radar, the preliminary report said, was recorded at 532 feet.
The final report issued Tuesday did not provide that detail, but said Dollard "reported to the tower controller that he was flying at 700 feet and 'coming in below' the thunderstorm." It said there were no further communications, but confirmed the last radar target indicated the Piper was at 532 feet about two miles south of the shoreline. The airplane, the report said, was later recovered from about 50 feet of water and "was fragmented in several pieces."
"It is likely that the pilot encountered gusting winds, turbulence, restricted visibility in heavy rain, and low cloud ceilings in the vicinity of the accident site and experienced an in-flight loss of control at low altitude," the NTSB said in its finding. "Such conditions are conducive to the development of spatial disorientation; however, the reason for the pilot's loss of control could not be determined based on the available information."
With Vera Chinese