Nov. 3—Two people on the ground at Keene's Dillant-Hopkins Airport who witnessed the plane crash that killed the pilot and lone passenger last month described hearing popping sounds coming from the aircraft before it descended, according to a federal report issued Thursday.
The National Transportation Safety Board's preliminary report says the witnesses at the airport around 6:45 p.m. on Friday, Oct. 21 — one pilot and a pilot-rated mechanic — said the airplane's engine sounded abnormal.
The engine "never sounded smooth during the entire time the airplane was on the runway or while airborne," one of the witnesses recounted, according to the report.
The mechanic who witnessed the crash stated that when the flight was airborne along the runway, he heard a momentary power reduction, followed by a power advance, the report says.
The single-engine airplane struck a shed attached to a multifamily residence shortly after takeoff, setting off a three-alarm blaze at the crash site on Lower Main Street. On the Monday following the crash, officials released the names of the two men killed, Lawrence Marchiony, 41, of Baldwinville, Mass., and Marvin David Dezendorf, 60, of Townshend, Vt.
Dezendorf's LinkedIn page lists him as a flight instructor at Monadnock Aviation, a flight school and aviation business based out of Dillant-Hopkins Airport that Keene Mayor George Hansel said owned the four-seater Beechcraft Sierra aircraft. A 2017 Monadnock Aviation newsletter says Marchiony trained with Dezendorf and had aspirations of becoming a flight instructor.
Both men were pilot-rated, said Tim Monville, an NTSB senior air-safety investigator, at a news conference in the days after the crash.
According to the report, the plane had made a shallow climb after taking off from the runway in Swanzey, with witness accounts stating it remained between 50 feet and 200 feet in the air.
Another witness about a half mile from the departure end of the runway said the plane was flying "not much higher than 50 ft above ground level when it flew by him," and that he heard "pop pop" sounds before the plane began to descend and the engine sound grew louder, according to the report.
In a phone interview Thursday, Dillant-Hopkins Airport Director David Hickling said it would be difficult to determine how high the plane should have been flying, but that it was "obviously very low." The occupants had traveled only approximately half a mile before the plane impacted the storage facility, the report states.
A representative of Monadnock Aviation declined to comment on the report Thursday.
None of the occupants of the apartments were injured, but nine people were displaced by the crash, according to American Red Cross, which is assisting them. The building's owner previously told The Sentinel it could take a year to repair the residence.
The federal report also notes that the two aircraft occupants did not make a distress call over the common traffic advisory frequency.
During the preliminary investigation, the NTSB has secured and retained both a pilot logbook as well as audio communications between one of the aircraft's occupants, which detail that the plane was to remain in a traffic pattern. The tapes contain no indications of things being awry prior to its crash half-mile away from the end of runway 2, according to Monville.
Monville said two security cameras captured the final portion of the flight and the impact of the crash. The footage includes sound, which will help investigators understand engine RPM prior to the crash into the building, he said.
The NTSB's final report — which will provide a description of the crash, a review of the investigative analysis and determine the probable cause of the crash — could take 18-24 months to complete.
Hunter Oberst can be reached at 355-8546, or firstname.lastname@example.org.