Aviation Accident Summaries

Aviation Accident Summary NYC97LA163

HOLLIS, NH, USA

Aircraft #1

N2400M

Elliot MONNETT MONI

Analysis

An FAA Inspector who witnessed the takeoff said the airplane 'lumbered' into the air. A witness on the river adjacent to the departure airport said his attention was drawn to the airplane by the increasing and decreasing engine noise and that nothing appeared wrong with the airplane. The pilot appeared to alternately lose and regain aircraft control. Approximately 400 feet above the ground, the engine accelerated to 'full throttle', the nose pitched up, and the airplane rolled inverted and descended into terrain. The engine did not stop producing power until the airplane was inverted and the nose had descended below the tail. Three weeks before the accident, the pilot logged .8 hours of dual instruction in a Cessna 152. Prior to that flight, the pilot had not flown in 14 months. The pilot had approximately 10 hours flight experience in the accident airplane. Prior to the accident flight, he had not flown the airplane in 2 years.

Factual Information

HISTORY OF FLIGHT On August 9, 1997, at 1137 eastern daylight time, an Elliott Monett Moni, N2400M, was destroyed when it collided with trees and terrain during an uncontrolled descent to Hollis, New Hampshire, after takeoff from the Pepperell Airport (MA09), Pepperell, Massachusetts. The certificated private pilot was fatally injured. Visual meteorological conditions prevailed for the personal flight that originated from MA09, at 1135. No flight plan had been filed for the flight conducted under 14 CFR Part 91. In a written statement, a Federal Aviation Administration Inspector said he was preparing to take a glider flight when he saw N2400M depart Runway 06. He stated: "The aircraft appeared to lumber into the air while making a left turn over the cleared dog leg [field]. At approximately 11:40 am, airport people came to me advising me that a glider went down. I could only presume that it was N2400M." The airport was located on the bank of the Nashua River. A canoeist on the river said his attention was drawn to the airplane by the engine noise. The witness said the engine speed was alternately increasing and decreasing. He stated: "When I first noticed him he was coming right towards me. I heard him, then I was looking for him ... The airplane was skewing diagonally in the air. He was skewing and dipping left, right, left, right. He was out of control, then back in control, then out of control again. It didn't look like there was anything wrong with the airplane, it looked like he was being pushed around. He was fighting it the whole way. He was out of control for 3 or 4 seconds, then back in control for 3 or 4 seconds ... then he went to full throttle..." The witness stated that when the airplane engine accelerated, the airplane's nose was up. The witness used a clock face to estimate the pitch angle. He further stated: "...the nose was at about the 1:30 position. The wings were tilting left, then right, then left ... then the airplane rolled inverted to the right. When the nose got lower than the tail, in an inverted position, the engine quit. The airplane was in an inverted position with the engine off before it contacted anything." The witness estimated the airplane was approximately 400 feet above the ground before rolling inverted. He stated the airplane descended "straight down" out of his view and that he heard the sound of impact. A second witness reported to the FAA Inspector that he heard the engine stop and observed the airplane perform a maneuver resembling a spin. PERSONNEL INFORMATION The pilot held a private pilot's certificate with ratings for airplane single engine land. His most recent FAA Third Class Medical Certificate was issued April 27, 1997. A review of the pilot's logbook revealed his total flight experience was 1372 hours. Three weeks before the accident, the pilot logged .8 hours of dual instruction in a Cessna 152. Prior to that flight, the pilot had not flown in 14 months. In a telephone conversation, the flight instructor who provided the dual instruction in the Cessna 152 stated the purpose of the flight was to complete a biennial flight review. The pilot had approximately 10 hours flight experience in the Monett Moni. Prior to the accident flight, he had not flown the airplane in 2 years. AIRCRAFT INFORMATION The Monett Moni, N2400M, was purchased as "parts" and was assembled by the pilot/owner. The airplane was issued a certificate of airworthiness on March 29, 1986. According to an advisory circular published by the engine manufacturer in May, 1984: "Several cases of motor stoppages have been reported. Investigation has revealed that in all cases, the vertical distance from the fuel pump inlet to the bottom of the fuel tank exceeded the 24-inch lift capability of the pump...If it is not possible to relocate the tank to a higher position, then a second pulse driven pump must be added. This pump must be installed midway in the fuel supply line." Examination of the wreckage by FAA Aviation Safety Inspectors revealed a single gravity-fed fuel line from the fuel tank to the carburetor. In a telephone interview, the FAA Inspector who witnessed the beginning of the accident flight stated he had observed N2400M approximately two weeks prior to the accident. He said the airplane could not produce enough power to taxi and had to be pushed from the runway. According to aircraft records, the airplane did not fly that day. TESTS AND RESEARCH The airplane was powered by a two-stroke engine that runs on a fuel mixture of gasoline and oil. A sample of the pilot/owner's fuel supply was delivered by the Hollis Police Department to GFW Aeroservices, Nashua, New Hampshire, for testing. According to the test report: "The fuel was examined and tested for water and none was found. Sediment was observed and its composition is unknown. The fuel was of a two stroke mixture and was tested by draining a two stroke snowblower, refilling with the sample fuel and the snowblower ran until the tank was empty. The snowblower developed full power in four inches of wet snow and ran without hesitation." ADDITIONAL INFORMATION According to the distributor of the Monett Moni aircraft kit, the airplane has an 18 to 1 glide ratio at 50 miles per hour. In a telephone interview, a friend and co-worker of the pilot stated: "About two weeks ago, we were cleaning up the airplane and flushing out the engine. I think it was the first time in two years that it had flown. [The pilot] said he just got re-qualified in a Cessna 150 and hated it. He said, 'Those aren't real airplanes, they're too easy to fly'."

Probable Cause and Findings

The pilot's failure to maintain adequate airspeed which resulted in an inadvertent stall spin and collision with terrain.

 

Source: NTSB Aviation Accident Database

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