Aviation Accident Summaries

Aviation Accident Summary MIA01LA057

Jacksonville, FL, USA

Aircraft #1

N6807N

Mooney M-20C

Analysis

According to the pilot, following power application after his first touch and go landing, the aircraft assumed an extremely nose high attitude, and he realized he had no pitch control, limited rudder control, and full aileron control. He was able to control pitch attitude with throttle setting, and conducted an emergency landing in a field adjacent to the airport, sustaining substantial damage. Postcrash examination revealed a disconnect in the pitch controls at the aft pitch control rod-end-to-bellcrank connection in the tailcone. Examination of the components revealed that the pitch control rod-end eye was missed when the connecting bolt was pushed through the bellcrank side plate holes. When the nut was fitted to the bolt and tightened, the result was a connection that was only a "squeezed", friction fit. About 12 flight hours before the accident, on October 24, 2000, the aircraft underwent a 100-hour inspection, at which time the following was entered in the logbook, "Checked all control push rods and rod end bearings. Lubricated Flight Controls". On April 24, 1980, Mooney Aircraft Corporation recognized a potential for a misconnection between the rod end and the bellcrank and promulgated Service Instruction M20-44, which had not been accomplished on this aircraft.

Factual Information

On January 7, 2001, about 1512 eastern standard time, a Mooney M-20C, N6807N, registered to a private individual, operating as a Title 14 CFR Part 91 personal flight, crashed while conducting landings at Jacksonville International Airport, Jacksonville, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The aircraft received substantial damage, and the airline transport-rated pilot and a passenger were not injured. The flight originated from the same airport about 42 minutes before the accident. According to the pilot, he was conducting touch-and-go landings on Jacksonville International's runway 25, and upon power application after his first touchdown, the aircraft climbed straight up. He quickly realized that he had no pitch control, and resorted to throttle adjustments for nose-up/-down control. He had full aileron control, but rudder control was limited, so he conducted a forced landing to a field in the vicinity of the airport. The nose landing gear, firewall, and the propeller were damaged in the off-airport emergency landing. According to an FAA inspector, initial inspection of the aircraft revealed that the elevator aft control rod, (P/N 915007-003) was not attached to the aft bellcrank, (P/N 913031-301). The elevator control rod was found jammed against the rudder control rod. Closer examination revealed wear and gouging on the inner surfaces of the elevator bellcrank just below the attachment hardware, indicating that the bolt attaching the aft elevator control rod end between the two side plates of the bellcrank completely missed the rod end eye. The aft elevator control rod was merely pinched between the two side plates of the bellcrank, which eventually worked loose after about 12 hours of flight time. Two photographs are included as an attachment to this report, photograph (1) showing the proper bolted connection, and photograph (2) showing the improper connection. According to maintenance records, the aircraft underwent a 100-hour inspection on October 24, 2000, at a tachometer and total airframe time of 2166.15 hours. According to an invoice dated October 24, 2000, describing parts and labor charged for the 100-hour inspection, one of the inspections performed was, "11.5 hrs labor charge-remove all 4 aft elevator control rods & 4 landing gear rods, cleaned rust & zinc chromate. Install all rods back on aircraft." The operator of the fixed base operation who conducted the annual inspection stated that his mechanics, "...did not have the aft control arm loose." Mooney Aircraft Corporation recognized that the elevator and rudder control rod end fittings had the potential for misconnections to their respective bellcranks in the aft tailcone, and promulgated Service Instruction M20-44 dated April 24, 1980, in an effort to preclude such an occurrence. Reference to photographs of the bellcranks installed on N6807N reveal the Service Instruction had not been complied with.

Probable Cause and Findings

The failure of maintenance personnel to properly reconnect the aircraft's elevator control system, resulting in an in-flight disconnection of the elevator control and jamming of the rudder control during climb, the subsequent in-flight loss of control, and terrain collision following an emergency descent and landing.

 

Source: NTSB Aviation Accident Database

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