Pilot Debrief

Beech 35 near Georgetown, SC — 2018-09-22

Final reportERA18LA258
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Date
2018-09-22
Location
Georgetown, SC, USA
Airport
GGE
Aircraft
Beech 35
Registration
N435RB
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Landing

Probable cause

A loss of directional control during landing due to overstress failure of the left seat’s left rudder pedal arm clevis, which occurred as a result of manufacturing defects.

NTSB narrative

While approaching the airport for landing during an instructional flight, the airplane entered an uncommanded yaw and roll to the right and began to pitch up. The flight instructor was able to maintain some control of the airplane by applying left rudder, left aileron, and forward elevator pressure, and trimming the airplane nose-down. The instructor noticed that the airplane’s right yaw increased as the airplane's speed decreased, and it became "impossible" to maintain alignment with the runway centerline. Upon touching down on the runway, the airplane immediately veered to the right about 90° and collided with trees, resulting in substantial damage to the firewall, fuselage, and both wings. Examination of the flight control system revealed that the left seat’s left rudder pedal arm clevis was fractured in multiple sections. Metallurgical examination identified cracks and voids created during the casting (manufacturing) process. The presence of these voids, cracks, and oxide layers reduced the cross-sectional area that could withstand the force applied over the pedal arm clevises. Once a high enough load input was applied to the pedal arm, the remaining material fractured in overstress. The separation of the pedal arm from the pushrod subsequently resulted in a failure of the rudder control system. Review of the airframe logbooks revealed that the rudder pedal arm was original to the airplane and had accrued a total of 6,203.62 flight hours.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Instructor could have aborted landing when control issues began.

NTSB coding

Evidence available

  • Photos
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

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