Pilot Debrief

PIPER PA-34 near Palm Coast, FL — 2013-07-17

Final reportERA13IA326
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Date
2013-07-17
Location
Palm Coast, FL, USA
Aircraft
PIPER PA-34
Registration
N767PE
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

The installation of an incorrect rudder trim tab control rod by unknown maintenance personnel, which resulted in the rod failing in flight due to overload and subsequent uncontrolled rudder oscillations.

NTSB narrative

The pilot receiving instruction was recovering the airplane from a demonstrated minimum control airspeed condition. According to the flight instructor, the airplane was initially about 5,000 ft in a "clean" configuration. Both pilots then felt two "kicks" in the rudder system, which they then verbally confirmed to each other did not result from either of them making inputs. The pilot receiving instruction then heard a "snap," and the rudder pedals began to "pump" full deflection right and left. Subsequently, the flight instructor took control of the airplane and found that neither applying full rudder nor using both feet on the rudder neutralized the deflections. Even with both pilots trying to neutralize the rudders, the deflections continued. The flight instructor subsequently diverted the airplane to a nearby airport and landed it uneventfully. During the on-scene examination, the rudder trim tab control rod was found fractured near the trim tab end. The control rod was replaced, and, during subsequent flights, no further rudder anomalies occurred. Metallurgical examination of the rod revealed that it had failed in overload, and no evidence of fatigue or corrosion was found. Further examination revealed that the rudder trim control rod was composed of a low-alloy, 1000-series carbon steel. An airplane manufacturer representative indicated that the rod should have been composed of a higher grade, 4000-series steel. The airplane was manufactured in 1972, acquired by the current owner in 2005, and had 11,575 hours of operation at the time of the incident. It could not be determined when or by whom the rod was installed on the airplane; it was not installed during the airplane's current ownership.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Inspect rudder control system before flight to prevent failure.

NTSB coding

  • Flight control sys malf/fail · Maneuvering
  • Maintenance

Evidence available

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

Docket documents6

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