Dutch Harbor, AK, USA
N41NE
Fairchild SA227-AC
The pilot of the nonscheduled cargo flight reported that during taxi for takeoff the airplane encountered a 68-knot wind gust, and he returned to the gate to examine the rudder. Finding no damage, he continued the flight. After takeoff, the pilot said there was very little left rudder control. An examination of the rudder was made after the airplane landed at its destination. From the pilot's rudder pedals, the rudder is controlled by a cable which makes a 180-degree turn toward the tail via two phenolic pulleys. Each pulley has two guard pins, which keep the cable from jumping off the pulleys if the cable becomes slack. The inspection showed that the cable had jumped off the upper pulley. The pulley's upper guard pin had retracted, and did not prevent the cable from jumping off the pulley. The guard pin has a perforated and deformed end, giving it a spring action which secures the pin after passing through the holes on either side of the pulley bracket. No service difficulty reports were found for the pins, and the pins do not have any service life limits. An examination of the operator's other, similar model airplanes, showed that several of their guard pins had also retracted. Evidence suggests that the pin's locking action becomes weakened and ineffective by repeated use. The operator submitted a service difficulty report, and as a result of this incident, the manufacturer has published service letters 226-SL-037, 227-SL052, and CC7-SL-045. The service letters indicate that the pins should be inspected, and that all pins should be replaced with improved pins, and secured with cotter pins.
On January 18, 2008, about 1245 Alaska standard time, a Fairchild SA227-AC airplane, N41NE, had a rudder malfunction after encountering a severe wind gust during taxi for takeoff at the Dutch Harbor Airport, Dutch Harbor, Alaska. The airplane was being operated by Peninsula Airways Inc., Anchorage, Alaska, as an instrument flight rules (IFR) nonscheduled cargo flight under Title 14, CFR Part 121. The airline transport certificated pilot and the first officer were not injured. Visual meteorological conditions prevailed at the departure airport, and an instrument flight rules flight plan was filed and activated. The airplane departed Dutch Harbor, and landed at the Ted Stevens International Airport, Anchorage, without incident. In a written statement, the pilot reported that during taxi for takeoff at Dutch Harbor, the airplane encountered a 68 knot wind gust. He said that they returned to the gate to examine the rudder because this airplane model has a history of rudder damage when encountering extreme wind gusts. Finding no damage, they elected to continue the flight. During initial climb after takeoff, the pilot said there was little, if any, left rudder control. The flight continued to the destination and landed without incident. The airplane was examined by an FAA air safety inspector. From the pilot's position, the rudder is controlled by a cable which makes a 180 degree turn toward the tail via two phenolic pulleys. Each of the pulleys has two guard pins (P/N: NAS427W18), which keep the cable from jumping off the pulleys if the cable becomes slack. During the inspection, the inspector reported that the cable had jumped off the upper pulley, disabling the rudder system. She noted that the pulley's guard pin was retracted, and did not prevent the cable from being dislodged. The guard pin is a hollow roll pin with a perforated and deformed end, giving it a spring action which secures the pin after passing through the holes on either side of the pulley bracket. She said there are no current service difficulty reports on file for the pins, and they do not have any service life limits. During an examination of all the same model airplanes in the operator's fleet, maintenance personnel found several guard pins that had come loose and retracted from their respective brackets. According to the director of maintenance for the operator, it appears that the pin's locking action becomes weakened by repeated use. The operator elected to replace all the pins in the operator's fleet, and submitted a service difficulty report to the FAA. As a result of this incident, the manufacturer has published service letters 226-SL-037, 227-SL052, and CC7-SL-045. The service letters require at the next scheduled access that the pins be inspected, and that all pins (P/N NAS427K18) be replaced with pins (P/N NAS427W18), and secured with cotter pins (P/N MS24665-132).
The disengagement of the rudder control cable and loose rudder cable retaining pins. A factor contributing to the accident was a wind gust.
Source: NTSB Aviation Accident Database
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