ANC08IA033

NTSB incident investigation · Fairchild SA227-AC · Dutch Harbor, AK · January 18, 2008

Incident · No injuriesIncident investigationFinal report
Date
January 18, 2008, 12:45 local (16:45 UTC)
Place
Dutch Harbor, AK
Injuries
2 uninjured
Damage
No damage
Phase of flight
Taxi
Aircraft
N41NEFairchild SA227-AC
Defining event
Taxi-to runway: Miscellaneous/other
Weather
Visual (VMC) · Day
Status
Completed · report May 28, 2008
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
Anchorage FSDO-03
FAA report
20080118010589I
Case key
67423

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.

On this page

Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

The disengagement of the rudder control cable and loose rudder cable retaining pins. A factor contributing to the accident was a wind gust.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.

Analysis

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.

Factual narrative

The factual narrative467 words

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).

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.

Aircraft

Registration
N41NE
Reported as
Fairchild SA227-AC
Category
Airplane
Serial number
741B
Airframe hours
36,207
Engine
Honeywell TPE331-11U, 1,000 horsepower, turbo prop
Damage
No damage
Flight
Part 121
Registered owner
Peninsula Airways Inc
Airworthiness certificate
Standard, Normal
Last inspection
Continuous airworthiness · January 1, 2008
Departed
L-2G · Dutch Harbor, AK
Destination
PANC · Anchorage, AK
Flight plan
IFR
Airport
L2G · Dutch Harbor, runway 12, asphalt

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
28
Injuries
None
Certificates
Commercial, Flight instructor, Airline transport
Airplane ratings
Single-engine land, Multi-engine land, Single-engine sea
Instrument ratings
Airplane
Medical
Class 1, Without waivers/limitations
Last flight review
August 1, 2007
Seat
Left
Flight hours
7,307 total · 5,002 in this make and model · 225 in the last 90 days · 72 in the last 30 days · 3 in the last 24 hours
Role
Co-pilot
Age
26
Injuries
None
Certificates
Commercial, Airline transport
Airplane ratings
Multi-engine land, Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, With waivers/limitations
Last flight review
April 1, 2007
Seat
Right
Flight hours
2,904 total · 1,407 in this make and model · 298 in the last 90 days · 119 in the last 30 days · 3 in the last 24 hours

Weather

Conditions
Visual (VMC) · Day
Wind
130° at 37 knots, gusting 47
Visibility
9 statute miles
Lowest ceiling
3,300 ft overcast
Temperature
45 °F, dew point 36 °F
Observed at
PAUD

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.