Service difficulty report · Actuator · Boeing 234

Difficulty date
August 22, 2009
Submitted
August 25, 2009
Operation
Air carrier
Aircraft
N246CH
Make and model
Boeing 234
Aircraft serial
MJ017
Aircraft time
10,875 hours
Engine
Lyc AL5512
Part
Actuator
Part number
234HS5603
Part serial
0088V
Condition
Restricted
Location
Flight Contorl
Part time
1,553 hours
Stage of operation
IN
How discovered
C
Nature of condition
F
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

DURING (FLIGHT CONTROLS TRAVEL AND FLIGHT BOOST SYS CK) AS PART OF PRE-FLIGHT CHECKS (DESCRIBED IN FLIGHT MANUAL PART 1, SECTION 2 PAGE 2-11 ITEM 29 (A)) PILOTS NOTICED ABNORMAL RESISTANCE OF LONGITUDINAL CYCLIC CONTROL MOVEMENT. AT THIS POINT ACFT WAS GROUNDED AND TURNED OVER TO MX. UPON FURTHER INVESTIGATION AND TROUBLESHOOTING, MORE THAN NORMAL RESISTANCE WAS NOTED IN (OUTPUT TRUNNION) OF (PITCH AXES LWR DUAL BOOST ACTUATOR) (PN 234HS560-3, SN 0088V). THIS SITUATION WAS CAUSING ABNORMAL CYCLIC CONTROL MOVEMENT RESISTANCE FELT BY PILOTS FROM FLIGHT DECK. DISCREPANT CONDITION WAS CORRECTED BY REPLACING MALFUNCTIONING ACTUATOR WITH A SERVICEABLE ONE, AND RETURNING THE ACFT TO SERVICE IAW CONTINUOUS AIRWORTHINESS MX PROGRAM. PILOTS PERFORMED ALL POST MX OP CHECKS AND CONFIRMED CONDITION WAS CORRECTED.

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