Uncommanded rudder boost on takeoff.

Attributes
ACN	310669
Time
Date	199507
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : shv
State Reference	LA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 210 flight time total : 3700 flight time type : 210
ASRS Report	310669
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa
Resolutory Action	aircraft : equipment problem dissipated flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

During routine takeoff uncommanded rudder boost occurred. Captain aborted takeoff. During taxi back to runway, system checked ok and a normal takeoff was made. Problem reoccurred during flight and was written up per MEL upon reaching the destination airport. Callback conversation with reporter revealed the following information: rudder boost, on the beech 1900, is a system to aid in directional control at low airspds with an engine failed. It senses a loss of engine torque and provides additional rudder capability. Apparently, the torque sensor malfunctioned causing a rudder power input on takeoff. The takeoff was aborted, the system checked thoroughly with the run up checklist. All checked normal and flight continued. During cruise, another uncommanded rudder input occurred and flight crew turned the system off.

Original NASA ASRS Text

Title: UNCOMMANDED RUDDER BOOST ON TKOF.

Narrative: DURING ROUTINE TKOF UNCOMMANDED RUDDER BOOST OCCURRED. CAPT ABORTED TKOF. DURING TAXI BACK TO RWY, SYS CHKED OK AND A NORMAL TKOF WAS MADE. PROB REOCCURRED DURING FLT AND WAS WRITTEN UP PER MEL UPON REACHING THE DEST ARPT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RUDDER BOOST, ON THE BEECH 1900, IS A SYS TO AID IN DIRECTIONAL CTL AT LOW AIRSPDS WITH AN ENG FAILED. IT SENSES A LOSS OF ENG TORQUE AND PROVIDES ADDITIONAL RUDDER CAPABILITY. APPARENTLY, THE TORQUE SENSOR MALFUNCTIONED CAUSING A RUDDER PWR INPUT ON TKOF. THE TKOF WAS ABORTED, THE SYS CHKED THOROUGHLY WITH THE RUN UP CHKLIST. ALL CHKED NORMAL AND FLT CONTINUED. DURING CRUISE, ANOTHER UNCOMMANDED RUDDER INPUT OCCURRED AND FLC TURNED THE SYS OFF.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.