Flight crew of an light transport declared an emergency and return land after experiencing abnormal ...

Attributes
ACN	291968
Time
Date	199411
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mcn
State Reference	GA
Altitude	msl bound lower : 2200 msl bound upper : 2200
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : mcn tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Brasilia EMB-120 All Series
Operating Under FAR Part	Part 135
Navigation In Use	Other Other
Flight Phase	climbout : initial other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 4000 flight time type : 500
ASRS Report	291968
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

After takeoff from the macon airport during the initial climb and before completion of the after takeoff checklist. The first officer said 'I think we have a control problem.' I told him to let me have the controls. I noticed a great deal of resistance in aileron movement, but elevator control seemed normal. I said, 'I have the airplane' and reduced engine power in the attempt to relieve some of the control pressure. When resistance to motion in the ailerons became worse I told the first officer to declare an emergency and tell departure control that we were returning to land. I then noticed that elevator control was becoming difficult and I depressed the autoplt disconnect button on the control wheel. Almost immediately the control forces diminished and I was able to regain control of the airplane. The rest of the approach and landing in macon was normal. Maintenance personnel checked the controls and autoplt system and concluded that the autoplt was inadvertently engaged. I also checked the autoplt and flight controls and they seemed to work normally on the ground. Apparently the first officer was attempting to engage the yaw damper but engaged the autoplt instead. The buttons are very close to each other. I think the problem/incident would not have occurred if the first officer had stated his intention to engage the yaw damper. Note: the first officer and I knew that the airplane had just come out of maintenance for a broken aileron cable before we flew it.

Original NASA ASRS Text

Title: FLC OF AN LTT DECLARED AN EMER AND RETURN LAND AFTER EXPERIENCING ABNORMAL FLT CTL PROB CAUSED BY THE FO INADVERTENTLY ACTIVATING THE AUTOPLT INSTEAD OF YAW DAMPER.

Narrative: AFTER TKOF FROM THE MACON ARPT DURING THE INITIAL CLB AND BEFORE COMPLETION OF THE AFTER TKOF CHKLIST. THE FO SAID 'I THINK WE HAVE A CTL PROB.' I TOLD HIM TO LET ME HAVE THE CTLS. I NOTICED A GREAT DEAL OF RESISTANCE IN AILERON MOVEMENT, BUT ELEVATOR CTL SEEMED NORMAL. I SAID, 'I HAVE THE AIRPLANE' AND REDUCED ENG PWR IN THE ATTEMPT TO RELIEVE SOME OF THE CTL PRESSURE. WHEN RESISTANCE TO MOTION IN THE AILERONS BECAME WORSE I TOLD THE FO TO DECLARE AN EMER AND TELL DEP CTL THAT WE WERE RETURNING TO LAND. I THEN NOTICED THAT ELEVATOR CTL WAS BECOMING DIFFICULT AND I DEPRESSED THE AUTOPLT DISCONNECT BUTTON ON THE CTL WHEEL. ALMOST IMMEDIATELY THE CTL FORCES DIMINISHED AND I WAS ABLE TO REGAIN CTL OF THE AIRPLANE. THE REST OF THE APCH AND LNDG IN MACON WAS NORMAL. MAINT PERSONNEL CHKED THE CTLS AND AUTOPLT SYS AND CONCLUDED THAT THE AUTOPLT WAS INADVERTENTLY ENGAGED. I ALSO CHKED THE AUTOPLT AND FLT CTLS AND THEY SEEMED TO WORK NORMALLY ON THE GND. APPARENTLY THE FO WAS ATTEMPTING TO ENGAGE THE YAW DAMPER BUT ENGAGED THE AUTOPLT INSTEAD. THE BUTTONS ARE VERY CLOSE TO EACH OTHER. I THINK THE PROB/INCIDENT WOULD NOT HAVE OCCURRED IF THE FO HAD STATED HIS INTENTION TO ENGAGE THE YAW DAMPER. NOTE: THE FO AND I KNEW THAT THE AIRPLANE HAD JUST COME OUT OF MAINT FOR A BROKEN AILERON CABLE BEFORE WE FLEW IT.

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.

Flight crew of an light transport declared an emergency and return land after experiencing abnormal flight control problem caused by the first officer inadvertently activating the autoplt instead of yaw damper.