Narrative:

Flight about 40-45 mins out of las at 41000' in stabilized cruise, we got a rudder ratio light and an aileron lockout light on icas. The captain's airspeed and altimeter started rapidly decreasing and the autoplt put in a pitch over with a right rudder input as the autothrottles went to maximum power. No control inputs were hard. I countered the control inputs by hand as I disconnected the autoplt and the autothrottles. By this time my altimeter and airspeed were moving up and down too fast to be used. I put in smooth control inputs to correct altitude and heading using the alternate altimeter and airspeed with my normal compass and xchking the copilot's instruments. I had asked the copilot to look up the abnormal procedures for the original lockout and ratio lights. By the time we had the airplane back to altitude, airspeed and heading, ARTCC called and asked if we were going direct to sps and we responded yes. By this time all of our lights and instruments had returned to normal. I re-engaged the autoplt and autothrottles, checked that we were back to normal cruise with everything working and on course to sps. I called abq ARTCC and explained what had happened and was advised that 'it was no problem,' they no traffic anywhere near us. I then called the maintenance coordinator and explained our problem and that we were putting the problem in the maintenance log book. I do not believe that we were more than +/-500' off our altitude or more than 30 degrees right of heading. I elected to use smooth, steady control inputs instead of trying to rapidly regain our altitude. We had excellent visibility and no contrails in sight. The controls felt very heavy with the aileron lockout on and the rudder ratio light on.

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Original NASA ASRS Text

Title: ACR HVT AUTOPLT MOMENTARY FAILURE AT FL410. HEADING AND ALT DEVIATION.

Narrative: FLT ABOUT 40-45 MINS OUT OF LAS AT 41000' IN STABILIZED CRUISE, WE GOT A RUDDER RATIO LIGHT AND AN AILERON LOCKOUT LIGHT ON ICAS. THE CAPT'S AIRSPD AND ALTIMETER STARTED RAPIDLY DECREASING AND THE AUTOPLT PUT IN A PITCH OVER WITH A RIGHT RUDDER INPUT AS THE AUTOTHROTTLES WENT TO MAX PWR. NO CONTROL INPUTS WERE HARD. I COUNTERED THE CONTROL INPUTS BY HAND AS I DISCONNECTED THE AUTOPLT AND THE AUTOTHROTTLES. BY THIS TIME MY ALTIMETER AND AIRSPD WERE MOVING UP AND DOWN TOO FAST TO BE USED. I PUT IN SMOOTH CONTROL INPUTS TO CORRECT ALT AND HDG USING THE ALTERNATE ALTIMETER AND AIRSPD WITH MY NORMAL COMPASS AND XCHKING THE COPLT'S INSTRUMENTS. I HAD ASKED THE COPLT TO LOOK UP THE ABNORMAL PROCS FOR THE ORIGINAL LOCKOUT AND RATIO LIGHTS. BY THE TIME WE HAD THE AIRPLANE BACK TO ALT, AIRSPD AND HDG, ARTCC CALLED AND ASKED IF WE WERE GOING DIRECT TO SPS AND WE RESPONDED YES. BY THIS TIME ALL OF OUR LIGHTS AND INSTRUMENTS HAD RETURNED TO NORMAL. I RE-ENGAGED THE AUTOPLT AND AUTOTHROTTLES, CHKED THAT WE WERE BACK TO NORMAL CRUISE WITH EVERYTHING WORKING AND ON COURSE TO SPS. I CALLED ABQ ARTCC AND EXPLAINED WHAT HAD HAPPENED AND WAS ADVISED THAT 'IT WAS NO PROB,' THEY NO TFC ANYWHERE NEAR US. I THEN CALLED THE MAINT COORDINATOR AND EXPLAINED OUR PROB AND THAT WE WERE PUTTING THE PROB IN THE MAINT LOG BOOK. I DO NOT BELIEVE THAT WE WERE MORE THAN +/-500' OFF OUR ALT OR MORE THAN 30 DEGS RIGHT OF HDG. I ELECTED TO USE SMOOTH, STEADY CONTROL INPUTS INSTEAD OF TRYING TO RAPIDLY REGAIN OUR ALT. WE HAD EXCELLENT VISIBILITY AND NO CONTRAILS IN SIGHT. THE CONTROLS FELT VERY HEAVY WITH THE AILERON LOCKOUT ON AND THE RUDDER RATIO LIGHT ON.

Data retrieved from NASA's ASRS site as of August 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.