|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Locale Reference||airport : tul|
|Altitude||agl bound lower : 0|
agl bound upper : 0
|Operator||common carrier : air carrier|
|Make Model Name||Medium Large Transport, Low Wing, 2 Turbojet Eng|
|Navigation In Use||Other|
|Affiliation||company : air carrier|
|Function||other personnel other|
|Qualification||other other : other|
|Anomaly||aircraft equipment problem : critical|
other anomaly other
|Independent Detector||other other : unspecified|
|Resolutory Action||none taken : anomaly accepted|
|Air Traffic Incident||other|
While working a light C check on an medium large transport aircraft daf, I was doing the EPR check on the engines in the hangar using the tester. I operated the throttles to check movement (free), but came upon the right throttle binding about 3' before the forward stop. The left throttle operated freely. I noticed this once I set EPR limits on the gauges, activated the autothrottles and pushed the EPR limit button momentarily. Throttles advanced up to 3' before the forward stop when the right one kicked back, but the left advanced forward to the stop. This is something we do in the hangar and I was instructing someone else how to do the check until this occurred. I told him to run the throttles through several times while I checked the throttle run through (cable linkage). I couldn't find anything obstructing the cables or linkages. I went to the cockpit and I personally operated the right throttle several times when something gave way and I immediate regained full throttle movement west/O any obstruction. I again went through the system checking for any damage along with 2 other mechanics. We cleaned the pedestal of debris and ran the check through west/O any problems. I inquired of avionics and the men who rigged the engines prior to me running the final check before engine run in 10/89 and they stated that nothing was wrong when they did their checks. I will check up on aircraft to see if the problem occurs again down the line. Something was there and then it wasn't.
Original NASA ASRS Text
Title: DURING ACFT OVERHAUL AT MAINTENANCE BASE A MECHANIC REPORTED THAT #2 THROTTLE WAS NOT FREE TO MOVE WHEN ADVANCED UP TO THE 3-INCH POSITION PRIOR TO THE THROTTLE STOP.
Narrative: WHILE WORKING A LIGHT C CHK ON AN MLG ACFT DAF, I WAS DOING THE EPR CHK ON THE ENGS IN THE HANGAR USING THE TESTER. I OPERATED THE THROTTLES TO CHK MOVEMENT (FREE), BUT CAME UPON THE RIGHT THROTTLE BINDING ABOUT 3' BEFORE THE FORWARD STOP. THE LEFT THROTTLE OPERATED FREELY. I NOTICED THIS ONCE I SET EPR LIMITS ON THE GAUGES, ACTIVATED THE AUTOTHROTTLES AND PUSHED THE EPR LIMIT BUTTON MOMENTARILY. THROTTLES ADVANCED UP TO 3' BEFORE THE FORWARD STOP WHEN THE RIGHT ONE KICKED BACK, BUT THE LEFT ADVANCED FORWARD TO THE STOP. THIS IS SOMETHING WE DO IN THE HANGAR AND I WAS INSTRUCTING SOMEONE ELSE HOW TO DO THE CHK UNTIL THIS OCCURRED. I TOLD HIM TO RUN THE THROTTLES THROUGH SEVERAL TIMES WHILE I CHKED THE THROTTLE RUN THROUGH (CABLE LINKAGE). I COULDN'T FIND ANYTHING OBSTRUCTING THE CABLES OR LINKAGES. I WENT TO THE COCKPIT AND I PERSONALLY OPERATED THE RIGHT THROTTLE SEVERAL TIMES WHEN SOMETHING GAVE WAY AND I IMMEDIATE REGAINED FULL THROTTLE MOVEMENT W/O ANY OBSTRUCTION. I AGAIN WENT THROUGH THE SYS CHKING FOR ANY DAMAGE ALONG WITH 2 OTHER MECHS. WE CLEANED THE PEDESTAL OF DEBRIS AND RAN THE CHK THROUGH W/O ANY PROBS. I INQUIRED OF AVIONICS AND THE MEN WHO RIGGED THE ENGS PRIOR TO ME RUNNING THE FINAL CHK BEFORE ENG RUN IN 10/89 AND THEY STATED THAT NOTHING WAS WRONG WHEN THEY DID THEIR CHKS. I WILL CHK UP ON ACFT TO SEE IF THE PROB OCCURS AGAIN DOWN THE LINE. SOMETHING WAS THERE AND THEN IT WASN'T.
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.