During aircraft overhaul at maintenance base a mechanic reported that #2 throttle was not free to mo...

Attributes
ACN	124837
Time
Date	198910
Place
Locale Reference	airport : tul
State Reference	OK
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	other
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	124837
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : anomaly accepted other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

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.

During aircraft 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.