2 CRM 56-3 engines may have been released for service with the incorrect torque applied to the air o...

Attributes
ACN	379781
Time
Date	199709
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz
State Reference	US
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	ground : parked other
Flight Plan	None
Aircraft 2
Make Model Name	DC-9 30
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	379781
Person 2
Affiliation	company : air carrier
Function	other personnel other oversight : supervisor
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Possible false torque put on nut retaining air/oil separator on aft end of cfm 56-3 motor. This false torque may have happened to me on 1 or 2 motors from nov/xx/96 to sep/xx/97. This problem was reported to my lead mechanic in sep/97 and air carrier engineers. Callback conversation with reporter revealed the following information: the reporter stated the procedure was as follows: the nut is torqued then backed off then retorqued to a witness mark with the lead mechanic observing the procedure. The reporter said using the torque value from the job card the fastener aligns past the witness mark. The reporter states that several methods were tried to get correct alignment and torque, lubricant, and using unplated nuts appeared to work. The reporter stated the problem was complicated by the requirement to use a torque multipler on the torque wrench which caused a loss of feel. The reporter advises the job card and maintenance manual are being revised.

Original NASA ASRS Text

Title: 2 CRM 56-3 ENGS MAY HAVE BEEN RELEASED FOR SVC WITH THE INCORRECT TORQUE APPLIED TO THE AIR OIL SEPARATOR FASTENERS.

Narrative: POSSIBLE FALSE TORQUE PUT ON NUT RETAINING AIR/OIL SEPARATOR ON AFT END OF CFM 56-3 MOTOR. THIS FALSE TORQUE MAY HAVE HAPPENED TO ME ON 1 OR 2 MOTORS FROM NOV/XX/96 TO SEP/XX/97. THIS PROB WAS RPTED TO MY LEAD MECH IN SEP/97 AND ACR ENGINEERS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE PROC WAS AS FOLLOWS: THE NUT IS TORQUED THEN BACKED OFF THEN RETORQUED TO A WITNESS MARK WITH THE LEAD MECH OBSERVING THE PROC. THE RPTR SAID USING THE TORQUE VALUE FROM THE JOB CARD THE FASTENER ALIGNS PAST THE WITNESS MARK. THE RPTR STATES THAT SEVERAL METHODS WERE TRIED TO GET CORRECT ALIGNMENT AND TORQUE, LUBRICANT, AND USING UNPLATED NUTS APPEARED TO WORK. THE RPTR STATED THE PROB WAS COMPLICATED BY THE REQUIREMENT TO USE A TORQUE MULTIPLER ON THE TORQUE WRENCH WHICH CAUSED A LOSS OF FEEL. THE RPTR ADVISES THE JOB CARD AND MAINT MANUAL ARE BEING REVISED.

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.

2 CRM 56-3 engines may have been released for service with the incorrect torque applied to the air oil separator fasteners.