A B737-200 returned to the gate after pushback due to the engine indications being swapped.

Attributes
ACN	379095
Time
Date	199709
Day	Tue
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	B737-200
Operating Under FAR Part	Part 121
Flight Phase	other
Flight Plan	None
Aircraft 2
Make Model Name	B737-200
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	379095
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure non adherence : far other anomaly other
Independent Detector	other flight crewa other other : unspecified cockpit
Resolutory Action	none taken : detected after the fact other
Consequence	Other
Supplementary
Air Traffic Incident	other

Narrative:

I was working a B737-200 on the night of sep/xx/97. I was working a maintenance change order on a fuel quantity gauge backgnd lighting. To complete this task most of the instrument panel needs to be removed. After completing the maintenance change order I began installing the cannon plugs. The cannon plugs were clearly marked. After getting most of the cannon plugs connected I had trouble getting my hands behind the panel to install the rest, therefore, I had to remove some plugs again to gain access. At this point of reinstalling the plugs I inadvertently crossed the N2 and fuel flow of the #1 engine with #2 engine. After I completed the installation I tested all the lights and indicators and all appeared normal. The aircraft pushed back and the flight crew started #1 engine. At this point the crew found that with #1 engine running, N2 and fuel flow were being indicated on #2 engine. The aircraft returned to the gate and the discrepancy was repaired. The aircraft then made its scheduled flight without further incident. Because there is no actual maintenance manual procedure for this job task, you have to rely on your own experience as a mechanic to accomplish such a task.

Original NASA ASRS Text

Title: A B737-200 RETURNED TO THE GATE AFTER PUSHBACK DUE TO THE ENG INDICATIONS BEING SWAPPED.

Narrative: I WAS WORKING A B737-200 ON THE NIGHT OF SEP/XX/97. I WAS WORKING A MAINT CHANGE ORDER ON A FUEL QUANTITY GAUGE BACKGND LIGHTING. TO COMPLETE THIS TASK MOST OF THE INST PANEL NEEDS TO BE REMOVED. AFTER COMPLETING THE MAINT CHANGE ORDER I BEGAN INSTALLING THE CANNON PLUGS. THE CANNON PLUGS WERE CLRLY MARKED. AFTER GETTING MOST OF THE CANNON PLUGS CONNECTED I HAD TROUBLE GETTING MY HANDS BEHIND THE PANEL TO INSTALL THE REST, THEREFORE, I HAD TO REMOVE SOME PLUGS AGAIN TO GAIN ACCESS. AT THIS POINT OF REINSTALLING THE PLUGS I INADVERTENTLY CROSSED THE N2 AND FUEL FLOW OF THE #1 ENG WITH #2 ENG. AFTER I COMPLETED THE INSTALLATION I TESTED ALL THE LIGHTS AND INDICATORS AND ALL APPEARED NORMAL. THE ACFT PUSHED BACK AND THE FLC STARTED #1 ENG. AT THIS POINT THE CREW FOUND THAT WITH #1 ENG RUNNING, N2 AND FUEL FLOW WERE BEING INDICATED ON #2 ENG. THE ACFT RETURNED TO THE GATE AND THE DISCREPANCY WAS REPAIRED. THE ACFT THEN MADE ITS SCHEDULED FLT WITHOUT FURTHER INCIDENT. BECAUSE THERE IS NO ACTUAL MAINT MANUAL PROC FOR THIS JOB TASK, YOU HAVE TO RELY ON YOUR OWN EXPERIENCE AS A MECH TO ACCOMPLISH SUCH A TASK.

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.