A B737-800 mechanic forgot to disconnect #1 engine nose cowl anti-ice valve canon plug after locking...

Attributes
ACN	757380
Time
Date	200710
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	ground : parked
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	757380
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe maintenance problem : improper maintenance maintenance problem : non compliance with mel non adherence : far non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : engine nose cowl anti-ice light on other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

Mr X and myself covered the turn of aircraft X in from ZZZ1 and going out to ZZZ2. The aircraft had a discrepancy on the #1 engine nose cowl anti-ice valve. Due to the constraints for troubleshooting; decision was made with maintenance control to MEL per MEL 30-3-xx. I locked the nose cowl anti-ice valve in the open position and locked the high stage valve in the closed position. After the aircraft departed; the captain called back and reported that the light was still on. I heard the call on the radio and then realized I had forgotten to disconnect the cannon plug on the cowl anti-ice valve and its pressure switch. The next station was notified by maintenance control to go out and disconnect the cannon plugs. Pilot reported it to dispatch that they still had a nose cowl anti-ice light and dispatch relayed it to maintenance control. As soon as I heard the conversation take place I realized what I had forgotten. Maintenance was notified in ZZZ2 to meet aircraft and disconnect the cannon plugs. I had locked the high stage valve closed first. It does not have a cannon plug to disconnect; I then locked open the cowl anti-ice valve and totally forgot about disconnecting the cannon plug on the valve and pressure switch. The lock-out procedure is mechanically similar on both valves and due to complacency of locking out the high stage valve I just plain forgot to disconnect the cannon plug when I locked open the cowl anti-ice valve.

Original NASA ASRS Text

Title: A B737-800 MECHANIC FORGOT TO DISCONNECT #1 ENG NOSE COWL ANTI-ICE VALVE CANON PLUG AFTER LOCKING VALVE IN THE OPEN POSITION. VALVE WAS DEFERRED. LIGHT REMAINED ON IN-FLIGHT.

Narrative: MR X AND MYSELF COVERED THE TURN OF ACFT X IN FROM ZZZ1 AND GOING OUT TO ZZZ2. THE ACFT HAD A DISCREPANCY ON THE #1 ENG NOSE COWL ANTI-ICE VALVE. DUE TO THE CONSTRAINTS FOR TROUBLESHOOTING; DECISION WAS MADE WITH MAINT CTL TO MEL PER MEL 30-3-XX. I LOCKED THE NOSE COWL ANTI-ICE VALVE IN THE OPEN POS AND LOCKED THE HIGH STAGE VALVE IN THE CLOSED POS. AFTER THE ACFT DEPARTED; THE CAPT CALLED BACK AND REPORTED THAT THE LIGHT WAS STILL ON. I HEARD THE CALL ON THE RADIO AND THEN REALIZED I HAD FORGOTTEN TO DISCONNECT THE CANNON PLUG ON THE COWL ANTI-ICE VALVE AND ITS PRESSURE SWITCH. THE NEXT STATION WAS NOTIFIED BY MAINT CTL TO GO OUT AND DISCONNECT THE CANNON PLUGS. PLT REPORTED IT TO DISPATCH THAT THEY STILL HAD A NOSE COWL ANTI-ICE LIGHT AND DISPATCH RELAYED IT TO MAINT CTL. AS SOON AS I HEARD THE CONVERSATION TAKE PLACE I REALIZED WHAT I HAD FORGOTTEN. MAINT WAS NOTIFIED IN ZZZ2 TO MEET ACFT AND DISCONNECT THE CANNON PLUGS. I HAD LOCKED THE HIGH STAGE VALVE CLOSED FIRST. IT DOES NOT HAVE A CANNON PLUG TO DISCONNECT; I THEN LOCKED OPEN THE COWL ANTI-ICE VALVE AND TOTALLY FORGOT ABOUT DISCONNECTING THE CANNON PLUG ON THE VALVE AND PRESSURE SWITCH. THE LOCK-OUT PROC IS MECHANICALLY SIMILAR ON BOTH VALVES AND DUE TO COMPLACENCY OF LOCKING OUT THE HIGH STAGE VALVE I JUST PLAIN FORGOT TO DISCONNECT THE CANNON PLUG WHEN I LOCKED OPEN THE COWL ANTI-ICE VALVE.

Data retrieved from NASA's ASRS site as of January 2009 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.

A B737-800 mechanic forgot to disconnect #1 engine nose cowl anti-ice valve canon plug after locking valve in the open position. Valve was deferred. Light remained on in-flight.