Narrative:

While deactivating an inlet cowl anti-ice valve I inadvertently removed the cannon plug and wired open the CSD ejector valve by mistake and dispatched the aircraft. The error was discovered down line and corrected. The valve was difficult to reach and was located in close proximity to 2 other valves of similar appearance. Maintenance manuals for a particular chapter label diagrams of valves including only the valves of that particular system. Valves that look the same but are in close proximity may or may not be depicted but are never labeled. If a valve or other part is near similar appearing items the maintenance manual diagrams should be more complete to avoid confusion. This error caused no further damage or incidents. Callback conversation with reporter revealed the following information: the reporter said the airplane he changed the valves on was a B727. There was a complication to his operation in that he was doing the valve change on contract for another airline. This is done all the time. Airlines cannot position a mechanic at all bases so if a problem occurs the airline acquires a mechanic from a local airline by a contract agreement. The problem is the mechanic cannot use his maintenance manuals for his airline but must use the data and information supplied by a facsimile machine from the airline whose airplane he is working on. The reason is all airlines, though the make and model may be the same, are configured differently. Some airplanes have general electric engines and some pratt and whitney and some rolls royce. Though they may not be all that different they frequently have different accessories.

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Original NASA ASRS Text

Title: MECH WIRES THE WRONG VALVE OPEN.

Narrative: WHILE DEACTIVATING AN INLET COWL ANTI-ICE VALVE I INADVERTENTLY REMOVED THE CANNON PLUG AND WIRED OPEN THE CSD EJECTOR VALVE BY MISTAKE AND DISPATCHED THE ACFT. THE ERROR WAS DISCOVERED DOWN LINE AND CORRECTED. THE VALVE WAS DIFFICULT TO REACH AND WAS LOCATED IN CLOSE PROX TO 2 OTHER VALVES OF SIMILAR APPEARANCE. MAINT MANUALS FOR A PARTICULAR CHAPTER LABEL DIAGRAMS OF VALVES INCLUDING ONLY THE VALVES OF THAT PARTICULAR SYS. VALVES THAT LOOK THE SAME BUT ARE IN CLOSE PROX MAY OR MAY NOT BE DEPICTED BUT ARE NEVER LABELED. IF A VALVE OR OTHER PART IS NEAR SIMILAR APPEARING ITEMS THE MAINT MANUAL DIAGRAMS SHOULD BE MORE COMPLETE TO AVOID CONFUSION. THIS ERROR CAUSED NO FURTHER DAMAGE OR INCIDENTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THE AIRPLANE HE CHANGED THE VALVES ON WAS A B727. THERE WAS A COMPLICATION TO HIS OP IN THAT HE WAS DOING THE VALVE CHANGE ON CONTRACT FOR ANOTHER AIRLINE. THIS IS DONE ALL THE TIME. AIRLINES CANNOT POS A MECH AT ALL BASES SO IF A PROB OCCURS THE AIRLINE ACQUIRES A MECH FROM A LCL AIRLINE BY A CONTRACT AGREEMENT. THE PROB IS THE MECH CANNOT USE HIS MAINT MANUALS FOR HIS AIRLINE BUT MUST USE THE DATA AND INFO SUPPLIED BY A FAX MACHINE FROM THE AIRLINE WHOSE AIRPLANE HE IS WORKING ON. THE REASON IS ALL AIRLINES, THOUGH THE MAKE AND MODEL MAY BE THE SAME, ARE CONFIGURED DIFFERENTLY. SOME AIRPLANES HAVE GENERAL ELECTRIC ENGS AND SOME PRATT AND WHITNEY AND SOME ROLLS ROYCE. THOUGH THEY MAY NOT BE ALL THAT DIFFERENT THEY FREQUENTLY HAVE DIFFERENT ACCESSORIES.

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.