Mechanic failed to reconnect all connectors after closure of a bleed air valve which became inoperat...

Attributes
ACN	282545
Time
Date	199409
Day	Sun
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sfo
State Reference	CA
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	B737-500
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	ground : preflight
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
ASRS Report	282545
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	other other : other
Events
Anomaly	aircraft equipment problem : critical non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Flight plan number, a B737-500, reported left engine pneumatic bleed system was inoperative. Airplane landed at okc and an item was entered to render the #1 bleed press regulation and shut-off valve to the closed and locked position per MM 36-11-15. Local FBO was called for a mechanic to inoperative the valve closed. All pertinent information, maintenance manual, pictures and diagrams were faxed to okc to assist the local mechanic. Local mechanic reported receiving this material. The procedure requires mechanically locking valve closed and disconnecting a electrical connector from the remotely mounted pressure regulator. Mechanic reported job was completed and signed off. At engine start for trip departure the crew reported #1 engine exhaust gas temperature indicator inoperative. Mechanic was requested to rechk the connector. He disconnected and tied back. A primary engine display was replaced with no help. Mechanic was requested to rechk the egt wiring harness for damage. He reported none found. I requested him to check the loop for continuity with an ohmmeter but was told he would need an avionics technician to accomplish this test. I elected to maintenance ferry the airplane to den. Den mechanics found the wrong connector disconnected and tied back, this connector rendered the pneumatic system, egt system and fire warning system inoperative. The pictures, manual descriptions I believe were adequate to avoid this situation. However I should have requested the mechanic to reconnect the connector and retest the egt!

Original NASA ASRS Text

Title: MECH FAILED TO RECONNECT ALL CONNECTORS AFTER CLOSURE OF A BLEED AIR VALVE WHICH BECAME INOP RESULTING THE EGT AND THE ENG FIRE WARNING SYS BECOMING INOP AND THE ACFT FERRIED TO A MAINT BASE FOR REPAIR.

Narrative: FLT PLAN NUMBER, A B737-500, RPTED L ENG PNEUMATIC BLEED SYS WAS INOP. AIRPLANE LANDED AT OKC AND AN ITEM WAS ENTERED TO RENDER THE #1 BLEED PRESS REG AND SHUT-OFF VALVE TO THE CLOSED AND LOCKED POS PER MM 36-11-15. LCL FBO WAS CALLED FOR A MECH TO INOP THE VALVE CLOSED. ALL PERTINENT INFO, MAINT MANUAL, PICTURES AND DIAGRAMS WERE FAXED TO OKC TO ASSIST THE LCL MECH. LCL MECH RPTED RECEIVING THIS MATERIAL. THE PROC REQUIRES MECHANICALLY LOCKING VALVE CLOSED AND DISCONNECTING A ELECTRICAL CONNECTOR FROM THE REMOTELY MOUNTED PRESSURE REGULATOR. MECH RPTED JOB WAS COMPLETED AND SIGNED OFF. AT ENG START FOR TRIP DEP THE CREW RPTED #1 ENG EXHAUST GAS TEMP INDICATOR INOP. MECH WAS REQUESTED TO RECHK THE CONNECTOR. HE DISCONNECTED AND TIED BACK. A PRIMARY ENG DISPLAY WAS REPLACED WITH NO HELP. MECH WAS REQUESTED TO RECHK THE EGT WIRING HARNESS FOR DAMAGE. HE RPTED NONE FOUND. I REQUESTED HIM TO CHK THE LOOP FOR CONTINUITY WITH AN OHMMETER BUT WAS TOLD HE WOULD NEED AN AVIONICS TECHNICIAN TO ACCOMPLISH THIS TEST. I ELECTED TO MAINT FERRY THE AIRPLANE TO DEN. DEN MECHS FOUND THE WRONG CONNECTOR DISCONNECTED AND TIED BACK, THIS CONNECTOR RENDERED THE PNEUMATIC SYS, EGT SYS AND FIRE WARNING SYS INOP. THE PICTURES, MANUAL DESCRIPTIONS I BELIEVE WERE ADEQUATE TO AVOID THIS SIT. HOWEVER I SHOULD HAVE REQUESTED THE MECH TO RECONNECT THE CONNECTOR AND RETEST THE EGT!

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.

Mechanic failed to reconnect all connectors after closure of a bleed air valve which became inoperative resulting the egt and the engine fire warning system becoming inoperative and the aircraft ferried to a maintenance base for repair.