Narrative:

During 'B' check pr-dock run-up found a left engine pneumatic flex hose leaking. I initially determined that the start valve could be manually operated with the flex hose removed and capped due to the part being unavailable in ZZZ. I obtained an engineering order and MEL for inoperative starter to operate the aircraft in this condition. On climb out from ZZZ the pilot noticed that the left pneumatic pressure was pegged out at 100 psi, he closed the bleed valve and continued the flight to ZZZ at or below 25 thousand ft. I feel that this problem was caused by operational pressure, lack of part availability at ZZZ and the poor quality of the ipc drawing that applied to this area. I also failed to see the tee-fitting down stream of this hose that was removed and capped. By removing and capping this flex hose I kept the pres controller from accomplishing its function. The controller had no reference air to base the regulation on. Callback conversation with reporter revealed the following information: the reporter stated the flexible line connected to the start valve was found leaking during a 'B' check in the hangar. The reporter said the line was removed and the ports capped and the start valve was deferred as electrically inoperative and manually ok per the minimum equipment list. The reporter stated the line part number was checked in the illustrated parts catalog but did not appear on the valve illustration and no line connections were shown. The reporter said power plant engineering was contacted and the ok was received to remove the line and some question arose as to the line function. The reporter stated the start valve was not tested in the hangar or on the gate prior to departure. The reporter said the crew discovered the left engine bleed system was at 100 psi and way out of limits and the left bleed valve was closed. The reporter said the line sensed engine bleed pressure to the pressure ratio bleed control and was a nonstandard configuration.

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Original NASA ASRS Text

Title: A B737-200 WAS DISPATCHED IN NONCOMPLIANCE WITH THE LEFT START VALVE DEFERRED INOPERATIVE PER THE MINIMUM EQUIP LIST, BUT SPECIAL PROCEDURES WERE NOT ACCOMPLISHED.

Narrative: DURING 'B' CHECK PR-DOCK RUN-UP FOUND A LEFT ENGINE PNEUMATIC FLEX HOSE LEAKING. I INITIALLY DETERMINED THAT THE START VALVE COULD BE MANUALLY OPERATED WITH THE FLEX HOSE REMOVED AND CAPPED DUE TO THE PART BEING UNAVAILABLE IN ZZZ. I OBTAINED AN ENGINEERING ORDER AND MEL FOR INOP STARTER TO OPERATE THE ACFT IN THIS CONDITION. ON CLIMB OUT FROM ZZZ THE PILOT NOTICED THAT THE LEFT PNEUMATIC PRESSURE WAS PEGGED OUT AT 100 PSI, HE CLOSED THE BLEED VALVE AND CONTINUED THE FLIGHT TO ZZZ AT OR BELOW 25 THOUSAND FT. I FEEL THAT THIS PROBLEM WAS CAUSED BY OPERATIONAL PRESSURE, LACK OF PART AVAILABILITY AT ZZZ AND THE POOR QUALITY OF THE IPC DRAWING THAT APPLIED TO THIS AREA. I ALSO FAILED TO SEE THE TEE-FITTING DOWN STREAM OF THIS HOSE THAT WAS REMOVED AND CAPPED. BY REMOVING AND CAPPING THIS FLEX HOSE I KEPT THE PRES CONTROLLER FROM ACCOMPLISHING ITS FUNCTION. THE CONTROLLER HAD NO REFERENCE AIR TO BASE THE REGULATION ON. CALLBACK CONVERSATION WITH REPORTER REVEALED THE FOLLOWING INFO: THE RPTR STATED THE FLEXIBLE LINE CONNECTED TO THE START VALVE WAS FOUND LEAKING DURING A 'B' CHECK IN THE HANGAR. THE RPTR SAID THE LINE WAS REMOVED AND THE PORTS CAPPED AND THE START VALVE WAS DEFERRED AS ELECTRICALLY INOPERATIVE AND MANUALLY OK PER THE MINIMUM EQUIP LIST. THE RPTR STATED THE LINE PART NUMBER WAS CHECKED IN THE ILLUSTRATED PARTS CATALOG BUT DID NOT APPEAR ON THE VALVE ILLUSTRATION AND NO LINE CONNECTIONS WERE SHOWN. THE RPTR SAID POWER PLANT ENGINEERING WAS CONTACTED AND THE OK WAS RECEIVED TO REMOVE THE LINE AND SOME QUESTION AROSE AS TO THE LINE FUNCTION. THE RPTR STATED THE START VALVE WAS NOT TESTED IN THE HANGAR OR ON THE GATE PRIOR TO DEPARTURE. THE RPTR SAID THE CREW DISCOVERED THE LEFT ENGINE BLEED SYSTEM WAS AT 100 PSI AND WAY OUT OF LIMITS AND THE LEFT BLEED VALVE WAS CLOSED. THE RPTR SAID THE LINE SENSED ENGINE BLEED PRESSURE TO THE PRESSURE RATIO BLEED CONTROL AND WAS A NONSTANDARD CONFIGURATION.

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.