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A B737-700 returned to the departure field due to #1 engine overheat warning at high power. The left high pressure turbine case cooling valve was previously replaced. Found valve clamp not positioned correctly.
| Attributes | |
| ACN | 704576 |
| Time | |
| Date | 200607 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : zzzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Environment | |
| Light | Night |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-700 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : maintenance |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| Qualification | technician : airframe technician : powerplant |
| Experience | maintenance technician : 2 |
| ASRS Report | 704576 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance non adherence : published procedure non adherence : far |
| Independent Detector | aircraft equipment other aircraft equipment : overheat warning other flight crewa other flight crewb |
| Resolutory Action | none taken : detected after the fact other |
| Consequence | other other |
| Factors | |
| Maintenance | contributing factor : work cards contributing factor : manuals performance deficiency : non compliance with legal requirements performance deficiency : logbook entry performance deficiency : installation performance deficiency : inspection |
| Supplementary | |
| Problem Areas | Maintenance Human Performance Chart Or Publication Aircraft |
| Primary Problem | Maintenance Human Performance |
Narrative:
I right&right'ed #1 engine hptacc valve. I was finishing up just before the crew showed up. After completing the 2 required operations checks we signed all of our paperwork and left the aircraft. I was working line overtime when I heard the captain; who was flying the aircraft; call over the radio that he had an overheat detection at full power but it went away when he retarded the throttles. The aircraft then did an air turn-back. The aircraft landed without incident and shops took the aircraft to the hangar. They informed me that they repositioned a clamp on the hptacc valve. When I performed the required operations checks (actuators test and low idle leak check) there were no abnormalities. There is no operations checks that I am aware of that can leak check the ducts at high power with the engine cores open.
Original NASA ASRS Text
Title: A B737-700 RETURNED TO THE DEP FIELD DUE TO #1 ENG OVERHEAT WARNING AT HIGH PWR. THE L HIGH PRESSURE TURBINE CASE COOLING VALVE WAS PREVIOUSLY REPLACED. FOUND VALVE CLAMP NOT POSITIONED CORRECTLY.
Narrative: I R&R'ED #1 ENG HPTACC VALVE. I WAS FINISHING UP JUST BEFORE THE CREW SHOWED UP. AFTER COMPLETING THE 2 REQUIRED OPS CHKS WE SIGNED ALL OF OUR PAPERWORK AND LEFT THE ACFT. I WAS WORKING LINE OVERTIME WHEN I HEARD THE CAPT; WHO WAS FLYING THE ACFT; CALL OVER THE RADIO THAT HE HAD AN OVERHEAT DETECTION AT FULL PWR BUT IT WENT AWAY WHEN HE RETARDED THE THROTTLES. THE ACFT THEN DID AN AIR TURN-BACK. THE ACFT LANDED WITHOUT INCIDENT AND SHOPS TOOK THE ACFT TO THE HANGAR. THEY INFORMED ME THAT THEY REPOSITIONED A CLAMP ON THE HPTACC VALVE. WHEN I PERFORMED THE REQUIRED OPS CHKS (ACTUATORS TEST AND LOW IDLE LEAK CHK) THERE WERE NO ABNORMALITIES. THERE IS NO OPS CHKS THAT I AM AWARE OF THAT CAN LEAK CHK THE DUCTS AT HIGH PWR WITH THE ENG CORES OPEN.
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.