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|
Attributes | |
ACN | 109093 |
Time | |
Date | 198904 |
Day | Sat |
Local Time Of Day | 1201 To 1800 |
Place | |
Locale Reference | airport : txl |
State Reference | FO |
Altitude | agl bound lower : 0 agl bound upper : 0 |
Environment | |
Flight Conditions | Mixed |
Light | Daylight |
Aircraft 1 | |
Operator | common carrier : air carrier |
Make Model Name | Medium Transport, High Wing, 2 Turboprop Eng |
Flight Phase | ground : preflight |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : atp pilot : commercial pilot : instrument |
Experience | flight time last 90 days : 150 flight time total : 5200 flight time type : 400 |
ASRS Report | 109093 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : commercial pilot : cfi pilot : instrument |
Experience | flight time last 90 days : 249 flight time total : 2459 flight time type : 885 |
ASRS Report | 109262 |
Events | |
Anomaly | aircraft equipment problem : critical non adherence : published procedure non adherence : far |
Independent Detector | other flight crewa |
Resolutory Action | none taken : anomaly accepted |
Consequence | Other |
Supplementary | |
Primary Problem | Aircraft |
Air Traffic Incident | Pilot Deviation |
Narrative:
During start of #1 engine, an unusually high itt acceleration and peak were noted. The start was aborted and a second start was normal. All engine parameters were normal. The aircraft was dispatched for 3 legs. At termination, the itt readings were noted in aircraft log. A maintenance supervisor informed me the next day that my log entry necessitated an engine change, and that the aircraft was not airworthy for yesterday's flight. I disagree because the aircraft is highly sophisticated with many electronic computers and buses that have a history of transient erroneous indications. I believe the itt reading was caused by an on board computer error, a tailwind up the exhaust stack and an under-pwred power cart. The problem can be corrected by the the aircraft flight manual being more specific as to handling abnormal readings. In no place does it say not to fly an aircraft that has an abnormal indication. The only reference is to (1) 'correct cause or indication,' which the aircraft apparently did by itself, and (2) 'notify maintenance,' which was done. Also, the on board computer records should be checked to determine validity of engine readings. Supplemental information from acn 109262: I did witness what I believed to have been an engine temperature limit being exceeded. It all happened very quickly. A new engine was installed and the old engine was sent back to the factory. I do not know whether or not there was any damage to the hot started engine, but the end did indeed exceed a published limiting temperature by as much as 50 degrees C.
Original NASA ASRS Text
Title: ACR MDT EXPERIENCED HIGH INLET TURBINE TEMPERATURE DURING ENGINE START. SECOND START NORMAL. AT THE END OF THE DAY'S FLT, MAINTENANCE REVIEWED THE ACFT LOG AND SAID AN ENGINE CHANGE WAS REQUIRED, AND THAT THE ACFT HAD BEEN UNAIRWORTHY THAT DAY AFTER THE HIGH TEMPERATURE ENGINE START.
Narrative: DURING START OF #1 ENG, AN UNUSUALLY HIGH ITT ACCELERATION AND PEAK WERE NOTED. THE START WAS ABORTED AND A SECOND START WAS NORMAL. ALL ENG PARAMETERS WERE NORMAL. THE ACFT WAS DISPATCHED FOR 3 LEGS. AT TERMINATION, THE ITT READINGS WERE NOTED IN ACFT LOG. A MAINT SUPVR INFORMED ME THE NEXT DAY THAT MY LOG ENTRY NECESSITATED AN ENG CHANGE, AND THAT THE ACFT WAS NOT AIRWORTHY FOR YESTERDAY'S FLT. I DISAGREE BECAUSE THE ACFT IS HIGHLY SOPHISTICATED WITH MANY ELECTRONIC COMPUTERS AND BUSES THAT HAVE A HISTORY OF TRANSIENT ERRONEOUS INDICATIONS. I BELIEVE THE ITT READING WAS CAUSED BY AN ON BOARD COMPUTER ERROR, A TAILWIND UP THE EXHAUST STACK AND AN UNDER-PWRED PWR CART. THE PROB CAN BE CORRECTED BY THE THE ACFT FLT MANUAL BEING MORE SPECIFIC AS TO HANDLING ABNORMAL READINGS. IN NO PLACE DOES IT SAY NOT TO FLY AN ACFT THAT HAS AN ABNORMAL INDICATION. THE ONLY REF IS TO (1) 'CORRECT CAUSE OR INDICATION,' WHICH THE ACFT APPARENTLY DID BY ITSELF, AND (2) 'NOTIFY MAINT,' WHICH WAS DONE. ALSO, THE ON BOARD COMPUTER RECORDS SHOULD BE CHKED TO DETERMINE VALIDITY OF ENG READINGS. SUPPLEMENTAL INFO FROM ACN 109262: I DID WITNESS WHAT I BELIEVED TO HAVE BEEN AN ENG TEMP LIMIT BEING EXCEEDED. IT ALL HAPPENED VERY QUICKLY. A NEW ENG WAS INSTALLED AND THE OLD ENG WAS SENT BACK TO THE FACTORY. I DO NOT KNOW WHETHER OR NOT THERE WAS ANY DAMAGE TO THE HOT STARTED ENG, BUT THE END DID INDEED EXCEED A PUBLISHED LIMITING TEMP BY AS MUCH AS 50 DEGS C.
Data retrieved from NASA's ASRS site as of August 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.