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A B757-200 in cruise at FL390 has left engine rollback caused by a faulty engine pressure ratio overspd input to the electronic engine control.
| Attributes | |
| ACN | 521038 |
| Time | |
| Date | 200108 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : mtpp.airport |
| State Reference | FO |
| Altitude | msl bound lower : 38300 msl bound upper : 39000 |
| Aircraft 1 | |
| Controlling Facilities | artcc : zma.artcc tracon : sct.tracon |
| Operator | common carrier : air carrier |
| Make Model Name | B757-200 |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | other |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 521038 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : commercial pilot : multi engine |
| ASRS Report | 521037 |
| Events | |
| Anomaly | aircraft equipment problem : critical other anomaly other |
| Independent Detector | aircraft equipment : left engine epr indicator aircraft equipment other aircraft equipment : epr indicator other flight crewa other flight crewb |
| Resolutory Action | aircraft : equipment problem dissipated flight crew : overcame equipment problem |
| Consequence | other |
| Supplementary | |
| Problem Areas | Aircraft Flight Crew Human Performance |
| Primary Problem | Aircraft |
Narrative:
At FL390, left engine EPR shot to 1.98 EPR while other engine indications declined. While troubleshooting, airspeed began to bleed off. Called port O prince for immediate descent to FL350. Nothing. Called again -- nothing. Airspeed getting low. Port O prince answered. Gave request. Stand by. Started slow descent. Port O prince gives us over to ZMA. Asked ZMA for immediate descent to FL280 for abnormal engine indications. 15 mins later, left engine power returned to normal as did all indicators. We were at FL383 when ZMA gave us lower altitude clearance. Probable engine problem. Erroneous high EPR gave false overboost and the electronic engine control caused an engine roll back. Lessons learned: 1) after talking to maintenance, turn off the electronic engine control, 2) get on ZMA frequency as soon as possible when in port O prince airspace, and 3) if you cannot get what you want, declare an emergency -- it can always be rescinded.
Original NASA ASRS Text
Title: A B757-200 IN CRUISE AT FL390 HAS L ENG ROLLBACK CAUSED BY A FAULTY ENG PRESSURE RATIO OVERSPD INPUT TO THE ELECTRONIC ENG CTL.
Narrative: AT FL390, L ENG EPR SHOT TO 1.98 EPR WHILE OTHER ENG INDICATIONS DECLINED. WHILE TROUBLESHOOTING, AIRSPD BEGAN TO BLEED OFF. CALLED PORT O PRINCE FOR IMMEDIATE DSCNT TO FL350. NOTHING. CALLED AGAIN -- NOTHING. AIRSPD GETTING LOW. PORT O PRINCE ANSWERED. GAVE REQUEST. STAND BY. STARTED SLOW DSCNT. PORT O PRINCE GIVES US OVER TO ZMA. ASKED ZMA FOR IMMEDIATE DSCNT TO FL280 FOR ABNORMAL ENG INDICATIONS. 15 MINS LATER, L ENG PWR RETURNED TO NORMAL AS DID ALL INDICATORS. WE WERE AT FL383 WHEN ZMA GAVE US LOWER ALT CLRNC. PROBABLE ENG PROB. ERRONEOUS HIGH EPR GAVE FALSE OVERBOOST AND THE ELECTRONIC ENG CTL CAUSED AN ENG ROLL BACK. LESSONS LEARNED: 1) AFTER TALKING TO MAINT, TURN OFF THE ELECTRONIC ENG CTL, 2) GET ON ZMA FREQ ASAP WHEN IN PORT O PRINCE AIRSPACE, AND 3) IF YOU CANNOT GET WHAT YOU WANT, DECLARE AN EMER -- IT CAN ALWAYS BE RESCINDED.
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.