Flight Crew Air Transport Pilot (ATP)
Confusion; Troubleshooting; Training / Qualification
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Diverted; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Overcame Equipment Problem; Flight Crew Landed As Precaution; General Declared Emergency; General Maintenance Action
Manuals; Aircraft; Chart Or Publication
Climbing through FL230 the right engine started surging and the engine indications were fluctuating with the surge. I felt a bump and heard a dull bang with every surge and fluctuation. I had the First Officer run the Engine Fluctuation QRH 72.15 because if the condition continued we would be directed to 72.8;9. The issue of the fluctuation occurred one more time after completion of the QRH and the engine performed normally for the duration of the flight. I notified Dispatch and Maintenance Control via the SAT Phone. After some the discussion with Maintenance made the determination to bring the aircraft to an enroute station as a precaution due to history on the aircraft. We coordinated with ATC and notified the passengers and flight attendants on the plan. I declared an emergency with Tower because of the overweight landing. The Operating Manual has guidance on overweight landings but there was a paragraph that may have not allowed for an overweight landing without declaring an emergency. No assistance was required and the landing was normal aside from the weight. Taxied to the gate and was met by Maintenance personnel. I then put the conditions I experienced in the aircraft maintenance log. Maintenance asked if I had looked at the duct pressure; I replied that I had not. The Fault Reporting Manual (FRM) suggests looking at the pressure to determine the proper write-up but there was no guidance in the QRH addressing to notation of duct pressure. I left the aircraft with maintenance. A few things I recommend after this experience. I recommend a note or addition to the QRH directing the pilot to note or look at the duct pressure. The Operating Manual was not clear on the need to declare an emergency or not in this case. It states to not land overweight for maintenance conditions that don't warrant an immediate action. I was unsure if the issue was an engine; EEC; or bleed air issue so I elected to declare the emergency going with the worst case scenario that there was a possible engine issue; although operating normal at the time of landing. The First Officer and I had some discussion on the proper QRH procedure to conduct. Both 72.8 and 72.15 seemed to be the correct procedures for what we were experiencing. 72.15 was the checklist procedure we elected to run first; if the condition continued then we would have run 72.8 as directed by 72.15. A couple notes regarding both these procedures. Neither procedure 72.8 or 72.15 directs you to note duct pressure. 72.15 directs you to page 72.9 but the procedure starts on 72.8. I feel it is bad procedure to jump in the middle of a checklist missing possible valuable information such as notes or conditions. 72.8 never directs to turn off the EEC and seems to be a more urgent procedure compared to 72.1. 72.8 under conditions state 'Engine indications are rapidly approaching or exceeding limits.' Rapidly approaching could be interpreted as a fluctuation. I feel that both of these procedures; 72.8 and 72.15 should be combined into one procedure with a step by step guidance to final engine shutdown after the procedure is complete. It would alleviate confusion on what procedure to complete and in the end 72.15 directs the pilot to the other procedure anyway. I think duct pressure check should be part of the procedure to help Maintenance determine the cause of the issue. It is listed in the FRM manual but honestly who is going to look through the FRM during this situation. I feel that the Operating Manual under my circumstances was unclear as to whether I should land overweight or not. I went with Operating Manual Section 11 and declared an emergency; thinking that worst case scenario there could be possible engine damage or malfunction although operating normally at the time after completion of the QRH procedure. I was asked to conference in on the phone with other departments after landing and felt that was a valuable tool and great idea. It enabled everyone to hear the accounts that took place immediately after the event occurred while still fresh in our minds.
A B757 right engine was surging with compressor stalls so the crew completed the QRH procedure; then declared an emergency and diverted. Maintenance requested the duct pressure indications but the QRH made no reference to a duct pressure requirement.