Date: 201211
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Night
Aircraft: MD-88
Operator: Air Carrier
Operating under: Part 91
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Turbine Engine
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Flight Engineer; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Anomaly: Aircraft Equipment Problem Critical
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Declared Emergency
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: On departure while climbing through FL230 (autopilot & autothrottles engaged) I hear a loud bang and observed the left engine instruments symmetrically decline below that of the other engine. I also observed the L GEN OFF and L CSD OIL PRESS LOW light illuminate on the OAP. The Captain immediately called out that the left engine was rolling back and I disconnected the autothrottles and brought the left throttle back to the idle position. At this time the engine instruments appeared to respond normally as the throttle was brought back and fluid levels and pressures were normal. Due to the loss of thrust we requested to discontinue our climb and I received clearance from ATC to descend back down to FL230. The Captain directed me to continue to fly the airplane and later to coordinate our return to departure airport while he got out the QRH and worked the problem. At this time we discussed in more detail what we thought the problem was. From previous experience on other jet aircraft I relayed that the bang sounded like a loud compressor stall. We both again scanned the instruments and observed that the left engine was running normally in the idle position. We also observed that the left generator freq/volts were low and out of limits. While flying with the left engine at idle all appeared very normal with no strange sounds or vibrations of any kind. After discussing the events we elected to address the situation prioritizing the engine issue first and then exploring the electrical issues next. Due to the fact that the sound immediately stopped following pulling-back the throttle and that the engine instruments now appeared normal (no erratic readings or losses of fluid); we elected to run the ENGINE COMPRESSOR STALL checklist. The checklist was completed and when reaching the section which offered the use of the engine at levels below where the compressor stall occurs; we elected to leave the engine at idle as it was operating normally and we did not want to potentially aggravate the situation further. Upon completion of the checklist it referred us to the ONE ENGINE INOPERATIVE/REDUCED THRUST LANDING CHECKLIST which was run up to the Descent deferred items. I declared an emergency and continued to fly the aircraft while the Captain communicated with the flight attendants; passengers and Dispatcher. At some point the APU was started; which caused a momentary power interruption. With the engine situation stabilized we turned our attention to the Annunciator Panel lights and ran the CSD OIL PRESS LOW checklist. Per the checklist we disconnected the CSD after multiple confirmations that we had the correct one (I think I even guarded the other one with my hand). Shortly following the completion of this checklist we noticed the L OIL PRESS LOW message had illuminated which prompted us to complete the OIL PRESS LOW CHECKLIST. Referring back to the engine instruments revealed that the left engine oil pressure was below 10 and the oil quantity was near zero. Following the checklist guidance we were directed to the ENGINE FAILURE OR SHUTDOWN CHECKLIST which was completed and again referred us to the ONE ENGINE INOPERATIVE/REDUCED LANDING CHECKLIST. During the arrival; and in accordance with the checklist; we balanced the fuel as a 600 pound balance had developed. We again updated ATC of our situation and requested to have emergency response vehicles available to look us over once we had landed. I coordinated our arrival with Approach and was told to expect an ILS. I briefed the approach and we finished the descent; approach and landing checklists contained in the ONE ENGINE INOPERATIVE/REDUCED LANDING CHECKLIST. During the approach we verbally reviewed Single-Engine Go-Around procedures and discussed potential landing rollout controllability issues using a single thrust reverser. The remainder of the approach and landing was uneventful. We taxied clear of the runway and allowed the Fire Chief an opportunity to inspect our left engine. He advised us of a hole in the side of our left engine and confirmed that we were not visibly leaking fuel from the engine. Due to a small amount of hydraulic fluid under the engine we pulled the fire handle to isolate any leak that may exist. The Captain made an additional call to Maintenance to get their input on any issues that would affect us taxiing back to the gate.  We were released by the Fire Chief and taxied uneventfully back to the gate.




Synopsis: MD88 First Officer reports a loud bang from the left engine climbing through FL230. The left engine thrust is retarded and the engine appears normal except for the CSD and generator off line. The left CSD is disconnected and eventually the left engine oil pressure and quantity go to zero and the engine is shut down. Flight returns to departure airport where post flight reveals a hole in the side of the left engine cowl.