Date: 201508
Local time of day: 0601-1200
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Light: Daylight
Aircraft: MD-83
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Diverted; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Flight in August 2015; was scheduled for ZZZ-ZZZ1 with MD-83 aircraft. Departure weather was rain low ceilings and thunderstorms until the middle of destination State; then clear sky's to ZZZ1 with no alternate. Pre-departure checks; Start/Taxi and Takeoff where all uneventful with no abnormal engine or system indications.In cruise; approximately 50 minutes into flight at FL 330 with no prior abnormalities noted; the Throttle Quadrant began a very loud grinding with a considerable vibration with no throttle movement. After a few seconds a faint smell of hot rubber began emitting from the quadrant so First Officer (FO) and myself performed our memory items for smoke/fumes in cockpit. I then took control of the aircraft and radios and asked FO for the QRH; we agreed upon the 'air conditioning smoke fumes' QRH 26.2; since it wasn't electrical and smelled like it could have been in the Aircraft system and he began to run it. I contacted ATC; requested a lower altitude and began a descent. As FO started the QRH I disconnected the Auto Throttles; the smell immediately dissipated with no further signs but the grinding and vibration continued; but at a lesser intensity. Immediately we noticed the Number-1 Engine rolled back slightly; I applied power and it responded and all engine indications where normal except the left EPR was slightly lower. At this point the vibration in the Quadrant increased. As I began reviewing the situation and current flight conditions (clear; no icing or precipitation) the Number-1 Engine began to roll back even further. FO and I agreed to discontinue the Smoke/Fumes QRH since there was no evidence of such and we started to focus our attention on the Number-1 Engine. I asked FO to run the 'engine flameout failure shutdown' QRH 72.3 (severe damage). I would like to note that the sequence from throttle issue to engine shutdown all happened very quickly; only a couple minutes. As FO worked the checklist; I verified our distance to ZZZ1 to be about 250 miles so I chose ZZZ2 off our wing at approximately 60 miles as our diversion airport. I then contacted ATC requested lower; [advised them of the situation] and asked for the divert to ZZZ2. I also requested ATC to pass along to our Air Carrier of our situation and that we were headed to ZZZ2.First Officer finished up with the initial checklist and prior to continuing into the S.E. Approach Landing checklist I asked him to brief the Flight attendants with the emergency info then give the passengers a quick brief. I would like to also add that the feedback that we received from the Flight attendants and the passengers were all very positive and appreciative of the level of calmness and information provided by First Officer. He did a great job keeping everyone relaxed and in the loop. Once the briefings were complete; FO continued into the S.E. Approach Landing checklists as I continued to fly and communicate with ATC. I then contacted ZZZ2 approached and confirmed our situation and we requested Fire Rescue. I also decided to stop on the runway and not taxi clear due to the continued vibration emitting from the Number-1 Engine. We were then cleared for landing on 23L a visual backed up by the ILS. FO took over the radios and we finished the checklist and the landing was made uneventfully. At brake set on 23L; I made the ' remain seated remain seated' announcement and had Fire Rescue sweep the aircraft while monitoring them on the radios. Fire Rescue gave us the all clear and I made a quick announcement to the passengers then we proceeded into the gate under our own power. The rest of the operation was uneventful through the de-planing. We debriefed with the Flight attendants and I then began communicating with company operations.




Synopsis: Captain reported a very loud grinding sound with considerable vibration and no throttle movement in the Throttle Quadrant of an MD-83 aircraft at cruise altitude. After Auto-Throttles were disconnected; a hot rubber smell dissipated with # 1 Engine rollback. Vibrations continued emanating from Number-1 Engine even after QRH shutdown had been accomplished. Flight diverted.