Date: 201509
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Night
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Cowling/Nacelle Fasteners; Latches
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Maintenance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; Flight Crew Overcame Equipment Problem; Flight Crew Landed in Emergency Condition
Contributing factors: Procedure; Aircraft
Primary problem: Ambiguous

Narrative: Aircraft departed with a clearance of heading 185 to 10;000 feet. The First Officer was the Pilot Flying (PF) and the Captain was the Pilot Monitoring. The takeoff was normal. While established on a heading of 185 at approximately 2;500 feet MSL and accelerating through approximately 220 KIAS; we heard a loud bang accompanied by a large shudder to the aircraft with a yaw to the right. It also felt as if we lost altitude even though we were climbing at approximately 1;500 fpm. The entire incident felt as if we made hard impact with a large object. A single chime; Master Caution of R REVERSER UNLOCKED occurred a few seconds later; accompanied by the R TR Emergency Stow switch light illuminated. The Right Thrust Lever did not auto-retract. All of these items led us to both believe the Right Thrust Reverser had deployed; then immediately stowed. About this time is when Departure Control wanted us to turn toward the north for our departure route; which I declined and stated I had a possible Thrust Reverser deploy which I was working on. A 'present heading' clearance was issued; with a level off of 4;000 feet MSL and the intention of returning for landing.The QRH Immediate Action Items were accomplished as well as the required QRH procedure; and use of the Right Thrust Lever was resumed per QRH guidance. We were vectored around to the east of the airport for the landing. Emergency vehicles were requested due to the uncertainty of further possible issues. The Flight Attendant was properly briefed on exactly what we believed occurred; and was also told brace positions would not be necessary due to an expected normal landing. The passengers were also briefed via PA on what we believed occurred (Thrust Reverser deployment followed by an immediate stow) and we were returning immediately. The passengers were also told to expect to see Emergency Vehicles along the runway due to our situation. Dispatch was also notified via ACARS of the situation and our immediate return to departure airport. The aircraft had brief; sudden; periodic shudders during the return. The First Officer remained the PF as he handled the situation superbly. He noted the aircraft seemed to shudder more as the Right Thrust Lever was increased; prompting the suggestion to use it as needed (with the thought to retract to Idle if the shudder increased over time). This made us both believe the Thrust Reverser was still possibly cracked open. The aircraft also seemed to need more Left Rudder as the Right Thrust Lever was increased; which solidified this belief. The approach and landing were normal; and below 47;000 lbs. I asked the First Officer to go outside a look at the right engine to see if the Thrust Reverser was partially cracked open. He returned and told me the 'top portion of the engine aft of the white cowling is gone. Missing.' The passengers were still on the aircraft so I first walked up to the gate and asked the customer service rep why the passengers haven't deplaned yet. I was told they were waiting for us to repo the next aircraft. I firmly but professionally told the customer service rep to deplane the passengers immediately; as we had too much to do and couldn't worry about them ourselves. I walked outside to the aircraft. I noticed the entire upper Cowl Core was missing from the right engine and the lower Cowl Core was severely damaged. I immediately went back into the aircraft; called Ground Control on the radio; and asked for a phone number to call them on as I felt the information I was about to share with them didn't need to be divulged on a radio frequency. I called the Tower and informed them of the missing aircraft part and where it approximately departed the aircraft at. An Ops vehicle arrived at our aircraft within a few minutes and asked about our departure gate information; exact taxi route; departure runway; and takeoff time. They then made the decision to close our departure runway until daylight when a thorough runway FOD inspection could be made.All personnel directly involved within our Company and Ops acted fully professionally at all times. Knowing the crew was obviously shaken by 'what could have been' (i.e.; had the Cowl Core impacted the tail upon departure from the aircraft); the chief pilot made the determination to remove us from the remainder of our pairing. The aircraft had a repeat logbook entry (five within the last three days) regarding a small access panel on the upper Cowl Core Panel which consistently opened in flight; and was personally written up by the operating flight crew twice during this day. This access panel (possibly for compressor washes) was serviced by maintenance personnel immediately prior to this particular flight. The response by maintenance (verbally) was that the latch on this particular panel was recently replaced; and was so stiff they 'needed a screwdriver to open it' and they didn't understand why this panel consistently opened in flight. The aircraft was visibly inspected by a member of the flight crew after the maintenance work was completed and no abnormalities were noticed which were visible from the ground. This aircraft engine also had a prior logbook entry from this incident day made by this flight crew regarding the Right Engine Jetpipe touching the Tailcone from approximately 3:30 to 5:30 positions; approximately 20 percent of the area. The Jetpipe was determined to be not touching the Tailcone by Maintenance personnel prior to the first flight of this aircraft by this flight crew. This was the 3rd flight of the day by this flight crew and 4th of the day by this aircraft.

Callback: The Captain stated that it was learned that subsequent maintenance investigation revealed the thrust reverser had not deployed and that the yawing and airframe shudder that the crew experience was likely due to the portions of the cowling that had separated from its latches but remained attached to the remaining cowling.

Second narrative: Upon initial walk around before departing I noticed on the right engine that the spacing between the inner and outer jet pipe was uneven and that there was an access door unlatched and partly open on the upper forward part of the jet pipe. I notified the captain and he wrote up both in the maintenance log. There were several previous write ups for the access door. Maintenance came out secured the door and inspected the jet pipe found it to be within tolerance. A cargo overheat message prior to door close and a significant amount of maintenance corrective action the flight left approximately 3 hours late. Upon postflight walk around I found the access door to be open again. Maintenance was notified; they came back out; secured the door and signed the maintenance log. With maintenance clear we ready to depart. Taxi out was uneventful other than our clearance dropping out due the delay. I was the pilot flying the captain was the pilot monitoring. The takeoff went normal and out instructions were to fly heading 185 on departure. We turned to heading 185 at 400 feet AGL. At approximately 2500 feet MSL we heard and felt a loud thump sounding similar to something impacting the aircraft. Less than a second later we got an R REV UNLOCKED message. There was a small amount of yaw to the right and the right thrust lever did not automatically retard. The captain complied with the immediate action items and the QRH. The QRH permitted us to use the affected thrust lever at the end. ATC vectored us to the east and back around to land in via visual. On final after getting configured to land with the N1 rpm matched the aircraft had a slight tendency to yaw to the right. Also it was taking approximately 5% more N1 RPM than normal to maintain glideslope on final. Landing was normal. We taxied off the runway and contacted company to get a gate. We taxied to the gate and shut the engines down. I exited the aircraft to inspect the right thrust reverser and found the upper forward portion of the jet pipe to be missing and the lower portion hanging down then went to inform the captain. The jet bridge was then connected and a [customer service agent] assisted in deplaning the passengers. The passengers remained calm and did not seem upset during deplaning.An undesired aircraft state was created by equipment failure. The workload and aircraft state that resulted from the equipment failure were threats. I am unaware of any errors on the part of the crew.Until the cause of the event is determined I cannot say what will prevent this kind of event in the future.


Synopsis: Shortly after takeoff; a CRJ crew heard a loud bang accompanied by aircraft shutter/yawing and warning lights indicating possible deployment of the right thrust reverser. Appropriate QRH procedure was accomplished and a landing made at the departure airport. Post flight inspection revealed that the right engine's upper Cowl Core Panel was missing and the lower panel was damaged. Crew notified Maintenance of the aircraft damage and ATC of the missing airplane parts.