Date: 201909
Local time of day: 1201-1800
Location: ZZZ3.Airport, US
Light: Daylight
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Airspace: Class B ZZZ3
ATC / advisory: Ground ZZZ3
Aircraft component: Cowling/Nacelle Fasteners; Latches
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Human factors: Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural MEL / CDL; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: Pre-flight
Result: Aircraft Aircraft Damaged; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: As we began our cockpit preparations and [the Relief Pilot] was performing the external pre-flight; the Agent informed us that the engineers/mechanics who were doing the ETOPS pre-flight inspection had found damage to the left engine. [The Communications Display] shortly indicated a delay until XA:00 local. I went down to see the damage for myself. I took several pictures and spoke to the engineers.The engine cowl consists of three clamshell doors which are hinged at the top. It is designed such that the aft clamshell doors close first and their leading edges are overlapped by the clamshell door in front of it. The forward clamshell doors closes last and again overlap the middle clamshell doors. The obvious damage was the aft edge of the outboard middle clamshell door was overlapped by the leading edge of the outboard aft clamshell door in the lower outboard portion; 7 o'clock or so when viewed from the rear; by about 12-18 in. when it should have been behind. The leading edge of the aft clamshell door was deformed where the overlap originated. Additionally; the cowling had a gap the entire circumference instead of fitting snuggly together.Also quite apparent; was a dent toward the rear of the aft cowling. It also appeared there was dent behind the area where the cowl overlap occurred. This dent and the dent at the rear were space such that it could have been dented from a belt loader impact.The engineers were experiencing difficulty opening the cowlings. They attempted to use the electric pump in the forward cowl to no avail. They finally opened the forward cowl using a hydraulic hand pump and a little pull. The middle cowl seemed hung up as well; but another little pull freed it. Both the left middle and aft clamshells were stuck together until the aft clamshell was jiggled and freed from the middle cowl. At this point I took additional pictures.Once the cowls were open; the dent which had been behind the overlap was almost invisible and may have just been a deformation caused by the overlap itself and not a belt loader but I am unsure. The Captain had spoken to [Maintenance Control]. He said they ordered a pylon inspection. The Engineer was making observations using a flashlight and mirror in preparation for that order.We were notified in [the Communications Display] that we were further delayed until XE:00. We were eventually canceled. After the cancellation; [the Communications Display] showed ferry flight ZZZ-ZZZ3. Sometime in the mid-afternoon; we were changed to fly ferry flight from ZZZ-ZZZ1; limo to ZZZ2; then DHD (Deadhead) ZZZ2-ZZZ3.When I woke up at XS:30 local on the [next day]; there was a silent notification under the door that we were canceled. Checking [the Communications Display] showed we were to be delayed a second day and fly [another] flight on the [following day].About XT:30; Captain called and asked if I had seen the schedule change. I mentioned I had seen the addition day delay. He asked if I was going to breakfast and I said yes. He said he would explain there. At breakfast; he explained that Crew Tracking had called to tell him another 767 had a mechanical problem and we would be delayed another day. He asked CT (Crew Tracking) why we were delayed another day; for a total of 2 days; and not assigned [the] flight on the [next day] with the other crew not delayed at all. CT changed it so we were operating [the] flight on the [next day].[The Communications Display] showed our aircraft as the one with the damaged engine. When we showed up; the engineers said there was an engineering authorization which allowed the aircraft to be operated 2 legs. The Captain noted the engineering authorization was in the paperwork. The [Relief Pilot] noted the cowl had been worked on and the damage could barely be seen.On landing in ZZZ3; the Captain was unable to get the left reverser to stow. We had a LEFT REV ISLN VLV light; caution message; and status message. On post flight inspection; the condition found on the [previous day] had reoccurred. Additionally; the right-side reverser of the left engine was stuck in the deployed position. Fortunately; that [was] the only difficulty we encountered. Had we needed to divert for any reason; we would have been stuck. The fact that the overlap occurred toward the bottom of the engine made me wonder if the engine was properly attached or somehow broken such that it could flex to allow this overlap to occur. This concerned me for my own safety and that of the rest of the crew and passengers.




Synopsis: B767 First Officer reported aircraft damage to engine cowls including thrust reverser resulting in flight cancellation and subsequent ferry flight and the thrust reverser on the damaged engine failing to stow during landing.