Date: 201708
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Dawn
Aircraft: A320
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Communication Breakdown
Second reporter function: Dispatcher
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Dispatch
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Procedure; Logbook Entry; Company Policy; Human Factors
Primary problem: Human Factors

Narrative: It was a normal morning. Inspected the cockpit and log book and found nothing out of the ordinary. I did the walk around and everything was in its place. The logbook had a sign off from the night before of a periodic inspection and the aircraft was signed back into service. So we boarded up and took off. When we were a little over an hour into the flight we got contacted by dispatch saying we were on maintenance and we were not supposed to leave. The dispatcher said he had 'blown out' our performance data so it wouldn't come up for Takeoff. Yet I ran the data 8 min prior to departure and it came back fine. We were not informed by dispatch; maintenance; [Operations]; the station; or anyone else of any delay. The red 'Do not operate' tag was not on the thrust levers and no entry was in the logbook indicating any maintenance was necessary. There was literally no way we as a crew could know anything was going on until after dispatch contacted us. At which point we continued on to [the destination] with no issues. Someone from the company or station needs to be aware of the mx event and inform the crew. The red out of service tag should be used and an entry made in the logbook of a maintenance event that is currently happening. That way a crew showing up knows there is maintenance.


Second narrative: Aircraft had a 'service must' bar on the plot and no [airworthiness alert]. Originally the aircraft was listed out of service until about XAz. When I asked [maintenance] about the aircrafts readiness; I was told aircraft should be good to make the departure time. As stations sometimes are very delayed in getting paperwork to [maintenance] to clear the [airworthiness alert]; we usually just ask if we had heard from the station in question. At that time [maintenance] either reviews emails or a phone call is made to the station if the aircraft would be good; at which point it is conveyed to dispatch and paperwork sent to avoid late dispatch release and delays. Dispatch release was prepared and sent at XB:30z with a release time of XC:45z based off that information. At around XC:25z [maintenance] informed [operations] and myself aircraft was AOG (Aircraft on Ground) for parts and the flight would need to be delayed until XE:30z. Per our policies; I immediately hit the button to prevent the crew from the ability to get an aerodata solution. I moved my flight down on the plot and even typed a remark for a [release] stating ' 1 NEW RELEASE TIME XE:30 AND INCREASED CI... XXXXZ CK' awaiting an actual time for a return to service. At XCz; after the [operations] pass down; the flight was then delayed an additional hour. At which time; I moved the flight down on my monitor again and adjusted my comment to show release time of XF:30z. At XD:00z [operations] sent an email to the station about the out of service aircraft and at XD:37 the station manager responded that the aircraft had already departed. At that time; there were no times on the plot and the flight was delayed until XF:30z. [Operations] asked if the flight was airborne and I called [the departure airport's] tower to confirm. Even though I reluctantly tried to tell the controller the aircraft was out of service with an engine issue; he said the flight departed more than 30 minutes prior. Checking on Flight Explorer; the flight was now showing [enroute]. I called ARINC to setup a phone patch and sent an ACARS XD:49z to confirm airborne status and XD:52z that it was imperative to contact dispatch. I inspected the ACARS log and found OUT and OFF times for the flight of XC:38z and XC:45z respectively. These times were entered on the plot shortly after. A phone patch was established and being more than half way; the decision was made to continue on to [the original destination]. During the conversation with the crew; they stated there was nothing in the log book or on the copy of the release they had showing that there was a reason not to depart. After talking to [maintenance]; this [maintenance action] did actually have 8 hours remaining on it. The decision was then made to complete the round trip and to perform the required actions upon return. Fortunately; there was no actual regulation violation as the [maintenance action] still had time remaining to do this round trip. However; there definitely were quite a few company policy violations on multiple fronts. The aircraft was listed out of service and although I was told by [maintenance] aircraft should be ready; release should have been held. After the fact; the takeoff data was run at XC:12z and again at XC:36z; so locking it out around that time would have had no effect seeing as how they already had the numbers in the box.After [maintenance] advised of the AOG status; dispatch should have not only hit the [disable] button; preventing the crew from getting takeoff data; but should have also called either [the departure airport] tower or Clearance Delivery to remove the strip. Although in this situation; the flight may have unknowingly actually been airborne at that point after reviewing the timeline of event due to the ACARS system not recording OUT or OFF times. Conferring with [maintenance]; there should have been some sort of placard on the throttles that should show the aircraft out of service. Afterthe aircraft landed; I spoke with [the Captain] about the situation. He says there were no placards stating that the aircraft was out of service on the aircraft; he had a signed off log book all the way back to a heavy check 3 days prior; and the station boarded for an on time departure. So he basically had no idea that the flight was delayed for any reason. While I don't know a whole lot about maintenance procedures on how an aircraft or when an aircraft is marked out of service; a greater thoroughness of making sure the correct placards are placed on aircraft when the aircraft is out of service may have at least caused a phone call to dispatch and prevented this situation. The station boarded the flight as though there were no delay although an almost 3 hour delay was published to the plot.During my conversation with the captain; he stated that in flight a few passengers had asked the flight attendants about a delay to the flight that was showing on Flightaware. They didn't really think anything of it until my communications started.A better communication between [operations] and stations on delayed flights. For this solution to work however; improvements need to be made on both sides. Our communication to the station of the delay posted on the plot should be enough; but a backup phone call would be welcomed. However; contacting stations via phone sometimes is difficult if not impossible. [Stations at large airports] are almost nearly impossible to contact via phone for any reason. Possibility of having a station contact this is actually present at the station; that would carry a duty cell phone on them at all times; that HAS to be answered would greatly improve communications


Synopsis: A320 Captain and the associated Dispatcher reported that the aircraft was flown on schedule with passengers when it was listed as out of service.