Date: 201308
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: Regional Jet 200 ER/LR (CRJ200)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
Aircraft component: Powerplant Installation
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Commercial
Human factors: Communication Breakdown; Situational Awareness
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Maintenance
When detected: Routine Inspection
Result: Flight Crew Became Reoriented; General Maintenance Action
Contributing factors: Aircraft; Human Factors; Procedure
Primary problem: Human Factors

Narrative: Upon arriving on the first flight; I left the flight deck to enter the terminal between flights; the Captain went to the LAV in the aircraft; and the Flight Attendant stayed on board.  Upon returning to the aircraft from my walk around; the Captain had returned to the Flight Deck from his short trip to the LAV.  I saw the Logbook lying on my seat with the red 'MX IN PROGRESS' placard lying on the center pedestal.  I asked what was going on and the Captain informed me that this is the way he found the flight deck upon returning to his seat.  The Flight Attendant said a Mechanic boarded the aircraft and greeted the Flight Attendant with a 'Hello' or 'Good morning.'   The Logbook did not have any open write-up's and did not show that any action was being performed on the aircraft.  The Mechanic was no where to be seen.  The gate personnel were not told of any maintenance action being performed.  I decided to walk back outside the aircraft to do another walk around to see if the Mechanic was around the aircraft or if there was any sign of a maintenance action being performed on the aircraft.  I did not see a Mechanic or defects to the aircraft.  I also asked ramp personnel and was informed that no Mechanic had been seen while they were working with the bags.  I returned to the Flight Deck to consult with the Captain.  The Captain advised that he is going to message Maintenance through the maintenance function of the ACARS to check the maintenance status of the aircraft.  He did this in front of me and received a reply from Maintenance stating: 'I do not show you in maintenance at this time... Have a good flight.'  The Captain and I concluded that this was the proper source for our maintenance condition and decided that we were maintenance clear per Maintenance Control.  We departed on time.  At about the second waypoint off of the runway we received a message from Dispatch via ACARS saying: 'The Mechanic needs to come back out to your aircraft;' or something along those lines.  The Captain messaged Dispatch back saying 'I asked Maintenance about 20 minutes ago and they said we are clear and have a good flight.  We are airborne.'  Dispatch responded with 'Copy that; have a good flight.  Upon arriving; the gate informed us that our aircraft was being ferried back to base and we were waiting for a hot spare to arrive to continue the rest of our trip.  After a contract Mechanic showed up we were very interested to know what the issue was.  The Mechanic informed us that he was told there was a part of the thrust reverser missing.  I informed the Mechanic that I didn't think anything was missing as I had performed three walk around's on the aircraft so far today and all of the parts appeared to be in place.  The Mechanic did a walk around himself and agreed with me.  He called Maintenance Control to get specifics and was informed that the part missing was a fairing on top of the engine pylon on the #2 engine.  The Mechanic grabbed his ladder; placed it behind the #2 engine; and found the fairing to be missing.  I found that if I stood roughly 40' behind the aircraft's tail; I could see part of where there appears that there should be a fairing of some sort as the zinc chromate primer was slightly visible.  This part on top of the engine pylon is invisible from a walk around in normal operations.  It became apparent to me that this aircraft had not only been operated on two legs with us; but also another leg with a different crew the night before to position the aircraft for our day of flying.  The details from Maintenance Control after we landed were very vague as to possibly how long this aircraft flew with the fairing missing.  The relief crew and aircraft arrived and the rest of our trip continued. In my opinion; communication was the biggest error in this event.  The Mechanic boarded the aircraft and didn't tell a soul that was involved with the flight that there was any action being taken on the aircraft.  He left the Logbook and MEL log fully clean from defects showing that the aircraft was airworthy.  Maintenance Control was contacted asking about our maintenance condition and was informed that we were not in maintenance and to have a good flight.  We were informed after the fact by management that the Maintenance function of the ACARS sends the message to Maintenance Control and Dispatch and that possibly the reply we received was from Dispatch.  We were not aware of this.  The fact that nothing was communicated with anyone about a maintenance action allowed us to conclude that the aircraft was maintenance cleared and that the only logical conclusion was that the placard was accidentally left on the center pedestal.  There are a couple of things that we maybe could have done to stop this event from continuing to departure.  We both felt that the Maintenance function of the ACARS was the perfect source for contacting Maintenance about maintenance issues and maintenance status reports.  Now that we have run into the issue of the  reply through the maintenance function of the ACARS; maybe a phone call would have been connected with  someone that [had] more information.  I personally try to maintain vigilance while conducting walk around inspections on my aircraft and try my best not to become complacent about a very repetitive responsibility.  Although I still would not have seen the missing fairing without walking a good distance away from the tail of the aircraft; this sort of event helps me maintain that vigilance to do my best to  ensure each aircraft is airworthy and legal to fly.  I also personally respect the red maintenance placard as the mechanic can be involved in a serious maintenance function that could get themselves injured if certain systems are activated.  We spent a good amount of time respecting that by trying to gather information about the aircraft condition/status and from the ramp and gate personnel.  All of our sources concluded that we were maintenance clear.  There are a couple of things that maintenance could have done keep the flight crew in the loop with this issue.  It's obvious that Maintenance Control either knew about this issue or realized what is going on at some point before we landed [after the first leg].  Maintenance Control could have either notified our Dispatcher or sent us an ACARS message in flight notified us that our aircraft is going to go into maintenance upon landing.  They didn't even need to tell us why.  It's common for a mechanic to take the logbook with them; to show the flight crew that the aircraft is being worked on without having to tell the flight crew face to face.  If the logbook is not there; we cannot depart.  The mechanic could have also told the FA that we were in maintenance; they also could have told the gate to hold boarding or that the aircraft will be clear soon and to continue boarding as scheduled.  Knowing now that the MTC function of the ACARS reaches both Maintenance Control and Dispatch; it may help for the reply to include which part of the company the message is from.  If we would have known that the reply was from the dispatcher only; we would not have considered the maintenance status to be clear.  Although I do not feel that the flight crew is largely responsible for this event; I certainly learned some lessons as to maintaining vigilance and ensuring our aircraft is airworthy in the future.  It's a good lesson to continue to learn that this operation is run by humans and that it takes a team effort to keep things running as close to legal and safe as possible.




Synopsis: CRJ200 First Officer reports returning to his aircraft during and intermediate stop to find a 'Maintenance In Progress' placard laying on the center pedestal.  The Logbook is present with no write ups and no one can be found who knows anythisg about the placard.  The crew elects to depart and is informed airborne that the aircraft was to be taken out of service for a missing fairing.