Date: 201502
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Weather elements / visibility: Windshear; Icing
Light: Night
Aircraft: Dash 8-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Parked
ATC / advisory: Ramp ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Time Pressure; Confusion; Distraction; Fatigue; Workload
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Maintenance Action
Contributing factors: Company Policy; Weather; Procedure; Human Factors
Primary problem: Procedure

Narrative: It's been brought to my attention that as the first officer of a crew we operated an aircraft with the cowl plug in place or lodged in the air intake. The cowl plug was discovered after we wrote up the aircraft for a large torque split and abnormal engine indications in flight. There are many holes in the Swiss cheese as they say that aligned to make this happen including; fatigue; weather; time pressure; operational hazards/considerations and poor dispatch/scheduling coordination all of which will be discussed.My day started at late evening. Our flight was delayed to three hours waiting for an inbound aircraft. Upon meeting the aircraft the previous crew had written up the crew O2; passenger placard; and right side nav light. This further delayed our night to another hour. The flight was not entirely uneventful. Prior to our descent the captain got the weather and while there was a high overcast layer the ground visibility was right at the minimums for the approach and the captain being high mins. To add; light snow and 30+ kts winds on the surface created a ground blizzard of sorts. The captain elected to contact dispatch to discuss the situation and weather with them. Our conversation with dispatch had to be relayed by another crew because dispatch could not hear us. The captain and dispatch concurred that we were still able to shoot the approach. On approach we were able to see the airport and approach lights quite far out and continued our descent to landing well after midnight.After deplaning and closing up the aircraft; we waited for a taxi to pick us up since the hotel shuttle was not operating at that time of night. During this time the captain was talking with scheduling to figure out how our late arrival would affect our morning. Our concern was we were infringing on our 3 hours of scheduled rest and that we were going to revert to a continuous duty overnight and table B making the morning flight very tight to get back to our base. The first two calls to scheduling were met by reassurance that there would be no effect because travel time was part of the 3 hours of rest. The captain and I did not agree and had referenced FAR Part 117.15(b). Scheduling refused to look up the regulation and discuss further. The third scheduler agreed to look up the regulation and then realized we would be infringing on our 3 hours of rest. He said to call when we got to the hotel and he would adjust our rest; delay the morning flight and we would still be afforded the 14 hour duty day. We got to the hotel at well after midnight and called scheduling. They said they moved our rest time. The captain and I agreed but both felt something was not quite right. Once in my hotel room and reread the 117 rules and realized our new plan didn't comply with 117.15(a). I spoke with the captain and he called scheduling again and it was decided that we would be on continuous duty and our duty would revert to table B making us only legal to sometime before mid-morning. I felt if I slept I would be much more tired feeling then if I stayed up or just took a short nap. I decided to watch a TV show and did doze off for about 25 minutes. Upon reaching the airport the captain got his morning brief and dispatch didn't seem concerned about our tight time getting to our destination. Upon questioning; dispatch knew nothing about our situation and thought we were still good for an additional about 4 hours. After a conversation with scheduling the captain was told we need to accept an extension or the flight would be canceled. The captain and [I] did not agree with this because there were not unforeseen circumstances at that point. While some of the things the previous night may not have been foreseen; as we currently were with no delays there was nothing unforeseen. We said if something came up we would consider an extension but at that moment we would not accept one. They agreed to let the flight go as scheduled.I did my normal first flight of the day walk around. However I did my walk around at a brisk pace with temperature near zero degrees and winds still gusting; wind chills would be well below zero. During my preflight I did not notice the cowl plugs in either cowl. The cowl bag hung in the cargo compartment although I did not look inside the bag to see if the plugs were in it. The only abnormal area I noted was the crew O2 was back down to 1200 PSI after just being filled the night prior.During startup; while deicing and while running checklist prior to takeoff I noticed no anomalies in the engine indications. The first indication that something wasn't right occurred during the takeoff roll when the captain said set power. With the power levers relatively close together the right side was producing 100% torque and the left was around 80%. I advanced the left power lever to match the torque on the right. At about 500 feet I looked down and again the torque was at 80% with the right engine producing 96%. The captain pushed the power lever forward to bring the torques closer together. At this time we noticed the NH and NL were near 100%; the ITT was high; and the fuel flow was about 200lbs per hour greater than the right. We elected to operate the engine in the 80% to 90% range to keep the other engine parameters in normal limits and continue to destination. During this decision making process we did look at recent trends and noted that the left engine had higher NL; NH; Fuel Flow and ITT in recent days. The rest of the flight and ground operation were uneventful. I did not do a post flight walk around as the next crew had already come out to the plane. As the first officer it is my job to make sure the exterior of the aircraft is in an adequate condition to perform a safe flight; and while we safely landed I failed to do that. It is my normal routine to look in both cowls on every preflight and I believe I did that on this flight.I have been told the cowl plugs are black; this would make them difficult to see whether they were in place or lying down in the air intake. The cowl plugs should be a bright color as to easily be seen. I have seen the cowl plugs used maybe twice before. Because they are not something we frequently use during the winter; a cowl plug lying down out of direct line of sight would be easily over looked. I am also not sure why one cowl plug would be used or if both were used why both weren't put away. Arbitrary use of cowl plugs is also an issue. It should be during winter months at our stations cowl plugs are put in on every RON aircraft. This way there is an expectation of them to be there. Do to the weather and our wheels up time we were in a rush to be the first to the deice pad; as the day prior we spent about 40 minutes on the ground waiting to be deiced. Had this occurred again we would have not made our wheels up time. Lastly the issues with scheduling and dispatch not communicating and not knowing the standup rules cause a great deal of extra stress that shouldn't have been put on us. We were spending rest time and time prior to boarding looking up stand up and extension regulations to make sure things were done correctly.




Synopsis: Following a continuous duty overnight; a DHC-8 First Officer failed to see a left engine cowl plug in place during his walkaround in very cold weather. The fatigued crew operated the flight after the plug was ingested noting only lower torque and higher fuel flow.