Date: 201710
Local time of day: 0601-1200
Location: EIDW.Airport, FO
Flight conditions: IMC
Weather elements / visibility: Haze / Smoke
Light: Daylight
Aircraft: B757 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
ATC / advisory: Center EISN
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Human factors: Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Attendant; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Aircraft Equipment Problem Dissipated; Flight Crew Overcame Equipment Problem
Contributing factors: Environment - Non Weather Related; Weather
Primary problem: Environment - Non Weather Related

Narrative: During climbout after we got the gear up and had made our first turn on the departure procedure. We all smelled smoke. We contacted the Flight Attendants and they too smelled it throughout the cabin. We immediately pulled out the QRH to run the smoke checklist. We completed all the steps in the checklist; which includes the statement to land as soon as practical. We contacted ATC and told them we needed to stop climb and return to the airfield due to a maintenance issue. They gave us delay vectors and cleared us to level off at FL090 while finished up the checklist. By the time we were done with the checklist; we no longer smelled the smoke neither did the flight attendants in the cabin. We decided it would still be pertinent to return and get it checked out. So we started asking for vectors for an approach to RWY 10. At that time; the controller asked us what our maintenance issue was and we told him it was the smell of smoke during climb out. At that point; he informed that we were at least the 3rd aircraft that had reported smoke in the cockpit and cabin during climbout.The clew and I discussed the possibility the smoke we smelled was environmental in nature and decided to turn back on everything that we had turned off to determine if the smoke was coming from inside the aircraft or outside. After all the systems that we selected off were turned back on; we all agreed that we no longer smelled the smoke. We then [contacted] dispatch and filled them in on our situation and what ATC had told us we felt confident that the smell we smelled was environmental in nature and posed no risk to the airplane or passengers. The dispatcher agreed with our assessment and we all decided to continue the flight as we had enough fuel on board to make it to our destination. One unintended consequence of running the smoke checklist was the overboard equipment exhaust valve opened and locked in the open position when we turned the L recirculation fan off as part of the checklist. This remained open for the remainder of the flight and initially caused us to fly at a lower altitude until we could get confirmation from maintenance control and the FODM (Flight Operations Documentation Manager) that we could fly higher.


Second narrative: [Report narrative contained no additional information.]


Synopsis: B757 flight crew reported that they smelled smoke in the aircraft; which dissipated after a while.