Date: 201911
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Fatigue; Communication Breakdown; Distraction
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: General None Reported / Taken
Contributing factors: Human Factors; Procedure
Primary problem: Human Factors

Narrative: We were vectored onto a visual approach for XXC at ZZZ. ATC asked us to maintain 210 kts. as long as practical. In order to maintain 210 kts. I asked for flaps 5. My plan was to maintain 210 kts. until two miles outside the final approach fix ZZZZZ. At that point I planned to start to fully configure the aircraft for final approach and landing. Upon reaching two miles outside of the final approach fix ZZZZZ I asked the Captain; who was Pilot Monitoring; for gear down and flaps 15. As the flaps were moving to 15; I looked at the airspeed indicator and realized that we were not below the Flap 15 airspeed limitation of 200 kts. I was about to ask for the flaps to be retracted to flaps 10 so as not to have a flaps 15 over speed but by that point the aircraft quickly started to decelerate to below 200 kts. and I decided against asking for flaps to be retracted to flaps 10. After that we configured the aircraft as we normally would for final approach and landing. Other than the flaps 15 over speed the approach and landing were normal.I believe this event was caused by three factors. Expectation bias on my part and the Pilot monitoring part; failure to monitor airspeed by the Pilot Monitoring; and fatigue. Normally ZZZ Approach asks us to maintain 170 or 180 kts. till the final approach fix. I would have normally configured the aircraft with flaps 10 in order to maintain 170 or 180 kts. till two miles outside the final approach then I would automatically ask for gear down and flaps 15 to start the final configuration of the aircraft for landing. 170 to 180 kts. is below the flaps 15 airspeed limitation. In this case Approach Control asked for 210 kts. as long as practical. As I said previously my plan was to start the slowing and final configuration of the aircraft for landing two miles outside the final approach fix ZZZZZ. Having numerous/countless times being at 170 to 180 kts. approaching two miles outside the final approach fix I 'automatically' started to configure the aircraft for final approach and landing by asking for gear down and flaps 15. If I was at 170 to 180 kts. asking for flaps 15 that would not have caused a flaps 15 over speed but in this case since I was at 210 kts. when I asked 'automatically' for gear down and flaps 15. The Pilot Monitoring apparently did not verify that we were below 200 kts. when I asked for flaps 15 and went ahead and selected flaps 15. It could very well be the Pilot Monitoring had expectation bias as I did and expected us to be at 170 to 180 kts. when he selected flaps 15 after I asked for it. I also believe fatigue played a minor role in this event. We were finishing a three day trip. This was the third day and we had an early morning wake up; van and report time. We left the hotel at XA:10 local time for a XB:26 local report time. This was our third leg of the final day of a trip. We were both tired when we started this approach which affected thought processes and monitoring skills.As far as expectation bias is concerned. I should treat every approach as a unique set of circumstances and not fall back on doing things 'automatically' as I have on countless other approaches and which I did on this particular approach to my regret and consternation. As far as monitoring goes one must strive to constantly maintain vigilance and not act 'automatically' when verification of a limit; airspeed in this case; is involved. The fatigue portion is difficult to deal with. Both of us had adequate sleep the night before this flight but the operational demands of the airline require us to fly and rest at hours different from the normal hours we would keep while home.




Synopsis: B737 First Officer reported exceeding maximum speed for flap setting during initial approach.