Date: 201809
Local time of day: 1201-1800
Location: LGA.Airport, US
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower LGA
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Human factors: Workload; Communication Breakdown; Distraction; Training / Qualification; Fatigue
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Became Reoriented
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: After nearly a 3 hour sit I was somewhat mentally fatigued. We had set up for a departure out of DCA but were asked if we could depart Runway 33. I had ran the numbers so we knew we could depart Runway 33 so we accepted it. I changed the V speeds; set Runway 33 as the departure runway on the flight plan page; and set flaps to 4. Since this was my first flaps 4 take off; I failed to set up a flaps 4 takeoff on the MCDU since I was unaware I had to do it. We were cleared to line up and wait for Runway 33 but when I pressed the Takeoff configure it stated 'no takeoff flaps' so we canceled our Takeoff clearance and the Captain set the MCDU for a flaps 4 departure. When it came time for the takeoff roll I advanced the thrust levers to where the auto throttles typically take over and called out TOGA. As we accelerated I realized that Takeoff didn't not come on the FMA and that the auto throttles did not further advance the throttles. Since we were on a short runway I briskly advanced the throttles to ensure we had adequate power for the takeoff but accidentally pushed one throttle past the toga detent which activated reserve thrust. We rotated and on the climb out the command bars went way up so I slowly pitched up towards them without fully meeting them since it seemed excessive. The Captain was concerned with the pitch angle so he told me to pitch it down which led to a rapid acceleration with reserve thrust engaged. I manipulated the throttles to the best of my abilities while attempting to follow the flight director for vertical and lateral guidance since we were on a RNAV departure. We were closing in on our limit of 4000ft so the captain told me to pitch down while the FD was still indicating a shallow climb so I lowered the nose; brought the throttles to idle but sped to approximately 263k. We did not bust any altitudes or aircraft limitations; but did exceed 250 below 10;000. I can confirm that my inexperience with flying without auto throttles; a flap 4 take off; and a breakdown in communication all contributed to this event. I was a little startled by the risk of not having full power on a short runway so I focused on getting off the ground; up to a safe altitude; and did not communicate the fact that we were on RSV (reserve) power and auto throttles were not engaged.




Synopsis: E175 First Officer reported that inexperience and a breakdown in communication with the Captain contributed to an overspeed below 10;000 feet.