Date: 201508
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: Cloudy
Light: Night
Aircraft: EMB ERJ 170/175 ER/LR
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Human-Machine Interface; Distraction
Second reporter function: Pilot Not Flying; Captain
Anomaly: ATC Issue All Types; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural FAR
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented; Flight Crew FLC Overrode Automation; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Procedure; Weather; Airspace Structure
Primary problem: Weather

Narrative: Was on climb out of ZZZ with an ATC instruction to keep visual separation with [carrier] flight; also on departure; in front of us about 3 miles. We were climbing on the RNAV departure at about 5;500 with clearance to 9;000 feet. Our configuration was LNAV; VNAV/FLCH. Clouds were scattered about 6;000 feet. The [carrier] flight in front went in to IMC; therefore us losing visual separation. The captain; pilot monitoring; made a call to ATC saying we had visual with the other aircraft. ATC then says 'then level off your altitude' with no call sign or flight number. At the time I was hand flying; so I simply pushed the nose over to level off and stay VMC. Since we were still configured in FLCH/VNAV; the aircraft continued to accelerate to about 280 KIAS; therefore breaking the 250 KIAS below 10;000 feet. I caught it quickly and reduced power; slowing back down to 250 knots and staying level in VMC. Shortly after we were given a clearance to climb to 7;000. The autopilot was then engaged; and continued to 7;000 with no further deviations. If we hadn't been left with a visual separation clearance for so long; this would have never happened. With the auto throttles engage and in FLCH climb mode; I realize the throttles will maintain takeoff thrust; they were overridden to fix the problem; but could have been caught a few seconds earlier. In the future; I will keep a better eye on the airspeed in other unusual circumstances like this one.


Second narrative: Taking off from ZZZ we were asked to maintain visual separation with the aircraft in front of us. We told them we could and took off runway with the preceding aircraft in sight. I checked in with departure and we were again told to maintain visual and climb to 9000. Shortly after that we lost sight of them when they went into the clouds. We were at 5000 and they were around 1000 above us and less than 3 miles out according to the TCAS. I told the controller we lost them in the clouds and his muttered response was 'level off your altitude'. No call sign; no specific altitude to maintain; or any other instructions. I didn't even catch what he said I had to ask the FO if he heard it. By this time the FO already had the nose on the horizon trying to keep us from entering the clouds. I was still looking outside trying to regain a visual when the FO said something about our speed. I looked down to see us doing about 280kts around 6000 ft. He quickly corrected the situation and shortly after that the controller turned us the departure away from the traffic. We continued to [our destination] without further incident.


Synopsis: An ERJ flight crew reported that; due to cloud conditions; they were unable to maintain visual reference from preceding traffic. After advising ATC of the situation they were told to level off immediately; resulting in a momentary speed excursion to 280 knots below 10;000 feet. A correction was accomplished and the flight continued uneventfully.