Date: 201512
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Climb
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness; Distraction; Fatigue
Second reporter function: First Officer; Pilot Flying
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Regained Aircraft Control
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: On climb out; we received an 'Airspeed Low' alert twice. Initially; we thought we may have taken off without flaps (1) extended. However; what we deduced was that I (PM) retracted the flaps when the FO called for 'Gear Up'. There were several additive conditions that probably contributed to my fault. First was fatigue. This was the first flight of the day with a relatively early start time for a PM trip. The overnight was short. For me; the room temperature was very warm and uncontrollable (central heat) providing for less than optimal sleeping conditions. The prior night was even worse; the crew hotel was host to a very large youth event and the kids were running all over the hotel at all times of the day and night. Second; the radar would not test properly and required us to troubleshoot with Maintenance. Third; our departure runway was changed immediately after pushback. Nevertheless; I did not feel rushed; and we completed the information only write up and departure plan review in a timely fashion. The taxi out and takeoff roll were uneventful. I don't remember the FO calling for gear retraction; I don't remember moving the flap handle either. Up to the point of the 'Airspeed Low' alert; it was a very quiet; systematic and normal takeoff. With the annunciation of the 'Airspeed Low' alert; I immediately looked at our airspeed. Initially; I was confused why the low airspeed caution band was 'higher' than what I would have expected; but the speed was as expected for that phase of flight in those conditions; we were accelerating normally; the pitch of the aircraft was normal as expected; and the power was normal and as expected. The alert soon dissipated and we began to analyze what had happened.I realize (with hindsight) that we could have added power since it had been a reduced thrust takeoff. Nevertheless; the FO (PF) continued to fly the aircraft through the whole incident. We immediately noticed that the flaps were in the up position and initially thought we had taken off without flaps. This led me to question myself; 'how this could have happened'; given all the procedures we would have had to miss. I then noticed that the gear was still down and then reached over to retract the gear. I don't know if I moved the flap handle when the FO called for gear up. I don't know if the FO incorrectly called for flaps up and I blindly complied. In either case; I failed to be an effective PM. I would hope that this event has forever elevated my awareness of my duties as a PM; especially during critical phases of flight.


Second narrative: The flight was the first flight of the day; which was the third day of a three-day trip. The preceding two days were uneventful; and I felt that the Captain and I were communicating and working well together as a team. We had a relatively short overnight; which was compounded by a 50 minute delay; but I felt well rested and ready for the challenging day. The weather was clear; with light winds. The preflight briefings; before start originating and before pushback checklists were completed; based on a Runway 32L departure. During pushback; Ground advised that 32R was now the active runway. After pushback; we computed takeoff data for the new runway; and completed the departure briefing. Takeoff computations called for a flaps 1; reduced thrust takeoff. I would have preferred to complete departure brief after the before taxi checklist; but the Captain called for the briefing before we performed the after push flows. After the departure brief was completed; we ran through the after push flows and before taxi checklist. We taxied to Runway 32R; and completed the before takeoff checklist as we crossed the hold short line for Runway 32R. The takeoff roll was uneventful; as were rotation and initial climb. Once a positive rate of climb was established; I called 'Landing Gear Up.' Approximately 10 seconds after I called for landing gear up; I heard the annunciation 'Airspeed Low; Airspeed Low.' I glanced down at the Primary Flight Display (PFD); and noted that the airspeed was now about 10 knots below the Minimum Maneuver Speed (amber) bar. Initially; both the Captain and I were unsure as to why we were hearing the caution; and why we were now below minimum maneuvering speed. Rather than discuss it then; I lowered the nose and reduced my rate of climb until the airspeed was above flaps up speed. Initially; both the Captain and I suspected that we had inadvertently performed a flaps up takeoff; but I was certain we positioned the flaps properly (flaps 1); having recalled waiting for the flaps to position during the before taxi checklist. Also; we checked flap position twice during the previous checklist; and we never experienced a takeoff warning annunciation during the takeoff roll. After discussing it with the Captain; he admitted that 'I think I raised the flaps instead of the gear.' He also stated that when he looked up at the gear while we were accelerating; he noted it was still down; when he expected it to have already been raised. The remainder of the flight was uneventful.This seems to be a clear case of pilot error caused by inattention. We debriefed the event extensively; and for what it's worth; the Pilot Monitoring (Captain) was mortified at his actions. He could give no explanation as to why he raised the flaps instead of the landing gear handle. Obviously; had I been watching the actions of the Pilot Monitoring; I would have caught the error; but that would have been difficult at such a crucial phase of flight (rotation and establishment of a stable climb). I'm not sure what else could be done to prevent this event from happening again; other than paying closer attention to what he/she is doing.


Synopsis: After takeoff; B737 crew raised the flaps from flaps 1 to up prior to reaching the minimum cleanup altitude or attaining minimum maneuvering speed for flaps up. Crew received an 'Airspeed Low; Airspeed Low' aural alert and reacted by lowering the nose and quickly gaining sufficient airspeed.