Date: 201410
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight phase: Takeoff / Launch
ATC / advisory: Ground ZZZ
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Human factors: Time Pressure; Confusion
Second reporter function: Captain; Pilot Not Flying
Anomaly: Deviation / Discrepancy - Procedural Weight And Balance; 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: I was the pilot flying. The aircraft seemed sluggish/mis-trimmed during rotation. I smoothly achieved an appropriate takeoff attitude and we departed uneventfully. Later during the flight; the Captain and I reviewed all of the paperwork that we had received on the ground. We had two copies of takeoff data printed out. One was from the original final weights and one was from a revision to the final weights. Upon examination; we noticed that the updated takeoff data (second printout) had a lower erroneous gross weight. This resulted in using lower V speeds and trim settings than what should have been used. The Captain and I remember quickly scanning the second final weights data and noting the same flap setting but different trim requirement. Though we were expecting some configuration changes from the change in final weights; I went ahead and requested another take off data report just to double check this new printout. (This message; though shown as a sent request; never arrived). The pushback and taxi seemed extremely rushed. We were at the top of the alley. We were given clearance to push in front of and blocking two other aircraft who had pushed back before us but were now stuck behind us. I quickly went through the push/start sequence and set up for a single engine taxi as directed. Upon initial taxi out; we were already number one for the runway and told to get the updated atis and monitor tower. The Captain also said to start the remaining engine. We quickly went through the appropriate start procedure and checklists and received immediate takeoff clearance. Other than the takeoff; the rest of the flight was completed uneventfully.


Second narrative: The First Officer (flying pilot) reported a sluggish feel during rotation but; to his credit; smoothly rotated and departure continued without issue. When time permitted we reviewed our data for takeoff. We got our 'perf init' and executed it. We then sent for takeoff data from sabre. Just after that received 'invalid data' message and received another 'perf init' we executed those numbers and sent for a new takeoff data from sabre. We received the corrected data and used those for takeoff. In hindsight we realized that the second 'final weights' was the incorrect one which resulted in a lower power setting and slower v-speeds. Being new to sabre and its use of different flap settings and different v1 speeds and larger v1-vr splits it wasn't readily apparent of the error. We're still not sure how or why the second 'final weights' were the incorrect ones.


Synopsis: B737 flight crew receiving bad takeoff data during a rushed departure; resulting in low V speeds and an improper trim setting. The aircraft feels sluggish to the First Officer during rotation.