B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 172; Flight Crew Type 6000
Time Pressure; Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Weight And Balance
Flight Crew FLC Overrode Automation
Human Factors
MEL for the performance computer. Received wrong numbers from Dispatch. Requested numbers via ACARS from Dispatch. Sent ZFW of 107XXX and TOW of 134XXX via ACARS from the loadsheet.  Received: Tail: XXX; CITY: PHX; RWY:25R; WIND: 240XX; GUST: 00; TEMP:35QNH: 29.92 WINSHEAR: NO; POWER: RED; GEAR: UP RWYCOND: DRY; FLAPS: OPT; BLEEDS: ON; AT: TOW: 107064Computed Results: Inputs Assumed Temp 59CFlaps - 1; V1 - 119; VR - 119; V2 - 123; V Flap Select 168. MAX POWER: 95.2 REDUCED POWER: 88.1 STOPPING MARGIN 5214 FTLEVEL OFF HEIGHT 2135 STAB TRIM SETTING 6.4The numbers seemed low to both of us but we failed to double check the numbers with Dispatch. TOFF acceleration was slower than usual. The FO delayed rotation a few knots and the aircraft was sluggish at rotate. I advanced power to max power at 500 FT and deleted the reduction. I believe we missed the incorrect TOW partially due to the format on ACARS being different than what we are normally used to looking at on the performance computer. We both thought the numbers looked low and we should have re-verified the numbers prior to takeoff with an additional request.
Arrived at aircraft late. Waited on the Flight Attendants who were also late. We were up against FAR 117 for block time for the day. With the original scheduled block time on the PHX to ZZZ leg; we would only be legal by 12 minutes. Once we boarded and received the loadsheet; I sent the ZFW 107xxx and the TOW 134xxx to Dispatch so they could calculate takeoff numbers. Within a couple minutes; I received the numbers as I was inputting the speeds and flap setting into the FMC. In the back of my head; I was thinking they seemed a little low and the assumed temperature seemed a little high; but we did only have 100 people onboard so we went ahead and did the checklist. We had a very short taxi to 25R in PHX and we were cleared for takeoff before we reached the runway. We were in a time crunch due to our 117 block limit so we accepted the takeoff clearance and I started my roll. After the initial thrust input; the acceleration seemed slow. I commented on this and we continued. As the captain called VR; I delayed the rotation because the aircraft seemed sluggish and felt like we didn't have enough speed. I probably rotated 10 to 15 knots past the 123 VR speed in the FMC. The aircraft was climbing slowly and felt sluggish so I told the Captain; 'I think the weight or our numbers are wrong.' At that point he said; 'I'm giving you full power.' We then continued our climb without further incident except we did retract the gear late due to the distraction of the sluggish rotation and initial climb.After takeoff we found that Dispatch had calculated our ZFW as our TOW and we didn't notice that prior to takeoff. The numbers he sent were 119; 119; and 123 for flaps 1 with an assumed temperature of 59 degrees. The numbers should have been 136; 136; and 139. The assumed temperature should have been 53. We should have caught this error! Due to that distraction of the performance computer being inop and being worried about 117 limits; we missed the error.Slowing down is the best way to prevent this. Also; when the numbers seemed off; we should have investigated before the push right then and there. Also; Dispatch may have been rushed as well due to the fact he read my ACARS message wrong. I sent the ACARS with the correct numbers.
Flight crew at PHX overlooked an error in their performance numbers which were calculated by Dispatch due to an inoperative performance computer. When the aircraft did not feel right on takeoff they responded with increased airspeed and full power.