B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 160
Communication Breakdown
Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Company Policy; Human Factors; Procedure
On flight from LAS; it felt like our takeoff V-speed was set low. Performance computer was MEL'd; so we were using ACARS to calculate our takeoff performance. The ATIS was calling for LLWS so we used max power; flaps 5 and a higher rotation speed. The Passenger load was light with a fuel load for a three and a half-hour flight. When we did the Before Push Checklist it was cumbersome to check the takeoff performance using the ACARS method. We tried to keep one FMC on the ACARS page and the other on the Takeoff Performance page. There are a lot of page changes on both FMC to complete the Before Push Checklist. I remember checking the weight and balance sheet against the Takeoff Performance page; but cannot remember checking the weight on the ACARS page. (It is easy to check the performance numbers on the performance computer because you are holding the computer and the numbers are in the correct order.) On takeoff; acceleration was good because of the max power takeoff. I felt the V1; VR; and V2 were low; but climb performance was good; again because of the max power takeoff.What would help in preventing this for occurring again is put the ACARS Takeoff Performance page in the same order as the Before Push Checklist and on a single page. That way you don't have page back and forth to find information to complete the checklist.
Unfortunately the output from the PERF module is not organized in any manner we are used to; and each item we use in the checklist is scattered throughout the pages of output. The information output by the PERF function should at least in some single page have the information we use in the order we use it so we can easily review and verify with the checklist. It can be an additional page to the several already in existence. Of course; each of us can; and should; independently go through each page and verify every item individually. It is difficult to do so but can be done.
Due to an inoperative performance computer; crew relied on ACARS takeoff performance data. Crew believed that the ACARS performance data generated incorrect V-speeds for takeoff. The crew was using max power because of LLWS at the airport. As a result; the takeoff was uneventful.