HiI have noticed many times that the FMC calculated takeoff speeds are not in accordance with actual conditions. First I suspected that perhaps the FMC calculates the speeds based on the ZFW instead of GW, but it seems this assumption is not true.Note: I have searched the forum already for this topic, and all I found relevant was this thread:http://forums.avsim.com/dcboard.php?az=sho...=7580&mode=fullHowever it did not provide an answer to the question at hand.Here is what I have right now in my FMC from the setup with full tanks (20 t) and a ZFW of 41.2 t: V1 = 118 Vr = 121 V2 = 130Whereas (for a GW of 61.2 t) the takeoff speeds for a 60 t configuration are: V1 = 129 Vr = 130 V2 = 135The speeds are in each case calculated for flaps 5, without any adjustments necessary due to optimal airport elevation, temperature and winds.The speeds calculated by the FMC are not related to the correct takeoff speeds for the ZFW either, as those would be significantly lower.(All speed values based on the Boeing 737-700 operations manual QRH PI.10.1.)Could someone explain how the FMC calculates these speeds? Even for a wet runway only the V1 speed would be significantly lower. Thanks in advance for any information, and please excuse me if this topic has already been asked: just trying to clarify the situation.Regards,Zoltan HegedusBudapest, Hungary

For 135,000lbs, in the Continenal tables for a -700 I get 126, 129, 136 (interpolating between 130,000 and 140,000), pretty close to Zoltan's numbers. These are for pressure altitude under 2000' and temperature under 85F, dry runway, no slope, no wind.Lee Hetherington (KBED)

I can confirm this. But for the meantime don

Hi Zoltan,The TO speeds and vref on the 700 are off. That issue is identified.cheersanthonyAnthony MertonPrecision Manuals Developmenthttp://www.precisionmanuals.com

Thanks alot for the replies. Great to hear it will be fixed, thanks for your support.Regards,Zoltan Hegedus