Did anyone ever have the problem of VNAV not connecting when pushing it after takeoff?....the thing i can think of was I never inserted a ZFW because no matter what # i entered none worked?...any reson for this?ThanksChad Moore

Just a few quick starters: Did you use 245,000 for your ZFW, set your altitude on the MCP to your assigned flight level, program your FMC with routing info, waypoints etc., and engage your autopilot when above 400ft??Regards,jack

No, I didn't use the number 245,000 exactly...I tried though 400,000 300,000 and so on and the FMC kept saying invalid or something like that...Chad Moore

Chad, please revert to read the 767 FMC manual. You will get the answer to your question..Andreas HermesEDDH

I read the maual with the Zero Fuel Weight part...but still don't understand what you mean by my answer will be ther...how do I change the ZFW in the aircraft...it doens't have a fuel planne to change it...I saw that you could download oneChad Moore

The CDU entry of a ZFW does not actually change the weight of the aircraft, it only changes the results of calculations derived from the value entered (V speeds, max cruise alt, etc).Unless you have edited the load in the aircraft.cfg, the ZFW to input in the CDU is 245 (assuming pounds). If you are editing the load, make sure you don't allow the new ZFW+fuel combination to exceed MGTW.Also, if you haven't completed the rest of the entries on the performance page then VNAV won't engage because it won't be able to derive the neccessary data for required vertical navigation.I've also noticed that if the battery is dead then LNAV/VNAV/autopilot won't engage, but I don't think you're getting far enough through the preflight setup to make this particular problem manifest itself.Luck,P

I always enter 245.2... because it looks cool. ;)Also: make sure you enter a Cost Index. 90 works for me.Daryl ShuttleworthDS 3339

Hi Chad,Did you look into "ACLoader", a program by Scott Campbell ???It gives you realistic AC loading AND alters the zero fuel weight.Nice program !

Just out of curiosity, what IS the empty - not ZFW - of the sim aircraft? Its no problem to actually change the weight in the CFG file. But its hard to know what to load if you don't know where to start!Jonno.

If you have KG instead of LB units (Metric) then the ZFW is 111.1 Metric Tonnes. (ie 111100kg) thus there are two different default possibilities (if you havn't edited the .air file to change it's weight)those being 245 and 111.1 (or just 111)