I have been flying the captioned aircraft for a couple of weeks. I find the VNav somewhat sensitive compared to the Level D 767. I usually lose it several times during a flight. Can get it back with some changes in the FMC routing legs but I dont seem to have near as many disconnects in the 767. Any comments? Thanks.Frank

Do you have the 800/900? Also, would be helpful to list a couple of routes your having issues with for us to take a look at.

>I have been flying the captioned aircraft for a couple of>weeks. I find the VNav somewhat sensitive compared to the>Level D 767. I usually lose it several times during a flight.>Can get it back with some changes in the FMC routing legs but>I dont seem to have near as many disconnects in the 767. Any>comments? Thanks.>>Frank Hello Frank, Could be many things but most likely are - Unrealistic restrictions on F/P (i.e. 250/10000 3 miles from the departure and many more like this) Overspeed on descent (Must use the S/:( Touching the controls with in A/P command You might also notice that VNAV in CLIMB has less issues whereas on descent, one has to be one step ahead of the aircraft at all times. This means that you must engage not just monitor the AFDS otherwise some things can get excessive (i.e. speed). Placing restrictions that directly relate to the performance limitations are also a culprit so it's good to know what your aircraft can do before inputting into the FMC. Best,Randy J. Smith

Thank you George and Randy. I suspect the problem might be overspeed as this seems to occur following T/D on decent. I learned right off that some crazy restrictions can do it. I guess there is no reason why 767 sould be any smoother in this regard than the 737. I do not have the 800 or 900 model.I love both aircraft and am having a ball trying to get a good handle on themThanks againFrank