Trouble with VNAV

[Guest Dual767]

Hey Guys I'm having a little problem with VNAV. I plan my flights, load fuel, program FMC etc... When it comes to the time that I have to descend the T/D mark is way off. I am using the rule where you multiply by 3. Like tonight I flew FLL-JAX cruising at FL270. Now using the rule I would have to descend around the area of 81nm but on my FMC is shows descent to occur at 60nm from the airport. I have to go to the DES button on the FMC and hit des now manually. This has also happened on a couple other flights of mine. Now when I get to the end of my flight and around the area of the airport it has a pink circle around it, but I think this is just for a go around.Please help me,Daniel

[Guest ba747heavy]

Daniel,Trust the FMC :) It knows the performance of the plane, and kows when to initiate the descent.

[crvm 0]

Please read my replies to this exact issue here: http://forums.avsim.net/dcboard.php?az=sho...ing_type=search To help you understand this clearly...[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/betaimg.jpg