hi all,just a quick question,once i reach the top of descent, the plane starts descending automatically as should be, but it never reduces speed, or i never hear the engine whirl back and N1 back to idle just before the descent, this causes me to use too much speed brake on descent, any reason why, am i doing something incorrect?

I do know that if you choose a SPD DES the throttles will go idle but this does not seem to be the case for a PTH DES, well it SHOULD go idle here too, in fact the FMC calculates a DES PTH for idle descent. In a SPD DES the aircraft pitches to keep the set DES SPD while not following the calculated DES PTH, in a PTH DES the aircraft will pitch to follow the PTH and you keep a desired SPD by use of the SPD BK or throttles. Maybe Anthony can key in here on PTH DES... [h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-8/196432/winglets_lg.jpg [h3] AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

Clayton, Randy, The path for PATH DES is derived from the cost index (not modelled yet). Note the ECON PATH DES on the page title. This means the flight path angle is the most economical path with regards to the cost index, thus the throttles won't necessarily get to idle during a PATH DES. Actually I think the higher CI (more expensive, but faster flight) the shallower path, but this must be checked from a more reliable source...lolHope it helps,

Hey Mats, get on ICQ buddy, I got something to show you hehehe![h4]Best Wishes,Randy J. Smithhttp://img.villagephotos.com/p/2003-8/196432/winglets_lg.jpg [h3] AMD XP 2200 |MUNCHKIN 512 DDR RAM |ECS[/b ][i] K7S5A MB[/i] |GF2 MX 32 MEG and still runs GOOD!|WIN XP PRO |MITSUBISHI DIAMOND PLUS 91 19"[/h3]

"....but this must be checked from a more reliable source...lol"Agreed :-)I believe that the thrust levers should always come back to the aft stop at TOD and will remain there until the first altitude/speed restriction. If you have selected a higher cost index, I believe the throttles still come back to the aft stop but the elevators just stick the nose down a bit more. The indicated N2 at the aft stop, however, does vary. See previous messages on Flight-, Approach- and Ground Idle ;-) Clayton... Watch out for winds. In the real world, you may have to enter wind data before you reach the expected TOD... This gives you a more accurate TOD and less chance of path deviation/necessity to use spoilers.Non-idle VNAV path is usually reserved for flight between two alt/speed restricted waypoints closer to the ground (well, at least it is on the bigger Boeings).Cheers.Ian.