This has been bothering me for quite some time. It seems that regardless of the aircraft I fly, PSS A320,777,747. DF737, PIC767 or PMDG 737NG I get told by ATC to start down anywhere from 20 to 40 miles before my flightplans TOD. It doesn't seem to matter what flightplanner I use either. It's the same thing with FsBuild, FSNavigator or programming the FMC myself I still get told to start down 20 to 40 miles earlier than my TOD. I even tried a suggestion I read on the forum that I enter a waypoint 40 miles from the airport with 10,000 feet but still got told to desend early. So my choices are not to let VNAV handle my desent or take the chewing out for busting my altitude. Here lately I've just been taking the chewing out because I don't really see the point of going from 33,000 feet to 24,000 feet 160 miles from the airport. Am I doing something wrong in my flightplanning or is there something else I can try to remedy this? Bill Stevens from FSDO is starting to know me by name. :-lol William

he knows a lot of people :-)i have always used the formula (plane_alt - arrival_elevation)/210 to determine how many miles it will take to go from the plane_alt to the arrival elevation.in your case, let's assume the arrival elevation is 0. that would mean to start down 157 miles out.you don't have to descend at 1800fpm, 300fpm will suffice to keep the atc heads from nagging you.since each plane probably has a different criteria for fuel efficiency, they will do things differently. i have to take the general/average/basic approach.jdto make this sound like a feature :-) - i'm simulating the controllers planning and spacing planes at different altitudes for seperation :-)

Thanks for the reply JD.William

You can also choose the NOTAMS option for destination in the RC Controller Options screen. This should prevent being nagged during the approach phase when you are switched off of center. It prefaces controller commands with "If feasible . . .". I use it with smaller commuter aircraft when following actual approach plates with the altitudes specified while still using ATC vectoring. If I am doing an IAP approach, I always have NOTAMS enabled.The new 3.1 options in the local area however do give you altitude options in the final phase. See the pinned topic regarding the 3.1 beta features.

Ron,If you request an IAP, you don't need NOTAMS. RC controllers are great at assuming you know what you're doing, foolish that they are. ;-)

notams won't help you during the center phase of your flight. only arrival or departure

I did find a work around for this problem. It's probably cheating a little but it works. Just before I get to that point 20-40 miles before my flight plan TOD I just tell ATC that I need to deviate for turbulence. They tell me to do what I have to do and then as soon as I get to my flight plan TOD I begin my descent with my FMC and let ATC know I'm clear of the turbulence. The rest of the ATC altitude calls seem to follow my flight plan to the letter so I have no further trouble being at the right altitude at the right time.William

William,Remember in the real world ATC doesn't necessarily follow your plan. They try to accommodate you as best they can, but theirs is the last decision. If they want you to descend at a certain point, then they expect you to do that, not when your plan says so. Failure to do so will invariably get you a visit from FSDO. They habe the big picture.That's just something to think about. ;-)

Your right Scott, however as JD stated he used an average calculation to begin descent. My flightplans are aircraft specific and give the best performance and fuel usage for the flight. In real world ATC I wouldn't question the controllers call to descend early as there would be a reason other than a calculated average for aircraft descent. :DWilliam

Hello Scott,Your point is well taken, but, it always ONE way - an early descent. Why not at some point in the future consider an option for "allow late descents" and put the pressure on us to meet the call and not bust any ear drums? Even as some of the chatter goes (roughly) "I'm going to have to keep you up there for another 3 minutes, and then I'll need a good rate of descent ..."Just a thought for the future.Thanks.Joe LorencPhiladelphia/Charlotte Hub Manager, Carolina Operations, VN7 Networkhttp://www.vn7network.com/

Along these lines of thought...Why not another option in the controller screen to allow us to fill in our prefered rate of descent? If not filled in, you could default to the existing formula. If filled in, you could have fun by adding or substracting a small percentage to it when you do the calculation. Nothing like a 'late' descent surprise to keep us on our toes or maybe scrambling for the speed brakes...And while I'm throwing out ideas...How about altitude holds at departure? As in, 'We're gonna hold you at 7000 for the next ten miles or so.' My scanner picks a lot of that out of CYYZ at heavy times when 23 or 24 is active and every flight wants to go east.After the transition to FL230 the most common question from the pilots is 'Got any ride reports?' (I'd love to see that implemented ;-) )-david-

>i have always used the formula (plane_alt ->arrival_elevation)/210 to determine how many miles it will>take to go from the plane_alt to the arrival elevation.>>in your case, let's assume the arrival elevation is 0. that>would mean to start down 157 miles out.>>you don't have to descend at 1800fpm, 300fpm will suffice to>keep the atc heads from nagging you.>>since each plane probably has a different criteria for fuel>efficiency, they will do things differently. i have to take>the general/average/basic approach.Hi jd,In real life the normal calculation for TOD is required altitude loss/1000 multiplied by three = distance in Nm.EG. CRZ ALT=39000feet, Land ALT=1000feet 38 x 3 = 114nmIn other words the descent point is 114nm (track miles) in still air.To work out required rated of descent, groundspeed multiplied by five will give you a three degree slope eg 450x5=2250 fpm.A lot of greek airfields tend on average to make you high (Very High) on the approach as they leave the descent late so a nice option would be to be able to request an orbit in present position, Germans tend to get you low sooner as RC does now. Many airfields give you crossing clearances at specific waypoints and leave the descent up to the individual ( eg inbound to CFU/LGKR entry point TIGRA Expect "TIGRA at FL240")I hope this input helps!

if you request an iap approach you can satisfy all those possibilities. that's it's main purpose, to let you flight specific approaches the way they are diagrammed on the platesjd