If you're out in the sticks with no one around you can always ask ATC for "high speed" below 10k, the 747s always ask for it (and they usually get it) because full manoeuvring margin is only available at or above Vref+100, which can be above 250kts for a heavily loaded 747.

 

This rarely if ever happens, the atc wont let you break the rules just because you don't want to fly with your flaps down for a few minutes.

Also Howard,

Enter your airports in "Top Routes" on the link below and use the routes and look at the ALT, but like above always look what the FMS ALT gives as the best. If you use a flight with a FL320 and your FMC says FL280, when using FSX ATC just ask for a different ALT you have to ask for decent by XXXXXft.

http://www.vataware.com/index.cfm

 

BTW old friend I thought you might have seen my post you know where?

Also Howard,

Enter your airports in "Top Routes" on the link below and use the routes and look at the ALT, but like above always look what the FMS ALT gives as the best. If you use a flight with a FL320 and your FMC says FL280, when using FSX ATC just ask for a different ALT you have to ask for decent by XXXXXft.

http://www.vataware.com/index.cfm

 

BTW old friend I thought you might have seen my post you know where?

 

Hi Dave, good to hear from you, thanks for the info. erm BTW old friend I thought you might have seen my post you know where? ??

From the charter work I do, i use the general rule of thumb. Take the distance and add 2 zeros up to a few thousand below your service ceiling. ex 250NM trip = FL250. If you go above this you are usually climbing to your cruise altitude then almost immediately descending for your intended approach(IFR).

 

 

This rarely if ever happens, the atc wont let you break the rules just because you don't want to fly with your flaps down for a few minutes.

 

Dude in canada this happens all the time, its not breaking the rules but more an exception. The other thing is Air Canada almost always flys 250-300knots below 10,000ft and tells Center that they are holding 250(buddy is a 25 year veteran ATC at YWG ACC).

I think the OP might be asking if there is an algorithm for a jet airliner that could be applied, with flight distance being the input variable and cruise altitude being the output, that would allow for:

- Climb with VNAV (assumed optimum rate of climb/ airspeed) to cruise alt

- Cruise for a minimum of 30 minutes

-Descent with VNAV (optimum descent rate to HAA of 2,000 feet

- Slow to VRef + 20

-Cross FAF, 2,000' HAA

 

There will be a critical number for "distance" that above which "altitude" will be capped at service ceiling, and (as othes have posted here) wind, weight and cost index might dictate the desired altitude. Below the critical number of "distance", service ceiling is not attainable in the distance, and regardless of all other factors, max altitude is governed primarily by distance.

 

Of course, the equation above would change radically for different categories of aircraft, although I would think that most pax jets could be separated into "light" or " heavy" and should be similar within their respective categories. What I might suggest is several flights of less than 1 hour duration and note the recommended altitude in the Perf Init screen, and make up a table.

 

Thanks, Bruce.

 

 

From the charter work I do, i use the general rule of thumb. Take the distance and add 2 zeros up to a few thousand below your service ceiling. ex 250NM trip = FL250.

 

That's what I wanted! Thanks, a godd tip...

I think the OP might be asking if there is an algorithm for a jet airliner that could be applied, with flight distance being the input variable and cruise altitude being the output, that would allow for:

- Climb with VNAV (assumed optimum rate of climb/ airspeed) to cruise alt

- Cruise for a minimum of 30 minutes

-Descent with VNAV (optimum descent rate to HAA of 2,000 feet

- Slow to VRef + 20

-Cross FAF, 2,000' HAA

 

There will be a critical number for "distance" that above which "altitude" will be capped at service ceiling, and (as othes have posted here) wind, weight and cost index might dictate the desired altitude. Below the critical number of "distance", service ceiling is not attainable in the distance, and regardless of all other factors, max altitude is governed primarily by distance.

 

Of course, the equation above would change radically for different categories of aircraft, although I would think that most pax jets could be separated into "light" or " heavy" and should be similar within their respective categories. What I might suggest is several flights of less than 1 hour duration and note the recommended altitude in the Perf Init screen, and make up a table.

 

Thanks, Bruce.

 

Cheers Bruce, yes, I was after some kind of formula, but what has been suggested above is a good guideline, thanks...

+1 to sgtscarfy

Anything less than 300 miles use the distance for the altitude, eg.

For 80nm use 8000ft (if westbound, I would use 9000ft for eastbound) and so on...

Dan