Simviation Forums

is there a formula which determines what cruise altitude you would select when planning a flight ,relevant to your type of aircraft and trip distance?For example,what altitude would I select for a 737 on a 300 nm journey compared to a 1500 nm trip? Would the same formula apply to smaller planes eg: cessna 172?
   

Hi Papallon...here's an extract from a web page I found on the subject..........should explain what you want. There may be other considerations under certain circumstances but this should keep you out of trouble I guess ...commoner.

..and I quote...
 
Flights being directed by air traffic control will be given levels at which to fly...


Quadrantal Rule
(This does NOT apply in the United States or Canada) Flight levels are 500 feet apart, but to further ensure the separation of aircraft, aircraft travelling in different directions below FL 245 (24,500 feet) are required to adopt flight levels according to the quadrantal rule, as follows:
Track 000 - 089

I think what he is after is an efficiancy/speed/time calculation for fuel burn and flight time.

Like it isn't logical or efficient to climb to 20,000ft if you are going 150 miles, but is if you are goin 400 miles (I use prop jobs, so this would be more like FL320 for a 757 going 500 miles or 1,500 miles).

I personally don;t know it, but I bet there is.

Also, cruising altitiudes are chosen based upon headwinds as well.  The lower you go, the less the headwind, so a pilot may elect to use the below 29,000 ft rule as opposed to being forced to fly at a FL where the headwinds would be very strong.  On the flip side, if it's a tailwind, the higher the better becasue the winds will be stronger at 330 than at 290.

or in most cases...you just have to accept where the ATC will put ya
Here in Europe, it's a pipedream to get the opt altitude since the airspace is so damn crowded, and we have RVSM!
Expect lower than opt. altitudes, that's the usual  :)
On a flight (real world) I did some months ago, our B737 was put at FL340 for the whole 3 hour trip, our opt altitude was FL380  ::)

Thanks for your replies guys !

I think Skligmund has pretty much nailed what i'm after.

I might be wrong here,but I always thought that when you plan a flight through fs2004 flight planner, they  give you the altitude relevant to the Victor or Jet  Airways for the route you want to fly,to maintain minimum clearance from the terrain.....Am I correct with this bit ?

Surely though,in the real world,( keeping the minimums in mind ) those altitudes would not be necessarily appropriate for the different aircraft types and journey lengths.
   Thanks in advance for any further thoughts.

Heya Papallon,

You are 100% correct in your last post.  According to what I've read the FS 9 Flight Planner will calculate the minimum altitude necessary to clear the terrain from your departure point to your destination.  I don't know about the Victor or Jet  Airways, however.