Reserve Fuel??

[sf340flyer]

Do you guys have a standard reseve fuel numbers or do they change on each flight? I'm talking about the 45 minute reserve.

 

[elag777]

121.647 goes into details,
Wind and Forecast wx conditions,
Anticipated traffic delays,
One instrument approach and possible missed approach at destination, etc.
A dispatch program will have your companies A/C performance preloaded and comes up with the 45 min rsv based on wx mainly, you will notice the 45 min fuel total will change from day to day dependant on forecast conditions and winds. It will change from flight to flight.

 

[sf340flyer]

that is the problem. 1 plane at my company has a set number and the other changes every leg. I was just trying to find out what other companies use.

Also why would wind have any effect on it?? it's just extra fuel, not to a destination?

 

[elag777]

121.639 in part says,

"Thereafter, to fly for 45 mins at normal cruising fuel consumption,..."

Some programs will take into account ambient temperatures and winds aloft to give a fuel in lbs for the 45 min rsv, so this is why you may see some different #s from day to day.
Others will just reproduce pre-loaded fuel burns for 45 mins as per the manufacturers data. The more technical programs will calculate for TT on the engine as older ones will have different perameters. You can define it as 121.639 states and be happy I think.