Rule of thumb equation or graph for sfc for turbofans
Hi folks,
Hard to believe, I know but our company yanked all our fuel consumption tables out of all of our manuals, so on a long flight all we have is our flt plan listing a number of different altitudes. Does any one have any rule of thumb formulas for fuel / sfc consumption on turbojet aircraft working down from your optimum to say 10,000'. I scanned my Aerodynamics for Naval Aviators and Handeling the Big Jets 2nd edition to no avail. Yes I know jets love high rpm and high altitude but I was looking for a formula or two that could be worked from a baseline known quantity.
The reason for the question is: when all goes to sh**t it really can bite you.
Thanx,
Phil