Hi everyone 🙂 I am little confused about how to calculate the Final reserve fuel. When I use bob Tait exams, we use cruise fuel flow but other exams the use the holding fuel flow. What is it? Holding fuel flow or Cruise fuel flow?Â
Simple.  The requirement permits the reserve to be based on holding fuel at 1500 ft.  If you don't have data that, then use cruise fuel flow, which is going to be conservative.
Caveat.  Be careful.  Some aircraft can produce relatively low holding fuel flows.  The inference should be obvious.  An Ansett colleague of mine killed himself and his lady friend when he ran out of gas flying his Shrike Commander back to Essendon some years ago.  Crashed and both killed on the Northcote golf course.  Many lobsters ended up wandering around the golf course rather confused.  Jim was a nice guy and actually trained me for my Electra clearance years ago.  However, with his own aircraft reserve requirements he was stupid and both he and his lady paid the ultimate price for his stupidity.
Be careful out there, folks.
Engineering specialist in aircraft performance and weight control.