by FF- I meant fuel flow..
Should'nt it increase the distance to PNR by 3%?
D = E(OH/O+H)
if Other factors remain constant say "X"
then D = E*X
NOW E = Flight Fuel/Fuel Flow
say FF decreases by 3% therefore taking an example say 60mins endurance
from 100 lit of fuel and fuel flow of 100 lit/hr.
so 97 lit/hr consumption will give u 1.85 mins of extra E
(1.85/60)*100 = 3% increase in DPNR.
Is this correct?