10 Left AFT Fuselage
AFT outflow valve
Water drains, service doors, waste vents
Air demand pump exhausts (2)
The only non-explicit hint in the flight manual is in the exterior inspection section above; searching the manual for "air demand" yields only one other result:
Sec. 6.2 Page 1 [...] Air Conditioning Packs
[...] Pack output is ...
What does the graph show?
The graph plots the average fuel required per distance as a function of the total flight distance. It does not show fuel flow rate as a function of time during the flight.
Why is it going up towards shorter flights?
For short flights (less than ~2500 NM for the 777), the takeoff and climb to cruise altitude are a larger fraction of ...