From 3c90a9264136640b25a2750cabb4789357e4382a Mon Sep 17 00:00:00 2001
From: Dan Albert <dan@gingerhq.net>
Date: Sat, 17 Jul 2021 18:23:20 -0700
Subject: [PATCH] Add fuel consumption data for the Hornet.

Will be used to calculate bingo and min remaining fuel for the
kneeboard.
---
 doc/fuel-consumption-measurement.md         | 80 +++++++++++++++++++++
 resources/units/aircraft/FA-18C_hornet.yaml | 10 +++
 2 files changed, 90 insertions(+)
 create mode 100644 doc/fuel-consumption-measurement.md

diff --git a/doc/fuel-consumption-measurement.md b/doc/fuel-consumption-measurement.md
new file mode 100644
index 00000000..62dd0a1b
--- /dev/null
+++ b/doc/fuel-consumption-measurement.md
@@ -0,0 +1,80 @@
+# Measuring estimated fuel consumption
+
+To estimate fuel consumption numbers for an aircraft, create a mission with a
+typical heavy load for the aircraft. For example, to measure for the F/A-18C, a
+loadout with two bags, two GBU-31s, two sidewinders, an AMRAAM, and an ATFLIR.
+Do **not** drop bags or weapons during the test flight.
+
+Start the aircraft on the ground at a large airport (for example, Akrotiri) at a
+parking space at the opposite end of the takeoff runway so you can estimate long
+taxi fuel consumption.
+
+When you enter the jet, note the amount of fuel below, then taxi to the far end
+of the runway. Hold short and note the remaining fuel below.
+
+Follow a typical takeoff pattern for the aircraft. For the F/A-18C, this might
+be AB takeoff, reduce to MIL at 350KIAS, and maintian 350KIAS/0.85 mach until
+cruise altitude (angles 25).
+
+Once you reach angels 25, pause the game. Note your remaining fuel below and
+measure the distance traveled from takeoff. Mark your location on the map.
+
+Level out and increase to cruise speed if needed. Liberation assumes 0.85 mach
+for supersonic aircraft, for subsonic aircraft it depends so pick something
+reasonable and note your descision in a comment in the file when done. Maintain
+speed, heading, and altitude for a long distance (the longer the distance, the
+more accurate the result, but be careful to leave enough fuel for the final
+section). Once complete, note the distance traveled and the remaining fuel.
+
+Finally, increase speed as you would for an attack. At least MIL power,
+potentially use AB sparingly, etc. The goal is to measure fuel consumption per
+mile traveled during an attack run.
+
+```
+start:
+taxi end:
+to 25k distance:
+at 25k fuel:
+cruise (.85 mach) distance:
+cruise (.85 mach) end fuel:
+combat distance:
+combat end fuel:
+```
+
+Finally, fill out the data in the aircraft data. Below is an example for the
+F/A-18C:
+
+```
+start: 15290
+taxi end: 15120
+climb distance: 40NM
+at 25k fuel: 13350
+cruise (.85 mach) distance: 100NM
+cruise (.85 mach) end fuel: 11140
+combat distance: 100NM
+combat end fuel: 8390
+
+taxi = start - taxi end = 15290 - 15120 = 170
+climb fuel = taxi end - at 25k fuel = 15120 - 13350 = 1770
+climb ppm = climb fuel / climb distance =  1770 / 40 = 44.25
+cruise fuel = at 25k fuel - cruise end fuel = 13350 - 11140 = 2210
+cruise ppm = cruise fuel / cruise distance = 2210 / 100 = 22.1
+combat fuel = cruise end fuel - combat end fuel = 11140 - 8390 = 2750
+combat ppm = combat fuel / combat distance = 2750 / 100 = 27.5
+```
+
+```yaml
+fuel:
+  # Parking A1 to RWY 32 at Akrotiri.
+  taxi: 170
+  # AB takeoff to 350/0.85, reduce to MIL and maintain 350 to 25k ft.
+  climb_ppm: 44.25
+  # 0.85 mach for 100NM.
+  cruise_ppm: 22.1
+  # ~0.9 mach for 100NM. Occasional AB use.
+  combat_ppm: 27.5
+  min_safe: 2000
+```
+
+The last entry (`min_safe`) is the minimum amount of fuel that the aircraft
+should land with.
diff --git a/resources/units/aircraft/FA-18C_hornet.yaml b/resources/units/aircraft/FA-18C_hornet.yaml
index 06f616d2..511a0b48 100644
--- a/resources/units/aircraft/FA-18C_hornet.yaml
+++ b/resources/units/aircraft/FA-18C_hornet.yaml
@@ -21,6 +21,16 @@ manufacturer: McDonnell Douglas
 origin: USA
 price: 24
 role: Carrier-based Multirole Fighter
+fuel:
+  # Parking A1 to RWY 32 at Akrotiri.
+  taxi: 170
+  # AB takeoff to 350/0.85, reduce to MIL and maintain 350 to 25k ft.
+  climb_ppm: 44.25
+  # 0.85 mach for 100NM.
+  cruise_ppm: 22.1
+  # ~0.9 mach for 100NM. Occasional AB use.
+  combat_ppm: 27.5
+  min_safe: 2000
 variants:
   CF-188 Hornet: {}
   EF-18A+ Hornet: {}