–WIP-- Alpha Jet data, based on WT data, some testing and GAF Manual. First section is the basic data as per WT, with a more detailed second section based on the real aircraft for anyone interested.
PART 1 - WT DATA
WEIGHTS
Basic Weight - 3600 kg (from Manual; localhost data gives 2078 kg for ‘Mfuel0, kg’ which I expected to be Zero Fuel Weight. However, that’s way too light and doesn’t change with loadout, so not sure what that is)
Fuel - 1600 kg (Manual and ‘Mfuel, kg’ both agree on this)
AIRFRAME LIMITATIONS
Take-off flap 280 KIAS; Landing flap 200 KIAS.
Landing gear 200 KIAS
Vne 580 KIAS
ENGINE LIMITATIONS
100% unlimited operation; can probably ignore temps.
PERFORMANCE
Based on Gunpod plus 2 napalm bombs (enough for one base) and 20 mins fuel; landing with empty pylons and 6 mins fuel. Full details in Part 2.
Take-off 116 KIAS (Use ‘Landing Flap’; Alpha Jet has HALF and FULL settings, 16/32 degrees, and FULL used for take-off and landing - but you’d be fine with ‘Take-off’ setting)
Climb speed 255 KIAS
Approach speed:120 KIAS Full flap; 152 KIAS Flapless.
Touchdown at 116 KIAS Full flap.
Stall speed in landing configuration 98 KIAS.
COCKPIT INSTRUMENTS
AoA
The AoA Indicator is immediately left of the HUD and consists of a moveable white tape set against a fixed scale. AoA is repeated in the HUD itself at bottom left, directly under the G reading, eg:
2.1
6.5
Indicates pulling 2.1 G at 6.5 AoA. (AoA is sensible and useable in WT)
RPM
(RPM does not read correctly in WT; the needle reaches its RL max reading of 100% at THR 75% then jumps to 0% and starts going around the dial again as THR increases from 75% to 100%)
Fuel
The in-game fuel gauge reads the final 500 kg of fuel in the tanks - IRL there were 2 needles, marked 1 & 2, which measured the final 500 kg in each of the 2 groups of fuel tanks (one per engine). However, WT just has the ‘1’ needle and it measures the final 500 kg of fuel in all tanks.
PART 2 - GAF MANUAL DATA
NORMAL OPERATION
Planning and Takeoff
Basic weight with no fuel, no load, is 3600 kg. This assumes no ejection seat (and obviously no pilot) in the second cockpit, as the ‘war role’ for the Alpha Jet would have been single-seat light attacker. WT appears to have a pilot in the rear seat, but, as mentioned above, I can’t determine what Basic Weight WT is using. 3600 kg assumed.
Fuel tanks hold 1600 kg when full, ie 400 kg per 25% or about 35 kg per minute.
Load weight can be found when you select a Preset. WT data doesn’t quite check out with the data from the manual in those loads I’ve checked, as the Preset data does not appear to include the weight of the pylons or TSC (Twin Store Carriers). As pylons, TSC are not present on the clean aircraft to start with, it seems they might not have any weight in WT. Four pylons add 180 kg and a couple TSC another 90 kg IRL - can probably ignore that and just go with the additional weight under Preset ‘Changes to specs’ data. Note too that the manual assumes an empty gunpod and WT seems to agree by ignoring the weight of any rounds - 0.6 kg per round, so another 90 kg for a loaded gunpod, although it’s little enough to be ignored.
Take-off Weight = 3600 + Fuel + Load, kg
Take-off Weight , kg, and corresponding take-off speed, (note 1 kt per 100 kg if you need to interpolate):
4500 - 104 KIAS
5000 - 110 KIAS
5500 - 116 KIAS
6000 - 122 KIAS
6500 - 128 KIAS
7000 - 133 KIAS (Max TOW)
7500 - 138 KIAS (if WT allows you to overload - not checked yet - but it seems there were circumstances when ‘normal’ MTOW could be exceeded).
Drag Index (for climb speed) by aircraft configuration:
0 - Clean aircraft
6 - 4 Pylons
10 - Gunpod
16 - Gunpod + 4 Pylons
25 - Gunpod + 4 Pylons + 2 TSC
26 - Gunpod + 4 Pylons + 2 M116A2
31 - Gunpod + 4 Pylons + 4 250 kg bombs
32 - Gunpod + 4 Pylons + 4 Mk 82 bombs
48 - Gunpod + 4 Pylons + 2 TSC + 6 Mk 82 bombs
52 - Gunpod + 4 Pylons + 4 LAU-51 (for info, as not a possible loadout in WT)
58 - Gunpod + 4 Pylons + 2 TSC + 6 250 kg bombs
To get Drag Index for any of those loads without the gunpod, just subtract 10 - if you’re the kind of weirdo who doesn’t want the gun.
For a normal take-off rotate nose 5 degrees up 20 kts below take-off speed from table above. However, in WT, based on my experience, the nosewheel will not lift off when you move the stick back, so you can’t actually achieve that 5 degree nose up attitude, but you will leap into the air pretty much on the speed from the table if you have the stick held back - it just isn’t quite as smooth and graceful as it should be.
When definitely airborne retract the landing gear. Hold the takeoff attitude. Set flaps to 1/2 at 160 KIAS, to UP at min 180 KIAS… Before reaching 200 KIAS gear and flaps must be fully retracted. This works nicely in-game, with no undue sink or trim change on flap retraction.
Climb
Climb speed is 280 KIAS for a clean aircraft; with a load simply subtract the Drag Index from 280, so 260 KIAS at Drag Index of 20, 240 KIAS at Drag Index 40 etc. This speed is good up to 25,000 ft after which best climb speed is defined by mach number… but you’re not going to be climbing above 25,000 ft.
Approach & Landing
Approaching the airfield SPEED BRAKES - OUT and turn onto a downwind leg. As speed drops below 200 KIAS GEAR - DOWN, FLAPS - DOWN; maintain 150 KIAS min. Abeam touchdown turn on to the base leg and adjust to 8 degrees AoA, which in a 45-60 degree banked turn will be about 140 KIAS; roll wings level when on the centreline (300’ min) and hold 8 AoA, about 120 KIAS, to touchdown. (By flying AoA the speed takes care of itself regardless of weight. If the circuit is kept tight I find WT works out very close to that ideal approach from the Manual. With a wider circuit the AoA will be lower and speed a bit higher, but can be corrected to 8 AoA on short finals.)
With load expended, ie 4 pylons and an empty gunpod, the Zero Fuel Weight ought to be 4000 kg (same as clean aircraft with 400 kg fuel (25%, ~11 min)). At 4000 kg, throttles idle, gear down:
- Approach Speed, Flap 0 - 10 AoA = 148 KIAS
- Approach Speed, Flap 32 - 8 AoA = 117 KIAS
- Touch-down Speed, Flap 32 - 12 AoA = 103 KIAS
- Stalling Speed, Flap 32 - 19 AoA = 94 KIAS
For every extra 100 kg, add 1 kt to those speeds. Assuming 4 pylons and empty gunpod, just add 1 kt to the above speeds for every 100 kg fuel remaining.
LIMITATIONS
Engine
IRL 100% was 22,561rpm and that’s what you get in WT too. Engine was cleared for unlimited operation at 100%, with limits on rpm >100%, but you can’t go over 100% in WT. Temperature limits were more complicated, but can be ignored in WT.
Airframe
The maximum speed for the gear…/for flap extension or retraction is 200 KIAS. (But see note about ‘takeoff’ flap limit in WT, Part 1)
Maximum speed:
- Clean 580 KIAS / M0.95
- Pylons/TSC/Gunpod 550 KIAS / M0.85
- External Stores 500 KIAS / M0.8
(Clean aircraft limit applies in all cases in WT)
EMERGENCIES
Loss of one engine
For single engine climb:
- The best single engine climb speed with flaps up is about 200 KIAS
- Do not exceed 8 AoA
Flapless landing
Damage to one flap will result in asymmetric flap extension, which could result in difficulty in keeping control - depending on other damage to the wings - making it safer to carry out a flapless landing, as follows:
- Flap lever - UP
- Excessive fuel - BURN
- Approach with an AoA of 10
(TBC)
Loss of both engines
Best glide speed 195 KIAS / 6.5 AoA. (In testing I found 195 KIAS gave a lower AoA and 6.5 AoA required around 170 KIAS. Holding the glide between those speeds at around 4.5 - 6.5 AoA I seem to have exceeded the Manual figure of 18 nm per 10k’). For every 5000’ lost in the glide you should cross one grid on large maps like Denmark, Afghanistan, Vietnam; 1-1/3 grids on Dover; 2 grids on other maps. (Will test further)
Ideally, arrive overhead airfield at 6000’ agl - High Key. Reduce speed to 200 KIAS, adopt a downwind leg, GEAR - DOWN, FLAPS - as required. Adjust descent and ground track to arrive at Low Key, 3000’ abeam touchdown point. Turn onto base leg/finals maintaining 150 KIAS min, FLAPS - DOWN. (TBC)
PART 3 - FURTHER INFORMATION
Corner speed about 300 KIAS. See post #17 by ‘LOMCEVAK’ regarding Alpha Jet v Hawk T1 in ACT from this thread on PPRuNe