Mig-21-Flight Model - Check six

Mig-21-FM-Identification-Rev. 14
Total fuel volume approximated to 1,300l
Load factor limitation set to :
- 8.0 (mach < 0.8)
- 6.0 (mach > 0.8)
Combat configuration “B”:
Aircraft loaded with 50% of internal fuel,
Center Line pylon (but no CL Tank), 4 R-3S
missiles with their pylon and launching rails
under wing (internal and external).
- Aircraft (zero usable fuel) : 5,760 kg
- 200 gun ammo (Gsh 23) : 75 kg
- 1 Center line pylon : 24 kg
- 2 Under-wing pylon : 45 kg
- Equipped zero usable fuel : 5,904 kg
- 50% usable internal fuel : 1,005 kg
(2,219 lbs @0.83 g/cm 3 )
- Clean Combat Weight : 6,909 kg
- 2 additional wing pylons : 45 kg
- 4 APU-3S rails for R-3S : 82 kg
- 4 Missile R-3S : 300 kg
- Conf. “B” Combat weight :7,336 kg
This defines a gross weight of 16,194 lbs /
7,336 kg and a Drag Index of 13.
Total fuel volume approximated to 1,300l
Load factor limitation set to :
- 7.0 (mach < 0.8)
- 6.0 (mach > 0.8)
Thrust Law validation.
Concerning the Military Thrust table, the values have been set using a proportional law:
As there is no available data to validate this information, I decide to keep it as it is.
The only available performance data available at the moment for Mig-21MF are 2 diagrams describing
sustained load factor and instantaneous climb rate (extra specific power) at 500m along air speed (but
the gross weight is unknown)
I shall use these figures to calibrate Thrust curve in using a constant factor (k) defined by:
It is clear that if the k factor is far away from 1.00, we would have to find an explanation.
Validation by Sustained load factor fitting:
The figure (Rys.11.2) gives Sustained load factor (Ng) along speed at 500m altitude. The relation
between thrust and Ng is given by:
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