Compared Air Combat Performances F-5E versus Mig-21

Thursday, March 07, 2013 Page - 1

Compared Air Combat Performances analysis Mig-21 versus F-5E

LICENSE: This document has been created by J.M. LANGERON / TOPOLO, (http://topolo.free.fr/). All the values used to model the aircraft behavior have been computed by him, like all performance charts presented here, based on data provided by the people mentioned in the CREDITS section. If you want to use these data, or part of it, please contact the author by personal message to TOPOLO on check-six forum: (http://www.checksix-forums.com/). CREDITS: It has been possible to build this document only due to the collection of many data regarding Mig-21 and F-5E performances, their use in dedicated conflict (Ogaden war) and many other details. The group involved in this project has also spent a lot of time in reviewing this document and those mentioned in the Bibliography section. I want to thanks particularly Tomislav MESARIC for his Mig-21 knowledge and data, Chuck CANYON for the F-5E, Tom COOPER (ACIG.org) for his huge knowledge on military aerospace in general, the history of these aircraft in particular, and the fact that he build the working group.

A. Introduction The aim of this document is to analyze the performances, mainly turning, climbing and acceleration, (roll rate is not part of the scope due to complete lack of objective data) of the two aircraft families to identify forces and weakness of each in close air combat scenario.

It will not be taken into account at all of weapon system capabilities, nor of aircrew training, tactics or strategy, but only focus on airframe and engine.

The two aircraft families will be represented by particular sub versions. For the Mig-21 the choice has been mainly driven by the idea to covers the complete performances range of the family and the available documentation. Performance charts of ex-Yugoslavian L-15 and L-17 enable the identification of the flight behavior of both Mig-21M (izd.96A) and Mig-21bis (izd.75A). The major role of the Mig-21MF (izd.96F) also leads to build a dedicated flight model for this version, even if the complete performance manual has not been found for it. For the F-5, the Tiger-II F5-E-3 has been chosen because it has the best performance of the family (its better instantaneous turn rate being the result of the efficiency of its auto-flaps device). A single sub version of the Northrop aircraft has been selected to limit the number of comparison to document (and also due to the quite homogeneous performance across the family compared to the Mig-21 very wide range)

All documents describing the individual aircraft performances and how they have been built are listed in the Bibliography section of this document.

B. Methodology description.

Aircraft configuration definition. For the three first sections of the document, the aircraft configurations have been defined with the same criteria: loading reduced to two infra-red guided short range

missiles and full gun ammo, all pylons that cannot be jettisoned and that are usually required for air combat mission take-off, fuel quantity set to half of the internal capacity. These configurations are named “Combat configuration”

For the last section, related to an historical scenario (Ogaden war) , both aircraft configurations have been built from our knowledge of the take-off configuration and estimation of the flight path, the fuel consumption, and the jettison strategy.

In all cases, these choices lead to the definition of the gross weight and the drag index value used to compute performances.

Caution: definition of drag index is very different in US and Soviet performance manuals so do not be surprised by the value differences.

Mig-21M combat configuration. Aircraft loaded with 50% of usable internal fuel, Center Line pylon (but no CL Tank), 2 R-3S missiles with their pylon under wing. This defines a gross weight of 15,673 lbs (7,100kg) and a Drag Index of 12. Clean Aircraft (no usable fuel) : 5,760 kg 200 gun ammo (Gsh 23) : 75 kg 2 Under-wing pylon : 45 kg 1 Center line pylon : 24 kg 2 Missile rails for R-3S : 41 kg 2 Missile R-3S : 150 kg 50% internal fuel : 1,005 kg This gross weight leads to the following load factor limitation: For Mach number lower than 0.8 : 8.0 G For Mach number greater than 0.8 : 6.0 G

Mig-21MF combat configuration. Aircraft loaded with 50% of usable internal fuel, Center Line pylon (but no CL Tank), 2 R-3S missiles with their pylon under wing.

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Compared Air Combat Performances F-5E versus Mig-21


This defines a gross weight of 15,673 lbs (7,100kg) and a Drag Index of 12. Clean Aircraft (no usable fuel) : 5,760 kg 200 gun ammo (Gsh 23) : 75 kg 2 Under-wing pylon : 45 kg 1 Center line pylon : 24 kg 2 Missile rails for R-3S : 41 kg 2 Missile R-3S : 150 kg 50% internal fuel : 1,005 kg This gross weight leads to the following load factor limitation: For Mach number lower than 0.8 : 8.0 G For Mach number greater than 0.8 : 6.0 G

Mig-21bis combat configuration. Aircraft loaded with 50% of internal usable fuel, Center Line pylon (but no CL Tank), 2 R-60 missiles with their pylon under wing. This defines a gross weight of 16,406 lbs (7,432 kg) and a Drag Index of 11. Clean Aircraft (no usable fuel) : 6,003 kg Gun ammo (250 rounds) : 95 kg 1 Center line pylon : 24 kg 2 Under-wing pylon : 50 kg 2 Missile rails for R-60 : 70 kg 2 Missile R-60 : 90 kg 50% internal fuel : 1,060 kg This gross weight leads to the following load factor limitation: For Mach number lower than 0.8 : 8.0 G For Mach number greater than 0.8 : 6.0 G For Mig-21Bis, the Special-After-Burner will always be used when possible (under 4,000m), even if only After-Burner is mentioned.

F-5E-3 combat configuration. Configuration has been defined according USAF F-5E/F flight manual (T.O. 1F-5E-1 or 1st of August 84 with Change 9 of 15th of November 1990) Aircraft loaded with 50% of internal fuel (2,259 lbs), 2 wing tip AIM-9 missiles with their rails. This defines a gross weight of 13,750 lbs and a Drag Index of 18. The load factor limitation is set to 7.33G and does not depend on Mach number. Clean Aircraft (no fuel, pilot) : 10,659 lbs Gun ammo : 394 lbs 2 Missiles AIM-9 : 340 lbs 2 Missile rails for AIM-9 : 98 lbs Zero fuel weight : 11,491 lbs Internal fuel (JP-4) : 2,259 lbs

Critical performances to be compared. For each altitude, we will compare turning, climbing and acceleration capabilities.

Turning Turning capabilities will be measured by following performances:

Quickest half turn: Minimum time required to perform a 180 deg turn with maximum G-Load (structural or maximum lift limits).

Maximum Sustained Turn Rate: Minimum time required to perform a constant speed 360 deg turn and related radius (maximum sustained turn rate).

Minimum Sustained Turn Radius: Minimum turn radius of a constant speed 360 deg turn and required time.

WARNING: for Mig-21, two tests need to be performed, in the first one the pilot is assumed to limit the AoA to 28 degrees, according to the black sector limit of his AoA indicator, in the second test, the pilot is assumed to reach and keep the maximum lift AoA.

The first test could be considered as representative of an average Mig-21 pilot, when the second is only to be considered for high skilled – highly trained pilots.

Climbing Non turning climb: both aircraft flying at their maximum constant speed climb rate, starting from same point, what time is required for an altitude gain of 2,000ft for the fastest, how many feet above is the other one at this time.

Turning climb: both aircrafts engaged in a constant speed, constant G-load (2G at 30,000ft, 3G at 15,000ft, 4G at 5,000ft) turn, which altitude gain after 90 degrees.

Acceleration Both aircrafts perform a level flight, starting at same speed (Mach 0.5 and Mach 0.9), the performance is the horizontal distance covered after three minutes.

Also expressed by the time and distance the fastest can be late and still rejoin its target in less than 3 minutes.

C. Medium level combat (15,000ft).

Turning performances.

Quickest half turn At 15,000ft the test compares planes on the quickest 180 deg turn.

The best F-5E-3 half turn start at mach 0.92 (477 Kts indicated air speed) and end in 11.8s at Mach 0.43 (214 Kts IAS) with an average turn radius of 2,590ft.

The best Mig-21MF half turn with AoA limited to max lift start at mach 0.87 (450 Kts IAS) and end in 13.2s (+2.4s) at Mach 0.52 (262 Kts IAS) with an average turn radius of 3,168 ft.

Graphic comparison in fig1.1



Mig-21MF with AoA limited 28 end its half turn in 14.4s (+4.6s) at Mach 0.68 (347 Kts IAS) with an average turn radius of 3,667 ft.


Other Mig-21 sub-types performances are described in the following diagrams.

Time (s) required for half turn

Average half turn radius (ft)

It can be seen that all other Mi-21 are slower to perform half turn and do it with a bigger average radius.

A deep analysis of the figure 2.1 shows that the Mig-21MF has a smaller turn rate at the beginning of the turn mainly because of the load factor limitation: when F-5E can pull 7.33G all along its speed range, Mig-21MF is limited to 6G when mach is over 0.8 (415 Kts IAS), and this limit is reached during more than 6 sec. (half of the half turn).

Maximum Sustained Turn Rate If we focus on Mig-21MF, the following figure shows that the two planes are equivalent under 320Kts, and F-5E has a positive margin only from 350 to 500Kts, that are the most common turn fight speed, if the Mig pilot can impose a speed lower than 320Kts, he will clear the advantage of its opponent, if both accept a 400Kts turn fight, the F-5E will be advantaged.

The comparative performances of the 4 aircrafts at their maximum sustained turn rate speed are described in the following table and diagram:

And in the appendix section, fig.1.3.

Compared to the Mig-21 family, we can see that the advantage still goes to the F-5E, the difference with the Mig-21MF or M is significant (3 sec. / 8% for a complete 360 deg turn), when Mig-21bis is clearly more (6 sec.) disadvantaged.

The speed range covered by this comparison allows us to say that this criterion (maximum sustained turn rate) defines the hierarchy in the high-speed turning capability (400 Kts IAS).

Minimum Sustained Turn Radius Focusing on Mig-21MF vs. F-5E3, the following figure show a very small difference between the two planes: 100ft in radius and 10Kts in speed, that cannot be considered as significant.

The comparative performances of the 4 aircrafts at their minimum sustained turn radius speed are described in the following table and diagram:

And in the appendix section, fig.1.4

The speed range covered by this comparison allows us to say that this criterion (maximum sustained turn rate) defines the hierarchy in the low-speed turning capability (150 Kts IAS).

The advantage goes to the Mig-21MF, then the F-5E, and Mig-21M and last the heavy Mig-21bis.

F-5

E-3

; 11

.80

Mig

-21

M m

ax li

ft; 1

3.20

Mig

-21

MF

max

lift

; 13.

20

Mig

-21

bis

max

lift

; 14.

20

Mig

-21

M A

oA

<2

8; 1

4.6

0

Mig

-21

MF

Ao

A<

28

; 14

.20

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-21

bis

Ao

A<

28; 1

5.4

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E-3

; 2,5

90

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-21

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ax li

ft; 3

,191

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-21

MF

max

lift

; 3,1

68

Mig

-21

bis

max

lift

; 3,4

85

Mig

-21

M A

oA

<2

8; 3

,65

6

Mig

-21

MF

Ao

A<

28

; 3,6

67

Mig

-21

bis

Ao

A<

28; 3

,934

0.00

1.00

2.00

3.00

4.00

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0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Sust

ain

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Tu

rn R

ate

(d

/s)

Mach number

F-5E-3

Mig-21MF

STR

deg/s

Turn

Radiusat Mach

Time for

360

F-5E-3 9.81 4,694 0.76 37

Mig-21M 8.91 4,963 0.69 40

Mig-21MF 9.00 5,315 0.79 40

Mig-21bis 8.46 5,726 0.80 43

15,000 ft

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Sust

ain

ed

Tu

rn R

adiu

s (f

t)

CAS (Kts)

F-5E-3

Mig-21MF

STR

deg/s

Turn

Radiusat Mach

Time for

360

F-5E-3 6.16 3,047 0.31 58

Mig-21M 6.36 3,146 0.33 57

Mig-21MF 6.22 2,920 0.30 58

Mig-21bis 5.99 3,336 0.33 60

15,000 ft



At 15,000 ft an F-5E has the quickest first half turn, the best maximum sustained turn rate, and the best turn rate and turn radius at 200Kts or more compared to any Mig-21. Only a Mig-21MF can try to take advantage of its smaller minimum turn radius at very low speed (150Kts and less).

In general, F-5E pilot would not be in bad position in accepting a dog-fight versus a Mig-21 at this altitude. He has equal or better turn performance than any Mig-21 between mach 0.60 and 0.95 (305 to 495 Kts), better than Mig-21M and Mi-21bis and similar to Mig-21MF between 150 and 305Kts, he would enter in bad shape only at very low speed against a Mig-21MF. So keeping the speed over 200Kts will keep a positive margin.

A Mig-21MF could also enter such a dogfight versus an F-5E without being disadvantaged, as soon as the speed rmain lower than 300Kts, he can even goes to very low speed (150 Kts) to take advantage of its turn radius but this will not give him a really significant benefit, and this will not be the case for Mig-21M or bis.

Climbing performances.

Non turning climb. Focusing on Mig-21MF vs. F-5E3, the following figure shows that the climb rate of the two planes are equivalent except between 420 and 510Kts, where the F-5 can claim being 30 ft/s faster.

The “constant speed climb rate” of each aircraft at 15,000 ft is described in figure 1.5 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed with Full (or Special) After Burner engaged.

We can see that the F-5E-3 has the best maximum climb rate: 383 ft/s (354 ft/s for the 21MF), and this value is reached at higher speed (mach 0.9 for F-5E when climb rate remain quite constant between M.8 and M0.88 for Mig-21MF). Mig-21Bis is not far away (366 ft/s at Mach 0.88 / 455Kts) and Mig-21M one step beyond (337 ft/s at Mach 0.82 / 425Kts IAS).

If all aircraft keep a constant speed corresponding to their best climb rate, the 2,000ft gain will require 5.2 seconds for the F-5E. During the same time the Mig-21bis gains 1,910ft (90 ft lower), the Mig-21MF gains 1,848 ft (152 ft lower), and the Mig-21M gains 1,760 ft (240 ft lower).

That means that if the F-5E pilot want to use his climb speed to break a high speed subsonic dogfight (M0.9 / 350 Kts indicated) fight and evade in climbing in , he can do it only against a Mig-21M, in a certain way when facing a Mig-21MF but not when facing a Mig-21bis.

If we consider the same scenario where the pilot want to evade a low speed dogfight (M0.5 / 250 Kts indicated) by climbing at constant speed, the situation is:

- The Mig-21bis requires 9 s to gain 2,000ft, during this time the F-5E will gain only 1,874 ft (126 ft lower)

- The Mig-21MF requires 9.5 s to gain 2,000ft, during this time the F-5E will gain only 1,963 ft (37 ft lower)

- The Mig-21M requires 10.2 s to gain 2,000ft, more than the F-5E (9.6s).

Meaning that 21bis can try to evade a low speed dogfight (IAS < 250 Kts) in front of the F-5, in climbing, but the Mig-21MF cannot and the Mig-21M will be surpassed.

On the other side, an F-5E pilot would not try to evade in climbing at low speed, as this will be successful only when facing an old Mig-21M.

So the non-turning climb rate comparison gives a small advantage to the modern variants of the Mig-21bis at low speed (IAS < 250Kts), when the high subsonic (M0.8-0.9 / 425-465Kts) case see the F-5E a bit better than the Mig-21bis and better than the Mig-21MF and M.

Turning Climb. Focusing on Mig-21MF vs. F-5E3, the following figure shows that the F-5 climbs faster in a 3G turn up to 510Kts indicated (up to 60 ft/s faster).

The “constant speed, constant 3G climb rate” of each aircraft at 15,000 ft is described in figure 1.6 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed and G-Load to 3.0 with Full (or Special) After Burner engaged.

In a high subsonic (M0.9 / 465 Kts indicated) 3G turn, the F-5E get the best climb rate. The turn rate is the same for all and allows a quarter turn in 16.4 sec (5.48 d/s), during this time,

- The F-5E will gain 4,312 ft (263 ft/s) - The Mig-21M will gain 2,876 ft (175 ft/s) and so

will be 1,436 ft lower.

0

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0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Clim

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ate

(ft

/s)

CAS (Kts)

F-5E-3

Mig-21MF

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Mig-21MF



- The Mig-21bis will gain 3,258 ft (198 ft/s) and so will be 1,054 ft lower.

- The Mig-21MF will gain 3,285 ft (200 ft/s) and so will be 1,028 ft lower.

In all case, it is obvious that the F-5E can evade a high-speed dogfight with such a maneuver, even against the best Mig-21, it will gain 1,000ft in a quarter of a turn, even in front of the best Mig-21.

Acceleration performances. Diagram show curves indicating along the time the distance from the plane to the location where all aircraft will be after 3 minutes. This way to present the data allows to quickly understanding:

- How much behind another a plane (b) can be the plane (a) to rejoin it 3 minutes later: vertical distance along t=0 axis between curves (a) and (b).

- How much time a plane (a) can be late compared to (b) and rejoin it in less than 3 minutes: search for the (b) distance at t=0, go horizontal along time up the cross the (a) curve, go vertical to read corresponding time.

Focusing on Mig-21MF, the figures:

can be analyzed as follow:

Both planes start their run at 250Kts indicated (end of a hard turn): Mig-21MF can rejoin the F-5E in 3 minutes being 7s late (time required to perform a 60deg turn at 250Kts) or 0.68Nm behind.

If both planes start their run at 465Kts indicated, Mig-21MF can rejoin the F-5E in 3 minutes being 6s late (time required to perform a 50deg turn at 465Kts) or 0.84Nm behind.

Meaning that, neither F-5E nor Mig-21MF can evade in simply accelerating, except if he has a significant advance (more than a quarter of a turn).

The distance covered in 3 minutes by Mig-21 and F-5E at 15,000 ft, all planes starting at mach 0.5 (250Kts indicated) is described in figure 1.7.

The same distance when all planes start at mach 0.9 (465Kts indicated) is in figure 1.8.

In any configuration, the F-5E is faster than the Mig-21M and slower than the Mig-21MF, the three planes being very close to each other.

The Mig-21bis is definitely the fastest.

If all planes start their run at 250Kts indicated (end of a hard turn):

- F5-E can rejoin the Mig-21M in 3 minutes being 9s late (time required to perform a 75deg turn at 250Kts) or 1Nm behind.

- Mig-21bis can rejoin the F-5E in 3 minutes being 36s late (time required to perform a 300deg turn at 250Kts) or 4.6Nm behind.

That means, that if both planes are engaged in a low speed turn, neither F-5E nor Mig-21 M nor MF can evade in simply accelerating, except if he has a significant advance (more than a quarter of a turn).

On the other side, in front of a Mig-21bis, an F-5E will have no chance at all to evade. The 21bis will be able to rejoin the F-5E, even if he needs to do quite a complete turn.

If all planes start their run at 465Kts indicated:

- F5-E can rejoin the Mig-21M in 3 minutes being 8s late (time required to perform a 68 deg turn at 465Kts) or 1.3Nm behind.


That means, that if both planes are engaged in a high speed turn, neither F-5E nor Mig-21 M nor MF can evade in simply accelerating, except if he has a significant advance (more than a quarter of a turn).

On the other side, in front of a Mig-21bis, an F-5E will have no chance at all to evade. The 21bis will be able to rejoin the F-5E, even if he needs to do 3 quarter of a turn.

Conclusion. At 15,000ft, after merge, the F-5E is able to take benefit of its quickest half turn, then the Mig-21MF and F-5E have very similar sustained turning performance when speed is lower than M0.6 (305Kts IAS) and no one will have a significant advantage in such a turning fight, if speed increase again, F-5E will take the lead. The F-5E has a bigger advantage on the 21M, but still not decisive. The heavy Mig-21bis is clearly disadvantaged at this altitude.

0

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0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)

Distance covered at 15,000 ft, start at Mach 0.5 / IAS 250 Kts

F-5E-3

Mig-21MF

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Distance covered at 15,000 ft, start at Mach 0.9/ IAS 465 Kts

F-5E-3

Mig-21MF



Nor Mig-21M neither Mig-21MF can evade a turn fight when it has started.

The Mig-21bis demonstrate its speed superiority, and can force the F-5E to the fight if this one does not climb, or quit the turn fight if he feels in bad situation.

On the other side, the F-5E has, in any case, a possibility to break the fight in performing a high speed turning climb that no Mig-21 can follow.

If we try to graphically represent the main seven normalized values, we get the following diagram:

D. Low level combat (5,000ft).


Quickest half turn At 5,000ft the test compare planes on the quickest 180 deg turn.

The best F-5E-3 half turn start at mach 0.75 (460Kts IAS) and end in 9.8s at Mach 0.40 (245Kts IAS) with an average turn radius of 2,040ft.

The best Mig-21MF half turn with AoA limited to max lift start at mach 0.80 (490Kts IAS) and end in 10s (+0.2s) at Mach 0.45 (275Kts IAS) with an average turn radius of 2,210 ft.





Time (s) required for half turn


It can be seen that the Mig-21M is equivalent to the MF when the 21bis is slower (0.8s) to perform half turn and do it with a bigger average radius.

Mig-21MF, M and F-5E are clearly equivalent in this area if the Mig-21 is flight to its lift limits, with an average turn rate of 18.4 d/s, and the Mig-21bis is only 0.8s slower ().

In the case where Mig-21 are limited to AoA28, the difference with F-5E is between 1 and 2s only.

This will not allow any of these planes to take a decisive advantage on the first turn after merge.

Maximum Sustained Turn Rate Focusing on Mig-21MF, the following figure clearly shows that the sustained turn rate of the F-5 is better from 150Kts to maximum speed. This can be considered as a clear advantage in any medium-to-high speed turn fight.


0%

25%

50%

75%

100%

Average turn rate in quickest half turn

Max Sustained turn rate

1000 ft / Min sustained turn radius

Max level flight climb rate

Max Turning climb rate

Max Distance in 3' from M0.5


F-5E3

Mig-21M

Mig-21MF

Mig-21bis

F-5

E-3

; 9.8

0

Mig

-21

M m

ax li

ft; 1

0.00

Mig

-21

MF

max

lift

; 10.

00

Mig

-21

bis

max

lift

; 10.

80

Mig

-21

M A

oA

<2

8; 1

1.2

0

Mig

-21

MF

Ao

A<

28

; 11

.00

Mig

-21

bis

Ao

A<

28; 1

1.8

0

F-5

E-3

; 2,0

40

Mig

-21

M m

ax li

ft; 2

,166

Mig

-21

MF

max

lift

; 2,2

09

Mig

-21

bis

max

lift

; 2,0

04

Mig

-21

M A

oA

<2

8; 2

,60

3

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-21

MF

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A<

28

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37

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A<

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,599

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Sust

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/s)

CAS (Kts)

F-5E-3

Mig-21MF




The advantage goes to the F-5E, the difference with the Mig-21bis is significant but not critical (3s. for a complete 360 deg turn, around 10%), when Mig-21MF (+5s) and 21M (+7s) are clearly disadvantaged.

The F-5E sustained turn rate is superior to any Mig-21 between Mach 0.25 and 0.9 (160Kts – 550Kts) and consequently have a constant advantage in offensive turn maneuver.

Minimum Sustained Turn Radius At 5,000ft, the figure bellow shows that the sustained turn radius are similar at low speed (under 250Kts), the Mig-21MF can turn sharper at very low speed (135Kts), but F-5E can stay inside its opponent as soon as speed goes over 300Kts.




Mig-21MF and F-5E are equivalent, then follow Mig-21bis and Mig-21M.

At 5,000 ft an F-5E has an equivalent quickest first half turn to the best Mig-21, the best maximum sustained turn rate, and the best turn rate and an equivalent or better sustained turn radius compared to any Mig-21.

In general, F-5E pilot would be in good position in accepting a dog-fight versus a Mig-21 at this altitude. He will have equal or better turn performance than any Mig-21 between mach 0.25 and 0.90 (160Kts – 550Kts).


Non turning climb. Focusing on Mig-21MF, the figure bellow shows that the F-5E climbs faster all along the speed range (except under 150Kts, that is not significant), with a difference up to 50 ft/s.

The “constant speed climb rate” of each aircraft at 5,000 ft is described in figure 2.5 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed with Full (or Special) After Burner engaged.

We can see that the Mig-21bis has a better climb rate than the F-5E for all speed over mach 0.5, with an exceeding value of quite 100ft/s

We can also see that the Mig-21MF climb slower than the F-5E-3 but the difference significantly increase when mach become higher tha 0.8, then F-5E get a serious advantage (466 ft/s vs 392 ft/s)

If F-5E and Mig-21bis keep a constant speed corresponding to their best climb rate, the 2,000ft gain will require 3.7 seconds for the Mig-21bis. During the same time the F-5E will gain 1,717 ft (283 ft lower).

If F-5E and Mig-21MF keep a constant speed corresponding to their best climb rate, the 2,000ft gain will require 4.3 seconds for the F-5E. During the same time the Mig-21MF will gain 1,682 ft (318 ft lower), and the Mig-21M will gain only 1,432 ft (568 ft lower)

That means that if the F-5E pilot want to use his climb speed to break a high speed subsonic dogfight (M0.9 / 550 Kts indicated) and evade in climbing, he can do it easily against a old Mig-21M, this can also be done against a Mig-21MF, but not when facing a Mig-21bis.

On the other hand, the Mig-21bis can evade in climbing against an F-5E at high speed.

If we consider the same scenario where the pilot want to evade a low speed dogfight (M0.5 / 250Kts indicated) by climbing at constant speed, we can see that the climb rate of the F-5E, 21bis are equivalent, then goes the Mig-21MF and last the Mig-21M.

STR

deg/s

Turn

Radiusat Mach

Time for

360

F-5E-3 13.27 3,411 0.72 27

Mig-21M 10.64 3,192 0.54 34

Mig-21MF 11.36 3,154 0.57 32

Mig-21bis 12.08 3,747 0.72 30

5,000 ft

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Sust

ain

ed

Tu

rn R

adiu

s (f

t)

CAS (Kts)

F-5E-3

Mig-21MF

STR

deg/s

Turn

Radiusat Mach

Time for

360

F-5E-3 7.72 1,873 0.23 47

Mig-21M 7.33 2,058 0.24 49

Mig-21MF 7.74 1,867 0.23 47

Mig-21bis 6.90 2,003 0.22 52

5,000 ft

0

50

100

150

200

250

300

350

400

450

500

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Clim

b R

ate

(ft

/s)

CAS (Kts)

F-5E-3

Mig-21MF



So the non-turning climb rate comparison gives the advantage to the Mig-21bis with a large margin, but the F-5E keep a positive one in front of the Mig-21MF at high speed (IAS < 490Kts), when the Mig-21M is behind in any case.

Turning Climb. The figure bellow clearly shows than is such a 4G turn, the Mig-21MF climbs much slower than the F-5E, the difference is large (more than 100 ft/s) and covers the complete speed range.

The “constant speed, constant 4G climb rate” of each aircraft at 5,000 ft is described in figure 2.6 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed and G-Load to 4.0 with Full (or Special) After Burner engaged.

At their respective best 4G turn climb speed, the F-5E get the best climb rate. The F-5E turn rate allows a quarter turn in 12.4 sec (7.2 d/s), during this time,

- The F-5E will gain 3,864 ft (311 ft/s) - The Mig-21bis will gain 3,819 ft (307 ft/s) and so

will be 44 ft lower. - The Mig-21MF will gain 2,157 ft (173 ft/s) and so

will be 1,706 ft lower. - The Mig-21M will gain 1,427 ft (115 ft/s) and so

will be 2,437 ft lower.

The F-5E can evade a high-speed dogfight with such a maneuver, against Mig-21MF or M, it will gain more than 1,700ft in a quarter of a turn.

But this cannot be used in front of the Mig-21bis (neither the opposite)

Acceleration performances. Comparison between Mig-21MF and F-5E in figures bellow shows that there is no significant difference between the two planes at this altitude.

The distance covered in 3 minutes by Mig-21 and F-5E at 5,000 ft, all planes starting at mach 0.5 (305Kts indicated) is described in figure 2.7.


In any configuration, the F-5E is faster than the Mig-21M and equivalent to the Mig-21MF, when the Mig-21bis is definitely the fastest.

If all planes start their run at 305Kts indicated (end of a hard turn):

- F5-E can rejoin the Mig-21M in 3 minutes being 17s late (time required to perform a 200deg turn at 305Kts) or 1.8Nm behind.


That means, that if F5-E and Mig-21M are engaged in a low speed turn, Mig-21M cannot evade in simply accelerating, but F-5E can.

If F5-E and Mig-21MF are engaged in a low speed turn, neither Mig-21MF nor F-5E can evade in simply accelerating.


If all planes start their run at 550Kts indicated:

- F5-E can rejoin the Mig-21M in 3 minutes being 10s late (time required to perform a 115 deg turn at 550Kts) or 1.7Nm behind.

0

50

100

150

200

250

300

350

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Clim

b R

ate

(ft

/s)

CAS (Kts)

F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF




That means, that if F5-E and Mig-21M are engaged in a high speed turn, Mig-21M cannot evade in simply accelerating, but F-5E can.

If F5-E and Mig-21MF are engaged in a high speed turn, neither Mig-21MF nor F-5E can evade in simply accelerating.


Conclusion. At 5,000ft, the F-5E has better turning performance than any Mig-21 (except at very low speed under 130Kts) and will have a significant advantage in a turning fight.

Nor Mig-21M neither Mig-21MF can evade a turn fight when it has started.

The Mig-21bis demonstrate its speed superiority, and can force the F-5E to the fight if this one does not climb, or quit the turn fight if he feels in bad situation.

The F-5E has, a possibility to break the fight in performing a high speed turning climb that no Mig-21M nor MF can follow, but not in front of a Mig-21bis


E. High level combat (30,000ft).


Quickest half turn At 30,000ft the test compare planes on the quickest 180 deg turn started at Mach 0.9 (350 Kts IAS).

The F-5E-3 ends its half turn in 25.6s at Mach 0.34 (127 Kts IAS, close to stall speed) with an average turn radius of 3,866ft.

Mig-21MF with AoA limited to max lift ends its half turn in 22.6s (-3.0s) at Mach 0.47 (172 Kts IAS) with an average turn radius of 4,521 ft.


Mig-21MF with AoA limited 28 end its half turn in 24.4s (-1.2s) at Mach 0.70 (267 Kts IAS) with an average turn radius of 5,948 ft.



Time (s) required for half turn Except for the heavy Mig-21bis, all other variants are faster than the F-5E, especially if driven at the max lift AoA by high-skilled pilots.


It is clear that the F-5E get the smallest radius, mostly due to its very low speed at the end of the turn, and that the Mig-21 appears in gross weight order. The advantage goes to the Mig-21MF that need less time for its half turn, and end it at higher speed, Mig-21M is close behind the MF, then F-5E and last the Mig-21bis.

Maximum Sustained Turn Rate If we focus on Mig-21MF, we can see that the F-5E advantage is only true on a very small speed range (280-320 Kts), at lower speed Mig-21MF has a much better sustained turn rate.

0%

25%

50%

75%

100%








F-5E3

Mig-21M

Mig-21MF

Mig-21bis

F-5

E-3

; 25

.60

Mig

-21

M m

ax li

ft; 2

3.00

Mig

-21

MF

max

lift

; 22.

60

Mig

-21

bis

max

lift

; 28.

40

Mig

-21

M A

oA

<2

8; 2

4.8

0

Mig

-21

MF

Ao

A<

28

; 24

.40

Mig

-21

bis

Ao

A<

28; 2

7.8

0

F-5

E-3

; 3,8

66

Mig

-21

M m

ax li

ft; 4

,545

Mig

-21

MF

max

lift

; 4,5

21

Mig

-21

bis

max

lift

; 4,6

43

Mig

-21

M A

oA

<2

8; 5

,98

8

Mig

-21

MF

Ao

A<

28

; 5,9

48

Mig

-21

bis

Ao

A<

28; 6

,354



Despite its smaller maximum sustained turn rate, I would give the advantage to the Mig-21MF for a medium-high speed turn rate at 30,000ft



The speed range covered by this comparison allows us to say that this criterion (maximum sustained turn rate) defines the hierarchy in the high-speed turning capability (350 Kts IAS).

The advantage goes to the F-5E, but the difference with the Mig-21MF is only 6% and then increases up to 8% for Mig-21M and Mig-21bis.

Minimum Sustained Turn Radius At 30,000ft, the Mig-21MF can turn inside the F-5E all along the possible speed range.

The comparative performances of the 4 aircrafts at their maximum minimum sustained turn radius speed are described in the following table and diagram:


The advantage goes to the Mig-21MF, all over the speed range (as stated before), Mig-21M is close to the MF, then the F-5E, and last the heavy Mig-21bis.


A Mig-21MF driven by a high-skilled pilot has the best performances over all turning criteria at 30,000ft bellow M0.75 / 290Kts IAS: quickest half turn, best sustained turn rate or radius. The F-5E pilot can only take advantage of a better turn rate between 290 and 330Kts. If the Mig-21MF pilot can chose its combat speed according the desired tactic he will keep an advantage in both offensive and defensive turn maneuver.

For and older Mig-21M, the advantage is not so clear, but it keep a quicker half turn and a better turn radius at low speed, so the pilot would prefer a low speed dogfight.

The heavier Mig-21bis had a slower half turn, high speed turn rate and a higher low speed turn radius, so the pilot would prefer avoiding dog-fighting versus F-5E at 30,000ft.

All Mig-21 can take advantage of the quickest first half turn, and then get in a low speed, low radius fight, Mig-21MF can even chose to go in a medium speed (250Kts) turn rate fight at its advantage.

In general, F-5E pilot would not be in good position in accepting a dog-fight versus a Mig-21 at this altitude, he would have superior performance only against old (Mig-21M) or heavy (Mig-21bis), or in a very small speed range (290-330Kts) against a Mig-21MF.


Non turning climb. The figures bellow shows that the Mig-21MF generally climbs faster than the F-5E. This is obvious in supersonic domain (that is not really relevant in close air combat as it is in an interceptor role), and the difference is much less significant at low speed. The only speed domain where the F-5E climbs better is the high-subsonic (M0.85/M0.92), and even there, the advantage is not so large.

The “constant speed climb rate” of each aircraft at 30,000 ft is described in figure 3.5 . The value (in ft /s) is the climb

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Sust

ain

ed

Tu

rn R

ate

(d

/s)

Cas (Kts)

F-5E-3

Mig-21MF

STR

deg/s

Turn

Radius (ft)at Mach

Time for

360

F-5E-3 5.76 7,917 0.80 63

Mig-21M 5.33 8,454 0.79 68

Mig-21MF 5.58 7,881 0.77 65

Mig-21bis 5.35 11,515 1.08 67

0

5,000

10,000

15,000

20,000

25,000

30,000

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Sust

ain

ed

Tu

rn R

adiu

s (f

t)

CAS (Kts)

F-5E-3

Mig-21MF

STR

deg/s

Turn

Radius (ft)at Mach

Time for

360

F-5E-3 4.10 6,955 0.50 88

Mig-21M 4.44 6,166 0.48 81

Mig-21MF 4.62 5,924 0.48 78

Mig-21bis 4.01 7,109 0.50 90

30,000 ft

0

50

100

150

200

250

300

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Clim

b R

ate

(ft

/s)

CAS (Kts)

F-5E-3

Mig-21MF



rate when fly path is adjusted to keep constant True Air Speed with Full After Burner engaged with Full (or Special) After Burner engaged.

We can see that the Mig-21 have a better maximum climb rate (243 ft/s for the 21M, 274 ft/s for 21MF, 304 ft/s for the 21bis) that the F-5E (235 ft/s), but these values are not reached at the same speed: when F-5E get its best climb rate in subsonic (M0.9 / 350 Kts IAS), Mig-21 get their own in low supersonic (M1.1 / 425 Kts IAS).

If we restrict the analysis to subsonic flight F-5E get the best climb rate at Mach 0.9: 235 ft/s compared to 197, 212 and 219 for respectively 21M, MF and bis.

If all aircraft keep a constant speed of mach 0.9 / 350 Kts indicated, the 2,000ft gain will require 8.4 seconds for the F-5E during the same time

- Mig-21M gains 1,676 ft (348 ft lower) - Mig-21MF gains 1,778ft (222 ft lower) - Mig-21bis gains 1,843 ft (157 ft lower).

That means that if the F-5E pilot want to use his climb speed to break a high speed subsonic dogfight (M0.9 / 350Kts indicated) fight and evade in climbing in , he can do it against a Mig-21M, it will be more difficult against a Mig-21MF and quite inefficient against a Mig-21bis.

If we consider the same scenario where the pilot want to evade a low speed dogfight (M0.5 / 185 Kts indicated) by climbing at constant speed, the situation is quite inverted:

- The Mig-21bis requires 16.6 s to gain 2,000ft, during this time the F-5E will gain only 1,540 ft (460 ft lower)

- The Mig-21MF requires 16.7 s to gain 2,000ft, during this time the F-5E will gain only 1,547 ft (453 ft lower)

- The Mig-21M requires 18.3 s to gain 2,000ft, during this time the F-5E will gain only 1,693 ft (307 ft lower)

Meaning that all Mig-21 can evade a low speed dogfight (IAS < 200 Kts) in climbing, but the F-5E cannot.

The last case is the one where all planes are in low supersonic fight (at M1.1 / 425 Kts indicated) and try to evade in climbing:

- The Mig-21bis require 6.6 s to gain 2,000ft, during this time the F-5E will gain only 625 ft (1,375 ft lower)

- The Mig-21MF require 7.3 s to gain 2,000ft, during this time the F-5E will gain only 693 ft (1,307 ft lower)

- The Mig-21M requires 8.2 s to gain 2,000ft, during this time the F-5E will gain only 781 ft (1,219 ft lower)

Meaning that all Mig-21 can evade a low supersonic speed in climbing, but the F-5E cannot.

So the non-turning climb rate comparison gives the advantage to the Mig-21 at low (IAS < 200 Kts) and supersonic speed (M1.1 / 425 Kts indicated), when the high subsonic (M0.9 / 350 Kts indicated) case see the F-5E better than all Mig-21.

Turning Climb. The figure bellow shows that the Mig-21MF climbs generally faster than the F-5E in a 2G turn, except in the speed domain of close air combat at this altitude, from 270Kts to 370Kts, the F-5E climbs faster. The advantage of the Mig-21MF in supersonic domain is very helpful in the last minutes of a high-speed/high altitude rear aspect interception, but not after the fight is really engaged, speed falling to subsonic quite immediately.

The “constant speed, constant 2G climb rate” of each aircraft at 30,000 ft is described in figure 3.6 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed and G-Load to 2.0 with Full After Burner engagedwith Full (or Special) After Burner engaged.

In a high subsonic (M0.9 / 350 Kts indicated) 2G turn, the F-5E get the best climb rate. The turn rate is the same for all and allows a quarter turn in 25.2 sec (3.57 d/s), during this time,

- The F-5E will gain 3,688 ft (146 ft/s) - The Mig-21M will gain 2,479 ft (98 ft/s) and so will

be 1,209 ft lower. - The Mig-21bis will gain 2,720 ft (108 ft/s) and so

will be 970 ft lower. - The Mig-21MF will gain 2,866 ft (114 ft/s) and so

will be 968 ft lower.

In all case, it is obvious that the F-5E can evade a high-speed dogfight with such a maneuver, even against the best Mig-21, it will gain 900ft in a quarter of a turn.

On the opposite, it is clear that as soon as both aircrafts enter a supersonic turn (Mach 1.1 / 425 Kts indicated), all Mig-21 can evade in a 2G turn climbing, as the F-5E is not even able to climb (less than 20 ft/s) when Mig-21 can reach 165 ft/s (21M), 195 ft/s (21MF) and 214 ft/s (21bis). But this cannot be used by the Mig-21 to evade a subsonic fight as it requires more than 20s to go from M0.9 to M1.1 (350 to 425 Kts indicated).

Acceleration performances. Focusing on Mig-21MF vs. F-5E give the following figures:

0

50

100

150

200

250

0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800

Clim

b R

ate

(ft

/s)

CAS (Kts)

F-5E-3

Mig-21MF



If both planes start their run at 185Kts indicated (M0.5, end of a hard turn), Mig-21MF can be 4.3Nm behind or 40s late. That means, that if both planes are close together at this speed, but facing each other, the F-5E deciding to accelerate straight forward, the Mig-21MF can make a half turn at constant speed (requiring less than 40s) then accelerate and find a firing solution less than 3 minutes after the first cross.

If all planes start their run at 350Kts indicated (M0.9), Mig-Mig-21MF can be 6Nm behind or 38s late

If both planes are close together at this high subsonic speed, but facing each other, the F-5E deciding to accelerate straight forward, the Mi-21MF can make a half turn at constant speed (requiring no more than 35s as explained in high speed turn performance section), then accelerate and find a firing solution less than 3 minutes after the first cross.

The distance covered in 3 minutes by Mig-21 and F-5E at 30,000 ft, all planes starting at mach 0.5 (185 Kts indicated) is described in figure 3.7.

The same distance when all planes start at mach 0.9 (350 Kts indicated) is in figure 3.8.

In any configuration, the F-5E is slower than any Mig-21, and Mig-21MF and Mig-21bis are very close.

Comparison with Mig-21bis gives:

If both planes start their run at 185Kts indicated (M0.5, end of a hard turn), Mig-21bis can be 6Nm behind the F-5E and rejoin it in less than 3 minutes.

Meaning the Mi-21bis can make a half turn at constant speed (requiring less than 45s), then accelerate and find a firing solution less than 3 minutes after the first cross.

If all planes start their run at 350Kts indicated (M0.9), Mig-21bis can be 7Nm behind the F-5E and rejoin it in less than 3 minutes.

Comment: if the Mig-21 choose the quickest half turn instead of constant speed one, the end of turn speed will not allow it to rejoin the F-5E in 3 minutes, so the good strategy for the Mig-21 at merge if the pilot see the F-5E trying to avoid the combat is clearly a constant high speed half turn.

Conclusion. At 30,000ft, the Mig-21MF has, compared to the F-5E-3, a quicker half turn, a better maximum sustained turn rate except between M0.75 and M0.9, a smaller minimum turn radius, it can rejoin it being 6 Nm behind or 40 second late, it has also a better equivalent maximum climb rate, even if it is true only when supersonicxcept between mach 0.85 and 0.95.

The only advantage of the F-5E in such a configuration is its high subsonic turning climb rate that can be used to go out the dogfight or better high speed turn rate if the Mig-21 stays in this speed range (M0.75-0.985).

So, it is easy to say that the Mig-21MF has a global advantage over the F-5E at this altitude especially is speed goes below M0.75, or become supersonic.

For the Mig-21M, the situation is similar at low speed (under 250Kts indicated), but the F-5E may take advantage of its better high subsonic turn capabilities in offensive maneuver, and of its subsonic climb rate to quit.

The Mig-21bis is clearly not at its advantage at this altitude in offensive sector, but it can disengage by accelerating, and F-5E will never be able to re-engage.

If we try to graphically represent the main seven values:

- Average turn rate during quickest half turn - Maximum Sustained Turn rate - 1000ft / Minimum Sustained Turn Radius - Maximum Subsonic lLevel flight Climb Rate (Mach

< 0.9) - Maximum Subsonic Turning Climb Rate (Mach <

0.9) - Distance Covered in 3’ from Mach 0.5 - Distance Covered in 3’ from Mach 0.9

In normalizing them (in percentage of the best value), we get the following diagram:

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF



F. Ogaden War: Combat over “Gode”

Aircraft configuration. F-5E-3 take off from Dire Dawa airbase in Ethiopia for Gode Mig CAP station which is positioned 50 km (30 Nm) from Gode in direction of Baidoa Mig base in Somalia. Mission is to protect F-5A strike in vicinity of Gode. Weapons load is two AIM-9B-2 and full gun ammo. Fuel load is full internal fuel and one 275Gal external fuel tank on CL station.

Mig-21MF take-off from Baidoa, weapons load is two R-3S missiles and full gun ammo. Fuel load is full internal fuel and one 765l external fuel tank on CL station.

Mig-21MF “Gode” configuration. At break release before take off the Mig-21MF have 2,480kg of fuel

Take off and climb to optimum cruise altitude of 9,000m leave it with 1,956 kg of fuel

CGI radar at Baidoa airbase vector the MIGs to F-5E, after external fuel is used, Mig-21 jettison their 765l tank from center line stations.

At 10 Nm (18 Km), visual contact is established, MIGs are accelerating to combat speed 10Nm from Gode MIG CAP Station to engage F-5E.

Mig-21MF configuration at start of combat (1,708 kg or 2,058l of fuel) defines a gross weight of 17,337 lbs (7,854 kg) and a Drag Index of 12.

Clean Aircraft (no fuel) : 5,760 kg 200 gun ammo (Gsh 23) : 75 kg 2 Under-wing pylon : 45 kg 1 Center line pylon : 24 kg 2 Missile rails for R-3S : 41 kg 2 Missile R-3S : 150 kg internal fuel : 1,708 kg This gross weight leads to the following load factor limitation: For Mach number lower than 0.8 : 7.0 G For Mach number greater than 0.8 : 6.0 G

F-5E-3 “Gode” configuration. At break release before take off the F-5E have 6,077lbs of fuel

Military thrust climb to optimum cruise altitude of 30,000ft is made to conserve fuel more time on MIG CAP Station. At top of climb, remaining fuel is 4,782 lbs.

All the way to MIG CAP station fighters receive information from ground radar at Marda pass. After external fuel is used, tank is not released (as fuel tanks are very soon used up in the war). It will be jettisoned only if combat occurs. After reaching Gode MIG CAP station, F-5E are resuming racetrack orbit pattern at 30,000ft.

At start of MIG CAP orbit remaining fuel is 3,879lbs.

In this scenario, Marda radar informs F-5E of several contacts taking off from Baidoa MIG base in Somalia and they meet the Mig with a remaining fuel load of 3,077 lbs.

F-5E-3 combat configuration at start of combat is Drag Index of 38. Clean Aircraft (no fuel, pilot) : 10,659 lbs DI 2 Gun ammo : 394 lbs DI +0 2 Missiles AIM-9 : 340 lbs DI +18 2 Missile rails for AIM-9 : 98 lbs DI +0 2 Under wing Hook : 0 lbs DI +4 1 Center Line pylon : 170 lbs DI +14 Zero fuel weight : 11,661 lbs Internal fuel (JP-4) : 3,077 lbs (68%)

Gross weight : 14,738 lbs

Entering the fight at 20,000ft In this section we will analyze the situation where the two opponents meet at medium altitude (20,000ft) with the gross weight defined previously. It seems to be compliant with the reported combat where merge occurred around 18,000ft.

Compared to the “Combat configuration” sections, we will see that the Mig-21MF is disadvantaged, because he has, in proportion, more fuel than the F-5E (88% of its internal capacity compared to 68%).



The F-5E-3 start its half turn at Mach 0.90 and end if in 16s at Mach 0.36 (167Kts IAS) with an average turn radius of 2,728ft.

Mig-21MF with AoA limited to max lift start its half turn at Mach 0.95 end its half turn in 16.0s (same time) at Mach 0.52 (241 Kts IAS) with an average turn radius of 3,763 ft.


0%

25%

50%

75%

100%




Max subsonic Climb rate




F-5E3

Mig-21M

Mig-21MF

Mig-21bis





Mig-21MF and F-5E need the same time to do the quickest half turn (if the Mig-21MF is flew to its max lift), and more do it with a much smaller radius, this will give the F-5E a very small advantage at the merge at this altitude.

Maximum Sustained Turn Rate The sustained turn rate of the 2 aircrafts are described the appendix section, fig.4.3.

The F-5E sustained turn rate is superior to the Mig-21MF one between Mach 0.34 and 0.9 (160Kts – 425Kts).

The difference between maximum values (7.7 d/s for F-5E and 6.9 for Mig-21MF) is not critical but give a constant advantage in offensive turn maneuver to the F-5E in quite all the subsonic area.

Minimum Sustained Turn Radius. The sustained turn radius of the 2 aircrafts are described the appendix section, fig.4.4.

The graphic shows clearly that the minimum radius goes to the F-5E, (but the difference remains very small: 80 ft) and there is no real advantage at low speed for the Mig-21MF.

Both aircraft have similar performance in defensive turn maneuver.

In general, at 20,000 ft is this particular configuration, the F-5E will have a marginal advantage at the merge, will keep it in sustained turn combat all along the speed range, and Mig-21MF does not even has its usual very low speed advantage.

If the tactical configuration of the engagement is not clearly in favor of the Mig-21MF, I will not be surprise the F-5E taking the advantage upon his opponent in a turn fight.


Non turning climb. The “constant speed climb rate” of each aircraft at 20,000 ft is described in figure 4.5 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed with Full (or Special) After Burner engaged.

We can see that the Mig-21MF and F-5E-3 have very similar climb rate up to Mach 0.9, with a small advantage to the F-5E, then, going supersonic the advantage changes to Mig21MF.

At mach 0.9 (425Kts IAS) the difference is really small (304ft/s versus 287) : when F-5E gains 2,000ft (in 6.6 s), the Mig-21MF gains 1,884 ft, and a difference of 116ft is not enough to say the higher plane has evade the turn fight this way.

If we consider the same scenario where the pilot want to evade a low speed dogfight (M0.5 / 230Kts indicated) by climbing at constant speed, we can see that the situation is the same, when F-5E gains 2,000ft (in 12.9 s), the Mig-21MF gains 1,892 ft, and a difference of 108ft is not enough to say the higher plane has evade the turn fight this way.

So the non-turning climb rate comparison gives no clear advantage, nor the F-5E, nor can the Mig-21MF evade a turn fight in just climbing, nor at low speed, neither at high subsonic speed.

Turning Climb. The “constant speed, constant 3G climb rate” of both aircraft at 20,000 ft is described in figure 4.6 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed and G-Load to 3.0 with Full (or Special) After Burner engaged.

In a high subsonic (M0.9 / 425Kts IAS) 3G turn, the F-5E get the best climb rate. The turn rate is the same for all and allows a quarter turn in 16.1 sec (5.6 d/s), during this time, the F-5E will gain 2,081 ft (129 ft/s), and the Mig-21MF will gain 1,473 ft (91 ft/s) and so will be 608 ft lower.

The F-5E can evade a high-speed dogfight with such a maneuver, it will gain 200ft in a quarter of a turn.

Acceleration performances. The distance covered in 3 minutes by Mig-21MF and F-5E at 20,000 ft, starting at mach 0.5 (230Kts indicated) is described in figure 4.7.


In any configuration, the Mig-21MF is faster than the F-5E.

If both planes start their run at 425Kts indicated (at the merge or in the middle end of a high G turn) Mig-21MF can rejoin the F-5E in 3 minutes being 21s late (time required to perform quite a 180deg turn at 425Kts) or 4.0Nm behind.

If both planes start their run at 230Kts indicated (end of a hard turn) Mig-21MF can rejoin the F-5E in 3 minutes being 24s late (time required to perform a 150deg turn at 250Kts) or 2.55Nm behind.

That means, that if both planes are merging or engaged in a turn, whatever the speed is, the F-5E cannot evade in simply accelerating, except if he has more than a half turn advance, on the other hand, Mig-21MF can evade quite easily this way.

Conclusion. At 20,000ft, the Mig-21MF can force the F-5E to the fight (if the F-5E localize its opponent at 4Nm or less), but as soon he will enter a turn fight, the F-5E will have the advantage.

The F-5E keeps the ability to break a turn fight in turn climbing, where the Mig-21MF cannot follow, if he goes to a bad situation. On the opposite, the Mig-21MF can also quit the dogfight in level-flight acceleration.



The Mig-21MF would take advantage of boom-and-zoom tactics at high (and even supersonic) speed, when the F-5E will try to enter a more classical turning dogfight.


Entering the fight at 1,500ft In this section we will analyze the situation where the two opponents meet at low altitude (1,500ft) with the gross weight defined previously.

Compared to the “Combat configuration” sections, we will see that the Mig-21MF is disadvantaged, because he has, in proportion, more fuel than the F-5E (88% of its internal capacity compared to 68%).



The quickest half turn of the F-5E-3 start at Mach 0.71 (460Kts IAS) and end in 9.6s at Mach 0.36 (230Kts IAS) with an average turn radius of 1,753ft.

Mig-21MF with AoA limited to max lift start at Mach 0.70 (450Kts IAS) and end in 10.6s (+2.0s) at Mach 0.33 (214Kts IAS) with an average turn radius of 1,925ft.


The quickest half turn of the Mig-21MF with AoA limited 28 start at Mach 0.70 (450Kts IAS) and end in 12.2s (+2.6s) at Mach 0.55 (350Kts IAS) with an average turn radius of 2,600ft.


It can be seen easily that the F-5E do the quickest half turn (2 or 3s, so 20 or 30% more), and more do it with a much smaller radius, this will give the F-5E a real advantage at the merge at this altitude.

Maximum Sustained Turn Rate The sustained turn rate of the 2 aircrafts are described the appendix section, fig.5.3.

The F-5E sustained turn rate is superior to the Mig-21MF one between Mach 0.2 and maximum speed around Mach 1.0 (145Kts – 645Kts).

The difference between maximum values (13.6 d/s for F-5E and 10.8 for Mig-21MF) give a constant advantage in offensive turn maneuver to the F-5E in quite all the speed domain.

Minimum Sustained Turn Radius. The sustained turn radius of the 2 aircrafts are described the appendix section, fig.5.4.

The graphic shows clearly that the minimum radius goes to the F-5E, (but the difference remains very small: 190 ft).

In general, at 1,500 ft is this particular configuration, the F-5E will have a clear advantage at the merge (quickest half turn), will keep it in sustained turn combat quite all along the speed range.

The Mig-21MF will clearly be disadvantaged facing an F-5E in a turn fight in such a configuration.


Non turning climb. The “constant speed climb rate” of each aircraft at 1,500 ft is described in figure 5.5 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed with Full (or Special) After Burner engaged.

We can see that the F-5E-3 has a better climb rate than the Mig-21MF over the complete speed range.

At their best climb speed, when F-5E gains 2,000ft in 4.5s (at mach 0.9 - 580Kts IAS), the Mig-21MF only gains 1,546 ft, 454ft lower (at mach 0.8).

If we consider the same scenario where the pilot want to evade a low speed dogfight (M0.5 / 325Kts indicated) by climbing at constant speed, when F-5E gains 2,000ft (in 6.9s), the Mig-21MF gains 1,648 ft, and a difference of 352ft is enough to say the higher plane has evade the turn fight this way.

So the non-turning climb rate comparison gives a clear advantage, to the F-5E. The Mig-21MF cannot evade a turn fight in just climbing, nor at low speed, neither at high subsonic speed.

Turning Climb. The “constant speed, constant 4G climb rate” of both aircraft at 1,500 ft is described in figure 5.6 . The value (in ft /s) is the climb rate when fly path is adjusted to keep constant True Air Speed and G-Load to 4.0 with Full After-Burner engaged.

In a high subsonic (M0.9 / 580Kts IAS) 4G turn, the F-5E get the best climb rate with a large margin, its turn rate allows a quarter turn in 12.6 sec (7.15 d/s), during this time, the F-5E will gain 3,730 ft (296 ft/s), The Mig-21MF, at M0.8/515Kts get a turn rate of 8.4 d/s allowing a quarter of turn in 11.2s and it will gain 1,408 ft (126ft/s) and so will be

0%

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F-5E3

Mig-21MF



2,322 ft lower, even if the Mig-21MF chose to keep a M0.9 speed, it will gain only 786 ft (62ft/s) and so will be 2,944 ft lower.

The F-5E can evade a high-speed dogfight with such a maneuver; it will gain at least 2,300ft in a quarter of a turn.

Acceleration performances. The distance covered in 3 minutes by Mig-21MF and F-5E at 1,500 ft, starting at mach 0.5 (325Kts indicated) is described in figure 5.7.


In any configuration, the F-5E is faster than the Mig-21MF, but the difference is never significant.

None of the plane can force the other to the combat (if detected at more than weapon range), nor evade a turn fight in a level-flight acceleration.

Conclusion. At 1,500ft, no one can force the other to the fight (if detected at more than weapon range, let’s say 1Nm), but as soon they enter a turn fight, the F-5E will have significant advantage in both offensive and defensive turn maneuver.

The F-5E is the only one having the ability to break a turn fight (in turn climbing)

The Mig-21MF would take a high risk in engaging a dog-fight at such an altitude in front of the F-5E, and cannot even use boom-and-zoom tactics if he has not a significant altitude advantage.


G. Conclusion. The first general statement that can be made is that the two aircraft families (Mig-21 and F-5E) are quite similar in term of air combat performances, at least for the one discussed here (turn rates, climb rates, acceleration).

This is to be related to the choice of USAF and US Navy to use one (the F-5E) to simulate the other one (Mig-21) in “Aggressor” squadrons.

But this relative similarity needs to be restricted: if performances of the two planes are close together in the sub-sonic (and transonic) domain, it must be said that Mig-21 have been designed as supersonic (Mach 2) interceptors, when this role cannot be assumed by F-5E. If we compare supersonic climb performances or acceleration, the gap is huge. Mig-21M and MF can fly supersonic (M1.2+) over 15,000ft, that means that bellow this flight level the similarity with F-5E is fully valid.

If we focus on Mig-21MF versus F5-E3 at their respective combat configuration, we can say in few words:

- At high altitude (30,000ft and more), the Mig-21MF turn better, climb better and accelerate better.

- At medium altitude (around 15,000ft), both have same turning capabilities at low and medium speed, F-5E turn better at high speed, climb better (specially in turn climb), acceleration are similar, those giving to the F-5E only the capability to quit an engaged dogfight in climbing.

- At low altitude (5,000ft and less) the F-5E turn better, climb better and accelerate like the Mig-21MF, meaning that the Mig-21 cannot quit a dog-fight where he is not at its advantage.

We also have to take in mind that these comparisons can be heavily modified if the conditions change (even not a lot). In the case of the Ogaden war engagement described here (Combat over Gode), we can see that a small modification of the relative gross weight (remaining fuel quantity) change the balance: according to regular “combat configuration” analysis, we would guess that the Mig-21MF takes the advantage on the F-5E at 20,000ft, but when it goes to facts, this small weight condition modification reverse the balance and put the F-5E on top.

Compared to Mig-21MF, the situation of the Mig-21M is simple to understand: just one step below the MF, everywhere.

If we assume that most of the air combats occur at medium or low altitude, we have to admit that the Mig-21 family, up to the Mig-21MF, has to be considered as a bit inferior to the F-5E in term of operational efficiency if we do not take into account the interceptor role, but only the Close Air Combat.

This analysis helps us to understand what was the purpose of the Mig-21bis: focus on low altitude high speed domain to give back the advantage to the Mig-21. This aim has been reached: even if low altitude (5,000ft and below) turn performances of the Mig-21bis stay a bit under the F-5E, there is no more a significant advantage to the F-5E in this domain and Mig-21bis climb rate, acceleration and pure speed allow him to engage and disengage the fight when he wants.

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F-5E3

Mig-21MF



These improvements at low level are paid by a reduction of the performances at medium and high altitude (15,000ft and above), making the Mig-21bis a kind of ‘specialized’

Mig-21, but they give it the superiority on its opponent (at least the F-5E) in several common combat conditions.


H. Appendix and Figures

Fig.1.1 F-5E and Mig-21MF ‘max lift’ quickest half turn at 15,000ft

Fig.1.2 F-5E and Mig-21MF ‘AoA < 28’ quickest half turn at 15,000ft

0

4,000

8,000

0 4,000 8,000

AC1 Path

AC2 Path

1 shoot 22 shoot 1AC1-5s

AC2-5s

F-5E Mig-21MF

t = 0smach = 0.92Ng = 7.33

t = 0smach = 0.87Ng = 6.00

t = 2smach = 0.86Ng = 7.33

t = 6smach = 0.71Ng = 7.33

t = 2smach 0.85Ng = 6.00

t = 10smach = 0.62Ng = 5.37

t = 13.2smach = 0.52Ng = 3.99

t = 10.8smach = 0.43Ng = 3.23

t = 12smach = 0.56Ng = 4.44

t = 8smach = 0.56Ng = 5.46

t = 4smach = 0.79Ng = 7.33

t = 10smach = 0.47Ng = 3.96

t = 4smach 0.83Ng = 6.00

t = 6smach 0.80Ng = 6.00

t = 8smach = 0.70Ng = 6.53

0

4,000

8,000

0 4,000 8,000

AC1 Path

AC2 Path


AC2-5s

F-5E Mig-21MF

t = 0smach = 0.92Ng = 7.33

t = 0smach = 0.87Ng = 6.00

t = 2smach = 0.86Ng = 7.33

t = 6smach = 0.71Ng = 7.33

t = 2smach 0.85Ng = 6.00

t = 10smach = 0.73Ng = 5.42

t = 14.4smach = 0.68Ng = 4.64

t = 10.8smach = 0.43Ng = 3.23

t = 12smach = 0.70Ng = 5.02

t = 8smach = 0.56Ng = 5.46

t = 4smach = 0.79Ng = 7.33

t = 10smach = 0.47Ng = 3.96

t = 4smach 0.83Ng = 6.00

t = 6smach 0.80Ng = 6.00

t = 8smach = 0.76Ng = 5.93

t = 14smach = 0.68Ng = 4.70



Fig.1.3. F5-E and Mig-21 Sustained Turn Rate at 15,000ft

Fig.1.4. F5-E and Mig-21 Sustained Turn Radius at 15,000ft

Fig.1.5. F5-E and Mig-21 Constant Speed Climb Rate at 15,000ft

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

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Mig-21M

Mig-21MF

Mig-21bis

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis



Fig.1.6. F5-E and Mig-21 Constant Speed and 3G Load turn Climb, Rate at 15,000ft

Fig.1.7. F5-E and Mig-21 Distance covered in 3’, from mach 0.5 at 15,000ft


0

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Mach number

F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

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Dis

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis




Fig.2.2 F-5E and Mig-21MF ‘AoA < 28 quickest half turn at 5,000ft

0

2,500

5,000

0 2,500 5,000

AC1 Path

AC2 Path


AC2-5s

F-5E Mig-21MF

t = 0smach = 0.75Ng = 7.33

t = 0smach = 0.80Ng = 8.00

t = 2smach = 0.72Ng = 7.33

t = 6smach = 0.58Ng = 7.33

t = 2smach 0.76Ng = 8.00

t = 10smach = 0.45Ng = 4.63

t = 8smach = 0.46Ng = 5.59

t = 4smach = 0.67Ng = 7.33

t = 9.80smach = 0.40Ng = 4.20

t = 4smach 0.71Ng = 8.00

t = 6smach 0.63Ng = 8.00

t = 8smach = 0.53Ng = 5.99

0

3,000

6,000

0 3,000 6,000

AC1 Path

AC2 Path


AC2-5s

F-5E

Mig-21MF

t = 0smach = 0.75Ng = 7.33

t = 0smach = 0.80Ng = 8.00

t = 2smach = 0.72Ng = 7.33

t = 6smach = 0.58Ng = 7.33

t = 2smach 0.76Ng = 8.00

t = 10smach = 0.61Ng = 5.39

t = 8smach = 0.46Ng = 5.59

t = 4smach = 0.67Ng = 7.33

t = 9.80smach = 0.40Ng = 4.20

t = 4smach 0.71Ng = 7.60

t = 6smach 0.68Ng = 6.72

t = 8smach = 0.64Ng = 6.08

t = 10smach = 0.62Ng = 5.58






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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

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Mach number

F-5E-3

Mig-21M

Mig-21MF

Mig-21bis






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Mach number

F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis




Fig.3.2 F-5E and Mig-21MF ‘AoA < 28’ quickest half turn at 30,000ft

0

5,000

10,000

-5,000 0 5,000

AC1 Path

AC2 Path


AC2-5s

F-5E Mig-21MF

t = 0smach = 0.90Ng = 6.45

t = 0smach = 0.9Ng = 5.31

t = 5smach = 0.66Ng = 3.73

t = 10smach = 0.50Ng = 2.29

t = 15smach = 0.43Ng = 1.70

t = 20smach = 0.38Ng = 1.37

t = 5smach 0.75Ng = 3.87

t = 15smach = 0.56Ng = 2.41

t = 22.6smach = 0.47Ng = 1.83

t = 25.6smach = 0.34Ng = 1.14

t = 20smach = 0.50Ng = 2.00

t = 10smach = 0.65Ng = 3.03

t = 25smach = 0.35Ng = 1.15

0

7,500

15,000

-7,500 0 7,500

AC1 Path

AC2 Path


AC2-5s

F-5E Mig-21MF

t = 0smach = 0.90Ng = 6.45

t = 0smach = 0.9Ng = 5.31

t = 5smach = 0.66Ng = 3.73

t = 10smach = 0.50Ng = 2.29

t = 15smach = 0.43Ng = 1.70

t = 20smach = 0.38Ng = 1.37

t = 5smach 0.83Ng = 3.78

t = 15smach = 0.75Ng = 3.01

t = 24.4smach = 0.70Ng = 2.65

t = 25.6smach = 0.34Ng = 1.14

t = 20smach = 0.72Ng = 2.79

t = 10smach = 0.78Ng = 3.34

t = 25smach = 0.35Ng = 1.15






0.00

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2.00

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7.00

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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Mig-21M

Mig-21MF

Mig-21bis

0

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Mach number

F-5E-3

Mig-21M

Mig-21MF

Mig-21bis






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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis

0

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F-5E-3

Mig-21M

Mig-21MF

Mig-21bis



Fig.4.1 F-5E and Mig-21MF ‘max lift’ quickest half turn at 20,000ft / Gode Configuration

Fig.4.2 F-5E and Mig-21MF ‘AoA < 28’ quickest half turn at 20,000ft / Gode Configuration

0

4,000

8,000

0 4,000 8,000

AC1 Path

AC2 Path


AC2-5s

F-5E Mig-21MF

t = 0smach = 0.90Ng = 7.33

t = 0smach = 0.95Ng = 6.00

t = 2smach = 0.78Ng = 7.22

t = 6smach = 0.55Ng = 4.02

t = 2smach 0.91Ng = 6.00

t = 16smach = 0.52Ng = 2.95

t = 14smach = 0.38Ng = 2.01

t = 4smach = 0.66Ng = 5.42

t = 16smach = 0.36Ng = 1.80

t = 4smach 0.87Ng = 6.00

t = 6smach 0.81Ng = 6.00

t = 12smach = 0.62Ng = 3.86

t = 14smach = 0.57Ng = 3.35

t = 12smach = 0.41Ng = 2.27

t = 10smach = 0.44Ng = 2.63

t = 8smach = 0.49Ng = 3.15

t = 10smach = 0.67Ng = 4.48

t = 8smach = 0.74Ng = 5.17

0

5,000

10,000

0 5,000 10,000

AC1 Path

AC2 Path


AC2-5s

F-5E

Mig-21MFt = 0smach = 0.90Ng = 7.33

t = 0smach = 0.95Ng = 6.00

t = 2smach = 0.78Ng = 7.22

t = 6smach = 0.55Ng = 4.02

t = 2smach 0.91Ng = 6.00

t = 17.4smach = 0.70Ng = 3.62

t = 14smach = 0.38Ng = 2.01

t = 4smach = 0.66Ng = 5.42

t = 16smach = 0.36Ng = 1.80

t = 4smach 0.87Ng = 5.79

t = 6smach 0.83Ng = 5.28

t = 12smach = 0.75Ng = 4.21

t = 14smach = 0.73Ng = 3.96

t = 12smach = 0.41Ng = 2.27 t = 10s

mach = 0.44Ng = 2.63

t = 8smach = 0.49Ng = 3.15

t = 10smach = 0.77Ng = 4.51

t = 8smach = 0.80Ng = 4.86

t = 16smach = 0.71Ng = 3.75



Fig.4.3. F5-E and Mig-21 Sustained Turn Rate at 20,000ft / Gode Configuration

Fig.4.4. F5-E and Mig-21 Sustained Turn Radius at 20,000ft / Gode Configuration

Fig.4.5. F5-E and Mig-21 Constant Speed Climb Rate at 20,000ft / Gode Configuration

0.00

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Mach number

F-5E-3

Mig-21MF

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

0.00 0.50 1.00 1.50 2.00

Sust

ain

ed

Tu

rn R

adiu

s (f

t)

Mach number

F-5E-3

Mig-21MF

0

50

100

150

200

250

300

350

0.00 0.50 1.00 1.50 2.00

Clim

b R

ate

(ft

/s)

Mach number

F-5E-3

Mig-21MF



Fig.4.6. F5-E and Mig-21 Constant Speed and 3G Load turn Climb, Rate at 20,000ft / Gode Configuration

Fig.4.7. F5-E and Mig-21 Distance covered in 3’, from mach 0.5 at 20,000ft / Gode Configuration


0

20

40

60

80

100

120

140

0.00 0.50 1.00 1.50 2.00

Clim

b R

ate

(ft

/s)

Mach number

F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

40

45

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)

Distance covered at 20,000 ft, start at Mach 0.9/ IAS 425Kts

F-5E-3

Mig-21MF



Fig.5.1 F-5E and Mig-21MF ‘max lift’ quickest half turn at 1,500ft / Gode Configuration

Fig.5.2 F-5E and Mig-21MF ‘AoA < 28’ quickest half turn at 1,500ft / Gode Configuration

0

3,000

6,000

0 3,000 6,000

AC1 Path

AC2 Path

1 shoot 2

2 shoot 1

AC1-5s

AC2-5s

F-5E

Mig-21

t = 0smach = 0.71Ng = 7.33

t = 0smach = 0.73Ng = 7.00

t = 2smach = 0.67Ng = 7.33

t = 4smach = .59Ng = 7.33

t = 6smach = .48Ng = 6.26

t = 8smach = .40Ng = 4.42

t = 2smach 0.69Ng = 7.00

t = 4smach = 0.64Ng = 7.00

t = 6smach = 0.54Ng = 7.00

t = 8smach = 0.41Ng = 4.52

t = 9.6smach = 0.36Ng = 3.58

t = 10smach = 0.30Ng = 3.03

t = 10.4smach = 0.28Ng = 2.77

0

3,000

6,000

0 3,000 6,000

AC1 Path

AC2 Path

1 shoot 2

2 shoot 1

AC1-5s

AC2-5s

F-5E

Mig-21

t = 0smach = 0.71Ng = 7.33

t = 0smach = 0.76Ng = 7.00

t = 2smach = 0.67Ng = 7.33

t = 4smach = .59Ng = 7.33

t = 6smach = .48Ng = 6.26

t = 8smach = .40Ng = 4.42

t = 2smach 0.72Ng = 7.00

t = 4smach = 0.70Ng = 7.00

t = 6smach = 0.65Ng = 6.88

t = 8smach = 0.60Ng = 5.84

t = 9.6smach = 0.36Ng = 3.58

t = 10smach = 0.56Ng = 5.17

t = 11.4smach = 0.54Ng = 4.80



Fig.5.3. F5-E and Mig-21 Sustained Turn Rate at 1,500ft / Gode Configuration

Fig.5.4. F5-E and Mig-21 Sustained Turn Radius at 1,500ft / Gode Configuration

Fig.5.5. F5-E and Mig-21 Constant Speed Climb Rate at 1,500ft / Gode Configuration

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

0.00 0.50 1.00 1.50 2.00

Sust

ain

ed

Tu

rn R

ate

(d

/s)

Mach number

F-5E-3

Mig-21MF

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

0.00 0.50 1.00 1.50 2.00

Sust

ain

ed

Tu

rn R

adiu

s (f

t)

Mach number

F-5E-3

Mig-21MF

0

50

100

150

200

250

300

350

400

450

500

0.00 0.50 1.00 1.50 2.00

Clim

b R

ate

(ft

/s)

Mach number

F-5E-3

Mig-21MF



Fig.5.6. F5-E and Mig-21 Constant Speed and 4G Load turn Climb, Rate at 1,500ft / Gode Configuration



0

50

100

150

200

250

300

350

0.00 0.50 1.00 1.50 2.00

Clim

b R

ate

(ft

/s)

Mach number

F-5E-3

Mig-21MF

0

5

10

15

20

25

30

35

0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF

0

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0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180

Dis

tan

ce (

Nm

)

time (s)


F-5E-3

Mig-21MF



I. Bibliography. All documents mentioned here can be found in Acrobat Reader (.pdf) format at http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21 Mikoyan-Gourevitch Mig-21 performances:

- Mig-21-Flight Model Identification, by J.M. LANGERON - NATOPS_FLIGHT_MANUAL-Mig-21M, by J.M. LANGERON - NATOPS_FLIGHT_MANUAL-Mig-21MF, by J.M. LANGERON - NATOPS_FLIGHT_MANUAL-Mig-21bis, by J.M. LANGERON

Northrop F-5E Tiger II performances: - NATOPS_FLIGHT_MANUAL-F-5E-2, by J.M. LANGERON - NATOPS_FLIGHT_MANUAL-F-5E-3, by J.M. LANGERON

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/Mig-21-Flight%20Model%20Identification.pdf

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/NATOPS_FLIGHT_MANUAL-Mig-21M.pdf

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/NATOPS_FLIGHT_MANUAL-Mig-21MF.pdf

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/NATOPS_FLIGHT_MANUAL-Mig-21bis.pdf

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/NATOPS_FLIGHT_MANUAL-F-5E-2.pdf

http://www.checksix-fr.com/downloads/falcon4/Topolo/zip/Project-21/NATOPS_FLIGHT_MANUAL-F-5E-3.pdf



Table of Contents A. Introduction ................................................................................................................................................................................ 1

B. Methodology description. ........................................................................................................................................................... 1

Aircraft configuration definition. .................................................................................................................................................... 1

Mig-21M combat configuration. ................................................................................................................................................. 1

Mig-21MF combat configuration. ............................................................................................................................................... 1

Mig-21bis combat configuration. ................................................................................................................................................ 2

F-5E-3 combat configuration. ..................................................................................................................................................... 2

Critical performances to be compared. .......................................................................................................................................... 2

Turning ........................................................................................................................................................................................ 2

Climbing ...................................................................................................................................................................................... 2

Acceleration ................................................................................................................................................................................ 2

C. Medium level combat (15,000ft). ............................................................................................................................................... 2

Turning performances. ................................................................................................................................................................... 2

Quickest half turn ....................................................................................................................................................................... 2

Maximum Sustained Turn Rate ................................................................................................................................................... 3

Minimum Sustained Turn Radius ................................................................................................................................................ 3

Climbing performances. .................................................................................................................................................................. 4

Non turning climb. ...................................................................................................................................................................... 4

Turning Climb. ............................................................................................................................................................................. 4

Acceleration performances. ............................................................................................................................................................ 5

Conclusion. ...................................................................................................................................................................................... 5

D. Low level combat (5,000ft). ........................................................................................................................................................ 6




Minimum Sustained Turn Radius ................................................................................................................................................ 7

Climbing performances. .................................................................................................................................................................. 7

Non turning climb. ...................................................................................................................................................................... 7

Turning Climb. ............................................................................................................................................................................. 8

Acceleration performances. ............................................................................................................................................................ 8

Conclusion. ...................................................................................................................................................................................... 9

E. High level combat (30,000ft). ..................................................................................................................................................... 9




Minimum Sustained Turn Radius .............................................................................................................................................. 10

Climbing performances. ................................................................................................................................................................ 10

Non turning climb. .................................................................................................................................................................... 10

Turning Climb. ........................................................................................................................................................................... 11

Acceleration performances. .......................................................................................................................................................... 11

Conclusion. .................................................................................................................................................................................... 12

F. Ogaden War: Combat over “Gode” .......................................................................................................................................... 13



Aircraft configuration. ................................................................................................................................................................... 13

Mig-21MF “Gode” configuration. ............................................................................................................................................. 13

F-5E-3 “Gode” configuration. .................................................................................................................................................... 13

Entering the fight at 20,000ft........................................................................................................................................................ 13

Turning performances. ............................................................................................................................................................. 13

Climbing performances. ............................................................................................................................................................ 14

Acceleration performances. ...................................................................................................................................................... 14

Conclusion. ................................................................................................................................................................................ 14

Entering the fight at 1,500ft.......................................................................................................................................................... 15

Turning performances. ............................................................................................................................................................. 15

Climbing performances. ............................................................................................................................................................ 15

Acceleration performances. ...................................................................................................................................................... 16

Conclusion. ................................................................................................................................................................................ 16

G. Conclusion. ................................................................................................................................................................................ 16

H. Appendix and Figures ................................................................................................................................................................ 18

I. Bibliography. ............................................................................................................................................................................. 33

Documents

Compared Air Combat Performances F-5E versus Mig-21