Vietnam Era MiG-21 top sea level speed?

[GalmOne 1]

I've been reading a lot recently on Vietnam air combat and have found differing figures for the MiG-21 top speed at sea level, particularly the MiG-21F-13.

 

Israel had received a MiG-21F-13 from an Iraqi defector. The US in turn received that same -21 from Israel then duly tested its capabilities in the HAVE Doughnut tests. They state that the fuel pump deficiencies and airframe design limited the maximum speed of the MiG-21F-13 to only 595 knots from sea level to 16000 feet. They say that at Ma = 0.93, the aircraft buffets severely: http://www.airforce-magazine.com/MagazineArchive/Documents/2010/June%202010/0610doughnut.pdf

 

Other websites like the MILAVIA database state that the -21F-13's top speed was ~ 809 mph at sea level.

 

If the MiG-21F-13 really had such limitations, how did this random "800+ mph" figure come from; calculations? Perhaps the Iraqi MiG-21F-13 was deficient and not reflective of other -21's of the same type? Did the North Vietnamese MiG-21F-13's perform the same as this Iraqi one?

Edited September 8, 2012 by GalmOne

[turkeydriver 4]

The later version of the MiG-21 supplied to Vietnam (MiG-21MF or ML?) had a revised intake and shockcone, plud other additions that gave it insane acceleration at low-level to deal with F-105s and F-4s. They had no problem catching and outrunning their American counterparts only they were limited by their tiny fuel tanks.

[GalmOne 1]

Ah yes, that's a more definitive MiG-21... the MiG-21MF. I'll go do my research on that. How would good pilots in the F-4E with slats and the F-8E/H fare against that version of the MiG?

 

So far, I've found that the -21MF seems to be almost 3000 lbs heavier than the standard MiG-21S which raises its wingloading approximately equal to W/S ~ 20723 lbs/247.60 ft^3 = 83.695 psf. This is a huge value while the F-8's wingloading is around 66 psf. albeit I used the max. weight I could find for the MiG-21MF.

Edited September 8, 2012 by GalmOne

[MigBuster 2,861]

For the actual technical figures Yefim Gordons books are pretty useful.

 

Figures by themselves arn't much use in determining actual combat performance - all the figures have to work together in a dynamic unpredictable environment.

 

for example - Weight will vary with fuel and stores carried - which will also cause drag and slow it down. In a hot environment you also have reduced thrust (jet engines are better in the cold etc) which will reduce performance significantly.

 

 

 

The VPAF were supplied with:

 

MiG-21F-13

MiG-21PF(V)

MiG-21PFM

MiG-21MF

MiG-21U/US/UM

 

 

How would good pilots in the F-4E with slats and the F-8E/H fare against that version of the MiG?

 

 

No answer really - depends on weapons used, IFF systems (used in 72), ROE, tactics used (still using fighting Wing?) experience of the MiG pilot (VPAF pilots got a lot of experience at that time - they flew for the entire conflict!), endurance.

 

In a lot of cases the MiG-21 was used as a hit and run fighter - it would intercept a US flight (via GCI) at speed, fire its missiles, which would hit the unsuspecting flyers, then hit the deck and get back to base at speed.

[Toryu 156]

The early MiG-21s were actually limited by their weak (reversible) hydraulic-system. The control-forces got so high at high speeds, that safe operation at low altitudes (< 15.000ft) required speed-limitations to below 600KIAS. Later, that problem was cured, and the Migs could go all the way to Mmo.

 

Acceleration is a function of excess-power.

With bombracks and other stuff dangling from the aircraft, F-4s and F-105s usually had a disadvantage. They also had a disadvantage concerning their pilot-training and tactics. Most F-4 pilots of that time had had their initial ACM-training syllabus on the F-4 (maybe 5-10 hops) and that was thought to be enough to send them overseas.

Those pilots had no clue how to handle the aircraft A-A effectively.

Only the 8th FW did possess serious A-A capability, and thus they were (almost exclusively) given the task of escort- or CAP missions.

 

I wouldn't call the MiG-21 pilots "experienced", as they mostly engaged under GCI-orders.

The MiG-17 pilots propably were better in actual dogfights.

 

 

The slatted F-4E wasn't used in combat (IIRC, there was only a single, slatted airframe in SEA). But even the unslatted F-4s could hold it's own - the pilot-quality is of much more importance than the airplane's performance.

Same is true about the F-8, or any aircraft for that matter.

[GalmOne 1]

I realize that I can't simply go by wing loading to determine turning capability. I based my assumptions off the HAVE Doughnut tests which indicate that the MiG-21F-13 has a better instantaneous turn rate than the F-4 or F-8 but bleeds speed more quickly. The MiG's wing loading is far lower than either.

 

Chances are with a higher T/W ratio, the heavier MiG-21MF is able to bleed speed at a lower rate, but since it has an almost identical wing loading as the Crusader, it's unlikely to turn better. Perhaps equal in some situations, but I don't believe a delta wing aircraft, such as the MiG-21MF - can reliably out-turn an aircraft with a less severe sweep, leading edge flaps and a variable incidence wing with a similar wing loading - i.e. the F-8.

[GalmOne 1]

Additionally, I found this book on the F-8 (http://www.scribd.co...Crusader-Part-1). On page 104, combat weight for the F-8H is 25,802 lbs. with a wing area of 375 sq. ft., the wing loading is 68.805 psf. Using the improved J57P-420 engine of a rate wet thrust of 19,500 lbf, the T/W ratio is 0.7596.

 

 

For the MiG-21, I found this book (http://www.scribd.co...5/MiG21-Fishbed) on page 98, in which the MiG-21MF weighs 18,104 lbs. with a wing area of 247.6 sq. ft. yielding a wing loading of 73.118 psf. The maximum thrust afforded by its R-13-300 engine is 14,308 lbf. This yields a T/W ratio of 0.7903, giving it a small advantage over the F-8H. For the sake of comparison, the MiG-21F-13 has a normal loaded weight of 15,245 lbs., a wet thrust of 12,654 lbf from its R-11F-300 engine and the same wing area as the -21MF. This yields a wing loading of 61.571 psf and a T/W ratio of 0.8300. We know that both a lower wing loading and a higher thrust-to-weight ratio of the MiG-21F-13 will lead to better instantaneous and sustained turning rates, and - at the very least - better low speed acceleration. Although the MiG-21F-13 did have its speed-limiting problems under 16,000 ft (namely it's dynamic pressure limit which limited top speed to 595 kn) meant that some of its advantages over the MiG-21MF would not have been exploited.

 

 

This really makes me believe that the MiG's going to be at some sort of disadvantage in the turning department against an F-8H, especially since the modifications on the F-8D to make it an F-8H put BLC on the flaps, just like the later MiGs.

Edited September 8, 2012 by GalmOne

[MigBuster 2,861]

See

 

area51specialprojects.com/video/have_doughnut_tactical.swf

 

area51specialprojects.com/video/havedoughnut_technical.swf

 

Its still too much of a generalization to me - where is the instantaneous turn better? in the 0 degrees horizontal only?, at what speed and altitude? and if the MiG-21 has missiles under the wings and the F-8 is clean, the MiGs advantage might be cancelled out for example - in combat 2 platforms are unlikely to meet up in exact configurations.

 

There is a chart in that lot for an F-4D (4 x Aim-7s + 50% fuel) vs Fishbed C (2 x Atolls and 50% fuel) - this is near the level of detail you want - however the performance changes if you change the stores and amount of fuel both have - so what 1 may be good at under one set of parameters - the other platform might be best under another set.

 

For example over Vietnam the F-4D might have jettisoned its stores because a MiG-21F was about (with 2 x Atolls) - but the F-4D now has 4 AIM-7s, 2 x AIM-9s and a Gun Pod all creating extra drag and weight and thus totally invalidating the chart - because the MiG-21F is potentially far more agile against that than the analysis suggests.

Edited September 8, 2012 by MigBuster

[GalmOne 1]

When one does an experiment, one controls the variables. In the case of what I'm analyzing here, I do indeed mean 0 rate of climb or decent during the turn. The numbers I supplied should be at least enough evidence to put the F-8H (in the case mentioned) at favour. The same F-8 for example has a maximum speed advantage over a MiG-19 of about 160 mph at max speed. That's a HUGE difference and is certainly an advantage. Whether this means that the F-8 kills the MiG-19 with boom and zoom attacks or ends up slow and shot down by the MiG is irrelevant. I am simply looking for possible advantages that can be capitalized on.

 

In all the configurations I mentioned, the aircraft are carrying just their 4 AAMs with no drop tanks. The charts in the book links I posted contains the weights and configurations of each plane. Of course, practically speaking maybe the MiG with full AAMs and drop tanks will meet an F-4 who has dropped all but his 4 AAMs. But how do we compare this situation? We can't say the F-4 is better in turn just because the F-4 pilot out-turns the MiG in this situation.

 

I appreciate your reasoning though, and it makes me optimistic that pilot flying skill will decide this close of a fight instead of technology.

 

EDIT: Lastly, MiGBuster, I have seen that powerpoint. I have found the ACTUAL report on HAVE Doughnut, but I can't find the link I downloaded it from and I don't know how to attach a PDF file greater than 1MB to this post.

Edited September 8, 2012 by GalmOne

[MigBuster 2,861]

This really makes me believe that the MiG's going to be at some sort of disadvantage in the turning department against an F-8H, especially since the modifications on the F-8D to make it an F-8H put BLC on the flaps, just like the later MiGs.

 

An EM chart for an F-8 is what you need - you should get a better idea of what altitudes and speeds the F-8 may be best at if you compare it against the MiG-21F-13 one from Have Doughnut.

 

Then all you need is a flight sim that does HF flight models of both!

[GalmOne 1]

Ohhh man, I've been looking for ages for an F-8 EM diagram, but someone once told me that the Navy never put them in their flight manuals! I'm also more concerned about the MiG-21MF since it seems to be the more definitive Vietnam era MiG-21. Also, check my post above. I'll keep looking for a link to that pdf.

Edited September 8, 2012 by GalmOne

[MigBuster 2,861]

EDIT: Lastly, MiGBuster, I have seen that powerpoint. I have found the ACTUAL report on HAVE Doughnut, but I can't find the link I downloaded it from and I don't know how to attach a PDF file greater than 1MB to this post.

 

Try compressing to a zip file - or create a Dropbox account and stick a link to the public folder - really easy.

[GalmOne 1]

True, well I found the link here since I haven't installed dropbox on this PC just yet.

 

http://www.cwam.org/blog/aircraft/MiG-21/have-doughnut.pdf

[Toryu 156]

The same F-8 for example has a maximum speed advantage over a MiG-19 of about 160 mph at max speed. That's a HUGE difference and is certainly an advantage.

 

160mph at the top-end of the speed-sprectrum is actually quite useless, as most dogfights never go supersonic (the turn-rate suffers largely, due to the aft-moving aerodynamic center). Also, going subsonic and pulling Gs, one might overstress the airframe (a couple of F-4s have been lost that way, it's a problem for ANY aircraft).

 

The MiG-19 is sort of controversial. The israelis thought it was the most dangerous of all MiGs, due to it's good subsonic acceleration and pretty good high-speed turn.

The US thought it was useless. Then again, there was only a hand-full of MiG-19s in Vietnam.

 

The MiG-21 has a delta-wing, which is always better for instantaneous turns than plain swept wings. Deltas suck at sustained turn, though, due to their increased amount of drag.

 

If you want a good EM-estimation about the different aircraft, pure T/W-consideration isn't gonna give you much.

What you need is specific excess power, which is v*(T-D)/W.

v is in TAS.

 

Generally, with increased experience on the type, the F-4 was considered the better overall-dogfighter than the F-8, but you had to know how to handle it.

The F-8 was much easier to be "good" in.

[GalmOne 1]

The top end speed differences is relevant mainly because the difference is so large. This is generally an indication that though the faster plane may not accelerate or climb better, its top speed at any altitude will allow it to disengage... I'm not concerned with turning. The huge speed difference is like an Me262 vs. a Spitfire Mk.21. It's just such a massive difference, the faster plane should be able to disengage at will. I doubt there's any altitude at all where the Crusader won't be able to run from a MiG-19.

 

Although I also believe if the Crusader gets slow enough, he's dead as the MiG-19 surely will accelerate better at low speeds.

 

As much as I'd like to build a P_s graph, the most difficult parameters to get are the thrust and drag, as they either vary as a function of velocity and/or angle of attack. For now, I've just used wing loading and T/W ratio in addition to the HAVE Doughnut tests to build an estimation. And, like you said, a MiG-21's going to bleed a lot of speed, and a higher wing loading coupled with a slightly higher T/W ratio is unlikely to alleviate the problem.

[Toryu 156]

Also, the Mig's engine is very slow to respond on throttle-movements.

A J79 takes 4 seconds from flight-idle to military power, while a R-11 may take up to 14 seconds!

That's a considerable edge when maneuvering right there!

 

An important issue that might also be of interest is roll-rate:

The F-8 is a pretty handy roller, while the F-4 is somewhat slower and the MiG-21 generally is slowest. Roll is not an important performance-figure at first glance, but it allows you to change the direction of your lift-vector quickly and as such it's very welcome for jinking and offensive maneuvering.

 

 

Concerning the top-speed issue, I'm not completey sold.

At high altitudes, the F-8 does have an edge due to it's higher top-speed/ attainable Mach.

However:

- attaining top-speed takes lots of time, thus if the enemy is not purely subsonic (MiG-17 or early MiG-21 below 15.000ft), you might not have that signifigant effect at hand at any time

- fighters are speed-limited (generally below 15-20kft) and the Mach-limit (where the F-8 wins hands-down!) changes into a much more conservative IAS-limit (usually 750KIAS)

- c_D-curves may differ largely in the transonic region

- both planes have fixed air-intakes, so the F-8's acceleration is not going to be very stellar above M1.5

 

Just looking at the MiG-19's three-side view, one can see that it had severe (longitudinal) stability-issues. Those highly-swept wings cry "pitch-up" pretty loudly.

That's another edge for the F-8, along with it's LE-droops.

 

BTW: "aerodynamic center" should be "center of pressure" in my post above...

Edited September 9, 2012 by Toryu

[MigBuster 2,861]

The top end speed differences is relevant mainly because the difference is so large. This is generally an indication that though the faster plane may not accelerate or climb better, its top speed at any altitude will allow it to disengage... I'm not concerned with turning. The huge speed difference is like an Me262 vs. a Spitfire Mk.21. It's just such a massive difference, the faster plane should be able to disengage at will. I doubt there's any altitude at all where the Crusader won't be able to run from a MiG-19.

 

Although I also believe if the Crusader gets slow enough, he's dead as the MiG-19 surely will accelerate better at low speeds.

 

As much as I'd like to build a P_s graph, the most difficult parameters to get are the thrust and drag, as they either vary as a function of velocity and/or angle of attack. For now, I've just used wing loading and T/W ratio in addition to the HAVE Doughnut tests to build an estimation. And, like you said, a MiG-21's going to bleed a lot of speed, and a higher wing loading coupled with a slightly higher T/W ratio is unlikely to alleviate the problem.

 

I would look carefully and go with Toryu on this one - because at lower altitudes the published top speed difference is probably next to nothing (Also note the MiG-19 is nearly always clean).

 

Production jets seldom go anywhere near their published top speeds (which were normally taken by a clean light airframe) - the time taken to get there and the amount of actual fuel they have are limiting factors.

 

Say you enter a merge at 5kft, 500TAS and the MiG-19 enters at 530TAS (which it can do) - who has the advantage? - thats right neither - it all depends on the next move - The MiG-19 has an initial energy advantage - but he might waste all that trying to turn - or maybe my wingman shoots the MiG down with Missiles, Or maybe the MiG keeps on going and by the time I turn around I cant catch him.

 

 

IMO you should be less concerned about published figures, and more concerned about where (what state) you enter the fight to give you an advantage.

[+Gepard 10,241]

My 2 cents with a view from the other side of the iron curtain.

The MiG-21 had proofed to be able to outturn all jets which the US used in Vietnam in real combat. That was the reason, because the USAF cried for a lightweight fighter.

The most agil plane in US inventory was the F-8 Crusader, which was close to the turn performance to the 21F-13.

You must also understand, that a lot of vietnamese pilots were physically unable to bring the MiG-21 to the outer limits of their performance range. Soviet flight trainers said, that it happend very often, that the vietnamese pilots fall into blackout, while the soviet instructors still had not had problems with grey or blackout.

 

If you talk about the MiG-21 you must say, which version of MiG-21 do you mean. While the MiG-21F-13 was so agil, that pilots said: "if you only think to move in a direction, the MiG is always turning from itself.", the MiG-21M was so stable and agil like a lorry (truck for our US guys). The MiG-21PF was called MiG-21 Sport or MiG-21GTI for its outstanding performance, while the MiG-21MF was not as loved.

 

The flight performance of the MiG-21 versions depends a lot of fuel volume and flight altittute.

 

MiG-21F-13 data by sources of the east german air force LSK (confirmed by MiG-21 pilots):

 

below 12.000 meters the speed limit was set to 1.000 km/h (with armament or tank) or 1.200 km/h clean

above 12.000 meters the speed limit was set to 2.150km/h clean and 1.650 km/h loaded. (You could go faster, but this was not healthy for plane and pilot)

Empty weight MiG-21F-13 was 4.871 kg.

Take off weight normal was 7.110 kg

take off weight with 2 R-3S and one fuel tank was 7,580 kg

take off weight with 2 FAB500 and one fuel tank was 8.386 kg

 

spooling time of the R-11F-300 12 - 15,5 sec from idle to 100%

spooling time of the R-11F-300 < 20 sec from idle to full afterburner

restart time in air 38 - 60 seconds (below 12.000 meters possible)

 

max g values for MiG-21F-13 with 2 R-2S missiles

speed < Mach 0,8 + fuel >1.600 liters max g is 7,0 g

speed < Mach 0,8 + fuel < 1.600 liters max g is 8,0 g

speed < Mach 0,8 + fuel < 1.200 liters max g is 8,5 g

 

speed > mach 0,8 + fuel > 1.200 liters max g is 6,0 g

speed > mach 0,8 + fuel < 1.200 liters max g is 7,0

(During vietnam war max g of 10g's and more was achieved. If i remember right at LSK training the max g was over 11g.)

 

max roll speed 90°/sec

 

 

And by the way, forget the strange system of lbs, feets, miles, knots etc.

The MiG-21 was a soviet plane, what means all data are given in metric system.

Edited September 9, 2012 by Gepard

[Toryu 156]

The MiG-21 had proofed to be able to outturn all jets which the US used in Vietnam in real combat.

 

That's not a very exact remark, as there are lots of uncertainties:

 

At which speeds/ gross-weight/ altitude did that happen?

What was each aircraft's configuration?

Did the pilot max-out the plane?

 

 

The term "outturning" is relative. During the US' evaluation of the MiG-21, there was an F-104C, that spiral-climbed away from the MiG, sustaining 4gs in the process. Everybody knows, that an F-104 normally won't out-turn a MiG-21, but that's what just happened. There's also the trial, where an F-104G (worst T/W of the family) out-scissor-rolled an F-5E (energetically a good MiG-21F-simulator).

Relative aircraft-performance isn't static and there are portions, where the "general picture" can be reversed.

 

90°/s is not a good roll-rate for a fighter. The F-8 should at least have double the rate.

 

Concerning the g-limits:

Stress-limits (specially overstress-limits) are also not quite static accross the fleet. Depending on production-quality, some aircraft may have a vastly better ultimate load (can take more Gs) than others of the same lot. Then there's the fatigue-history of the aircraft. There were some incidents of pilots pulling off the wing-assembly on F-8s (sometimes at "just" 6g), because the planes were generally operating in a high-g environment. Then, there was an RF-8 that made it home after doing a frantic 11g break-turn (evading a SAM) - every panel on the outer-wing was boken, but the plane made it back!

There was a low-time Luftwaffe F-104G, that lost a wing during a moderate weapons-delivery pullout (pilot K). It turned out, that Lockheed had mis-calculated the fatigue-cycles of the wings (figuring one 4g-pull per flight on average, while in the actual bombing-range-pattern, every CORNER was flown with ~4g!). Then, there was a Luftwaffe F-104G, that took more than 12gs on a low-level pullout and lived to tell the story...

 

Those are just a couple of examples where aircraft under- or overperformed in therms of the amount of g-load taken.

Edited September 9, 2012 by Toryu

[Lexx_Luthor 57]

Toryu, what about Su-7? At the bottom of this Indian page, they describe a -7 vs -21 flyoff.

 

~> http://www.bharat-rakshak.com/IAF/History/Aircraft/Su-7.html

 

For those of you playing WoV, just for fun replace -all- MiG-21Fs with Su-7, and MiG-21MFs with (early) Su-17s; either Thudwire or 3rd Party models. Su-7 was originally a frontline tac fighter, but for some reason they chose -21 for that role, leaving -7 to evolve into the -7B strike fighter.

 

In my game, well someday, I intend to have Su-7 (original) as PVO fighter either with MiG-21 or instead of it, depending on variables (like if MiG's or Su's dispersed and buried factories get pounded by SAC for one example). Later in the 1960s, if the campaign goes that far, Su-7 and MiG-21 will act like Bf-109s that supported, or protected, the Fw bomber killers, and support/protect MiG-25s or Su-15s and such, well depending on the extent of small-vs-large PVO airfield damage at the hands of SAC. LEXX SHUT UP. Yea I better stop here. Anyways, think of Su-7/Su-17 as a possible fun substitute for various MiG-21s as frontline tac fighter in ya'lls games.

[+SupGen 78]

Lexx, do not STFU. I, for one look forward to your "unique" perspective.

[Toryu 156]

The Su is propably a pretty good contender at low altitudes(although it suffers from the same issues as does the MiG-19, mainly longitudinal stability-issues at high AoA).

 

One thing, though:

 

I've had a discussion with MiGBuster about the relative performance of F-4s and F-104s in air-combat some time ago, wherein he put up an important point:

Just being the better maneuvering-platform (Starfighter) isn't enough, when you can ONLY bring a gun to the game (we're talking of a self-defense scenario on a strike-mission).

Whereas the F-4 could squeeze-off four Sidewinders (plus maybe two ballistic Sparrows) and go home afterwards (no guns in SEA-Rhinos untill 1968), the F-104 would have to get into gun-range, first - using afterburner and thus precious fuel.

Now, there have been multiple gun-only kills by F-105s, but that aircraft had been known for it's non-maneuverability. It's doubtful, that MiGs might have stayed in-range, had the strikes been flown by more capable A-A platforms.

The F-104 had a good radar-gunsight combo, though, so deflection-shooting at least gives you a limited all-aspect capability.

 

The Su-7 is in a similar situation: Very few hardpoints and (AFAIK), none for A-A missiles. Therefore, the Su would have had counted on guns only, which is a pretty bad thing, concerning it's low-fuel situation. Then, there was no LCOS in the Su-7, so anything else than "dead six"-shooting was a game of luck/ talent. Only about 1-2% of all pilots are natural deflection-shooters.

Thus, the Su-7 (though being a good general-performer) would have made a rather poor interceptor.

It might have been a good fighter-bomber killer for low altitudes (where the early MiG-21 sucked), but it's limited combat-radius was a spoiler.

The long afterburner ignition-time doesn't help either...

Edited September 10, 2012 by Toryu

[GalmOne 1]

I've been playing flight sims for about 6 years now, and if there's anything I learned other than the physics behind aircraft performance, it's how a seemingly predictable fight can end very differently.

 

Many times I've flown with my friends - all of whom I considered just as good in a dogfight as myself. We'd fly the same plane and shoot each other down at a 1:1 kill-death rate. Then we'd select different planes... and lo and behold, sometimes the lower performing plane would come out on top! Sometimes a Spitfire V would be beaten by a higher-performing but far worse turning Spitfire XVI in a turn fight simply because of the energy states that the pilots had by the end of the fight.

 

Sometimes a Spitfire could catch an Me 262 who was still accelerating after leveling off from a climb.

 

I completely understand and appreciate the value of analyzing air combat from a practical perspective, but when it comes down to my questions here, I'm simply asking about the most sterile, straight-up scientific performance figures. If only I could find an EM diagram of later MiG-21's like the -21PF and -21MF as well as the F-8E (which is lighter than the F-8H). Then I could really just overlap the diagrams and be done with the research lol.

Edited September 10, 2012 by GalmOne

[MigBuster 2,861]

 

The most agil plane in US inventory was the F-8 Crusader, which was close to the turn performance to the 21F-13.

.

Well errr - you might want to define what you mean by agility! - this might be true at certain speeds and altitudes (that you don't mention) - If you actually look at the Have Drill comparisons - the charts list that the F-5 was the only in theatre jet evaluated (F-8 was also compared) that had a superior turn rate (do we assume horizontal only??) under 450KIAS to the MiG-17 - so does that not make it more agile to the F-8 in the lower speed regime! - or are we talking about specific versions?

 

 

 

 

(During vietnam war max g of 10g's and more was achieved. If i remember right at LSK training the max g was over 11g.)

 

To add to the above - I have an account from an Israeli Mirage pilot where after pulling out of dive in combat and nearly blacking out the G meter was stuck at 12G - so does that mean its a 12 G rated airframe? No it means that for very short periods of time Aircraft can sometimes be subjected to high G forces and still be in a state to fly (although be interesting to know if the frame was written off!!). Now how long could that 12G pull last before the wings fell off? - An airframe designed and rated to 12G should be fine though (baring any design assumptions as per the F-104G etc ).

[+Gepard 10,241]

You are right, that the Skoshi Tiger was the most agile plane in US inventory, but only if you see North and South Vietnam as one theatre. The F-5A and E were never used over the north. They were used only in South Vietnam, so that their air superiority was wasted. By the way, personally i believe that the small Tiger was the best US plane in that timeframe of Vietnam war, but i think other guys have other favorits.

 

 

And to your second point. I wanted to show, what the manuals stated (the data i posted are taken from a east german flight manual of the MiG-21F-13) and that was a plane was able to withstand were two different figures. And i wanted to show how the max g loads differed at different fuel loads.

That other planes could reach a max g of 12 or 15 is not disputed by me. The MiG-21 was not the strongest plane, there were a lot of types which were much stronger. And i also dont want to say, that the MiG-21 was the best of the best fighters.

 

That american pilots were unable to get the maximum out of the MiG-21 had a lot to do with a completly different design philosophy. The american planes had very comfortable cockpits, while the MiG cockpits were very small. The data system are completly different, metric vs imperial, what means, that you must first calculate befor you can act if you have a bird with the wrong data display system. My personal experience is, that i get better results in game if i fly the F-4 with showing datas in metric than in imperial style.

And an other experience i made: A lot of east german car drivers had had no problems to switch from the old and outdated Trabant car to modern western car and drove the western car in a good way. The other way was much more difficult, i have rarely seen guys who have learned driving on a comfortable western car who were able to drive the Trabi in a good and efficient style. Its simpler to "upgrate" than to "downgrate". Thats so in cars and for planes too. For an american pilote the step from Phantom to the MiG-21 was a very big downgrate, so he has big problems to drive the MiG to their limits. But this does not mean, that a guy, who had always been a MiG jock wont also be unable to reach the limits of a MiG-21.

Edited September 10, 2012 by Gepard