Phantom vs XXX

[Kalasnkova74]

What I suspect will happen is people unfamiliar with how to fight the F-4E will fly it like an oversized Hornet , die , and then proclaim the Phantom II useless in a BFM scenario. As the old newsreels once said, you heard it here first! 

[Aussie_Mantis]

1 hour ago, Kalasnkova74 said:

What I suspect will happen is people unfamiliar with how to fight the F-4E will fly it like an oversized Hornet , die , and then proclaim the Phantom II useless in a BFM scenario. As the old newsreels once said, you heard it here first! 

Probably. They'll see "HIGH AOA" and try to do a low speed AOA fight against a MiG-21.

[Czechnology]

The word on fighting migs from books and pilots was keeping knots up and using the vertical, but the problem is that the 21 and 19 are both pretty darn good in the vertical too in theory. 

To my very, very vague understanding, the Vietnamese just didn't really train in the vertical, and thus didn't use it much in practice. BIG HUGE NOTE HERE that this is heard from US sources, so possibly entirely wrong.

But like I said, 19 and 21 both have good TWR and powerful afterburning engines. Do know they can't keep up in a straight line. The in game Bis as it stands quite literally, F-4E flying at theoretical max speed is beyond what the 21 can fly before it chokes its own engine. 19 won't choke itself, but still, doesn't keep up. 

[Heinlein]

I read that you could stall the phantom easily at 400 knots and enter a spin so I guess keeping an eye on AOA during fights will be crucial. But to add to what @Kalasnkova74 said, people say that about many planes and it comes from not knowing how to fly it. 

[AndytotheD]

29 minutes ago, Heinlein said:

I read that you could stall the phantom easily at 400 knots and enter a spin so I guess keeping an eye on AOA during fights will be crucial. But to add to what @Kalasnkova74 said, people say that about many planes and it comes from not knowing how to fly it. 

To be fair, you can stall any plane at 400 knots if you pull hard enough and the plane doesn’t break on the way there

[Bremspropeller]

7 hours ago, Kalasnkova74 said:

In reality, the F-4 was a monster in the vertical and could give even F-15s and F-16s fits if flown well enough.

Got any more of them superlatives?

If the F-4 was a "monster in the vertical" - what was an EE Lightning or the Dash-19 motor 104A then?

7 hours ago, Kalasnkova74 said:

A  Mirage 2000 would need to take care fighting a Phantom, to say nothing of an F-1. 

lol

You do realize that both the HAF and RoCAF M2ks are regularily winning against their neighbouring Viper-drivers? F-4E against the RDI M2k will blow in both BVR and WVR. Like really bad.

From what I've heard, the F1 wasn't half bad against the F-4.

[Czechnology]

56 minutes ago, Heinlein said:

I read that you could stall the phantom easily at 400 knots and enter a spin so I guess keeping an eye on AOA during fights will be crucial. But to add to what @Kalasnkova74 said, people say that about many planes and it comes from not knowing how to fly it. 

No that's actually very real. Adverse yaw at high AoA on Phantoms was notorious, but it's also true it's partially not knowing how to fly it. Our E was partially trying to address the problem, but it's still something to be aware of. Don't know the number for the E, but for the hardwings, as you approach 15 units of AoA, you must use more and more rudder instead of aileron, and surpassing 15 you must not give ANY aileron input or risk flat spin. Again. These are numbers for the hardwings, so we might have more wiggle room

[Kalasnkova74]

4 hours ago, Czechnology said:

The word on fighting migs from books and pilots was keeping knots up and using the vertical, but the problem is that the 21 and 19 are both pretty darn good in the vertical too in theory. 

To my very, very vague understanding, the Vietnamese just didn't really train in the vertical, and thus didn't use it much in practice. BIG HUGE NOTE HERE that this is heard from US sources, so possibly entirely wrong.

But like I said, 19 and 21 both have good TWR and powerful afterburning engines. Do know they can't keep up in a straight line. The in game Bis as it stands quite literally, F-4E flying at theoretical max speed is beyond what the 21 can fly before it chokes its own engine. 19 won't choke itself, but still, doesn't keep up. 

Based on Istvan Toperczer’s book on the NVA MiGs, their more skilled pilots had no issue going in the vertical. As usual, pilot skill plays a large factor. Note that Driscoll & Cunningham got into multiple vertical climbs against a MiG-17 before pulling the “hitting the brakes & they’ll fly right by” move. We need not elaborate how often US aggressor pilots in the 4477th TES also stomped on F-4s that made bad BFM decisions.
 

Essentially if a MiG got close enough to an F-4 where their acceleration could be leveraged (and the Phantom got slow)  , it was bad news for the Phantom. The key was keeping one’s distance /speed and letting the MiG bleed energy. 

1 hour ago, Bremspropeller said:

Got any more of them superlatives?

If the F-4 was a "monster in the vertical" - what was an EE Lightning or the Dash-19 motor 104A then?

lol

You do realize that both the HAF and RoCAF M2ks are regularily winning against their neighbouring Viper-drivers? F-4E against the RDI M2k will blow in both BVR and WVR. Like really bad.

From what I've heard, the F1 wasn't half bad against the F-4.

I’m not read up on RAF Lightnings to verify this, but F-104s were dangerously capable planes when -again- flown correctly. The flying pencil was hard to see visually, difficult to acquire on Radar pre-AESA, and if flown fast was basically untouchable by anything else flying. I see no reason why the British Lightnings wouldn’t be any less capable. 
 

As far as equipment vs equipment goes, again pilot skill is the big variable. That a Mirage 2000 beat a Viper says nothing about how an F-4E will stack up. F-22s flown by new pilots lose to T-38s flown by expert qualified Red Air in exercises. Should we conclude the T-38 is a god tier air superiority fighter?

Bottom line it’s the crew, not the crate.  Supporting documentation: 

 

 

 

 

 

[Bremspropeller]

57 minutes ago, Kalasnkova74 said:

Based on Istvan Toperczer’s book on the NVA MiGs, their more skilled pilots had no issue going in the vertical. As usual, pilot skill plays a large factor. Note that Driscoll & Cunningham got into multiple vertical climbs against a MiG-17 before pulling the “hitting the brakes & they’ll fly right by” move. We need not elaborate how often US aggressor pilots in the 4477th TES also stomped on F-4s that made bad BFM decisions.
 

Essentially if a MiG got close enough to an F-4 where their acceleration could be leveraged (and the Phantom got slow)  , it was bad news for the Phantom. The key was keeping one’s distance /speed and letting the MiG bleed energy. 

I’m not read up on RAF Lightnings to verify this, but F-104s were dangerously capable planes when -again- flown correctly. The flying pencil was hard to see visually, difficult to acquire on Radar pre-AESA, and if flown fast was basically untouchable by anything else flying. I see no reason why the British Lightnings wouldn’t be any less capable. 
 

As far as equipment vs equipment goes, again pilot skill is the big variable. That a Mirage 2000 beat a Viper says nothing about how an F-4E will stack up. F-22s flown by new pilots lose to T-38s flown by expert qualified Red Air in exercises. Should we conclude the T-38 is a god tier air superiority fighter?

Bottom line it’s the crew, not the crate.  Supporting documentation: 

Cunningham and Driscoll benefited from their BFM training, which the MiG pilots mostly did not. It's evident that skilled MiG pilots (those existed) with enough training (many less existed) and capable equipment* (even less) could and would provide serious trouble for an evenly skilled/ trained/ equipped F-4 crew. That's basicly what Have Doughnut and the follow on projects showed.

It's not that a skilled and tactically savvy F-4 crew couldn't cash in on an unexperienced opponent. But that's also forgetting that an actual war isn't fought 1v1 allthe time and that the enemy has a working set of brains, too. The more capable fighter will eventually come out on top, all else being equal. That's just a matter of rolling the dice often enough.

The F-4 will be able to exploit tactical blunders by Vipers and Hornets (or any other opponent), but that's for the most part just hanging on. It's going to be quite competitive against contemporaries, but I wouldn't expect to easily walk all over MiG-21s either, as there are some pretty savvy Fishbed-drivers out there, that will be able to negate the F-4's strengths.

I'm fairly sure you know all of this, but I'm trying to kind of manage expectations of the casual reader/ player here.

 

BTW: Love that tiger-noseart!

____

* It's mostly being said that the IDF won against the arab air forces because of better training. That's both true and false, as arab air forces not only were trained by the Soviets (bad), but they also had a good deal of RAF heritage (good) to draw from. What couldn't be helped was the mostly blowing soviet hardware.The R-3S was a very sh1tty missile that was very hard to employ effectively on a MiG-21 in a dogfight.

Edited January 9, 2023 by Bremspropeller

[Spurts]

2 hours ago, Bremspropeller said:

 what was ... the Dash-19 motor 104A then?

god?  using "115%" throttle (if 100% is mil and 120% is full blower) to cruise at 73,000ft at M2 kinda qualifies for a fighter, no?

[Bremspropeller]

29 minutes ago, Spurts said:

god?  using "115%" throttle (if 100% is mil and 120% is full blower) to cruise at 73,000ft at M2 kinda qualifies for a fighter, no?

My favoutite story is about Tom Delashaw barrel-rolling around a U-2 (supersonic, of course!) and nearly tearing off it's wings.

That was with a -3 or -7 motor and a different squadron, though. IIRC.

 

I also like Ed Rasimus reconciling his time flying F-4Cs out of Torrejon, engaging a spanish Mirage III at high altitude and the little Mirage literally running circles around him.

 

We need more CW aircraft.

[Lurker]

I love it when people speculate. This thread has been a lot of fun to read, there are a lot of very, very knowledgeable people posting here and it shows. The thing is, we won't know really until the Phantom gets here, and more importantly until people become proficient with it and learn how to operate it. 

When the F14 was first released into early access people were throwing tantrums that it flies like total crap. However it wasn't the plane, it was the pilots. When eventually people learned how to handle it at high AOA and how to actually fly it properly (rolling the plane with pedals at extreme AoA or a combination of stick and pedals) it was a whole different story. 

[Bremspropeller]

9 minutes ago, Бойовий Сокіл said:

especially 23

The 23 is still somewhat of a black box to me, as there's very conflicting (anecdotal) data onhow it handles.

Did the wing-swep g-restrictions still apply to the later MLx models? Was the StabAug System improved to actually not try and kill the pilot?

What I do know is that the -23 (and certainly all the MLx variants) will go vertical like knife in a guillotine. Times minus one.

Edited January 9, 2023 by Bremspropeller

[Joe1978]

If I remember correctly, Robert Powell commented in his book that during his evaluation, the F106 pilots gave the phantoms a hard time...

[Spurts]

32 minutes ago, Lurker said:

When the F14 was first released into early access people were throwing tantrums that it flies like total crap. However it wasn't the plane, it was the pilots. When eventually people learned how to handle it at high AOA and how to actually fly it properly (rolling the plane with pedals at extreme AoA or a combination of stick and pedals) it was a whole different story. 

Hey, that's me!  Tried to fly it in BFM like a Hornet and never got shot down, because I stall/spun/crashed/exploded myself.  Decided to never go over 15 AoA and realized I could control it.  I eventually step by stepped by comfort zone up the AoA ladder until I am just fine with 30 AoA, but ya still need to know when and how.

[Kalasnkova74]

19 minutes ago, Бойовий Сокіл said:

Sure, how it is flown will absolutely matter. Good tactics and airmanship will make or break that plane. But as far as public, charted data goes it is pretty clear how far one can take it. Provided the FM in DCS matches that data of course.

The sticking point will be the F-4Es learning curve.  HAL9000 won’t be flying overwatch to save you from a poor control input. 

That’s going to be a big change for players used to the current roster of FBW aircraft. The F-14 is perhaps the most “manual” of the Cold War jets in game, and it’s fairly tame vs the F-4E which will punish the crew for poor control decisions. Even the F-4E with slats will adverse yaw and depart if one’s not careful. 

Flip side is without a FBW computer supervising things,just like the F-14 one can do trickbag maneuvers with the Phantom too.
 

18 minutes ago, Bremspropeller said:

The 23 is still somewhat of a black box to me, as there's very conflicting (anecdotal) data onhow it handles.

Did the wing-swep g-restrictions still apply to the later MLx models? Was the StabAug System improved to actually not try and kill the pilot?

What I do know is that the -23 (and certainly all the MLx variants) will go vertical like knife in a guillotine. Times minus one.

 

Isn’t the -MLA and -MLD wing structure strengthened for a 6G maximum turn? I was under the impression when MiG lightened the MiG-23 they also corrected structural problems (thus one justification for the 4G limit) with the wing carry through box encountered on earlier models. 

8 minutes ago, Бойовий Сокіл said:

Not really a black box - the data is there and most of the anecdotal stuff is based on the early M, BN and MS variants which the US and some western countries got. 
To your questions, yes, the 4G limit applies to the ML and MLD but the 45degree setting has no speed limitations, so if you set that before a merge you were golden. The SAU was more than fine on the ML and improved on the MLD - in fact it was more sophisticated than the Phantom's.
Yes, they are very fast and will have the best acceleration of any jet in DCS (especially that era) but that does not mean the ML series can't out-sustain a Phantom E or cant point the nose (albeit not quite like a 21 could). If you think about it, it has a lot going for it outside of a pure gun fight. True lookdown BVR capabilities with a very potent AAM (R-24R). Up close, a very maneuverable R-60M with a very short Rmin, which makes it fairly difficult to defeat by geometry. And you won't be able to just run away from a 23MLx, or catch one unless you put a missile down his pipe. 

 

If memory serves, a MiG-23MLD can sustain a 16 Degree/Sec turn at 360 ish knots. Much like other MiGs the later Flogger can out turn the Phantom in terms of radius and can certainly outrun one , but it can’t match the F-4s turn rate at the same speed. 

Earlier MiG-23 models couldn’t hope to hang with an F-4 (or any tactical fighter) without grave risk of departing above 3.5G. 

[Bremspropeller]

1 hour ago, Kalasnkova74 said:

That’s going to be a big change for players used to the current roster of FBW aircraft. The F-14 is perhaps the most “manual” of the Cold War jets in game, and it’s fairly tame vs the F-4E which will punish the crew for poor control decisions. Even the F-4E with slats will adverse yaw and depart if one’s not careful. 

I'm not sure if there's a bit too much mystique going on about using rudder in the F-4. First, you'd better use coordinated rudder at high AoA in any aircraft. My intro to spinning was in fact in a Bocian glider, using outside aileron in a slow turn. The result was a very gentlemanly rolling departure, but it kind of underlines the non-speciality of the issue here. And second, there are other aircraft in DCS, where using rudder is at least beneficial, if not mandatory at higher incidences. The F1 is one of them.

I think if people have been flying those CW jets before, they'll globally be alright.

If you're coming from the Horpner, though, and last time you touched the rudder was lining up on the runway....

Edited January 9, 2023 by Bremspropeller

[SgtPappy]

14 hours ago, Aussie_Mantis said:

Hi, necro'ing this thread for two reasons.

1. plz gib F-4E slat test program report, I wish to read it.

2. Nobody here's actually addressed what the F-4E will be like against the MiG-21 and the Mirage. In [REDACTED], the Most Accurate and Best Modelled Game in The Entire World, No Questions Asked, Praise The Snail, the F-4E struggles to retain any kind of energy against any opponent- even the early MiG-23 and MiG-21, forcing you into playing extremely passively, while in other "Lite" Flight sims (SF2) it somehow manages to outturn PFMs and then some. It's horribly modeled and all my friends who play both [DCS] and [REDACTED] claim that the F-4E will be no better in DCS but I think they are wrong from performance graphs alone.

What'll it be like against the F1C in DCS?

 

For 1. see here (report from 1972): https://apps.dtic.mil/sti/citations/AD0904287

For 2. Ok this is going to be a lot of data, so if anyone has any corrections, please let me know. I've seen multiple charts, some of them without much context so I may be missing some things. See the MiG-21bis performance chart here from a German manual that I have (7500 kg, 2x R-3S. Right is special afterburner, left is regular afterburner.). I also have a Russian manual that says the has the same plots but the language barrier has stopped me from delving deep into them.

Note that there's another plot which I think is a very light MiG-21bis that's sustaining ~8.4 G at Mach 0.95 or so which seems incredible but I don't know where it's from. Thread is here:

 

 

Comparing this to the plots in the TO 1F-4E-1, the slatted F-4E appears to have a noticeable advantage at what I believe is 60% fuel and 4xAIM-7E's (42,777 lbs) - see figure A9-97 on digital page 446. The following chart is on page 1 of this thread as well. I recommend you download the manual if you don't have it already: http://aviationarchives.blogspot.com/2015/09/f-4e-flight-manual-complete.html

 

 

Turn rates for the Mirage III and F-106 is a little tricky. See the plots I have below which I believe are instantaneous G's (I don't think they can be sustained rates, because they'd be way better than the F-15A/C sustained rates per TO 1F-15A-1).

Mirage IIIE:

https://imgur.com/a/ohoRApq

F-106A, 7700 lbs fuel:

https://imgur.com/a/xsv32hB

The closest analogue I have in my notes for the sustained rates of these jets is this J35 Draken which is of somewhat similar delta configuration (yes I know the intakes are weird) and has a similar T/W and wing loading. See that page below. Again take this with a grain of salt as I don't have the whole manual so I could be missing context, but if it's any indicator of the sustained rates of the Mirage IIIC, E or F-106, the F-4E is also a decent amount better.

https://imgur.com/a/pvclj8b

Another close analogue could be the clean MiG-21F that was tested by the US which has an almost identical STR to the slatted F-4E at 5000' (you'd have to eye-ball/interpolate the data in the F-4E chart):

 

The F-4E also has a lot of ITR charts but they are all at a very light weight of 37,500 lbs which is drops of fuel. That's why, to get a SL best ITR at a representative weight of 42000 lbs, I used a different chart... see the F-4E max load diagram at SL below. It actually appears to be able to reach 6G at Mach ~0.55 with the F-106A reaching 6G just past Mach ~0.5 at sea level. Very similar ITR! 

https://imgur.com/a/65ov9WT

 

 

14 hours ago, Kalasnkova74 said:

In [REDACTED] (hallowed be the snail) , the F-4E is divergent enough from the real thing that it may as well be a Generic Airplane in The Shape of A Phantom. 

In reality, the F-4 was a monster in the vertical and could give even F-15s and F-16s fits if flown well enough. Keep the knots high, don’t get slow, use the vertical and lag pursuit BFM. Flown that way the F-4E will be untouchable in the Cold War server, and a dangerous foe even in the high tech confines of the later servers. A  Mirage 2000 would need to take care fighting a Phantom, to say nothing of an F-1. 

True for any pilot vs pilot but in a 1v1 BFM fight (like is often the case in DCS), any 4th gen fighter will eat the F-4E for breakfast assuming competent pilots who keep tally on each other. I don't mean to be a downer, but we probably just should be realistic. The F-4E cannot compete with an F-15, let alone a Mirage 2000.

 

6 hours ago, Bremspropeller said:

Got any more of them superlatives?

If the F-4 was a "monster in the vertical" - what was an EE Lightning or the Dash-19 motor 104A then?

lol

You do realize that both the HAF and RoCAF M2ks are regularily winning against their neighbouring Viper-drivers? F-4E against the RDI M2k will blow in both BVR and WVR. Like really bad.

From what I've heard, the F1 wasn't half bad against the F-4.

So maybe you can clear something up for me. Either I can't read anymore or the plots I have aren't 100% clear but I have some Lightning F6 plots from a manual and my conclusions for time to climb is that the F-4E is quite noticeably superior when I look at the plots, but anecdotes have always said the Lightning was the best on earth:

Lightning Mk 6 time to climb:

https://imgur.com/a/Hz9dzTH

 

F-4E time to climb with my notes overlaid:

https://imgur.com/a/OfF7pmn

 

And below is the Lightning F6 load diagram but I can't tell 100% if it shows sustained or instantaneous loads (like the Mirage III and F-106 charts). On one hand, the 3G line is almost the same Mach at SL compared to the F-106 and any of the lines are only slightly worse than the sustained plots for the F-15. So either the Lightning was very, very good for its time in STR, or it was a little worse than the F-106 in ITR. Both seem possible, but the plot must be one or the other.

https://imgur.com/a/JxkkyYM

 

 

Finally for what it's worth, F-104A pilot Walt Bjorneby's perspective on the F-4 with and without slats:

"I was in the 319th FIS flying the F104A; friends of mine were in the 479th TFW flying the C model. I can confirm both outfits did use DACT (loose deuce) and emphasized use of the vertical. 319th was an Air Defense unit and primarily flew in pairs, thus 'loose deuce' was a natural choice. Our A models after mod had the G flap limits; 1.8M or 550KIAS. Thus we could actually out-turn F4s in level flight, that is, until they got the new slats, in which case we went vertical and ran them out of fuel because of the extra drag when their slats extended and they had to use lots of AB to keep their energy up. They got a lower corner velocity; we got the J79-19 engine and a LOT more Ps."

Edited January 9, 2023 by SgtPappy

[BIGNEWY]

Thread cleaned, 

a reminder if you want to use our forum please stick to our rules. 

Do not discuss other games or sims and keep the discussion clean, no profanity or insults. 

 

[Bremspropeller]

56 minutes ago, SgtPappy said:

So maybe you can clear something up for me. Either I can't read anymore or the plots I have aren't 100% clear but I have some Lightning F6 plots from a manual and my conclusions for time to climb is that the F-4E is quite noticeable superior when I look at the plots, but anecdotes have always said the Lightning was the best on earth:

I can't really wrap my head around it, other than the Lightning climbing at an airspeed/ Mach that seems slow'ish at first glance. That may be a procedural thing, getting the nose up sooner and getting away from people/ airspace quicker. Not sure, though. I'm usually assuming 600KIAS and M0.9 when I don't have any numbers.

What's curious is the following (start of T/O-run to reaching climb-speed, see figure A3-1 below):

The Lightning will reach it's climb speed ~15s sooner (.75min vs 1min), in almost half the distance (2nm vs 5nm) and using ~150lbs less fuel. And that seems to not even include the startup and taxi-fuel, whichapparently is included in that figure. The Phantom's initial climb speed is about 586 (?) KIAS, which explains the different figures (450:586 is roundabout 0.75:1, just assuming linear acceleration for a second). It backs up the question why the Lightning would climb so much slower, though.

Fig. A3-1 https://imgur.com/a/DMKcjDF

 

 

Edited January 9, 2023 by Bremspropeller

[SgtPappy]

2 hours ago, Bremspropeller said:

I can't really wrap my head around it, other than the Lightning climbing at an airspeed/ Mach that seems slow'ish at first glance. That may be a procedural thing, getting the nose up sooner and getting away from people/ airspace quicker. Not sure, though. I'm usually assuming 600KIAS and M0.9 when I don't have any numbers.

What's curious is the following (start of T/O-run to reaching climb-speed, see figure A3-1 below):

The Lightning will reach it's climb speed ~15s sooner (.75min vs 1min), in almost half the distance (2nm vs 5nm) and using ~150lbs less fuel. And that seems to not even include the startup and taxi-fuel, whichapparently is included in that figure. The Phantom's initial climb speed is about 586 (?) KIAS, which explains the different figures (450:586 is roundabout 0.75:1, just assuming linear acceleration for a second). It backs up the question why the Lightning would climb so much slower, though.

Fig. A3-1 https://imgur.com/a/DMKcjDF

 

 

 

The Ps and T/W advantages clearly help the Lightning here. 

However, I noticed that the Lightning charts show a climb at Mach = 0.87 past ~15,000 ft, so I subtracted the time to 15,000 ft and checked the time from there to 30,000 ft showing about 42 sec, standard ICAO day.

Doing the same thing with the F-4E at full fuel gave me a very rough, spitball check of about 45 sec ± a few seconds since I'm essentially guessing lines from a fuzzy graph. So it appears they have a very similar climb, but maybe I'm missing something because evidence suggests the Lightning should be even better... although I did notice it has a 700 KIAS limit to 36,000 ft so the Phantom has a higher limit up until 36,000 ft where their speed limits intercept.

All in all, they seem pretty darn close. 

[SuperKermit]

Hey guys! That‘s some very informative data here!

 

However, could anybody please elaborate on how to derive the STR (and turn radius) out of those MiG charts that only show max g under a given regime. 
 

Thx in advance!

[SgtPappy]

1 hour ago, ChrisKermit said:

Hey guys! That‘s some very informative data here!

 

However, could anybody please elaborate on how to derive the STR (and turn radius) out of those MiG charts that only show max g under a given regime. 
 

Thx in advance!

Turn rate in radians/s = [g*(n² - 1)^1/2]/v where g = acceleration due to gravity (9.81 m/s²), n = load factor in G's, v is true airspeed (in m/s if you are using g = 9.81 m/s²). Of course you can do other units too but make sure they are consistent. You can convert in deg/s by multiplying your answer by 180/pi (i.e. deg/s = (180/pi)*[g*(n² - 1)^1/2]/v).

Turn radius assuming a circular turn (which it would be in a perfectly sustained, constant angular velocity turn) is r = v²/(g*(n² - 1)^1/2).

I believe the Phantom graphs actually have the formula on it in Imperial units which you can use for any other graph.

 

 

Edited January 9, 2023 by SgtPappy

[SuperKermit]

Am 9.1.2023 um 23:47 schrieb SgtPappy:

Turn rate in radians/s = [g*(n² - 1)^1/2]/v where g = acceleration due to gravity (9.81 m/s²), n = load factor in G's, v is true airspeed (in m/s if you are using g = 9.81 m/s²). Of course you can do other units too but make sure they are consistent. You can convert in deg/s by multiplying your answer by 180/pi (i.e. deg/s = (180/pi)*[g*(n² - 1)^1/2]/v).

Turn radius assuming a circular turn (which it would be in a perfectly sustained, constant angular velocity turn) is r = v²/(g*(n² - 1)^1/2).

I believe the Phantom graphs actually have the formula on it in Imperial units which you can use for any other graph.

Fantastic, thank you very much  Thinking about it, it makes sense that only g load and speed are the relevant factors and the way how this g load is achieved (aircraft and wing design) does not matter.

Considering that the MiG-21 and the Phantom have their highest possible g-loads at more or less the same speed, I see that comparing the max g is sufficient for comparing their rough turn performance, right?

[SgtPappy]

8 hours ago, ChrisKermit said:

Fantastic, thank you very much  Thinking about it, it makes sense that only g load and speed are the relevant factors and the way how this g load is achieved (aircraft and wing design) does not matter.

Sorry, I'm not sure I understand.

Wing and aircraft design are indeed relevant when we engineers determine (at least on paper) how an aircraft will perform.

I suppose you are actually saying why we don't need aircraft-specific parameters in the formula? The calculations I provided don't require parameters like C_L, C_D etc because they are saying that: "given that an aircraft can pull n G's at speed v, what is its turn radius?" That is, the formulas are just basic kinematic formulas that work on anything that is turning. It assumes that the values you plugged in can be achieved by whatever aircraft/car/boat/thing you are calculating it for.

 

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Considering that the MiG-21 and the Phantom have their highest possible g-loads at more or less the same speed, I see that comparing the max g is sufficient for comparing their rough turn performance, right?

Yes, this is correct.

Edited January 13, 2023 by SgtPappy