P-47: bad at boom and zoom?

[Raven109]

42 minutes ago, Legioneod said:

Not really, plenty of P-47s engaged enemies at lower altitudes and came out on top. P-47 wasn't a dog like it seems to be in Il2, it was mostly on par with 190s at lower altitudes and superior the higher it got.

 

But what was the skill of the pilots, what was the energy state? I'm talking about co-alt, same energy, neutral set-up. IRL, you rarely get this set-up. Were the defenders taken by surprise, etc. Many questions, which just show that pilot stories lack a lot of information, and you can't infer the performance of a plane from vague stories. It's not that simple, unfortunately.

It's not a dog in Il-2, at least not against the AI. Online I would expect it to do worse, since there are a lot of experts flying there.

 

Here are some excerpts from this link https://vintageaviationecho.com/p-47-thunderbolt-nellie/ (posted by @Atomic_Spaniel and apparently ignored by everyone):

 

---------------------------

----------------------------

 

I find these to be very much true for the in-game P-47. Smooth attitude changes, keep speed above 200mph most of the time and you'll be happy. Extend when overwhelmed (aka run away when you did something wrong).  

Edited June 6, 2020 by Raven109

[-=PHX=-SuperEtendard]

I made some zoom tests with different airplanes, basically starting from 3500 meters, diving down to the deck leveling out then waiting until the speed decreased to 710 km/h and then zoom up for a 90º climb trying to say around 3G while pitching up.  I took note of the altitude reached when down to 300 km/h, and finally the max altitude reached as the plane stalled downwards. I took the 300 km/h value as the planes with very good power to weight ratios can prop hang for some time at the edge of the stall gaining some extra alt so it wouldn't be that representative to just take max altitude achieved only.

My conclusion is that basically good aerodynamics and power to weight ratio are key for good zoom abilities in game, the best zoomer is the Bf 109 K-4 specially with DC engine, followed closely by the P-51 with 150 octane fuel. The worse that I tested was the Yak-1 s69.  The P-47 in this regard doesn't have good aerodynamics (a big plane so it has lots of drag compared to the smaller fighters) and the power to weight ratio isn't good at low altitudes compared to the rest, so it's sits in the mid-lowmid part of the stack.   P-47 fuel level was at 50% and P-51 fuel level was at 70%, the rest of the fighters had 100% fuel.

You can see how the aerodynamics and power to weight ratio affects the planes when comparing similar variants like the G-6 vs G-14, or A-5 vs A-8 vs A-8 1.58 ata.

Yak-1 s69                  altitude at 300 kmh:       1351 m       max altitude:       1910 m

Spitfire IX                  altitude at 300 kmh:       1400 m       max altitude:       2040 m

Spitfire IX 150 oct   altitude at 300 kmh:       1438 m       max altitude:        2110 m

P-47D-28                   altitude at 300 kmh:       1431 m       max altitude:       2070 m

Bf 109 F-4                 altitude at 300 kmh:       1484 m       max altitude:       2137 m
Bf 109 G-6:               altitude at 300 kmh:       1364 m       max altitude:       2001 m
Bf 109 G-14:             altitude at 300 kmh:       1482 m       max altitude:       2116 m
Bf 109 K-4                altitude at 300 kmh:        1577 m       max altitude:       2221 m
Bf 109 K-4 DC          altitude at 300 kmh:        1630 m       max altitude:       2245 m

Fw 190 A-5                altitude at 300 kmh:       1476 m       max altitude:       2055 m
Fw 190 A-8 1.42       altitude at 300 kmh:       1438 m       max altitude:      2035 m
Fw 190 A-8 1.58       altitude at 300 kmh:       1464 m       max altitude:       2027 m

P-51D-15                   altitude at 300 kmh:       1502m       max altitude:       2115 m
P-51D-15 150oct      altitude at 300kmh:        1550m       max altitude:       2172 m


The P-47 sits closer to the Fw 190s, better than the Yak, the 109 G-6 and normal Spit IX.    The more aerodynamic/high power to weight ratio 109s (F-4, G-14, K-4) and P-51 are better.

Edited June 6, 2020 by -=PHX=-SuperEtendard

[Legioneod]

1 hour ago, Raven109 said:

 

But what was the skill of the pilots, what was the energy state? I'm talking about co-alt, same energy, neutral set-up. IRL, you rarely get this set-up. Were the defenders taken by surprise, etc. Many questions, which just show that pilot stories lack a lot of information, and you can't infer the performance of a plane from vague stories. It's not that simple, unfortunately.

It's not a dog in Il-2, at least not against the AI. Online I would expect it to do worse, since there are a lot of experts flying there.

 

Here are some excerpts from this link https://vintageaviationecho.com/p-47-thunderbolt-nellie/ (posted by @Atomic_Spaniel and apparently ignored by everyone):

 

---------------------------

----------------------------

 

I find these to be very much true for the in-game P-47. Smooth attitude changes, keep speed above 200mph most of the time and you'll be happy. Extend when overwhelmed (aka run away when you did something wrong).  

One thing to consider is he wasn't using anywhere near wartime power. I doubt he was pushing more than 40-50" MAP whereas wartime P-47s were pushing 64-70" MAP.

Huge difference.

[Bremspropeller]

7 minutes ago, Legioneod said:

One thing to consider is he wasn't using anywhere near wartime power. I doubt he was pushing more than 40-50" MAP whereas wartime P-47s were pushing 64-70" MAP.

Huge difference.

 

True, but he wouldn't push the other airplanes he's referencing the shallower climb against to wartime MAP-settings either.

All warbirds are limited by the 100LL avgas available today. The relative performance is probably still given and presented reasonably well.

Also the airplane is probably a good deal lighter than the war-time example.

 

I think it's safe to say that the energy model needs a little tweaking with the Jug. It should be about comparable with a Fw 190, when equipped with any type of paddle-blade prop and with water-injection.

 

Adding some 150 octane gasoline would also help a lot - especially when dealing with german K-4 DC ufos.

 

And hopefully they'll eventually cure those flaps...

Edited June 6, 2020 by Bremspropeller

[Raven109]

7 hours ago, Legioneod said:

One thing to consider is he wasn't using anywhere near wartime power. I doubt he was pushing more than 40-50" MAP whereas wartime P-47s were pushing 64-70" MAP.

Huge difference.

 

Yes, that is certainly right. But the other birds which they fly are also de-rated. So, I think it's a fair comparison. In-game, if you don't man-handle the stick, you can hold your energy quite well. It's not a small, highly aerodynamic fighter with that huge engine in front. There was a good reason why other aircraft manufacturers chose to add a streamlined cowling to their a/c.

 

7 hours ago, Bremspropeller said:

And hopefully they'll eventually cure those flaps...

 

That would be great. And the FM behavior at low speeds, when doing abrupt power changes - this should help make prop-hanging much more difficult.

Edited June 6, 2020 by Raven109

[Atomic_Spaniel]

10 hours ago, Legioneod said:

One thing to consider is he wasn't using anywhere near wartime power. I doubt he was pushing more than 40-50" MAP whereas wartime P-47s were pushing 64-70" MAP.

Huge difference.

 

It's about the aircraft having more  induced drag when you pull some g in manoeuvres compared to other aircraft. The pilot says it is worse than other warbirds. This is aerodynamics,  so I don't think that would change with more power?

[MeoW.Scharfi]

The problem of the P47 in IL2 is that it's not so maneuverable at higher speeds as i thought it would be. It gets a bit too stiff.

[Talon_]

10 hours ago, -=PHX=-SuperEtendard said:

I made some zoom tests with different airplanes

 

This test needs the Tempest  

[Atomic_Spaniel]

10 hours ago, Bremspropeller said:

And hopefully they'll eventually cure those flaps...

 

Yeah! If the IL-2 P-47 FM has a problem it's at the low speed end of the flight envelope more than the high-speed end.

[blitze]

Moral of this story - don't confuse 2020 online Multiplay with a genuine WW2 aviation experience.

 

The two are far removed.?

 

If you must fly the P47, lighten the fuel load to 250 or less liters and take her up high in a "Safe Space" before heading out to deal with the opposition.  Don't work alone.

[[CPT]Crunch]

Take a couple of P-40's as defensive escort.

[Bremspropeller]

4 hours ago, MeoW.Scharfi said:

The problem of the P47 in IL2 is that it's not so maneuverable at higher speeds as i thought it would be. It gets a bit too stiff.

 

Flew the P-47 on the Combat Box training server yesterday and had the exact same thought.

 

Stick-displacement per airplane-response seems quite large and I'm not sure this is congruent with pilot-reports.

[MattS]

3 hours ago, [CPT]Crunch said:

Take a couple of P-40's as defensive escort.

 

MEATSHIELD ONE STANDING BY

[Legioneod]

2 hours ago, Bremspropeller said:

 

Flew the P-47 on the Combat Box training server yesterday and had the exact same thought.

 

Stick-displacement per airplane-response seems quite large and I'm not sure this is congruent with pilot-reports.

http://www.wwiiaircraftperformance.org/p-47/Naca_TN_2899__F-47D-30_Flight_Test.pdf

 

Not sure if this would be any help in testing and seeing if things are in error. I've read through it but I'm not sufre how I would even begin to test.

I've always felt that at high speeds I wasnt able to get full deflection on the elevators which made it very difficult to pull out of dives or do BnZ attacks. Imo P-47 elevator authority is lacking a bit.

 

The controls do get stiff irl , it's mentioned in multiple reports but I'm under the impression that they get stiff too soon.

Edited June 6, 2020 by Legioneod

[SJ_Butcher]

It's a really big cow that only shine at really high altitudes, I don't think that big and heavy plane was soo good mantaining the energy after a dive

[Gambit21]

4 minutes ago, SJ_Butcher said:

It's a really big cow that only shine at really high altitudes, I don't think that big and heavy plane was soo good mantaining the energy after a dive

 

It was subject to the laws of physics just like any other aircraft. Big heavy airplane in a fast dive meant that it wasn’t going to slow down very quickly, especially if the pilot kept his foot in it.

[SJ_Butcher]

1 minute ago, Gambit21 said:

 

It was subject to the laws of physics just like any other aircraft. Big heavy airplane in a fast dive meant that it wasn’t going to slow down very quickly, especially if the pilot kept his foot in it.

 

What? Really? On a dive should catch speed fast but on climb should loss it fast too

[Legioneod]

12 minutes ago, SJ_Butcher said:

 

What? Really? On a dive should catch speed fast but on climb should loss it fast too

Conservation of energy (I think). It'll lose speed faster in a climb sure but it would still hang onto it for a bit especially with 2600-2800hp pulling it up into the air.

 

What people don't realize is the power required for a P-47 to stay in the air is very little compared to how much power it actually had.

Edited June 7, 2020 by Legioneod

[Gambit21]

23 minutes ago, SJ_Butcher said:

 

What? Really? On a dive should catch speed fast but on climb should loss it fast too

 

Again - Newton.

[SAS_Storebror]

On 6/6/2020 at 1:52 AM, Raven109 said:

Here are some excerpts from this link https://vintageaviationecho.com/p-47-thunderbolt-nellie/ (posted by @Atomic_Spaniel and apparently ignored by everyone):

 

<--snip-->

I find these to be very much true for the in-game P-47. Smooth attitude changes, keep speed above 200mph most of the time and you'll be happy. Extend when overwhelmed (aka run away when you did something wrong).  

 

Interesting style of quoting sources so they fit your bias.

That particular quote goes on like this:

Quote

We flew a formation take-off with the Thunderbolt and Mustang last year. Jon Gowdy was in the P-47 and I was in TF-51 Contrary Mary. I thought, I’ll build up power on the brakes and release as soon as the Thunderbolt starts to roll. I expected I would need to come back on the power, and would end up getting airborne before the P-47. It was the polar opposite! The second he let his brakes off, I released mine and it was like nothing happened by comparison – I was sat watching the P-47 disappearing off down the runway! I put on as much power as you’d want to put on in a Mustang, and he was airborne before me. The Mustang cleans up faster than the Thunderbolt, so I closed the gap as the undercarriage was retracting on both aeroplanes, but the second the wheels were up the P-47 just went. It was a good 10kts faster and I eventually had to ask him to come back on the power as I was giving it everything and couldn’t catch up!

 

That's the exact opposite of what the P-47 can do in IL-2 GB.

Ingame, the Jug accelerates like a fully loaded concrete mixer and anything but FC planes and the Podwa can easily run away from it, including bombers!

 

18 hours ago, blitze said:

lighten the fuel load to 250 or less liters and take her up high in a "Safe Space" before heading out to deal with the opposition

Eh... lol?

The Jug engine's fuel consumption at combat power exceeds 1000 litres per hour!

With 250 litres fuel, you don't even have sufficient fuel to exceed your combat mode time 

You would barely reach your "safe space" if you manage to climb perfectly, and then your fuel runs out.

This "hint" might work in QMB with airstart @10.000m altitude - other than that, this is just ridiculous.

 

Mike

Edited June 7, 2020 by SAS_Storebror

[Tomsk]

4 hours ago, SJ_Butcher said:

 

What? Really? On a dive should catch speed fast but on climb should loss it fast too

So heavier planes, in general, dive and zoom better than light ones. This is because of air resistance. Imagine two balls of the same shape, but one is very light and the other is very heavy. The force of air resistance depends only in the shape, which is the same for both balls. However  F = ma, so the heavier ball feels the same air resistance force but divided by the heavier mass the acceleration (deceleration in this case) is much smaller. The acceleration due to gravity is the same for both balls (it’s g so approx 9.8 m/s^2). That said in real aircraft engine power does play a role as well, still all else being equal heavier aircraft dive and zoom better.

 

19 hours ago, MeoW.Scharfi said:

The problem of the P47 in IL2 is that it's not so maneuverable at higher speeds as i thought it would be. It gets a bit too stiff.

I agree this is also a problem, it’s pretty stiff at high speeds and also bleeds energy fast in high speed turns. The end result is it’s bad at pulling for snapshots making it bad at BnZ.

Edited June 7, 2020 by Tomsk

[-=PHX=-SuperEtendard]

10 minutes ago, Tomsk said:

So heavier planes, in general, dive and zoom better than light ones. This is because of air resistance. Imagine two balls of the same shape, but one is very light and the other is very heavy. The force of air resistance depends only in the shape, which is the same for both balls. However  F = ma, so the heavier ball feels the same air resistance force but divided by the heavier mass the acceleration (deceleration in this case) is much smaller. The acceleration due to gravity is the same for both balls (it’s g so approx 9.8 m/s^2). That said in real aircraft engine power does play a role as well, still all else being equal heavier aircraft dive and zoom better.

Yes, but this assumes the same drag for both of them. The P-47 is a very draggy airframe on it's own because of it's size.

Think that at sea level with 2600 HP it reaches slightly slower speed as a Bf 109 F-4 with 1330 HP,  basically half the power.  The reason the P-47 is so fast at high altitudes is because the turbo mantains that amount of power all the way up there while other planes lose a good chunk of their engine power in comparison.

The test I made in game at least shows that for the FMs drag is very important, that's why there is so much difference between the Bf 109 K-4 DC and Spitfire Mk IX 150 oct, both planes with similar weights and similarly high power to weight ratios, but the K-4 just zooms away from the Spit at similar conditions being a much aerodynamic airframe overall (the huge wings of the Spit hurts it in this regard).

At least that's how it works in the game. In the real world I don't know which one ends up winning in this drag vs inertia situation.

[6./ZG26_Klaus_Mann]

27 minutes ago, -=PHX=-SuperEtendard said:

Yes, but this assumes the same drag for both of them. The P-47 is a very draggy airframe on it's own because of it's size.

Think that at sea level with 2600 HP it reaches slightly slower speed as a Bf 109 F-4 with 1330 HP,  basically half the power.  The reason the P-47 is so fast at high altitudes is because the turbo mantains that amount of power all the way up there while other planes lose a good chunk of their engine power in comparison.

The test I made in game at least shows that for the FMs drag is very important, that's why there is so much difference between the Bf 109 K-4 DC and Spitfire Mk IX 150 oct, both planes with similar weights and similarly high power to weight ratios, but the K-4 just zooms away from the Spit at similar conditions being a much aerodynamic airframe overall (the huge wings of the Spit hurts it in this regard).

At least that's how it works in the game. In the real world I don't know which one ends up winning in this drag vs inertia situation.

That seems Off to me.

 

The P-47 ingame with its 2600hp reaches the same Top Speed as the G-14 with Full Water Injection which has 1700hp. at Sea Level, while the P-47 weighs twice as much. To achieve the same Speed at Higher Weight means it is Aerodynamically more efficient.

This also born out by the Lower Rate of Climb of the P-47s.

 

Just Draw the Polar Curve for both Aircraft and extrapolate it past Top Speed. The P-47s is less draggy.

 

As a general Rule, if you see Two Aircraft with the same Top Speed, the one with the higher Maximum Rate of Climb normally also is the one that has a Draggier Airframe.

Edited June 7, 2020 by 6./ZG26_Klaus_Mann

[Tomsk]

2 hours ago, -=PHX=-SuperEtendard said:

Yes, but this assumes the same drag for both of them. The P-47 is a very draggy airframe on it's own because of it's size.

 

Yup I agree, I was only explaining how weight affects dive/zoom, I wasn't making a specific point in regards to the P-47. As you say, it depends on the drag.

 

1 hour ago, 6./ZG26_Klaus_Mann said:

The P-47 ingame with its 2600hp reaches the same Top Speed as the G-14 with Full Water Injection which has 1700hp. at Sea Level, while the P-47 weighs twice as much. To achieve the same Speed at Higher Weight means it is Aerodynamically more efficient.

 

So I'm not an expert but as I understand it top-speed is mostly about power vs drag, and weight plays a relatively minor role. This is in contrast to sustained climb rate or acceleration where power-to-weight is the deciding factor. As such if the P-47 is the same speed as the G-14, but has much more power, the conclusion should be that it is significantly more draggy. Which is what you'd expect: it's got a much larger frontal surface area.

 

Of none of this is particular relevant to my original point which was the P-47 seems to be bad as high-speed turning in IL2:GB. Much more so than in any other simulation, and in contrast to statements made in real life about the P-47.

Edited June 7, 2020 by Tomsk

[6./ZG26_Klaus_Mann]

25 minutes ago, Tomsk said:

So I'm not an expert but as I understand it top-speed is mostly about power vs drag, and weight plays a relatively minor role. This is in contrast to sustained climb rate or acceleration where power-to-weight is the deciding factor. As such if the P-47 is the same speed as the G-14, but has much more power, the conclusion should be that it is significantly more draggy. Which is what you'd expect: it's got a much larger frontal surface area.

 

The Flatter the Polar Curve, the less Draggy the Plane, it is that simple. Unfortunately the only make them for Gliders, but you can plot one for Motorplanes just as easily. And the P-47 at the same Top Speed has a flatter Polar Curve, meaning it is more Aerodynamically efficient.

 

Just create a simple Polar Curve for both using Stall Speed, Best Climb and Top Speed. The Graph for the P-47 will be significantly flatter, meaning less Energy Loss even above Top Speed. Below Top Speed the 109 will always gain Energy more quickly. Above Top Speed the 47 wins.

[Tomsk]

6 minutes ago, 6./ZG26_Klaus_Mann said:

The Graph for the P-47 will be significantly flatter, meaning less Energy Loss even above Top Speed. Below Top Speed the 109 will always gain Energy more quickly. Above Top Speed the 47 wins.

 

Ah yeah, I agree with you here. Heavier planes carry excess speed better, same argument I gave above on why they dive/zoom better: less affected by parasitic drag ? Of course probably the best plane at this is the P-51: actually a pretty heavy plane, and incredibly aerodynamically efficient.

Edited June 7, 2020 by Tomsk

[6./ZG26_Klaus_Mann]

3 minutes ago, Tomsk said:

 

Ah yeah, I agree with you here. Heavier planes carry excess speed better, same argument I gave above on why they dive/zoom better: less affected by parasitic drag ?

It's why Gliders take Water Ballast for Long Flights. High Speed Drag is Lower, Low Speed Drag is Higher, or better explained, the Drag is the same, but the Force moving it through the Air is higher.

Edited June 7, 2020 by 6./ZG26_Klaus_Mann

[Raven109]

On 6/7/2020 at 10:02 AM, SAS_Storebror said:

 

Interesting style of quoting sources so they fit your bias.

That particular quote goes on like this:

 

That's the exact opposite of what the P-47 can do in IL-2 GB.

Ingame, the Jug accelerates like a fully loaded concrete mixer and anything but FC planes and the Podwa can easily run away from it, including bombers!

 

 

I'm sorry, but what's my bias - aviation? Is it possible we don't turn every thread into red vs blue (imaginary) politics; the war is over.... and by the way, this is a game... not reality, it will never abide to the rules of reality (because of technical reasons, but also because of gameplay reasons). As much as some here don't want it, reality is (a lot) different and the outcome of the war was decided by complex factors much more powerful than individual aircraft performance.

 

No one here was talking about acceleration on the ground, so that's why I did not quote that paragraph. The point of contention is that the P-47 cannot boom and zoom against the AI, since it cannot hold its energy (as the OP expects it to BnZ). The quotes were posted to address <<specifically>> that point. In-game it can BnZ, if you don't go yanking and banking like it's a Spitfire. Also, don't expect it to climb at a high pitch angle. Over 6000m, it cannot be defeated if it has an energy advantage, which BnZ implies. Down low it's harder to pull off but can still be done.

 

Anyway, I pasted the whole link (just like the original poster did), so everybody can read the original, which means that they can get the whole picture - not sure how that counts as bias.

 

As everyone here, you are free to read the P-47 manual (please don't let anyone's "bias" stop you); it states that for a loop or an Immelmann the P-47 needs an entry speed of at least 350mph which drops to 140-150mph at the top. Now try that in-game. (page https://ww2aircraft.net/forum/attachments/p-47-aaf-manual-pdf.67677/). 

 

 

Most threads around here are always asking for (sometimes imaginary) advantages to be modeled, but never the quirks, like these:

 

 

 

In-game I can:

Maneuver violently, do acrobatics and do high speed dives with fuel in the belly tank. Doesn't apply to the in-game P-47. The manual is talking about <external> belly tanks, and not about one of the internal fuel tanks as I thought initially. (Thanks to Legioneod for pointing this out)

Slow roll at speeds over 313 mph IAS.

 

In spite of it not being a possibility, I would like to see all planes modeled with all their FM quirks, so that we can see that flying those birds was not as easy (or even as fun) as current simulations make them to be. Having the planes modeled in full detail, will help us understand that BnZ doesn't mean looping above the defender to infinity as the game makes it seem to be. BnZ most of the time meant an initial high speed attack, followed by an extension and then turn around if the situation allowed. (I'm afraid that if they modeled them correctly/completely, then many would not play since it would be too hard to get a kill - just like it was in real life. And who has time for hard stuff, right?).

 

Edited June 8, 2020 by Raven109

[blitze]

7 hours ago, SAS_Storebror said:

Eh... lol?

The Jug engine's fuel consumption at combat power exceeds 1000 litres per hour!

With 250 litres fuel, you don't even have sufficient fuel to exceed your combat mode time 

You would barely reach your "safe space" if you manage to climb perfectly, and then your fuel runs out.

This "hint" might work in QMB with airstart @10.000m altitude - other than that, this is just ridiculous.

 

Mike

 

Online in the P47- you will either get hot quickly as online flying does or get shot down so what does it matter ?

 

No, your right, a careful pilot would need more juice to get to operational altitude to be effective.  Thing is though, to work out the flight time you expect to be doing and take fuel to match.  A fully fueled Jug is quite a lot to deal with and most flights would be lucky to last long online.

[Tomsk]

57 minutes ago, Raven109 said:

No one here was talking about acceleration on the ground, so that's why I did not quote that paragraph. The point of contention is that the P-47 cannot boom and zoom against the AI, since it cannot hold its energy (as the OP expects it to BnZ). The quotes were posted to address <<specifically>> that point. In-game it can BnZ, if you don't go yanking and banking like it's a Spitfire.

 

Thanks for your input. I didn't actually say the P-47 cannot boom and zoom against the AI. What I said is that compared to other similar planes the P-47 is bad at BnZ. I do not doubt there are better pilots than myself, but I do have a lot of experience in this style, many hundreds of hours online and offline and have done very well for myself on popular public servers flying this style exclusively. As such I feel fairly well qualified to say the P-47 in IL2:GB is bad at BnZ, in particular it bleeds energy very badly in high speed turns in a way that the P-51, FW-190 and Tempest do not. It's high speed maneuverability is also not great in IL2:GB. In other simulations the P-47 does not have these problems, only IL2:GB. High speed turns are often necessary when flying BnZ against a defending opponent to make a guns solution: it's not a question of "yanking and banking like it's a Spitfire", BnZ often requires pulling G ... this is just how it works.

 

Quote

Having the planes modeled in full detail, will help us understand that BnZ doesn't mean looping above the defender to infinity as the game makes it seem to be. BnZ most of the time meant an initial high speed attack, followed by an extension and then turn around if the situation allowed. 

 

Yes that's certainly one way to do a BnZ attack, but it's not the only way. Sometimes looping back over is perfectly reasonable, sometimes it's not. Sometimes a straight zoom climb away is a better choice, sometimes a horizontal extension is better. It all depends on your energy and the situation, and all of these tactics have been described in accounts by real pilots. 

Edited June 7, 2020 by Tomsk

[Raven109]

8 minutes ago, Tomsk said:

Thanks for your input. I didn't actually say the P-47 cannot boom and zoom against the AI. What I said is that compared to other similar planes the P-47 is bad at BnZ. 

Yes, no misunderstanding here. It's the reason why I said  "(as the OP expects it to BnZ)".

 

8 minutes ago, Tomsk said:

Yes that's certainly one way to do a BnZ attack, but it's not the only way. Sometimes looping back over is perfectly reasonable, sometimes it's not. Sometimes a straight zoom climb away is a better choice, sometimes a horizontal extension is better. It all depends on your energy and the situation, and all of these tactics have been described by real pilots. 

 

I was talking about how it was done in real life. As you see, even the P-47 manual mentions that "acrobatics are rarely needed in combat". The situation rarely required IRL for the pilot to do the maneuvers that you see done on-line, or even off-line. That's why I see a distinction between what BnZ meant in real life and what it means in game, and that's why I see an issue when comparing RL to the overly simplified game-world (this includes pilot reports as well).

Edited June 7, 2020 by Raven109

[Tomsk]

2 minutes ago, Raven109 said:

That's why I see a distinction about what BnZ meant in real life and what it means in game, and that's why I see an issue when comparing RL to the overly simplified game-world (this includes pilot reports as well).

 

I do not doubt that actually flying in combat in WWII would have been very different in many ways to how it happens in a game. Many of those differences we cannot recreate .. or in many cases would even want to. However, I am still of the opinion that the flight model for the P-47 is off, especially in having too much energy bleed in high speed turns, at least compared to other planes we have in game. After reading around on the internet, I certainly don't seem to be the only one who holds this opinion.

[-=PHX=-SuperEtendard]

9 hours ago, 6./ZG26_Klaus_Mann said:

That seems Off to me.

 

The P-47 ingame with its 2600hp reaches the same Top Speed as the G-14 with Full Water Injection which has 1700hp. at Sea Level, while the P-47 weighs twice as much. To achieve the same Speed at Higher Weight means it is Aerodynamically more efficient.

This also born out by the Lower Rate of Climb of the P-47s.

 

Just Draw the Polar Curve for both Aircraft and extrapolate it past Top Speed. The P-47s is less draggy.

 

As a general Rule, if you see Two Aircraft with the same Top Speed, the one with the higher Maximum Rate of Climb normally also is the one that has a Draggier Airframe.

The P-47 doing G-14 speeds is by doing "tricks" like going full rich mixture, decreasing RPM and overboosting the engine to 67", this is more than 2600HP.

If you stick to the corrrect engine regime of auto rich, 2700 RPM, 64" it will go to 552 km/h without wing racks, and 546 km/h with wing racks.

Also weight doesn't play an important role in top speed, it's effect is small and depends on how much more or less angle of attack the wings needs to have to mantain level flight by comparing different weights.  If you take the lightest P-47 configuration (4x MG, no ammo, minimum fuel) and the heaviest P-47 configuration without affecting drag (8xMG, full ammo, full fuel, gyro gunsight) there is a difference of 1500 Kg in weight, (6686 vs 5163) yet this only makes a 12 kmh difference in top speed at 64" (549 kmh vs 561 kmh  neither with wing racks).

If anything weight discussion matters for plane with the same wings, if they have different wings it's more of an apple to oranges comparison since both planes will be affected differently by it.

[SJ_Butcher]

11 hours ago, Tomsk said:

So heavier planes, in general, dive and zoom better than light ones. This is because of air resistance. Imagine two balls of the same shape, but one is very light and the other is very heavy. The force of air resistance depends only in the shape, which is the same for both balls. However  F = ma, so the heavier ball feels the same air resistance force but divided by the heavier mass the acceleration (deceleration in this case) is much smaller. The acceleration due to gravity is the same for both balls (it’s g so approx 9.8 m/s^2). That said in real aircraft engine power does play a role as well, still all else being equal heavier aircraft dive and zoom better.

 

I agree this is also a problem, it’s pretty stiff at high speeds and also bleeds energy fast in high speed turns. The end result is it’s bad at pulling for snapshots making it bad at BnZ.

 

 

I understand that in a dive, but it's hard to me to believe that the acceleration wont drop in a zoom as fast, the heavier ball should loss the acceleration on a zoom faster than a light ball

[Raven109]

10 hours ago, 6./ZG26_Klaus_Mann said:

The P-47 ingame with its 2600hp reaches the same Top Speed as the G-14 with Full Water Injection which has 1700hp. at Sea Level, while the P-47 weighs twice as much. To achieve the same Speed at Higher Weight means it is Aerodynamically more efficient.

 

The fact that they reach the same level speed means that both of them have the necessary thrust to overpower their total drag. The fact that a much more powerful aircraft can only have the same speed as a smaller, less powerful aircraft at sea-level indicates that the drag is quite higher on the P-47 (either parasitic or induced) that on the 109. Usually a wing which must produce bigger lift (to oppose a bigger weight) will also produce more drag, but drag depends on speed of course and wing design, so both planes might see different drag at different flight regimes.

 

But why compare it to the 109G-14. Compare it to the G6. They were for many months in a deadly competition. Once you do that the Thunderbolt's advantages appear more clear. Take a 109G6/G14 over 6000m, where the bombers where, and where both aircraft lose their power. The Thunderbolt will shine there.

 

2 hours ago, Tomsk said:

 

I do not doubt that actually flying in combat in WWII would have been very different in many ways to how it happens in a game. Many of those differences we cannot recreate .. or in many cases would even want to. However, I am still of the opinion that the flight model for the P-47 is off, especially in having too much energy bleed in high speed turns, at least compared to other planes we have in game. After reading around on the internet, I certainly don't seem to be the only one who holds this opinion.

 

How many Gs are you pulling during the high speed turns, and at what altitude? - I understand that you are an experienced BnZ'er - not doubting that, I'm just curios about the expectations.

Edited June 7, 2020 by Raven109

[Legioneod]

9 hours ago, Raven109 said:

 

I'm sorry, but what's my bias - aviation? Is it possible we don't turn every thread into red vs blue (imaginary) politics; the war is over.... and by the way, this is a game... not reality, it will never abide to the rules of reality (because of technical reasons, but also because of gameplay reasons). As much as some here don't want it, reality is (a lot) different and the outcome of the war was decided by complex factors much more powerful than individual aircraft performance.

 

No one here was talking about acceleration on the ground, so that's why I did not quote that paragraph. The point of contention is that the P-47 cannot boom and zoom against the AI, since it cannot hold its energy (as the OP expects it to BnZ). The quotes were posted to address <<specifically>> that point. In-game it can BnZ, if you don't go yanking and banking like it's a Spitfire. Also, don't expect it to climb at a high pitch angle. Over 6000m, it cannot be defeated if it has an energy advantage, which BnZ implies. Down low it's harder to pull off but can still be done.

 

Anyway, I pasted the whole link (just like the original poster did), so everybody can read the original, which means that they can get the whole picture - not sure how that counts as bias.

 

As everyone here, you are free to read the P-47 manual (please don't let anyone's "bias" stop you); it states that for a loop or an Immelmann the P-47 needs an entry speed of at least 350mph which drops to 140-150mph at the top. Now try that in-game. (page https://ww2aircraft.net/forum/attachments/p-47-aaf-manual-pdf.67677/). 

 

 

Most threads around here are always asking for (sometimes imaginary) advantages to be modeled, but never the quirks, like these:

 

 

 

In-game I can:

Maneuver violently, do acrobatics and do high speed dives with fuel in the belly tank.

Slow roll at speeds over 313 mph IAS.

 

In spite of it not being a possibility, I would like to see all planes modeled with all their FM quirks, so that we can see that flying those birds was not as easy (or even as fun) as current simulations make them to be. Having the planes modeled in full detail, will help us understand that BnZ doesn't mean looping above the defender to infinity as the game makes it seem to be. BnZ most of the time meant an initial high speed attack, followed by an extension and then turn around if the situation allowed. (I'm afraid that if they modeled them correctly/completely, then many would not play since it would be too hard to get a kill - just like it was in real life. And who has time for hard stuff, right?).

 

P-47 in-game does not have belly tanks, it has internal fuselage tanks which is different. The belly tanks mentioned in the manual is drop tanks, not internal tanks. P-47 doesn't have internal wing tanks either. 

Also keep in mind these restrictions weren't set because it was impossible for a P-47 to do them but because they were either dangerous or cause undue stress to the aircraft.

 

6 hours ago, -=PHX=-SuperEtendard said:

The P-47 doing G-14 speeds is by doing "tricks" like going full rich mixture, decreasing RPM and overboosting the engine to 67", this is more than 2600HP.

If you stick to the corrrect engine regime of auto rich, 2700 RPM, 64" it will go to 552 km/h without wing racks, and 546 km/h with wing racks.

Also weight doesn't play an important role in top speed, it's effect is small and depends on how much more or less angle of attack the wings needs to have to mantain level flight by comparing different weights.  If you take the lightest P-47 configuration (4x MG, no ammo, minimum fuel) and the heaviest P-47 configuration without affecting drag (8xMG, full ammo, full fuel, gyro gunsight) there is a difference of 1500 Kg in weight, (6686 vs 5163) yet this only makes a 12 kmh difference in top speed at 64" (549 kmh vs 561 kmh  neither with wing racks).

If anything weight discussion matters for plane with the same wings, if they have different wings it's more of an apple to oranges comparison since both planes will be affected differently by it.

 

The P-47 is a draggy aircraft no doubt but it's not as draggy as some people think. And while I agree that weight doesn't mean much when it comes to top speed, it does matter when it comes to keeping that speed. One of the reasons the P-47 was so good at diving and zooming is because it had all that mass and excess power to help it keep it's speed that it built up.

 

We see things in game like spitfires diving right alongside the P-47 and staying with it after the dive, yet logically it seems that the P-47 with all it's weight/power should be able to hold onto it's speed after the dive much better than a light aircraft like the spitfire.

 

 

EDIT: If anyone is interesting in looking through and finding different NACA reports this list all various reports from 1915-1949. It includes reports on various aircraft including the P-47. You can use it as a way to find a specific NACA report (I think)

 

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003570.pdf

 

 

Here's just a few reports, I'm sure there's more but I don't really feel like looking for them and I'm not really smart enough to understand most of it anyways.

 

Preliminary vibration and flutter studies on P-47 tail.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930092909.pdf

 

Flight investigation of boundary layer and profile drag characteristics of smooth wing sections of P-47 airplane.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093001.pdf

 

Flight investigation at high speeds of profile drag of wing of a P-47D airplane having production surfaces covered with camouflage paint.

https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930092751.pdf

 

Measurements of flying qualities of P-47D airplane to determine lateral and directional stability and control characteristics.

http://www.wwiiaircraftperformance.org/p-47/Naca_TN_2675__F-47D-30_Flight_Test.pdf

 

Measurements of flying qualities of P-47D airplane to determine longitudinal stability and control and stalling characteristics.

http://www.wwiiaircraftperformance.org/p-47/Naca_TN_2899__F-47D-30_Flight_Test.pdf

 

NASA Website also has lots of reports for various things/aircraft.

https://ntrs.nasa.gov/search.jsp?Nm=17|Collection|NACA||4294059423|Publication Year|1945&N=0&No=30

 

Edited June 8, 2020 by Legioneod

[Tomsk]

14 hours ago, SJ_Butcher said:

I understand that in a dive, but it's hard to me to believe that the acceleration wont drop in a zoom as fast, the heavier ball should loss the acceleration on a zoom faster than a light ball

 

It's counter-intuitive right. However, the key is understanding it is that acceleration due to gravity does not depend on mass. A 1Kg weight or a 1000Kg weight both experience the same 9.81m/s^2 due to gravity. One way to work this is out is to calculate the force of gravity on an object (using F = m * 9.81) and then calculate the acceleration that produces with a = F / m, the mass cancels out. The same is not true for air resistance, where the amount of deceleration decreases with increasing mass. So the heavy ball and the light ball experience the same 9.81m/s^2 deceleration due to gravity, but the heavy ball experiences less deceleration due to air resistance, so it goes higher. 

 

One intuitive way to grasp this is to imagine you were in a throwing competition to throw as far (or as a high) as you could, and you were offered two different objects to throw. They are the same shape but one is very light like a ping-pong ball, the other is a solid heavy stone. Which object do you think you could throw further/higher?

 

14 hours ago, Raven109 said:

How many Gs are you pulling during the high speed turns, and at what altitude? - I understand that you are an experienced BnZ'er - not doubting that, I'm just curios about the expectations.

 

This varies hugely! The G is "as needed" and is always a trade-off: do I want to spend more energy here to get a shot, or should I let this pass go and save energy for the next pass? You use as little as you can because it costs energy, however, sometimes it is worth pulling quite a lot of G for a shot, right up to the black-out limit at times. Similarly the altitude varies depending on your altitude and the altitude of the target.

 

Honestly the issue is hard to quantify exactly. It's more a qualitative thing: the P-47 doesn't give you many passes, and it's not great at making shots during those passes. It's not that it can't be done, but just that it is decidedly inferior to other planes. Hell I'd rather do BnZ in a Spitfire, even with the terrible roll rate at high speed, just because it retains energy better, the weapons have more punch and it has no problem pulling for shots at high speeds (which seems a little suspect). 

Edited June 8, 2020 by Tomsk

[Raven109]

9 hours ago, Legioneod said:

P-47 in-game does not have belly tanks, it has internal fuselage tanks which is different. The belly tanks mentioned in the manual is drop tanks, not internal tanks. P-47 doesn't have internal wing tanks either. 

Also keep in mind these restrictions weren't set because it was impossible for a P-47 to do them but because they were either dangerous or cause undue stress to the aircraft.

...

 

That is right. For some reason I thought the manual was using "belly tank" to refer to one of the 2 internal fuel tanks. I have updated my post with this information. (The P-47N does have wing fuel tanks though, but that is another subject). Not saying that the maneuvers were impossible, far from it. I posted them as a side note, to highlight that the a/c (all of them) had limitations, which are not present in-game, and because of which in real life you could not do many of the crazy maneuvers we get away with in game. What happens is that the game might create unreal expectations about the RL life performance of the aircraft and about how they were used during combat.

 

I've also checked some of these maneuvers in-game and some do check out, others don't.

 

The relevant maneuvers to this discussion were the acrobatics, which apparently show the amount of speed lost by the P-47. It's the best I could find when it comes to speed loss during maneuvering, something that can easily be tested in game.

Edited June 8, 2020 by Raven109

[ICDP]

Please have a read of the following tactical trials of a P-47D compared to Fw190 and of USAAF fighters compared to an A6M5.

 

http://www.wwiiaircraftperformance.org/japan/zeke52-taic38.pdf

 

A6M5 vs USAAF P38J, P51D and P47D-30.

 

Some excerpts of note comparing A6M5 to P47D

 

Level Flight Acceleration

Beginning from level flight at 200IAS, the P47D accelerated rapidly away form the Zeke when full power was applied.  After one minute, the P-47D was approximately 400 yards ahead (365 metres).  After two minutes, this lead had increased to 800 yards (730 metres).

 

Dive Acceleration

From 10,000 feet.  The P-47D was approximately 100 yards (91 metres) ahead after 30 seconds.

From 25,000 feet.  The P-47D was approximately 300 yards (272 metres) ahead after 30 seconds.

 

Zoom from Level Flight

10,000 Feet.  The P-47D was approximately 400 feet above and ahead of the Zeke after a full power zoom from level flight.

25,000 Feet, Results were approximately the same as those obtained at 10,000 feet.

 

Zoom from Dive

10,000 Feet.  After a zoom from 310 IAS to 130 IAS, the P-47D was approximately 600 feet above and far ahead of the Zeke

25,000 Feet, Results were approximately the same as those obtained at 10,000 feet.

 

Against the Fw190

http://www.wwiiaircraftperformance.org/p-47/P-47_versus_FW-190.pdf

 

Both planes enter a dive from cruise speeds at 10,000ft.  The 190 initially left the P-47D behind and it took the P-47D until 3,000ft (7,000ft of altitude) to catch and overtake the 190.

 

So in every single case the P-47D was still within shooting range of the Zeke after zooms and dives.  It took well over a minute for the P47-D to pull out of shooting range in level flight acceleration.  Against the Fw190A the Fw actually had the initial advantage in a dive and acceleration at low to medium speeds.  So these tests would indicate that a P-47s advantage in maintaining energy in boom and zoom was marginal. I don't think a 100 yard (91 metre) advantage over a Zeke after a 30 second dive is something to write home about.  I mean all that is to me is 30 seconds in the sights of a Zeke, more than ample time for him to shoot you down.  So if you are at anything between 250 and 300 TAS in a P47D then you have lost any advantage and a 109 or Fw190 will begin to take control of the fight and running or diving or zooming is no longer an option.  You are now almost totally defensive and absolutely well out of any semblance of "boom and zoom" territory.

Edited June 8, 2020 by ICDP

[Raven109]

1 hour ago, Tomsk said:

 

It's counter-intuitive right. However, the key is understanding it is that acceleration due to gravity does not depend on mass. A 1Kg weight or a 1000Kg weight both experience the same 9.81m/s^2 due to gravity. One way to work this is out is to calculate the force of gravity on an object (using F = m * 9.81) and then calculate the acceleration that produces with a = F / m, the mass cancels out. The same is not true for air resistance, where the amount of deceleration decreases with increasing mass. So the heavy ball and the light ball experience the same 9.81m/s^2 deceleration due to gravity, but the heavy ball experiences less deceleration due to air resistance, so it goes higher. 

 

One intuitive way to grasp this is to imagine you were in a throwing competition to throw as far (or as a high) as you could, and you were offered two different objects to throw. They are the same shape but one is very light like a ping-pong ball, the other is a solid heavy stone. Which object do you think you could throw further/higher?

 

Here you are assuming that the drag is the same for both balls. If the drag is the same, why does the P-47, which is ~1000HP more powerful than the 109G-14, only reach a SL max speed of 544km/h, a bit less than that of the 109?

 

Even if we consider prop efficiency, and we assume that the 109 had 100% efficiency (wild assumption to make a point), while the 47 had only 85%, it still cannot account for such SL relative performance.

 

Instead of a ball, think of a heavy steel cube sliding along a steel ramp and another lighter steel cube sliding along a ramp made of ice, both ramps are angled the same. Sure, weight is important, but so is friction (drag). Even better yet, think about a 1t of steel shaped as a parachute and 1t of steel shaped as a projectile; which one of these will reach the ground first in free fall from 2000m?

 

The weight of the P-47 should matter more higher up, where the air density is reduced, and even more considering that it can hold it's output power much better at higher altitudes than the opposition. But at SL, it can only hold the same speed as a less powerful aircraft.

 

Something must be holding it back, don't you agree?

Edited June 8, 2020 by Raven109