The Thunderbolt Conundrum

[ICDP]

The thing with the JFC is that I use it as another source rather than the only source.  I have seen enough USAAF and RAF tactical trials along with actual test results to conclude, that any advantage the P47D had in performance at high altitude were not so significant that it would be handing all other fighters their asses with ease.

Edited May 10, 2021 by ICDP

[Bremspropeller]

40 minutes ago, JtD said:

Why would the F4U not come in before the P-47 in terms of best fighter bomber? It carried a bigger, more versatile load to start with, had some things speaking for it in between and was equipped with dive brakes to end with.

 

The P-38 had poor sideways ground vision and a pretty stiff elevator at higher speeds. Nothing you'd really want in a low level diving attack, not matter what load the aircraft carries (less than the F4U, anyway).

 

So you're looking for the better dive-bomber. They're supposed to look for the better fighter-bomber, though.

 

The F4U could carry a larger bomb-load in terms of tonnage. The P-47 had two more guns and 1000 rounds more ammo to play with.

The F4U could lower it's landing gear, while late Jugs had dive-recovery flaps. Neither are optimal.

How is the F4U's load more versatile?

 

The P-38 could carry 4000lbs - just like the F4U. And it arguably had the better strafing-setup (unless counting the 4x 20mm Hogs).

On top, the P-38 could carry twice the number of bombs of the Hog and it brought a spare engine.

[Legioneod]

33 minutes ago, ICDP said:

The thing with the JFC is that I use it as another source rather than the only source.  I have seen enough USAAF and RAF tactical trials along with actual test results to conclude, that any advantage the P47D had in performance at high altitude were not so significant that it would be handing all other fighters their asses with ease.

I don't think anyone is saying it should be easy but I think some are frustrated by some of the odd quirks of the aircraft that don't seem correct. (some stall characteristics, damage model causing huge loss of lift and drag, losing controls in a dive, energy retention, etc.)

Based off of in-game stats alone the P-47 is the best fighter 20,000ft and above, it has better climb, speed, sustained turn than any other aircraft as far as I know. In-game stats would lead you to believe that it starts gaining the advantage as low as 10,000ft but the performance is so close it's impossible to really gain any advantage that low.

 

At the end of the day the P-47 is just a very difficult aircraft to be good in, it's hard to fly it to its full potential in-game. I've had my fair share of victories online but I find the P-47 to be much less enjoyable just because of how difficult it is to fly, Imo it's the most difficult fighter to fly in-game.

Edited May 10, 2021 by Legioneod

[ICDP]

1 hour ago, Legioneod said:

I don't think anyone is saying it should be easy but I think some are frustrated by some of the odd quirks of the aircraft that don't seem correct. (some stall characteristics, damage model causing huge loss of lift and drag, losing controls in a dive, energy retention, etc.)

Based off of in-game stats alone the P-47 is the best fighter 20,000ft and above, it has better climb, speed, sustained turn than any other aircraft as far as I know. In-game stats would lead you to believe that it starts gaining the advantage as low as 10,000ft but the performance is so close it's impossible to really gain any advantage that low.

 

At the end of the day the P-47 is just a very difficult aircraft to be good in, it's hard to fly it to its full potential in-game. I've had my fair share of victories online but I find the P-47 to be much less enjoyable just because of how difficult it is to fly, Imo it's the most difficult fighter to fly in-game.

 

Your two paragraphs are a bit contradictory.  Your first is saying nobody wants it to be easy to fly and the second is saying it needs to be easier to fly.  I get that these are not mutually exclussive statments but are you asking for the P47D to be slightly easier to fly?  The problem we have is it is harder to objectively prove something based on subjective opinions.

 

You and others feel the P47D is off at altitude by varying degrees yet it meets performance figures reasonably well.  I find it matches roughly were the numbers and my own testing say it should be.  It is transformed from a bit of a dog a lower altitudes, into a plane that more than holds it's own and can with patience control the fight agains its foes given equal pilots and equal energy states.

Edited May 10, 2021 by ICDP

[HR_Zunzun]

The test pilots only had a few hours in any of the planes. While it was good information that the organizer did retrieved from them I would take their opinion with a huge pinch of salt when clasifying anything as the "the best...."

They didn´t have a great deal of information on how to get the most of the planes they were not familiar with. Probably very biased by the way they use their asigned planes.

[Legioneod]

54 minutes ago, ICDP said:

 

Your two paragraphs are a bit contradictory.  Your first is saying nobody wants it to be easy to fly and the second is saying it needs to be easier to fly.  I get that these are not mutually exclussive statments but are you asking for the P47D to be slightly easier to fly?  The problem we have is it is harder to objectively prove something based on subjective opinions.

 

You and others feel the P47D is off at altitude by varying degrees yet it meets performance figures reasonably well.  I find it matches roughly were the numbers and my own testing say it should be.  It is transformed from a bit of a dog a lower altitudes, into a plane that more than holds it's own and can with patience control the fight agains its foes given equal pilots and equal energy states.

I can see how my post looks contradictory. I didn’t mean that I want the P47 to be easier to fly or that it should mop the floor with German aircraft at altitude.

I was just saying that it is a difficult aircraft to fly, not that it should necessarily be easier, though I do believe there are a few things that may be making it harder to fly than it has to be, some of these things effect more than just the P47.

 

Overall performance is mostly ok but there are a few things that need fixing (power drops too soon) and I’m unconvinced that the stall characteristics are correct, but I have no hard proof currently to confirm or deny that.

 

I made a post in the beta tester flood section about the power problem that needs to be looked at.

Edited May 10, 2021 by Legioneod

[ICDP]

35 minutes ago, Legioneod said:

I can see how my post looks contradictory. I didn’t mean that I want the P47 to be easier to fly or that it should mop the floor with German aircraft at altitude.

I was just saying that it is a difficult aircraft to fly, not that it should necessarily be easier, though I do believe there are a few things that may be making it harder to fly than it has to be, some of these things effect more than just the P47.

 

Overall performance is mostly ok but there are a few things that need fixing (power drops too soon) and I’m unconvinced that the stall characteristics are correct, but I have no hard proof currently to confirm or deny that.

 

I made a post in the beta tester flood section about the power problem that needs to be looked at.

 

Yeah I think I remember that thread where we discussed the AHT speed curve showing a straight line from 20,000 - 30,000ft.  In fact I just remembered I kept it for easy reference.  I think (there's that word again) we are not too far off getting it right and if they fix the power loss at altidue it would make the P47D marginally better at higher alt without it becoming too far the other way.

Edited May 10, 2021 by ICDP

[Legioneod]

2 minutes ago, ICDP said:

 

Yeah I think I remember that thread where we discussed the AHT speed curve showing a straight line from 20,000 - 30,000ft.  In fact I just remembered I kept it for easy reference.  I think (there's that word again) we are not too far off getting it right and if they fix the power loss at altidue it would make the P47D marginally better at higher alt without it becoming too far the other way.

Yep, I tried to go into more detail in the beta tester thread, posted some more charts.

Edited May 10, 2021 by Legioneod

[oc2209]

5 hours ago, ICDP said:

This thread is specific to the P47D in the hope of finding any issues that should be reported to the devs re the P47D performance.

 

I was thinking about this last night, and it occurred to me that the issues with the P-47 might not be isolated to its individual flight model; there could be an issue with the way all planes dive.

 

The Spitfire Wikipedia page has several examples of Spitfires from the IX on up, reaching anywhere from 600-690 MPH in dives without taking significant damage. That would be impossible in this sim, based on my testing of Spitfires in dives.

 

A proper test of P-47 diving potential in the sim would be to have two human pilots start at 30,000 feet. One would be in a G-6 Late or G-14 (to represent the most commonly encountered 109 model for '43 and much of '44, i.e, the P-47's most likely enemy). The other would be in either P-47 model (both should be tested). The 109 should get a head start in the dive, 5-10 seconds maybe.

 

We should ascertain when (what altitude) the P-47 catches the 109; what condition both planes are in (regarding control surface damage); and whether the P-47 is able to accurately fire on the 109 while in a dive.

 

We have two famous historical examples of 109s being caught in sustained dives by 47s, at least. The two that come to mind for me are Rall's account of being shot down, and Johnson's account of chasing a 109. Surely we should be able to approximate these stories in some fashion.

 

Also from Wikipedia:

 

"Rall was flying at 36,000 ft (11,000 metres) without cabin heating or pressurisation, and 10,000 ft above the Fw 190s. Rall attacked claiming a Thunderbolt. His staffel were then ambushed by other P-47s. Rall dived to escape, but his Bf 109 could not out-dive the Thunderbolts, which were attacking in line-abreast, preventing him from turning left or right. Rall was near to 620 mph, but took hits in his engine and radiator by pilots of the 56th Fighter Group."

 

If P-47s can't dive at the same speeds as they did in real life, it's no surprise the 47 feels lame in the sim; since diving was, after all, its bread and butter tactic both offensively and defensively.

[Dakpilot]

Somewhere we all went through this dive issue with Yaks out diving 109's and 190's the maths was done and the realities were proven

 

How many times do people try and do a run to the deck from 30,000 ft in MP anyway. 

 

The separation gained is not enough to get out of gun range most of the time anyway even if you have a good speed advantage 

 

Edit

 

Another thing, when were P-47's operating at 30,000ft and what were they up against

 

Cheers, Dakpilot 

Edited May 10, 2021 by Dakpilot

[oc2209]

12 hours ago, JtD said:

The only region where it did enjoy a reasonable speed advantage was far above the full throttle altitudes of the competition, where it still produced 2000hp whereas the power of the other engines fell off. The A6M and Bf109G would still be able to climb with it, and in a turning fight outturn it - because it's just so friggin heavy.

 

I have books that say the P-47 could turn tighter than 109s (and obviously 190s) at high altitudes. Game data also indicates this to be true. Specifically, tight climbing turns are mentioned in the Osprey book I'm referencing.

20 minutes ago, Dakpilot said:

How many times do people try and do a run to the deck from 30,000 ft in MP anyway.

 

The point would be to prove that the P-47 is not living up to its potential even at its optimum performance altitudes. That would, naturally, make its performance at sub-optimal altitudes even more notably inferior than it should be.

 

A 47 that can't dive is largely worthless. Whether at 15k or 30k feet. It inhibits the top speed gained in the dive, and most likely dive acceleration as well. This precludes copying dive and zoom tactics that were used in real life.

 

Which, again, is another reason the 47 can't live up to its historical value. Rather than arguing it was merely irrationally overhyped by everyone who ever had anything good to say about it, or that it doesn't matter if it can't dive because no one ever uses it at high altitudes, we should try to ascertain the source of its problems.

[Dakpilot]

Out diving is overhyped 

 

Do some time and distance calculations 

 

Cheers, Dakpilot 

[oc2209]

15 minutes ago, Dakpilot said:

Out diving is overhyped 

 

Do some time and distance calculations

 

If a simulation can't recreate real events, then what exactly is being simulated?

[HR_Zunzun]

Diving advantage is not about puting the nose straight down and magically leaving everyone behind. It is more what Walter Beckham described during the Munster raid in October 1943:

"I turned towards home and looked around to clear my tail. Eight or ten single engine enemy aircraft were behind, but a bit too far away to fire at me. I used full throttle and nosed down at about 1000fpm dive, and turned slightly off my homeward course to the left so as to be flying directly into the sun. I must have begun to widen the gap, because after about five minutes I was about one-third of the way across the Zuider Zee, heading directly towards Amsterdam when the enemy fighters gave up the chase and turned away."

[oc2209]

36 minutes ago, HR_Zunzun said:

Diving advantage is not about puting the nose straight down and magically leaving everyone behind.

 

The problem with the P-47 is that it doesn't gradually outpace pursuers or targets.

 

Take a 47 and start at 9500m. Dive at a roughly 45 degree angle. Midway to the ground (around 15,000ft), you will:

 

A) not be over 600MPH

 

B) no longer be able to control the plane, except maybe to pull out of the dive with trim.

 

This means a P-47 cannot catch another diving plane; and damn well cannot shoot one down. I actually found a diving 109G-6 Late to be more controllable circa 540 MPH.

 

Even so, the only way you reach 600 MPH in a dive in this sim is after you've shed controls, and just a few thousand feet before you smack the ground. There's clearly a discrepancy between dive acceleration and dive survivability in real life descriptions versus the sim.

 

 

The Spit XIV actually tore itself apart before it hit the ground. Wings and everything came off.

 

Compare this to (from Wikipedia):

 

"Beginning in late 1943, high-speed diving trials were undertaken at Farnborough to investigate the handling characteristics of aircraft travelling at speeds near the sound barrier (i.e., the onset of compressibility effects). Because it had the highest limiting Mach number of any aircraft at that time, a Spitfire XI was chosen to take part in these trials. Due to the high altitudes necessary for these dives, a fully feathering Rotol propeller was fitted to prevent overspeeding. During these trials, EN409, flown by Squadron Leader J. R. Tobin, reached 606 mph (975 km/h) (Mach 0.891) in a 45° dive.

In April 1944, the same aircraft suffered engine failure in another dive while being flown by Squadron Leader Anthony F. Martindale, Royal Air Force Volunteer Reserve, when the propeller and reduction gear broke off. The dive put the aircraft to Mach 0.92, the fastest ever recorded in a piston-engined aircraft, but when the propeller came off, the Spitfire, now tail-heavy, zoom-climbed back to altitude. Martindale blacked out under the 11 g loading, but when he resumed consciousness, he found the aircraft at about 40,000 feet with its (originally straight) wings now slightly swept back.[128] Martindale successfully glided the Spitfire 20 mi (32 km) back to the airfield and landed safely.[129] Martindale was awarded the Air Force Cross for his exploits.[130]"

 

And here's my P-47 test:

 

 

It takes the entire dive from 9500m to even approach 600 MPH. And, again, with zero control left.

[Legioneod]

1 hour ago, oc2209 said:

 

The problem with the P-47 is that it doesn't gradually outpace pursuers or targets.

 

Take a 47 and start at 9500m. Dive at a roughly 45 degree angle. Midway to the ground (around 15,000ft), you will:

 

A) not be over 600MPH

 

B) no longer be able to control the plane, except maybe to pull out of the dive with trim.

 

This means a P-47 cannot catch another diving plane; and damn well cannot shoot one down. I actually found a diving 109G-6 Late to be more controllable circa 540 MPH.

 

Even so, the only way you reach 600 MPH in a dive in this sim is after you've shed controls, and just a few thousand feet before you smack the ground. There's clearly a discrepancy between dive acceleration and dive survivability in real life descriptions versus the sim.

 

 

The Spit XIV actually tore itself apart before it hit the ground. Wings and everything came off.

 

Compare this to (from Wikipedia):

 

"Beginning in late 1943, high-speed diving trials were undertaken at Farnborough to investigate the handling characteristics of aircraft travelling at speeds near the sound barrier (i.e., the onset of compressibility effects). Because it had the highest limiting Mach number of any aircraft at that time, a Spitfire XI was chosen to take part in these trials. Due to the high altitudes necessary for these dives, a fully feathering Rotol propeller was fitted to prevent overspeeding. During these trials, EN409, flown by Squadron Leader J. R. Tobin, reached 606 mph (975 km/h) (Mach 0.891) in a 45° dive.

In April 1944, the same aircraft suffered engine failure in another dive while being flown by Squadron Leader Anthony F. Martindale, Royal Air Force Volunteer Reserve, when the propeller and reduction gear broke off. The dive put the aircraft to Mach 0.92, the fastest ever recorded in a piston-engined aircraft, but when the propeller came off, the Spitfire, now tail-heavy, zoom-climbed back to altitude. Martindale blacked out under the 11 g loading, but when he resumed consciousness, he found the aircraft at about 40,000 feet with its (originally straight) wings now slightly swept back.[128] Martindale successfully glided the Spitfire 20 mi (32 km) back to the airfield and landed safely.[129] Martindale was awarded the Air Force Cross for his exploits.[130]"

 

And here's my P-47 test:

 

 

It takes the entire dive from 9500m to even approach 600 MPH. And, again, with zero control left.

Don't expect the P-47 to be able to easily pull out of a dive above 540mph+ The P-47 entered into compressibility at these speeds and its control surfaces would become increasingly stiff. Sometimes the only way to get out of a high speed dive was to add power and some positive trim.

 

I wrote a little about how it should be, never updated this thread though, probably should one day.

Copy paste from that thread.

Structural Integrity in a dive and maximum dive speed. (WIP)

Proposal: Increase P-47 structural integrity up to or around it's maximum Mach of around Mach 0.83. 

Loss of structure should still occur under certain circumstances (previous damage, high g) but in a stable dive no loss of structure should occur.

(Keep in mind I'm not talking about the P-47s critical mach in this section but the structural integrity and maximum possible speed in a dive. I will go over critical mach and compressability later on)

 

Currently in game the P-47 has a dive limit of around 560 mph IAS, this is due to the loss of structural surfaces at speeds at or in excess 560-570 mph. Structural loss at these speeds is incorrect to the actual dive capability of the P-47 and should be changed.

 

The P-47 should not lose any structural surfaces in a dive (even up to it's maximum speed) apart from being damaged before entering into the dive or excessive G on pullout.

 

Structural damage to the P-47 in a dive was pretty much unheard of and the only documented reports of it happening (as far as I'm aware) was on the early fabric covered tail surfaces of the P-47.

 

The fastest capable dive speed of the P-47 is around Mach 0.83 (around 630 mph give or take, not 100% sure) 

Below and up to this speed the P-47 had very little chance of structural failure and could safely recover from dives up to its maximum mach.

 

Loss of structure due to high speed dive is incorrect for the P-47 and should only occur under certain circumstances (damage being the primary cause)

Edited May 10, 2021 by Legioneod

[HR_Zunzun]

1 hour ago, oc2209 said:

 

The problem with the P-47 is that it doesn't gradually outpace pursuers or targets.

 

Take a 47 and start at 9500m. Dive at a roughly 45 degree angle. Midway to the ground (around 15,000ft), you will:

 

A) not be over 600MPH

 

B) no longer be able to control the plane, except maybe to pull out of the dive with trim.

 

 

I doubt that dives seeking terminal velocity was what it was done. That was too much of a risk (in any plane) of not being able to pull out of it. Many times there was an overcast where you didn´t know what it was below.

I think the type of dives they did was more in line what Beckham described. More shallow dives that allow the plane to accelerate beyond the horizontal maximum speed and there, the weight and inertia of the jug give it the advantage. Not a huge advantage but enough to chase the enemy planes or to escape in a shallow dive and cover dozens of miles on the way.

I think the main problem (apart from Guns/DM) is the lack of enough elevator authority. According to a NACA paper on longitudinal stability, the p-47 could have low G stick forces. The other sim -47 seems to follow that (the plane feels more crispy at the stick, without necesseraly losing the feeling of a heavy plane).

[oc2209]

53 minutes ago, HR_Zunzun said:

 

I doubt that dives seeking terminal velocity was what it was done. That was too much of a risk (in any plane) of not being able to pull out of it. Many times there was an overcast where you didn´t know what it was below.

I think the type of dives they did was more in line what Beckham described. More shallow dives that allow the plane to accelerate beyond the horizontal maximum speed and there, the weight and inertia of the jug give it the advantage.

 

The point I've been trying to make is that the P-47 can't even stay in one piece in a sustained dive, so it certainly can't shoot anyone down.

 

Elsewhere in this thread, ICDP said the 47 wouldn't accelerate quickly into a dive, but should eventually catch up to whatever it's chasing. Fine, I can live with that. Makes sense. What doesn't make sense, is that from what I can tell, the 47 can't catch anyone in a long, shallow dive either. Which is why I'm saying someone should test it and either put the issue to bed for once and for all, or, if the results of the tests warrant it, investigate the issue further.

 

I've already shown that the Spitfire can't sustain any kind of dive speeds close to what it could in reality; and neither, evidently, can the P-47 here. Therefore, if diving or high speed mechanics are somehow flawed, the P-47 would be the plane to suffer most from said flaw. While every other plane that doesn't rely so much on dive and zoom tactics will be largely unaffected.

 

As for the whole .50 cal issue, I'm not convinced it's a problem. In testing P-47s and P-51s at high altitudes lately, I've managed to flame 109s with very short bursts from longer ranges (300+ yards) than I'm normally comfortable with. The interesting thing about high-alt combat is that everything happens relatively slowly compared to down near the deck; which, I believe, makes aiming wing-mounted guns a little easier. I also hit a 109 in the wing with a short burst, and a minute or so later, at the bottom of a split-S, the wing snapped off in the middle (not at the end, where the 109 wing more commonly breaks).

 

I don't think the .50 is underperforming catastrophically. If there is a problem, it's more likely related to the pattern dispersion of the guns, not the ammunition itself and damage calculations.

[ICDP]

The loss of control surfaces is an easy way for the devs to give each aircraft some semblance of terminal velocity issues.  Please don't forget that all other aircraft lose controls at speeds that seem very arbitrary.

 

My tests in game have shown the P47D  dive and zoom to be slightly behind the P51D, marginally better than 109G14 and a fair bit better than a 109G6 (didn't test the G6 late).  Results vary slightly between the stock and 150 Octane models as would be expected.

 

Testing methods are as follows:

 

Kuban spring, flying level at 25,000ft.

• 25,000 feet alt.  200IAS
• Set full power
• Entered a dive of roughly 30-35 degree and rapidly reached VNE at around 18,000.
• I began a roughly 2.5G pull-out at ~20,000 feet and levelled out at just over 16,000 feet.   I did need to use trim in some cases which matches the manual of the P47.
• Pulled through into a ~40 degree climb.
• Continued climb until 145mph IAS.

 

P47D 100 Octane (stock)

Speed at 16,000ft was ~436mph

Final altitude was ~23,000 feet

145mph IAS

 

P47D 150 Octane

Speed at 16,000ft was ~444mph

Final altitude was ~24,000 feet

145mph IAS

 

P51D 62" Boost (as per Zero Tactical Test settings) This required roughly 94% throttle.

Speed at 16,000ft was ~430mph

Final altitude was ~23,000 feet

145mph IAS

 

P51D 67" Boost (stock)

Speed at 16,000ft was ~440mph

Final altitude was ~24,000 feet

145mp IAS

Bf109G-14

Speed at 16,000ft was ~430mph

Final altitude was ~23,000 feet

145mph IAS

 

Bf109G-6

Speed at 16,000ft was ~400mph

Final altitude was ~21,500 feet

145mph IAS

 

EDIT:

 

I have added the results of these zoom climb tests for the P47D with 150 Octane fuel and also for the P51D running at 62" manifold pressure which is identical to the results from the Zeke 52 TAIC tactical trials.  The lower setting for the P51D is because the in sim P51D is 67" stock. So as can be seen things swing as these fighters evolved.  Performance between a 109G6 and a later model G14 is up due to the increase in power available.  Same for a P51D running 62" boost compared to the 67" (NOT 150 Octane) boost we have in sim.  Also the 150 Octane P47D obvioulsy improved the result for the P47D.

Edited May 11, 2021 by ICDP

[gimpy117]

I wonder if mass isn't correctly modeled when it comes to momentum...just a thought. no evidence to back it up, but It might account for some heavier aircraft bleeding speed faster too. I know there was some discussion about the P40 bleeding speed very fast in the past. 

[Cpt_Siddy]

On 5/10/2021 at 11:26 PM, oc2209 said:

 

If a simulation can't recreate real events, then what exactly is being simulated?

In real life, unlike in our MP, people did not follow you for 100km behind enemy lines just to statpad a kill while risking his plane and life to do so. 

 

In any proper MP server that simulates war conditions even remotely, 190's have a huge advantage when they dive from high and run home with shallow dive. 

Players do not follow them for long even, if they have a chance catching them after 15 minutes chase, for the same reason real life pilots brake off the chase. 

[Gambit21]

On 5/15/2021 at 10:12 AM, Cpt_Siddy said:

In any proper MP server that simulates war conditions even remotely...

 

Such a thing has never existed.

[Strewth]

Well. I am no Ace, but the P47, especially the 28 appears to fly like a brick. Even worse than the razorback.
I have tried all different altitudes, especially after reading so much on this enormous supercharger setup that allows better performance at 27000ft. My personal experience is that the thing flies even worse at those altitudes in the game and a 109G has me removed even quicker than at low altitudes. Forget a turn or manoeuvre of any sort at these altitudes.
Love the sim and can cope with most aircraft, even the razorback. But personally, the later P47 is a cross between a brick and a pig.
Cheers.