P-47N Thunderbolt vs. F4U-4 Corsair - Which was superior?

[DerAdlerIstGelandet]

Wow you really get into this, I have to say. Good postings though Jon. I may not respong much in this thread, but I enjoy reading it.

[pbfoot]

i really don't think you taken into consideration the variables that affect an a/c such as humidity, temperature etc each a/c will respond to differently to these variables plus the numbers you quote are also affected as to the state of the a/c all those max speeds you name depend on fit and finish of a/c from the factory when they achieve max speeds the a/c will have all rough edges smoothed rivets etc plus some poor guy will be waxing it down it rarely happens in real life even the amount of paint is a variable an example of that being a painted 747 can carry 10 fewer pax or equivalent fuel as a unpainted one i think it would be a rare day when any unit a/c can achieve its max speed as stated in manuals back before modern technology every a/c was different some flew higher some were slower then others of same type

[FLYBOYJ]

Great stuff JJ! Some of the infomation mentioned is actually shown on modern airspeed indicators, i threw this in here just for ref......

The green should actually be normal operating speeds

Originally Posted by pbfoot

i really don't think you taken into consideration the variables that affect an a/c such as humidity, temperature etc each a/c will respond to differently to these variables plus the numbers you quote are also affected as to the state of the a/c all those max speeds you name depend on fit and finish of a/c from the factory when they achieve max speeds the a/c will have all rough edges smoothed rivets etc plus some poor guy will be waxing it down it rarely happens in real life even the amount of paint is a variable an example of that being a painted 747 can carry 10 fewer pax or equivalent fuel as a unpainted one i think it would be a rare day when any unit a/c can achieve its max speed as stated in manuals back before modern technology every a/c was different some flew higher some were slower then others of same type

The air temp, humidity etc is know as "Density Altitude" and is usually calculated in a chart within the POH. Everything else you mention is true and can even go the other way....

[DerAdlerIstGelandet]

That is true, FBJ. I know that before we go and fly, we calculate our performance based off of performance charts that include weather, temp, pressure altitude and other variables. This all helps plan our time to target and what we must do in emergencies such as engine failures and stuff like that.

[JonJGoldberg]

Reply to Syscom3 >>>
You guys seem always able to ask questions that require thought, however simple on the surface they appear. My answer to the torque effect question is complicated, for the most part is true only for single engine aircraft, & would include the -4 as well.

Both the T-bolt & Corsair’s flight manuals, confirmed by their accompanying ‘flight movies’ (both available at www.zenoswarbirdvideos.com; all materials seem deletion edited; editorial additions seem limited to company logos, & opening credits) present a very simplified, ‘official’ answer: No applying power changes, other than ‘gentle’ subtraction, while diving, rolling not withstanding. Further, the training movies strongly ‘imply’ Half Roll training be preformed in the direction of torque, & only one turn (interesting trivia for those ’38 enthusiasts) at high altitude, & with the power OFF (meaning only enough to prevent your prop from acting as a brake). I believe this strongly suggests, as I’m not a pilot, the seriousness of two factors, torque & airframe limits. Not much beyond what was mentioned above is offered in the manuals with regard to torque; there are some further ‘clarifications’ in explanation of related trim/prop/engine speed settings, but beyond repetitive ‘gentle’ reminders of respect, imbedded within ‘flight envelope’ warnings, such as during take-offs, or stalls, they do no go.

What is added now, are my opinions, for single engine aircraft, based on my much modified CFS-2 game & its math (flight dynamics) engine, now about 2 & ½ generations behind the ‘best’ games flight engines.

1stly > In an aircraft not modified to perform within the CFS-2 limitations of representing reality, I can do anything. In these modified aircraft I construct I can not, especially when combined with my ‘environments’, containing weather & density altitude variables.

2ndly > The CFS-2 flight dynamics engine is not, with regards to torque effects, very accurate. So far I can not make it completely accurate (math wise); I can not model, nor have I ever seen (flown) a CFS-2 or MS-FS2000 flight model that can correctly represent a ’38 on take off, every model pulls one or the other way, slightly, there can be no parity/symmetry; the torque effect must be ‘happening’ within the game (this has been finally eliminated in MS-FS2K4, but to start again from scratch, in a game that does not support ‘combat’ is no fun. I await CFS-4).

3rdly > Torque effects are normally (greatly) offset by trim settings implemented during preflight & cruise flying. These compensations are evidenced by drag, with dividends including reduced speed, reduced range, & increased pilot stress. Once in combat, your trim settings are yet another factor in the equation, by circumstance just as easily representing no correction, as partial correction, or over correction, changing as quickly or remaining as affixed as time, damage & or physics allow. Hopefully at least we have as fighter pilots (make believe, or real) acquired the ability to trim the dam aircraft correctly, to compensate for the effects of torque during preflight, & the flying time before combat. Anyway, as of today, my sim (make-believe) pilot’s opinion is that in most single engine aircraft torque effect is usually best not happening, as it is very difficult to control; you can not retard power during a climb, usually needing all the power she’s got to climb; you can not up power in a dive, as gentle reduction of power during a dive to idle is required to stay below Vne & keep the engine from over-revving, nor can you usually ‘trim’ your controls in combat... But the effects of torque are always in fact ‘happening’ while flying (explaining both the ‘short cut’ taken in implementing the torque effects in CFS-2, described well above, &, although rarely actually put to combat, contra-rotational prop experimentation by all in the real world).

OK now… On my modified aircraft, its taken a few years (starting with less accurate, moving to more accurate as time passed, flight models) to be able to fly either a ’47 or ‘F4U (high relative mass & wing loading) in a sustained powered diving roll needed to induce significant controlled torque effects, in combat, with out causing structural damage, game forced ‘over/under ‘g’ blackout during recovery, engine damage due to ‘over rev’, or more than 10 sec. of inverted flight, or of more dramatic impact, running out of room/control & hitting the ground at 550 mph plus. It’s taken some more time, about an additional year or so, to learn how to use this skill, acquired through repetitive reset commands & new airframes appearing at command saving my butt, far away from the ‘features’ available in reality (in other words, acquired through cheating), to an advantage so that I may destroy my sim-enemy, without cheating. I still can not perform them in any ‘weather’. The air must be relatively free of added turbulence, IE standard, in box modeled combat missions, containing no turbulence, what so ever (not even those caused by your victim directly in front of you; OK, the CFS-2 flight engine can not reproduce turbulence from your adversary, nor can MS2K4, super computer territory for now) are best for this maneuver; factious dynamic ‘missions’ where I author in density altitudes, & weather (to the limits of CFS-2), are more challenging; rolls are never to be held for more than one roll rotation, extending beyond half roll rotation, except in ‘emergency’ is not reasonable as you are acquiring speed as fast as gravity, momentum, & streamlining can propel you without adding power. A 25 mph gust against your recovery angle, adding to your roll speed, quickly varying your nose & dive angles, deflecting your bank angles, as you approach Vne, now there is bound to be some parachuting happening, once you recover from ‘g’ black out, if you haven’t dug a hole, or been killed by your adversary as you pass uncontrollably by offering a wonderful target opportunity. Now you might think you can throw just about everything said directly above, in the trash if we were to be talking about, say a Zero. This aircraft does not accelerate or roll well in a dive, it is of low mass, & low wing loading, reasonably, & in fact making it far more buoyant, if you would, than either the F4U, or ’47. Torque effects may be applied (no films or manuals here, so this is not to say it was/is recommended, or ‘officially approved’) more easily, but due to narrower flight envelopes, would you? Yep, a skilled pilot during an emergency effectively will, as for the other pilots, there’s many a WW2 story about the Zeros wings crumpling while trying to remain on the tail of an American fighter, & lots of gun camera footage showing what happens to them in a rolling power dive, as the plane looses controllability. The extremely effective use of power restraint during a dive, enabling & combined with relatively high roll rate at speed & a higher Vne, further exploited by the wingman tactic as devised by the AVG allowed many a P-40 pilot, to flame, or escape from their Japanese adversaries, fighter & bomber alike.

A screen shot of the P-47D’s Half Roll Dive Chart is attached. The cut-off altitude numbers are to be found this way on my copy of this film.

As for rolling climbs, this is another matter, one where torque effects are more easily seen, can rarely be exploited by WW2 aircraft, & are more often paid for. You usually need all the power she’s got to climb in the 1st place, so you’re usually running close to, at, or beyond full throttle. Roll speed, & bank angles seriously affect climb rates, enough to turn a climb into a dive using a half roll. This is/was done all the time, as by WW2, airframes & engines were formidable enough to ‘tolerate’ these stresses. Using two engines (which my flight sticks throttle can not faithfully reproduce, having only one throttle control) torque may be used, in this envelope to serious advantage. However, this requires of the pilot great skill & familiarity with their mount.

So syscom3, to wrap up, the T-bolt could have seriously ‘excellent’ roll effects from the powerful engine & prop. They are rarely wanted, & probably contribute to the ‘47’s achievements; at the time (WW2) the ’47 had one of shortest life expectancies (not due solely to combat losses, but those losses are included), & some of the highest training accidental loss rates (http://www.taphilo.com/history/WWII/...Training.shtml). These honors are duly offset by the fact that most of its Aces survived the war.

Reply to pbfoot >>>
FBJ answered well for me. Thanks FBJ. I’d like to apologize for not defining the term density altitude contained in my reply to Monkeysee1. I’d also like to add to FBJ’s comments on the effects of paint rivets & finish. I find your arguments, for the most part, very valid. As to why they are not considered, I would answer you this way: To be able to accurately model ‘Aircraft X’ into a single representative I can embody the measured flight characteristics of a ‘number’ of known examples ‘Aircraft X’ into a single representative model. This to you would be accurate, but I’d argue the degree of accuracy depends on the skill of the pilot, the number of samples, & their condition vs. the stats, the number produced & thier delivered condition. Rather I feel the numbers that would best represent ‘Aircraft X’, & offer the least variance would be one developed from the specifications that represent the ‘goal’ of production. After we agree that this model indeed accurately represents ‘Aircraft X’, we may from here reproduce the flight characteristics of any uniquely aged, finished, painted, assembled, or cared for example of ‘Aircraft X’ you or I desire. This discussion is, how ever valid your point, not centered on any single example, rather it is centered on the single representative of Aircraft X.

Reply to DerAdlerIstGelandet >>>
Thanks for the compliments, & affirmations.

[lesofprimus]

God how I hate that blue font....

[syscom3]

Jon, thanks for the info.

Reason I asked is I thought I remembered seeing some of those WW2 drawings used for training aids, that mentioned "rolling" into the direction of the prop in a shallow dive. According to the prints, it would allow a Jug to get on the tail of a more maneuverable opponent.

[DerAdlerIstGelandet]

Originally Posted by lesofprimus

God how I hate that blue font....

I agree.

Also please tell me all of this is not based off of CFS-2 experiences.

[JonJGoldberg]

Reply to all >>>
OK No more blue font.

Reply to DerAdlerIstGelandet >>>
If you are referring the chart, due to Zeno’s logo appearing, & marketing, please be assured, they are not from, nor altered for a simulator, they are from the 1943 Republic/AAF film, available through Zeno’s flight shop (www.zenoswarbirdviedos.com). Oh, & if this is the case, please disregard the below. If the above has nothing to do with what you were asking, please continue…

I answered Syscom3 with information based on my review of the pilot’s manual & training films. I then offered an opinion based on experience, qualifying the experience as a highly modified CFS-2 game experience before the rendering.

By doing this, I’ve somehow managed to ‘lower the value’ of all I’ve posted? How? I’ve only been forthcoming with regard to the source/s of any of my data or calculations, & the methods I’ve used to assimilate them, to a crowd whose scrutiny is aided by an attendance of ‘real’ pilots. I produced a fighter comparison table with this data; as I’ve applied tweaks to my installation of CFS-2 with this data.

As for my opinions, unless stated otherwise, such as the CFS-2 qualification before rendering my opinion on torque effects, they are usually based on, & supported by info & data acquired outside CFS-2, & again offered to a crowd whose scrutiny is aided by an attendance of ‘real’ pilots, regardless of my basis.

DerAdlerIstGelandet, it’s OK with me that you do not agree on this, as it is CFS-2 generated, even if it’s my CFS-2, so it’s junk to you; OK. Just don’t associate everything else I’ve posted with a single opinion clearly distinguished as being junk before it was conveyed.

Reply to Syscom3 >>>
I did not see this in the films of this training set, but I imagine this to be more successful used in a shallow climb than a dive.

[DerAdlerIstGelandet]

LOL oh boy.

[gabbys]

From: http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf

-4 top speed about 446 max rate of climb (WEP) about 4500.

[FLYBOYJ]

Originally Posted by syscom3

Jon, thanks for the info.

Reason I asked is I thought I remembered seeing some of those WW2 drawings used for training aids, that mentioned "rolling" into the direction of the prop in a shallow dive. According to the prints, it would allow a Jug to get on the tail of a more maneuverable opponent.

That's becuase you're using P factor to you're advantage..

[Jank]

I wonder if that f4u-4 table is after wwII. It lists the military and war emergency horsepower at 2,800. I know the f4u-4 didn't have as high of horsepower as the P-47N. Something is fishy.

accepting the table though, At 26,000 feet and War emergency power, she's only pulling 2,080 horsepower though and the P-47N can pull 2,800 horsepower at 32,000 feet. There's a big power disavantage to the F4u-4 when up high.

[gabbys]

Originally Posted by Jank

I wonder if that f4u-4 table is after wwII. It lists the military and war emergency horsepower at 2,800. I know the f4u-4 didn't have as high of horsepower as the P-47N. Something is fishy.

accepting the table though, At 26,000 feet and War emergency power, she's only pulling 2,080 horsepower though and the P-47N can pull 2,800 horsepower at 32,000 feet. There's a big power disavantage to the F4u-4 when up high.

That table is a little hard to read, I think that what you are looking at is RPM.

BHP at sea level using WEP was 2450

The advantage of the P-47 Turbocharger was the ability to maintain BHP from sea level to its ceiling.

[FLYBOYJ]

A question to all

Are these charts from the POH?