Hey TD can you look again at the Corsair..

[IceFire]

Thing about the P-39 was that it was more experimental than something like the P-40 design.

The P-40 was based on the Hawk 75/P-36 which traces its lineage back to the early 1930s. The landing gear is not stored in the cleanest arrangement, the radiator systems are draggy (partly for looks apparently), the whole design is traditional.

The P-39 has a number of advanced features including a low drag coefficient, tricycle landing gear, car-door style canopy opening, and it was designed initially to have but never allowed to use the turbo supercharging gear.

I'm sure when the P-39 showed up at Port Moresby the USAAF personnel there... who were having difficulty with the traditional P-40 would have seen these as some sort of aberration. I've read something to that effect before anyways. So the poor frontline conditions, the need to fight high over the mountains, the much more difficult handling of the P-39 with the center of gravity pushed much further back... no wonder it was called the "Iron Dog" and disregarded as a poor fighter. Everything was working against it in early US service and that reputation killed it I think. But the plane itself, in the right hands and performing the kinds of tasks that its best suited for, is actually quite a good performer.

Especially if you have a hot rodded version like the D-2 that we have in-game with 1500hp on tap. Thats an incredible amount of power. Still don't understand why the D-2 has 1500hp and everything else has between 1100 and 1300hp.

[Pursuivant]

Originally Posted by IceFire

Everything was working against it in early US service and that reputation killed it I think. But the plane itself, in the right hands and performing the kinds of tasks that its best suited for, is actually quite a good performer.

One American fighter pilot who served in NG said that the main strike against the P-39 was lack of range, since the Allies had to cross the Owen Stanley Mountains in order to strike at the Japanese.

Additionally, by the time the P-39 got to NG, better fighters, such as the P-38 and P-47, were starting to become available. But, Army policy was that fighter squadrons didn't get newer fighters until the P-39s they had were unserviceable. Not surprisingly, U.S. pilots did everything they could to help that process along - such as bailing out of potentially salvageable aircraft.

I could also imagine that taking care of a relatively advanced plane like the P-39 in some of the most unforgiving terrain on earth was a nightmare for ground crews. Armchair historians tend to forget about boring logistical issues like maintenance intervals and serviceability rates.

Finally, the American pilots in NG in 1942/43 were still figuring out how to beat the Japanese, who were masters of the conventional turning dogfight. Part of the reason that they didn't have confidence in their planes is because they were blaming the planes for their own lack of tactical skill. It's telling that non-U.S. forces were able to take the same planes that the U.S. considered to be "dogs" and use them successfully. (Finns with the Buffalo, Soviets with the P-39, Australians with the Vengeance).

[IceFire]

Originally Posted by Pursuivant

One American fighter pilot who served in NG said that the main strike against the P-39 was lack of range, since the Allies had to cross the Owen Stanley Mountains in order to strike at the Japanese.

Additionally, by the time the P-39 got to NG, better fighters, such as the P-38 and P-47, were starting to become available. But, Army policy was that fighter squadrons didn't get newer fighters until the P-39s they had were unserviceable. Not surprisingly, U.S. pilots did everything they could to help that process along - such as bailing out of potentially salvageable aircraft.

I could also imagine that taking care of a relatively advanced plane like the P-39 in some of the most unforgiving terrain on earth was a nightmare for ground crews. Armchair historians tend to forget about boring logistical issues like maintenance intervals and serviceability rates.

Finally, the American pilots in NG in 1942/43 were still figuring out how to beat the Japanese, who were masters of the conventional turning dogfight. Part of the reason that they didn't have confidence in their planes is because they were blaming the planes for their own lack of tactical skill. It's telling that non-U.S. forces were able to take the same planes that the U.S. considered to be "dogs" and use them successfully. (Finns with the Buffalo, Soviets with the P-39, Australians with the Vengeance).

Agreed completely! All of these factors shaped the American experience with the P-39 and that reputation has stuck with it in Western circles of aviation many decades later. I don't think it was until I started learning more about the Eastern Front did I reconsider the P-39... and then when I did some reading on the technical details things started to pop out that didn't fit the conventional historical narrative.

[RPS69]

The funny thing about the P39, is that when you look at it from the sides, it looks very well on the front half, and with an older concept in the rear. Also the wings seem inapropriate too.
And that's what was actually changed on the P63.
Nice plane to talk about, but aren't we gettting a bit out off topic here?

[IceFire]

Originally Posted by RPS69

The funny thing about the P39, is that when you look at it from the sides, it looks very well on the front half, and with an older concept in the rear. Also the wings seem inapropriate too.
And that's what was actually changed on the P63.
Nice plane to talk about, but aren't we gettting a bit out off topic here?

Probably

I think the Corsair thing may have been at least partially put to bed. The acceleration tests show the Corsair to be anything but the dog that some say it is.

On the other hand... the tests show a lot of fascinating acceleration information for a whole variety of aircraft.

[horseback]

Originally Posted by Pursuivant

One American fighter pilot who served in NG said that the main strike against the P-39 was lack of range, since the Allies had to cross the Owen Stanley Mountains in order to strike at the Japanese.

Additionally, by the time the P-39 got to NG, better fighters, such as the P-38 and P-47, were starting to become available. But, Army policy was that fighter squadrons didn't get newer fighters until the P-39s they had were unserviceable. Not surprisingly, U.S. pilots did everything they could to help that process along - such as bailing out of potentially salvageable aircraft.

I could also imagine that taking care of a relatively advanced plane like the P-39 in some of the most unforgiving terrain on earth was a nightmare for ground crews. Armchair historians tend to forget about boring logistical issues like maintenance intervals and serviceability rates.

Finally, the American pilots in NG in 1942/43 were still figuring out how to beat the Japanese, who were masters of the conventional turning dogfight. Part of the reason that they didn't have confidence in their planes is because they were blaming the planes for their own lack of tactical skill. It's telling that non-U.S. forces were able to take the same planes that the U.S. considered to be "dogs" and use them successfully. (Finns with the Buffalo, Soviets with the P-39, Australians with the Vengeance).

The P-39 in the early war period had a number of problems; poor serviceability, uneven quality, and the fact that when it was sent to the Pacific, there were often several different models of the aircraft going to the same squadron or group, often without the necessary jigs, special tools and maintenance manuals. The pilots themselves in that early period were often fresh out of training, and had no previous experience with the Airacobra beyond seeing pictures of it in Life magazine. I doubt that any aircraft put together in that sort of conditions is likely to perform to factory specs.

Add in the fact that no one in the Pacific in 1942-43 seems to have had the slightest idea of what Japanese fighters looked like, much less what they could do, and that the US fighters like the Warhawk and the P-39 were considered better dogfighters than their European counterparts at their best altitudes (and that the British and German fighters were supposed to be the best in the world at the time), and you have the makings of a dog's dinner or in the US military vernacular, a word that starts with "cluster."

I doubt that there was a P-39 anywhere in the Pacific before mid-1943 that performed as well as the game depicts every model of the Airacobra; it is possible that the ones in New York or the Kuban actually were that nifty, but not in New Guinea and certainly not at Guadalcanal, which is where they established their reputation with American combat pilots.

As for the Buffalo, the US Navy's problem with it was that normal carrier landings tended to literally shave portions off the landing gear struts; over a period of months, this led to aircraft becoming unserviceable when the US Navy desperately needed carrier fighters. The Grumman F4F was simply much more reliable and not all that different in capability.

As for the Vengeance, again, not that good as a carrier divebomber; the SBD was a better and more reliable weapon and it was what the Navy and Marines stuck with. Some manufacturers' products were primarily dedicated to Lend-Lease, not because they made lesser products necessarily, but because their products duplicated but did not exceed the products our military was already using.

cheers

horseback

[horseback]

Okay, time for the results of the 10K flyoff between the F4F-4, the F6F-3, the Spitfire Mk Vb (CW), and the Bf 109G-2. As before, Crimea map at noon, 10,000 ft, 270kph IAS, trimmed for level flight over the sea heading west before pushing throttle and prop pitch forward and hitting WEP if available (in this group, only the Spitfire has WEP). In the case of the 109G-2, I left the radiators in auto; I believe that they were used that way. I list the indicated speed and the time for each aircraft to reach it.

From 270 to 350 kph: F4F-4, 36 seconds; F6F-3, 23 seconds; Bf 109G-2, 15 seconds; Spitfire Mk Vb, 13 seconds

To 370kph: F4F-4, 52 seconds; F6F-3, 30 seconds; Bf 109G-2, 19 seconds; Spitfire Mk Vb, 17 seconds.

To 380kph: F4F-4, 1 minute 3 seconds; F6F-3, 34 seconds; Bf 109G-2, 22 seconds; Spitfire Mk Vb, 19 seconds.

To 390kph: F4F-4, 1 minute 18 seconds; F6F-3, 40 seconds; Bf 109G-2, 24 seconds; Spitfire Mk Vb, 21 seconds.

To 400kph: F4F-4, 2 minutes 1 second; F6F-3, 47 seconds; Bf 109G-2, 27 seconds; Spitfire Mk Vb, 23 seconds.

To 410kph: F4F-4, 2 minutes 31 seconds (Top Speed); F6F-3, 54 seconds; Bf 109G-2, 30 seconds; Spitfire Mk Vb, 26 seconds.

To 420kph: F6F-3, 1 minute 2 seconds; Bf 109G-2, 34 seconds; Spitfire Mk Vb, 29 seconds.

To 430kph: F6F-3, 1 minute 16 seconds; Bf 109G-2, 39 seconds; Spitfire Mk Vb, 33 seconds.

To 440kph: F6F-3, 1 minute 28 seconds; Bf 109G-2, 44 seconds; Spitfire Mk Vb, 36 seconds.

To 450kph: F6F-3, 1 minute 44 seconds (Top Speed); Bf 109G-2, 52 seconds; Spitfire Mk Vb, 41 seconds.

To 460kph: Bf 109G-2,1 minute 4 seconds; Spitfire Mk Vb, 48 seconds.

To 470kph:Bf 109G-2, 1 minute 14 seconds; Spitfire Mk Vb, 1 minute 1 second.

To 480kph: Bf 109G-2, 1 minute 20 seconds; Spitfire Mk Vb, 1 minute 19 seconds. This is where both aircraft topped out.

Time to overheat: F4F-4, 1:44, F6F-3, 1:48, Spitfire Mk Vb, 1:55, and the Bf 109G-2, 4:04.

Notes:

Bf 109 and Spitfire were extremely sensitive to shallow climbs and dives; variations of as little as 40m became critical at higher speeds, adding or subtracting between 2 and 6 six seconds to a 10kph interval. Being a 'good stick' improves your performance greatly, and this was made easier by the turn and bank indicators on both aircraft being exceptionally accurate and quick to respond. I'm a bit skeptical about the Spit V; it seems much faster than the so-called 'fighter' version of the FW 190, which is not what my history books tell me...

Note that both these light-weight hod rods exhibited a 'twist' when the throttle & prop pitch was shoved to the stops, just like the Airacobra earlier.

The F6F-3 is extremely trim sensitive; trim sometimes seemed to have an extra delay, which could have the effects of three or four trim button pushes showing up at once, rather than in succession. It took me FIVE sessions with the Hellcat before I could make three consecutive runs that were reasonably straight and level. Trimming this aircraft at any speed is in no way intuitive; it can choose to nose down slightly at some speeds and nose up at others. The problem is compounded by the depiction of the climb and turn & bank indicators as slow and sometimes just plain wrong, compared to the vector ball in Wonder Woman view. This is a contradiction of the aircraft's reputation; the Hellcat is regarded as one of the easiest fighters of any era to master, and the Hellcat's trim section of America's Hundred Thousand says that it's handling characteristics were notably benign and it was easily trimmed. In addition, the Hellcat was not quite in the Corsair's class for acceleration, but it should be a lot closer than it is here, and a good bit faster at this altitude as well. This thing in the game is a slug. It's hard not to take this personally.

By contrast, the Wildcat was supposed to be an aircraft that required its pilot to pay attention all the time, and the in-game F4F-4 is tractable and comparably easy to trim. It was indeed considered to be slow for a fighter, but like the Zero and the P-40, I'm having a tough time believing that it was quite this slow.

Yaks, Lags, 'standard' FW 190s and La-5s next time.

cheers

horseback

[gaunt1]

Please, can you test the Yak-9 (1942) first? It has the most realistic FM amongst russian aircraft.

[horseback]

I notice that several people want specific aircraft tested at various altitudes; I should mention that every test of three to four runs for a given aircraft can take 45 minutes for the actual test, another 45 minutes to get the raw data from the track and then another hour to reduce the information to a usable form.

If I weren't currently unemployed, I couldn't have accomplished what I have in the time I did it. In a sense, this sort of 'keeps my hand in' my professional calling; I spent several years writing technical test procedures aimed at proving whether an electronic or RF system or specific subunit met its required specs.

Anyone should be able to closely or nearly reproduce my results using the same methods with a little patience. Here's how I do it:

Acceleration testing is simple if you are consistent. Every test has to meet certain basic standards, and those standards have to be applied to every aircraft tested. 'Fairness' doesn't come into it; at altitude X, aircraft Y will fly in a straight and level course from starting speed Z until it can no longer accelerate (or the engine bursts into flames). Aircraft either reach a certain speed at a certain rate or they won't. Make sure that you record a track for every run, or series of runs--I have found that a maximum of four 'runs' will give you a consistent (and easily reproduced) result in a single track; after that, you have burned off a fair amount of fuel or exhausted the WEP additive's reservoir. The overheat light may also start coming on a bit sooner.

The Crimea map is assumed to be the ideal for testing conditions, and it has the added advantage of having a convenient large body of water for a consistent surface (none of those annoying 'bumps' as you cross rivers and lakes); by default, we set the time as noon, and in the QMB, you can select the nearest height to the desired test altitude, divert a bit south to get over the water, and then head due west, or 270°, obtain the desired test alt and speed. Trim for level flight at that speed and altitude; it can take time, but the idea is that every aircraft tested will start at the same speed and in the same flight condition. Make sure that your cooling flaps are in closed/auto position, your temps are in the normal range, and that your track is running. Then slam the throttle and prop pitch all the way forward and if available, add WEP.

Do your very best to maintain your altitude and course with stick and rudder until you can trim out and even then, some aircraft simply will NOT trim out in a dynamic (changing speeds) situation, so you must keep a close eye on your climb and turn & bank indicators and do your best to stay on the straight and level with the stick and rudder and try to keep as close as possible with your trim inputs. Keep going until the aircraft simply will not reach a greater indicated speed and/or the overheat gets critical (some aircraft are more sensitive to overheat than others, but the best indicator is the aircraft slowing down a bit instead of maintaining or gaining speed in level flight). End your run, reduce throttle and prop pitch (except LW fighters with their automatic controls), turn off WEP and open your radiator or cowl flaps all the way, and return to near your starting point at no more than 55% throttle; in all but the most extreme cases, this will cool your engine off to a reasonable level for the next run.

Rinse and repeat two or three more times. Make sure that you close your cowl or radiator flaps; these are very easy to forget, and they will reduce your acceleration by quite a bit in most cases.

Here comes the hard (and tedious) part: Reducing the Data.

You have flown your runs and recorded them, and you are satisfied that the 'runs' are as straight and level as you can get them (and I have found that this standard will evolve as you become more practiced in the test process). You have obtained the 'raw' data, which means that you've invested about 45 minutes to an hour and a half so far for each aircraft you test. Now you must extract the data by running the track and noting the times you reach each speed, along with relevant information.

Running the track immediately afterward you have recorded them should reproduce the results accurately, and you will be able to pause at every speed increase and note altitude and course as well as time: in many cases, seemingly slight variations of altitude or direction can raise or lower the time between 10kph intervals quite a bit. I also recommend watching the track in Wonder Woman view, but flying the tests in cockpit view; this will give you a clear indication of how accurate the instruments are--the needle and ball can be graded/compared against the vector ball, and the altitude and true speed are indicated in single digits, versus the basic 10 unit increments in the speedbar. This means that you must de-select Loop, select Manual Time Compression (this is a sanity preservation measure--you don't want to spend 10-15 minutes waiting for your aircraft to return to the start point after every run), Manual View Control and In-Flight Messages before starting the track.

DO NOT START WITH A BLANK SHEET OF PAPER. I recommend using a notebook of lined paper, with your start speed and target speeds listed from top to bottom in descending order on the left, with room for at least six columns: alt/course and time for each run, with space at the bottom for rows noting the overheat and end run times. Record the 'raw' time as each speed is reached, along with the alt/course; the best way to do this is to Pause the track immediately. Some aircraft transition across 10kph points in 2 seconds or less, so most of us will be unable to keep up with the data without pausing. It is a good idea to note the aircraft type on the top of the page, just in case you can't get around to reducing the raw data until later.

By 'raw' time, I mean the track time noted in the lower right hand corner; you can convert the start time to 0:00 and measure from that point for each run later.

I have been recording data from 270/280 to 350 kph, 350 to 370, and then in 10kph increments thereafter. I use Indicated Air Speed, because in-cockpit that is all you will have, even with the Speedbar. You can get the True Air Speed from Wonder Woman view if you like, but the conversion at a given altitude is the same for all aircraft. The starting speed is more or less arbitrary, the fact is that some of the faster and heavier American types are hard to get stable at that speed; you might prefer to start at the aircraft's economy cruise speed or at the speed that you believe that WWII squadrons flying that aircraft would get to before entering the combat area (pilots flying slower accelerating types like the P-40 often made sure to be already 'fast', or over 350kph indicated, as they entered the area of likely enemy contact--units that did this usually suffered fewer casualties as a result).

Simply put, if you aren't quick, you had better already be fast when the feces starts.

So far, I have limited testing to 10,000 ft/3050m, but anyone can choose to test at any altitude as long as he compares all of the aircraft he tests at the same altitude--no apples to oranges comparisons allowed.
Okay, we have the raw data for three or four runs written down--now we reduce it to basic units.

I prefer to simply subtract the start time from the next measuring point, which gives us the time from 'zero' to the first marker. If your run's start time is 1:17 and you reach 350 kph at 1:33, the interval time would be 0:16, or 16 seconds. For the sake of simplicity, I measure the times between markers, so the next interval is from 350 to 370. If you reach 370 at a raw time of 1:39, you record a time of 0:06, or six seconds. Continue in this manner for each of your runs. Each interval is recorded in terms of the time between designated speeds, and your times between those speeds should be fairly similar for each run. If they are very different, we will want to refer back to the alt/course columns for that interval; if you climbed 40-60 meters during a given interval on one run, that time will likely be a bit slower than the others, and if you were in a steady shallow climb or shallow diving condition the effect can be cumulative. If run #1 and run #3 are fairly straight & level and have a near identical time for a given interval while run #2 is in a bit of a climb and is clearly slower, or in a bit of a dive and a lot shorter, you may choose not to use run #2 for that interval.

What I try to do is get a reasonable average time for each interval, and then add them up for an 'ideal' average for the whole range of start to finish speeds. You can then add the times to get a clear idea of how long it takes most pilots to reach a given speed from the starting speed in that aircraft at that altitude. This allows you to see that by the time an FW 190A-5(1.65 ata) reaches 400kph at 3050m (45 seconds from start at 270kph), a Spitfire Mk Vb (CW) is between 450 and 460 kph and has been doing over 400kph for almost 20 seconds, which would confer an almost insurmountable lead and the initiative to the pilot of the Spitfire at that altitude.

You may notice that the accuracy with which you can fly straight and level is at least partly dependent on the cockpit instruments' clarity and honesty (for lack of a better word); this is very much a factor in how much you can squeeze out of a given aircraft. A steady slight climb or dive can result in the addition or loss of two or three hundred meters in a matter of seconds at high speeds and a change of vital seconds in an interval time. If it is a factor, make sure to note it; that is partly why I suggest switching back and forth from Wonder Woman view while viewing the track.

I have created a series of Word documents with tables listing the results and notes, but they are too big right now to attach; I'll see if I can just copy the data from the tables to get under the 19.5 kb limit. I also plan to create a chart in Excel in a week or so (again, because it helps keep my hand in).

In any case, I believe that using my methods, anyone can create a fairly accurate picture of what plane A can do versus plane B in terms of level acceleration. I welcome others to try it and report their results.

cheers

horseback

[Notorious M.i.G.]

Out of curiosity, do you stay at 100% pitch the whole time for manual pitch aircraft? I'd think that at higher speeds you wouldn't get as much out of the engine with pitch at 100%.

Maybe a few runs in a 109 or 190 to compare auto pitch vs manually having it on 100% could result in some different numbers. I'd be interested to know how efficient the auto pitch on the German fighters are - maybe smart manual management would be preferable in some instances.

Either way, thanks for putting the effort into this in-depth testing. Turning out some interesting results and it's good to see some solid numbers from ingame.