1. #1
    TAGERT.'s Avatar Banned
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    Here is the results from Loki's dive tests between the F4F and ZERO



    DAY 1
    I have not had time to take a look at all the graphs, so Im providing you all with the excel file where I graphed just about all the variables from DeviceLink. For the ones I didnt graph the data is there for you to play with. Also note that I combined the two seperate track files into one excel file and used the PITCH variable to sync up the data. The assumption here is that Loki and Fenris started diving (push forward) at the same time. Like I said, I have not had much time to look at it those dont know just what to make of it yet. But here is the link if you want to.

    DAY 2
    I updated the graph, I noticed something I did not expect, the F4F starts shaking before the zero does at a given speed, and shakes more! I half expected that to be the other way around from my general readings on the two aircraft. This sake is what causes things to fall off the plane. The next thing I would like to look at is the roll speeds, but, we will need new tests for that. PS I fixed the kph error, it is not shown in mph and the scale factor data was multiplied by 500 to scale it to the graph.

    http://www.geocities.com/grantsenn/4...4F_VS_ZERO.zip

    Also note that I have not had a chance to do the Control Atohroty tests yet, I hope I can get to it by the end of the week.

    Enjoy
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  2. #2
    TAGERT.'s Avatar Banned
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    Here is the results from Loki's dive tests between the F4F and ZERO



    DAY 1
    I have not had time to take a look at all the graphs, so Im providing you all with the excel file where I graphed just about all the variables from DeviceLink. For the ones I didnt graph the data is there for you to play with. Also note that I combined the two seperate track files into one excel file and used the PITCH variable to sync up the data. The assumption here is that Loki and Fenris started diving (push forward) at the same time. Like I said, I have not had much time to look at it those dont know just what to make of it yet. But here is the link if you want to.

    DAY 2
    I updated the graph, I noticed something I did not expect, the F4F starts shaking before the zero does at a given speed, and shakes more! I half expected that to be the other way around from my general readings on the two aircraft. This sake is what causes things to fall off the plane. The next thing I would like to look at is the roll speeds, but, we will need new tests for that. PS I fixed the kph error, it is not shown in mph and the scale factor data was multiplied by 500 to scale it to the graph.

    http://www.geocities.com/grantsenn/4...4F_VS_ZERO.zip

    Also note that I have not had a chance to do the Control Atohroty tests yet, I hope I can get to it by the end of the week.

    Enjoy
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  3. #3
    so they started diving at 18-ish seconds ?

    difference in speeds starts around 70-ish seconds ?

    they did slight dives ? like 30 degrees or there-abouts ?
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  4. #4
    I think we are using the times as 'time units' rather than say they are exact seconds, there may be a slight variation here. Also is the scale of the speed bit right, indicated mph? If so, those planes will outdive first-generation jets. Nice going, Grumman and Mitsubishi. Seriously, this show the F4F moving ahead eventually, just what you might expect. The Zero, with its better thrust/weight, should be better first, than they ought to be about equal, having similar top speeds, then faster than that the greater weight of the F4F will take effect.
    And nothing should really fall to bits.
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  5. #5
    im with you that something isnt correct in the Wildcat-Reisen stuff !

    BUT , Zero isnt like Zero !!
    ALWAYS say with Zero model you use !!
    they have quit difference performance.
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  6. #6
    <BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by k5054:
    I think we are using the times as 'time units' rather than say they are exact seconds, there may be a slight variation here. <HR></BLOCKQUOTE>
    that would explain a lot !

    <BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by k5054:
    The Zero, with its better thrust/weight, should be better first, than they ought to be about equal, having similar top speeds, then faster than that the greater weight of the F4F will take effect. <HR></BLOCKQUOTE>
    makes sense!
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  7. #7
    Tater-SW-'s Avatar Senior Member
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    The mph units are probably a typo, that's gotta be kph on the Y axis, BTW.

    The problem isn't so much the dive speeds, but rather that the Zero does not lose control authority, and the F4F breaks up earlier (which is insane). Zero pilots would not follow dives because they knew they'd lose control authority, which is why the dives work. The drill was to dive and make a shallow turn to the right. The Zero could follow the dive, perhaps, but would NOT be able to turn at the same rate while doing so, and so the F4F would gain separation.

    This really needs some fixing, and maybe a new test where the F4F rolls right, and sees if he can separate.

    tater
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  8. #8
    Loki-PF's Avatar Senior Member
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    Guys and Gals,

    Just to answer a couple of questions, and clear up a few things (especially for those of you that havent actually watched the tracks).

    The wildcat model is an 1942 F4F3. We chose the F4F3 because it did not have folding wings...We thought it might be more rugged because the Wildcat was coming apart in the dive tests before the Zero!

    The Zero model was a 1942 A6M3. We wanted to keep it 1942 vs 1942.

    Even though the curves of the dive speed vs time look favorable towards the Wildcat. Keep in mind that the wings an of the Wildcat came off at ~420 to 430 Mph. Everything after that on the chart reflects Fenris's balistic trajectory as he becomes a dirt torpedo!

    It would be great to see the first part of the graph in finer detail or granularity.... Say between time 0 and time step 55. Dont know if this is possible or not? Tagert?

    Also, the tracks we recorded for documenting control authority are actually quite interesting regarding dive performance. In these tracks we go into a shallower dive in order to get our speed up around 350 Mph so we can start playing with rolls and loops. In this test both planes are only at 100% power, no 110%, no boost. The Zero driver has to take evasive action to avoid ramming into the Wildcat. It's very obvious that the Zero is overtaking the Wildcat.
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  9. #9
    You chose a Zero with a two-speed supercharger, which probably has more speed at your entry altitude than the Wildcat. You have a heavier Zero and a lighter Wildcat. This means the weight advantage in the later stages will count for less.

    Note that none of this makes your 1942 standard invalid, far from it. But it would be interesting to see the heavier F4F-4 vs the Zeke 21, just to see if the expected differences materialize. That would be a test of the so-called dive modelling. (So-called because the FM has to apply the same formulae to the aircraft regardless of attitude, and level flight is only a special case where dive angle = zero.)

    I hope Tagert will eventually show us the relevant part of the flight in a different scale...
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  10. #10
    Info on the A6M3 :

    * The Model 21 was followed by a new major variant, the "A6M3", which flew for the first time in June 1941. It featured a new engine, the Nakajima NK1F Sakae 21, with a two-speed instead of a single-speed supercharger and 845 kW (1,130 HP); a wider propeller; ammunition supply for the 20 millimeter cannon increased from 60 to 100 RPG; and clipped wings with no folding wingtips, reducing the wingspan by a meter (3 feet 4 inches). The wingtips were removed to improve manufacturability and maintainability. Early A6M3 production had featured the folding wingtips, but pilots suggested that they could do without them and they were deleted.

    Aside from the clipped wings, the A6M3 was difficult to distinguish from the A6M2, the most visible difference being that the A6M2 had the supercharger air intake in the lower lip of the cowling, while in the A6M3 the intake was moved to the upper lip. The initial A6M3 variant was designated the "Model 32", and 343 were built.

    Integral wing tanks were fitted in the "Model 22". The Sakae 21 engine used in the A6M3 was larger and thirstier than the Sakae 12 used in the A6M2, and led to reduced fuel tankage and range. This resulted in losses of planes and pilots during the battle for Guadalcanal, when aircraft simply ran out of fuel during the long flight down the Solomons chain. The wing tanks gave the A6M3 Model 22 the longest range of all Zero variants. The folding wingtips were restored to reduce wing loading, which had been increasing due to "weight creep" as improvements were added to the Zero.

    At least three A6M3 Model 22s were fitted with 30 millimeter cannon in place of the 20 millimeter guns and tested under combat conditions, but nothing came of this exercise. A final variant of the A6M3, the "Model 22a", featured Type 99 Model 2 20 millimeter cannon with longer barrels, higher muzzle velocity, and greater rate of fire. A total of 560 Model 22s and Model 22a's were built by Mitsubishi to summer 1943, and a number were built by Nakajima as well.

    Stolen from here: http://www.faqs.org/docs/air/avzero.html
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