Zero Flight Model

[nschley]

Hi all,

after a longer time, my interest recently shifted back to the PTO again, and by comparing B24Guy's and Akemi's A6M2 I noticed that the "default" Zero is more agile than Akemi's.
Obviously, there is also a airfile modification from AF=Midway Project adding more flap lift to the "default" Zero.
I mean it's just a game and as always, it's at least question of personal taste, and FDE file can easily be exchanged, but I wondered which one would be nearer to the real one?
Has anyone an idea?

br
Norbert

 

[Ivan]

Hello nschley,

My suggestion is to do a little bit of reading on what that particular model of the Zero in real life could do. There are plenty of anecdotes.
Examples would be the low speed at which it could be looped.
Extremely high roll rate at low speeds.
Very good low speed acceleration.
Straight line performance such as maximum speeds, climb rates, etc.

The IIS 85 Report resulting from the test of the A6M2 wreck captured in the Aleutians and rebuilt is a pretty good start but my opinion is that it seriously understates the performance capabilities.
Richard Dunn's assessment of the maximum speed of the A6M2 found at J-Aircraft is another good source.

See how each flight model matches up to the performance and handling from these reports.
From there, you should have a pretty good idea which one is more correct.

- Ivan.

 

[nschley]

Hi Ivan,

thank you for your valuable suggestions. I will do some deeper research over the (rainy) weekend.

br
Norbert

 

[johannesl]

Above about 250 mph and especially above 300 mph the role rate of the Zero went down as stick forces went up. That's one reason Allied pilots were told to keep their speed up, if they slowed down to dog fight they were falling right into the sweet spot for the Zero.

 

[Ivan]

A6M Engine Performance

Perhaps I can save you some research time. This is from a post I made last night in another forum.
This information is not that easy to find, but I have been collecting information for years on the A6M series.
The A6M2 that you are interested in would be using the Sakae 12 engine.
The A6M3 and A6M5 would be using the Sakae 21 engine.

EB-201, right? That was the A6M3 Model 32 "Hap" rebuilt from a collection of wrecks at Eagle Farm.

The reality of the Sakae 21 performance may surprise you a bit.
It wasn't quite as much of an improvement over the Sakae 12 as you might be thinking.
The Sakae 21 wasn't that much more powerful than the Sakae 12. It just had a greater critical altitude because of its two speed supercharger instead of the single speed supercharger on the earlier engine.

I believe their Take-Off is equivalent to War Emergency and that is how TAIC evaluated it even though Japanese never listed in their manuals as anything but Take-Off and never listed it as something that could be used at altitude though evidence is that some pilots obviously did this.
Rated is probably equivalent to what we consider "Military Power".
Normal Power is most likely equivalent to "Maximum Continuous"
Boost pressures are mm Hg over ambient at Sea Level (760 mm Hg).

Sakae 12:
Take-Off
+250 mm Hg @ 2550 RPM - 940 HP

Rated Power - Sea Level
+150 mm Hg @ 2500 RPM - 830 HP

Critical Altitude 4200 Meters - Single Stage, Single Speed.
Rated Power - 4200 Meters
+150 mm Hg @ 2500 RPM - 950 HP

Normal Power
+50 mm Hg @ 2350 RPM -??? HP.

.......

Sakae 21
Take-Off
+300 mm Hg @ 2750 RPM - 1130 HP

Rated Power - Sea Level (Low Blower)
+200 mm Hg @ 2700 RPM - 1010 HP

Rated Power - Sea Level (High Blower) - Yes, this is listed in the manual.
+200 mm Hg @ 2700 RPM - 810 HP

Critical Altitude - Low Blower -2850 Meters
Rated Power Critical Altitude Low Blower
+200 mm Hg @ 2700 RPM - 1100 HP

Critical Altitude - High Blower - 6000 Meters
Rated Power Critical Altitude High Blower
+200 mm Hg @ 2700 RPM - 980 HP

Normal Power
+75 mm Hg @ 2500 RPM - ??? HP

.......

Now here is a rather screwy thing and probably a reason the folks at Eagle Farm and others got a bit confused:
The manifold pressure gauge apparently was the same on aircraft equipped with the Sakae 12 and Sakae 21.
Please see attached image which is a crop from NASM A6M5 panel image.
Note that it reads from -450 mm to +250 mm which is just fine for a Sakae 12 engine.
Who-da thunk they would use the SAME gauge for aircraft with a Sakae 21 that can get to +300 mm at Take-Off???

To save some calculation time:
+50 mm == 31.89 inches Hg
+75 mm == 32.87 inches Hg
+150 mm == 35.83 inches Hg
+ 200 mm == 37.80 inches Hg
+250 mm == 39.76 inches Hg
+300 mm == 41.73 inches Hg

- Ivan.

P.S. I programmed this gauge for my CFS1 A6M2 Model 21. Eventually I thought it would be a good idea to program the version needed by the A6M3 and A6M5 and found that there WASN'T a different version for those aircraft....
Details are in my Gauge Programming threads.