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View Full Version : Question about A6M2-21 altitude performance



sledgehammer2
02-05-2006, 06:25 PM
The max airspeed for the Model 21 Zeke that I see quoted in tables is 288 KTS at 15000 ft. I don't know if that is TAS or IAS.

I did some testing out of curiosity and I got 210 KTS IAS at 15000 ft. What does that work out to be TAS? I know someone here has posted a link to a conversion table and I was going to look at it but I don't have excel.

My test makes me think that the oft quoted figure has got to be TAS. I also got 190 KTS at 20,000, and 130 KTS at 30,000. Does this seem about right?

Thanks,
Hammer2

mortoma
02-05-2006, 09:04 PM
As far as top speeds at given altitudes, TAS is ALWAYS used, same for cruise speeds. IAS is only used for best climb speeds, best descent speeds, stall speeds, approach speeds, flap down/up speeds, gear up/down speeds, etc., etc........
In other words pilots fly by IAS to fly the plane at optimum and keep the thing from crashing. If someone is using IAS to quote a planes top speed at a given alt or it's cruise speed, that person is simply an idiot. TAS is also used by the pilot to figure ground speed to estimate ETE, ETA for navigation purposes.

VW-IceFire
02-05-2006, 09:22 PM
IAS is relative to the altitude that the aircraft is at. The air thins as altitude increases so the speed measured by the aircraft changes as a result. Most aircraft have IAS on the instruments as its important for manuevering.

In-game if you use the virutal cockpit view it shows the speed in TAS so you can measure it. Its in KPH only so you'll have to convert after (there's lots of automatic converters online you can use to look it up).

With the Zero, be sure you're using the second stage supercharger when above low altitude (I forget what alt its recommended you kick it in, around 3000m probably). Your KTS seem a little low to me...maybe.

sledgehammer2
02-06-2006, 03:53 AM
Icefire, the -21 Zeke only had a single stage supercharger. The 2 stage didn't come about until the -22 and -32 and beyond. At least that is what I thought. I have a key mapped to the blower on my CH Pro and it doesn't do anything on te Model 21, whereas on the Mdel 32 it will shift .

Also, I tried to hit CtrlF1 to get no C/P view but it won't work. I have no idea why.

JG53Frankyboy
02-06-2006, 05:21 AM
ctrl+F1 is the default setting to change the views, perhaps you changed something in your keysettings ?
and btw, when doing speed checks you should use the crimea map - the one with standart settings for atmosphere

you are correct, the A6M2(Model 11) and A6M2-21 have a single stage, single speed supercharger - nothing to shift.
the A6M3 and later models have the single stage, two speed supercharger.

VW-IceFire
02-06-2006, 03:45 PM
Originally posted by sledgehammer2:
Icefire, the -21 Zeke only had a single stage supercharger. The 2 stage didn't come about until the -22 and -32 and beyond. At least that is what I thought. I have a key mapped to the blower on my CH Pro and it doesn't do anything on te Model 21, whereas on the Mdel 32 it will shift .

Also, I tried to hit CtrlF1 to get no C/P view but it won't work. I have no idea why.
Ahh good point. I usually fly the later variants...