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#71
10-26-2011, 07:59 PM
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If you are as smart as you think then Google French units of measure. While the French did use metric, they had their own unique system. http://en.wikipedia.org/wiki/Units_o...ment_in_France I don't know what they used but it is not the German Technical Atmosphere and the test was not flown at a 5 minute rating for the duration. Pffft.....back to ignoring you until you have something to contribute. 
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#72
10-26-2011, 08:16 PM
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His reply was on a bad tone but he might be right with respect of atm being not equal to ata. I myself was not sure if atm = ata that's why I used atm for my calculation.
Unfortunately there is little information about the outdated ata but 1 at (technichal atmosphere = pressure produced by a column of 10m water) is equivalent to 735.56 torr (almost identical to 735.56 mmHg). ata is with a reference point of 0 (I assume 0m that is sea level), so this would be the pressure produced by a 10m column of water at sea level. That's what wiki told me. I am quite sure they used the ata gauge in the plane to measure it and then translated it into mmHg. There is one minor uncertainty with respect to the French measurement of the manifold pressure however. The mmHg values depend on the knowledge of the density of mercury. This knowledge may have evolved since ww2 so there is a slim risk that they used a different mercury density for their mmHg units. However I think there is quite a weak chance that knowledge on density of mercury evolved so much that the mmHg values would be impacted by this to the precision that is of interest here. So basically the French obtained 494 kph at 600m with 2400 rpm and 1.346 ata. Extrapolating pessimistically to 0m they would have obtained 478 kph at 0m with 2400 rpm and 1.332 ata. The ingame performances are still enormously off these values. Last edited by 41Sqn_Stormcrow; 10-26-2011 at 08:18 PM.
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#73
10-26-2011, 09:01 PM
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The French were instrumental in forming the ICAO in 1912 and adopting a standard atmospheric model of that organization, the ISA. The ISA uses 760mm as 1 ATA. Once more, the 1.28 corresponds to the 1.3 ata rating. There is NO 1.35ata rating cleared for the DB601A according to any documentation I have seen.
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#74
10-26-2011, 09:10 PM
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I suggest looking at this link for Pressure units http://en.wikipedia.org/wiki/Atmosphere_%28unit%29
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#75
10-26-2011, 09:25 PM
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The limitations of their own instrument measurements: Quote:
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#77
10-26-2011, 09:34 PM
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http://en.wikipedia.org/wiki/Interna...ard_Atmosphere p0 sea level standard atmospheric pressure 101325 Pa = 760mmHg.... There is nothing that says WHAT the French used on that report so this whole line of discussion is a complete sidetrack.
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#78
10-26-2011, 09:43 PM
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It is what it is and the answers are written in black and white. There is no need to guess or offer opinions. The report flatly states the data is raw and not converted to standard conditions. It was flown at a 5 minute rating. We can speculate until the cows come home about which of the 5 minute ratings were used. 980mmHg/760mmHg = 1.289 or 1.3 ata or 1% error 990mmHg/735mmHg = 1.346 ata or 1.35ata or 1% error It does not matter because in the end, nobody knows for sure. It is a fact, if you convert the French data to standard conditions, it very much agrees with Mtt's published mean performance of 500kph at 0 meters with a -/+ 5% range.
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#79
10-26-2011, 09:46 PM
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I dunno but you sound a bit excited.
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#80
10-26-2011, 09:59 PM
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Linear Mode
