PPRuNe Forums - View Single Post - No assumed temperature for contaminated runway
Old 28th Nov 2022, 17:47
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FlightDetent

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Originally Posted by Denti
Well, Flex or Assumed Temperature is not allowed. However, derated thrust settings, if available, are allowed
Dare I ask, what's the logic behind forbidding one and allowing the other? Honestly clueless (only flew AST airplanes. Guess I share a reasonable insight how both of these work and what the differences are but at the first ask struggle to see the enabling difference for DRT.

So far I believed the CONTA = NO AST was a philosophical / systematic choice. Just not to try all the luck in all cases, supported by the empirical inability to correctly describe what the actual contaminant of the day really is like, let alone the aircraft's behaviour over it.

The AST calculation has some margins (density) and limits (Vmcg/a) embedded which the DRT does not, correct? Why is the ruling the other way around....
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