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Old 2nd Sep 2004, 07:36
  #31 (permalink)  
Alex Whittingham
 
Join Date: May 1999
Location: Bristol, England
Age: 65
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I think the concepts are the same. As the Mad (Flt) Scientist neatly summarised above the difference only lies in the definitions.

The B737 charts I have to hand input 'Field Length Available' (I'm assuming this is TORA=TODA=ASDA) to output FLL TOM. A second set of tables take density altitude and TOM to derive a V1. The whole arrangement seems designed for simplicity at the possible expense of accuracy. The British balanced field charts of the '50s and '60s, not just the V bombers - I used them only as an example, are identical in concept. The only issue is the definition, the Americans refer to a balanced field as occurring when TODR=ASDR, the Brits when TODA=ASDA.
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