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Old 22nd September 2015 | 22:59
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FE Hoppy
 
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maximum range speed (jet) [Archive] - PPRuNe Forums

What was your level off altitude? What was LRC at your level off altitude?

And why do you think drift down speed is Vmd?

At high alt wave drag starts to negate the 1.32 rule in modern jets but not so much at lower alts. You need to look at the single eng holding speed at bottom of descent and MRC at the same alt. Less likely to be above Mcrit and below MDD.



so to add a little flesh.

on a small jet I know well.

Drift down speed at 46 T = 209kt (best L/D)
Level off alt at 209Kt = 21800kg gross Level off weight @ 44T
Max alt single eng LRC 44T = 15000
LRC 44T at FL150 = 254
Holding speed at FL150 44T = 192

1.32* 192 = 253.44

Last edited by FE Hoppy; 22nd September 2015 at 23:25.
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