PPRuNe Forums - View Single Post - is there such thing as Improved Vr for lighties.
Old 26th Jan 2012, 07:50
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Captain Nomad
 
Join Date: Jun 2001
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Just scanned a few SE POH's in my collection and it is worth making a point of noting that aside from stall considerations, it is usually recommended to fly the TOSS/50' spd until obstacles are cleared. Quite often this speed will be lower than the Vx speed (bear in mind that TOSS will take into account take off flap settings also). Increasing Vr and subsequently climbing at a faster speed (as in the original post) WILL serously jeopardise your obstacle clearance ability.

Take the 750XL pilot mentioned previously. Can't believe the nonsense of rotating at TOSS, but that aside, I wonder if he had memorized the speeds for weight variations? At 7500lb the book recomends Vr 61, TOSS 74. However at 4500lb that drops to Vr 49, and TOSS 59! Quite a big difference there. If he only used the stock max weight figures there could be an occasion at low weight where you are trying to hold on the runway for 25 kts beyond the recommend Vr for weight - preposterous! Someone like that needs to go and fly into some short bush strips where there are some solid 'incentives' to fly the poor plane properly...
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