JT,
Ah, my usual lack of precision in paraphrasing my thoughts brings me undone.
My understanding was that many turboprop aeroplanes such as the B1900 are most often much more limited by the continued takeoff requirements then they are by the RTO case and thus V1/Vr=1.0 simply because ratios of greater than 1 are somewhat redundant. My presumption (presented to be disputed, if appropriate) was that the actual V1 was generally greater than Vr. I had no intention to suggest that 1.0 could not be a real ratio, merely that it often is not.
Should that be the case, then my logic was simply that the performance planning for obstacle avoidance would be conducted for the most limiting case and, all things such as tyre speed limits and brake energy limits being equal, operating the aircraft to the higher speeds of the limiting weight would not compromise obstacle clearance. Moreover, given that V2 is the first and lowest speed at which the certification gradient requirements can be satisfactorily met, operating to the speeds for the higher weight would enhance the performance in all segments because the climb speeds are closer to optimum for the lower weight and the acceleration segment will be shorter because there should be greater excess power to accelerate less mass than the planning envisaged.
Your reference to when Vlof is achieved is not disputed, I was merely trying to indicate that the take-off would be initiated at Vr and thus before reaching a V1 significantly higher than Vr. There is no satisfactory way of second guessing the RTO once you have initiated rotation.
In turn, I was confused by your usage of "V1/Vr is pushed to 1.00" - from what real ratio??
As for your last comment, I thought I was safe in assuming that I didn't have to specify that we rotate in order to achieve V2 and that thereafter my comments related to the second and later segment speeds as appropriate. Apart from that, I am unsure about which bits I stuffed up as you read them.
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Stay Alive,
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