Originally Posted by
212man
Sorry, I have a glitch and cannot see your reply unless I make this reply!
To answer the first point, the drag is much higher in the first segment, as you are at a much lower speed and also the gear is down (I think the gear alone is worth a 50 ft/min penalty), so even though you have more power, the overall effect is that the RTOM is limited by the performance in that segment with lower Vtoss values. From memory, the demarcation point is Vtoss = 60 kias, when the second segment becomes limiting - which is logical because the Vtoss airspeed is closer to Vy.
I don't believe your second point is a factor - the rejected take off will never limit the RTOM in a runway take off profile (it will do in a helipad profile though).
We are operating from a clear runway, using MAX TDP (on S92 is 48kt), VTOSS will be TDP+15kt (63kt).
Suppose that appropriate Reject take off area will not be an issue.
We are using max TDP so we can have max payload for each flight, and still operating PC1 / CAT A
At these conditions, payload will have to be restricted if temperature goes above 32ºC.
My point of view is that PC1 and PC2 should be the same for us. The only difference is that for PC1 you have to be able to safe reject and landing without any damaged to the aircraft, and for PC2 you could use unpaved areas that are not suitable for a reject landing but are for a SFL (safe force landing).