If in the shaded area compare V1 with VMCG. If V1 is less than VMCG you cannot take off!!
Yesterday 10:23
if you check it and find that VMCG is greater than V1 you cannot take off at that weight.
I do not believe that the situation as clear cut as that, but if it is then what exactly can we do about it?
If we assume that we are already at the FLTOM, then increasing weight to increase V1 will make us overweight for the field lengths.
Looking at the tables it looks like we couuld wait until the temperature or pressure altitude increase to move us to the right, to give a greater V1. But again if we were already filed limited then this is not an option.
The only other options appear to be to wait for a strong headwind come salong, or else arrange road transport to get teh aircraft out?
But instruction vii states: "Compare V1 with minimum Mmcg. If it is less make V1 = min Vmcg."
Now this poses a problem in that if the aircraft is at its FLTOM, then increasing V1 to Vmcg will risk an overrun in the event of an RTO.
Instruction viii then states: "Check TORA exceeds TORR. If it does not, the take-off weight must be reduced."
This appears to provide a bit of reassurance regarding the risk of an overrun, but there is still room for doubt, because Figure 4.4 which will be used to ensure that TORA is greater than TORR does not include any arbitrary increase in V1.
And if we are already at the bottom row of the tables where the weights are lowest (40000 kg) how exactly can be do the calulations for a lower weight?
I am intrigued by the term "Assumed Higher Weight" in the OP.
Could it be that SpringboK 260 is refering to a system whereby we assume that the weight is higher than it actuially is, in order to get V1 greater than Vmcg? Provided we then check that the TORA exceeds the TORR for that assumed weight, then the above risks will be eliminated.
How exactly does your "Assumed Weight" system work Springbok?