HV curve
Geoff,
what you say about the HV curve, is wrong.
CS29.59(a)(1) "Take-off path:Category A" establishes the requiremnts .
If a Cat A profile penetrates the "true" HV envelope a Rejected Take-off /Landing can not be carried out.
The "true" HV envelope is a family of variable HV envelope as a function of the Take-off/Landing Mass and density altitude.
Quite often, manufacturers do not spend to many efforts in defining the HV curves but simply presents the biggest envelope valid for the maximum density altitude and Maximum Take off/Landing mass.
In this case a Cat A vertical TO/Land procedure, carried out at a specified mass and at a specified DA, migth cross the HV.
But if it has been demonstrated that in those condition a RTO/OEI Land can be carried out, no doubt that the trajectory is outside the HV.
The region outside the HV envelope is a safe OEI reject take off and landing area. And this is also the requirements defined by Cat A.
gmrwiz