You are mixing oranges and apples.
Firstly for PC1: the RFM explains the calculations for take-off mass and distance calculation for the CAT A procedure thus:
CATEGORY A HORIZONTAL TAKEOFF DISTANCE
The Category A horizontal takeoff procedure shown diagrammatically in Figure 4-7 features variable Takeoff Decision Points (TDP) and Takeoff Safety Speeds (Vtoss). The TDP, expressed only in terms of airspeed, is selectable in 1 knot increments between 30 and 48 knots. Vtoss is TDP + 15 knots. This permits payload to be traded off against available field length in such a manner that Category 9A9 one engine inoperative (OEI) climb performance minima can be maintained over a wide range of environmental conditions.
Figure 4-8 shows the Rejected Takeoff (RTO) and Continued Takeoff (CTO) distances as a function of pressure altitude, temperature, TDP speed, and headwind component. RTO and CTO distances are directly proportional to TDP speed, therefore lower TDP speeds equate to shorter field lengths. Figure 4-9 shows the maximum takeoff and landing gross weight as a function of pressure altitude, temperature, and TDP speed. Maximum takeoff and landing gross weight is also directly proportional to TDP speed, therefore higher TDP speeds equate to higher maximum takeoff gross weights.
The Category A takeoff procedure provides the flexibility to address specific payload and/or field length requirements appropriate to either of the following operational scenarios: - Determine the maximum takeoff gross weight, given the available field length.
- Determine the required field length, given the desired mission takeoff gross weight.
From the TDP the aircraft is level-accelerated to Vtoss then climbed at 100% Nr (with the gear up) to 200ft.
The graphs are produced from extensive flight testing and represent those dimensions that can be achieved by the average pilot with an aircraft that meets the minimum performance standard. The provision of those graphs is a complex process and provides the best operational data within the certification criteria.
For PC2 the calculation is less complex: for certification purposes the reject does not need to considered so (for example) the aircraft can be flown directly to Vy and thence into the climb. The PC2 imiting mass will the governed by: the maximum Certificated take-off mass; the environmental conditions; and the ability to achieve a ROC of 150ft/min at 1,000ft above the take-off surface.
There is no simple answer to you question as the limiting temperature/mass for PC1 might be one of a number of those mentioned in the RFM description.
The flight test engineer who produced those graphs lurks around the board; he might intervene and discuss this with you (as he has done with me in the past).
Jim