alexandre.vidual:
The answer to your question can be found in the RFM which contains take-off WAT, the first segment (Figure 4-10) and second segment (Figure 4-11) graphs - you should be more familiar with those than me. As heliTester has said:
The PC1 chart is essentially constructed by superimposing the first segment chart on top of the second segment chart and plotting the most restrictive in terms of allowable gross weight for all combinations of altitude and temperature
By chosing your test conditions and then examining the relevant graphs, your limiting case will be revealed (I have never flown the S92 so I am not as familiar with the RFM as you might (should) be). However, there are some general points that emerge from this discussion that might be worth considering.
The S92 RFM provides a trade off between the restricted take-off mass and the length of the reject area. The acceleration to the defined (but variable) Vtoss is protected (in the sense of meeting the PC1 conditions of 'safe landing' or 'safe continued flight') by the length of the reject area. As the speed increases: the required rejected area increases; but the ability to climb improves - up to Vy from where it then decreases.
However, none of this exists in isolation; the objective of providing the Category A procedure is to allow the pilot/aicraft to stay within the limitations of the heliport which include: the rejected take-off area available, the take-off distance available and the Obstacle Limitation Surfaces (OLSs). The take-off OLS emanates from the end of the FATO (rejected take-off area) or the clearway.
With a PC2 heliport, there is effectively no requirement for a rejected take-off area (which permits a safe landing - i.e. one that does not result in an unservicable aircraft); however, there is a requirement for a surface which permits a safe-forced-landing (one for which the probability of
no injury to the occupants is high). Providing that the SFL area (which is in effect a clearway) is sufficiently large enough, the aircraft can accelerate to Vy before rotating to the climb.
The provision of the surfaces at the PC1 heliport is the responsibility of the heliport owner. The responsibility for defining the SFL area rests with the operator/pilot. There is no defined first climb segment for PC2 (but the Category A graph could be considered).
For PC2 the helicopter remains within the limitation of the RFM for Category A when more than 9 passengers are carried by 1. applying the maximum mass; 2. staying within the limitation of the HV diagram, and; 3. meeting the conditions for the second segment climb. A number of RFMs provide a basic Category A WAT which satisfies the conditions of 1 and 3.
The requirement to apply the PC1 or PC2 operational limitations rests with the Authority (as in the State's regulations or the Operators OM).
Some other observations that are not confined to the S92:
During recent work to establish suitable obstacle limitation surfaces for PC 1 vertical procedures, it has been noted that almost all small and medium twins (which may apply to the super-mediums) have a better first segment climb performance than second (sometimes in excess of 500ft/min, this results from the improved 2.5 minute (30 seconds plus 2 minutes or just 2.5 minutes) power output).
The largest problem with the Category A procedures is the level acceleration segment at 200ft (from Vtoss to Vy) which halts the climb and, in a number of cases, drives the helicopter into the take-off OLS. However, these small and medium twins have the ability with a power-unit failure at TDP, to reach 1000ft within the 2.5 minutes. Manufacturers have become aware of this and are now providing modified profiles that do not require a level climb at 200 ft above the take-off point (or the TDP when that is in excess of 200 ft).
This has a knock-on effect for PC2 where the application of the 2.5 minute power can provide a healthy reserve should a power-unit fail soon after take-off; however, unless a defined profile is flown (and the graphs applied), it is not clear how that will impact upon the obstacle clearance ability.
Mods please note: This is a wider subject than the S92 in Brazil and perhaps the title of the thread should be modified to signify this.
I'll pause now for others to comment but will continue if there are any questions.