alatriste,
It might serve you well to check if the regulatory authority allows the benefit of the 15ft screen height offered by the Wet runway performance data.
Wet runway performance data makes 2 mojor concessions not normally available for Dry runway operations, namely -
(1) Full credit for reverse thrust is allowed for accelerate-stop. and
(2) Screen height is reduced from 35 ft to 15 ft.
In some circumstances, in SOME aircraft, there are some occasions where reference to Wet runway data can lead to a higher RTOW than if Dry runway data is used. This was so for the last aircraft for which I created the full performance analysis / Airport analysis / Special Procedures for an operator's Air Operator's Certificate. It necessitated insertion of an instruction that if the runway was Wet, then the Wet runway RTOW should be compared to the Dry runway data, and the least of the two weights used as the limiting weight.
For the same aircraft, whilst the regulatory authority (Australian) allowed full credit for reverse thrust for the rejected takeoff, it firmly rejected any credit for a reduced screen height, necessitating "restructuring" of the Wet runway continued takeoff AFM performance data to allow for a 35 ft screen height, and obstacle clearance height. This had a very significant effect upon field length and obstacle limited data (difficult to separate the two). Consider the minimum (for 2 engined aircraft) 1.6% gradient subtended back to the TODA for an increase of 20 ft in screen height provided in the Wet runway data, on a level runway this reduces the available TODA by 1250 ft (381 M), a significant penalty.
Your operator may have been subject to the same limitation by the regulatory authority.
Regards,
Old Smokey