So, your statement is not 100% correct. The only case where it could be correct is where you require a Cat C aircraft to fly the Final faster than they normally would and than they're normally certified for.
There are a few issues here.
First off is the difference between ICAO and FAA criteria.
Next is the procedure design. Procedure design and coding is by leg. The final approach segment, from the FAF to threshold is a leg. You cannot set a variable speed on the final approach leg, as it is a terminator.
ie you cannot begin a leg at 160 and end it at 140...you begin the leg at the speed. If the procedure is a CAT C, the ac will hit 140kts at the beginning of that leg. That is just the way the coding works.
This is why there is a disco with RNP vs non-RNP traffic.
For a CAT C aircraft, the RNP ac will be at 140 kts at the FAF, it will not be at 160 kts, and slow to 140 at threshold.
Also, the B738 is an Approach Category C.
According to Boeing table, from Boeing the 738 is CAT D...(provided in post #6)
Boeing 737-800 D-III 142
Boeing 737-800W D-III 142
This is based on Flaps 30 and 60K wt, a bit less than the MLW (flaps 40 is 141 at 65K) but you dont get to pick and chose CAT
The categories are based on Vat. End of story.
Far from the end of the story, what do you think the procedure is designed for?
Here is the FAA design criteria table right from the manual...it shows the MAX speeds for the different
SEGMENTS. It may be based on the 1.3Vs, but it is for the segment...
According to the FAA criteria, the CAT C ac cannot exceed 140 kts for the entire final approach segment.