Missed Approach Climb gradient and missed approach requirements

[FlightPathOBN]

cleveland...

you had it close, but read the regs very closely...

and I know exactly how each aircraft CAT is determined, and how is is different that the procedure design CAT designation

Boeing and Airbus both specify Vref, for the certification process...and they way they do it is the secret sauce....if it was just Vref at MLW, then what were the flap settings? What about winds?

note: "or if VREF is not specified, 1.3 VS0 at the maximum certificated landing weight."

"VAT = speed at threshold based on 1.3 times VS0 or 1.23 times Vs1g at maximum certificated weight."

The Boeing table illustrates this how this is calculated very well...
From Boeing Airport reference code, D-III ref approach speed. 142 kts
from the 800 QRH MLW 73T
flaps 40 151 kts
flaps 30 158 kts
flaps 15 167 kts

From Boeing Airport reference code, D-III ref approach speed. 142 kts, so if you were designing a procedure for a 737-800...would you use the Boeing data, or the criteria data?

The Airport Reference Code (ARC) is a coding system developed by the Federal Aviation Administration to relate airport design criteria to the operational and physical characteristics of the airplane types that will operate at a particular airport. (The ARC is part of design standards established in the FAA Advisory Circular 150/5300-13A)

The ARC has two components relating to the airport design aircraft. The first component, depicted by a letter, is the "approach category" and is based on aircraft approach speed. The second component, depicted by a Roman numeral, is the airplane "design group" and is based on airplane wingspan.

Here is ICAO definition of Vref:
1.3 times the stalling speed in the stated landing configuration and at the prevailing aircraft weight. This is the speed required as the landing runway threshold is crossed at 50 feet height if calculated aircraft performance is to be achieved.

and then there is the reference stall speed VSR and 1.23 VSR