Approach Catergory

[alf5071h]

I believe the following information to be reliable in that it originates from ICAO PANS-OPS.
The design of takeoff, approach, and landing procedures is governed by the aircraft classification (A - E). This classification is based primarily on the threshold speed (Vat) which is 1.3 x stall speed (Vs) for the maximum certificated landing mass. Note that some operators have lower landing wt certification for noise / en-route / landing fee reduction. I don’t know of anyone who has done this for approach criteria, but there has been discussion between an operator and authority re landings on short / low strength runways. Thus same version of aircraft as well as different versions may not have the same approach category.

Also note that some aircraft will have a higher category than specified by Vat due to the speeds that have to be flown during a procedure because of the aircraft design (N.B. abnormal configuration operations / icing limits).

Thus for a MLW Vat of 120 kts the aircraft would be Cat B, but all categories also considers the maximum takeoff speed (165), the range of speeds for the initial approach (120/180, but 140 for reversal / racetrack), the range of speeds for final approach (85/130), maximum circling speed (135), and the maximum speeds during ‘intermediate’ and ‘final’ missed approach (130 and 150). All examples ( ) relate to Cat B.

Some approaches are specifically defined for lower speeds, these must be followed. From Captain Smiley’s question and his reference to a speed limit in Jeps I suspect that this is the limiting factor. Therefore whilst the aircraft is Cat B, it would be incorrect to fly the 140 kt SOP speed on any procedure with a lower speed restriction. Note that the procedure is owned by the national authority of the country who licenses the airfield, thus it may be inappropriate to seek a dispensation from your own authority or inspector as they may not have the relevant information

Also beware that for procedures designed by TERPS (US) whilst generally giving the same obstacle clearance, the circling and maneuvering areas may differ significantly; e.g. 767 CFIT at Busan Korea during circling procedure.

Edit: threshold (Vat) replaced touchdown