Standard Missed Approach procedure designed i.a.w ICAO Doc 8168 requires you to make 2,5% gradient. Warning: there is no allowance for a level acceleration segment, just 2,5% all the way until the MisApch altitude.
For OEI, it is the operators' responsibility to do the math (tkof, enrt and ldg) - at all times. The performance for MisApch from the airworthiness requirements requires is 2,4% for modern twins (Perf class A), and so 2,5 is doable or you must restrict the LW accordingly anyway. So the AOC holder should run the figures for 2,5 (or as charted) before dispatch and later following the prescribed MisApch is enough. Well, until you run out of MAX TOGA time on the remaining engine (maybe keep this element for a later debate).
Cannot speak for quads, trimotors or other performance classes.
A pretty decent layout is (in general)
- AEO at minima or above -> follow the MAPr
- AEO below minima -> avoid close-in obstacles visually and rejoin the MAPr
- OEI at minima or above AND the charted gradient (2,5% unless stated higher) is checked OK -> follow the MAPr
- OEI below minima OR unable to make the published gradient -> follow a specific procedure (most likely the OEI instrument tkof procedure for that runway)
If the above is not sufficient, then by definition we are talking about an airport requiring special performance considerations. The assessment of which is a legal responsibility of the AOC holder, who must then provide the necessary procedure / calculated solution AND training how to apply it to the crews.
That's how I heard it.
Last edited by FlightDetent; 13th Aug 2019 at 14:53.
Reason: grammar, at least some.