APP CLB GRAD & LDG CLB GRAD?

[Manicured garden]

Hello guys, just a question got stuck on my mind.

While applying approach, minimums may vary depending on Go-Around Climb gradient. In the company that I m flying, we calculate with the help of Electronic Flight Bag. There, after calculations; gives us 2 results; APP CLB GRAD & LDG CLB GRAD.

So according to which we have to select minimums/GA climb gradient?
And what are the differences ? I think I missed the logic so anyone could explain briefly?

Thanks in advance.

[safelife]

Approach climb gradient.
That's gear up, approach flaps, single engine.
Landing climb gradient would be gear down, all engines, hence hardly ever limiting.

[zlin77]

My dim memory tells me : Approach climb, one engine inoperative, gear retracted, intermediate flap setting, speed not above 1.5 x VS= 2.5% gradient.

: Landing climb, all engines operative, full flap, not above 1.3 x VS= 3.2% gradient.

[piratepete]

Yes but Mr Garden, what you are being referred to are the MINIMUM gradients, generally mandated by ICAO, however take a look at the case of VHHH runway 07L.There are two missed approach gradients, one is 7% because it starts at 222 feet the other much less around 3% because it starts at 1200 feet or so with no approach lights, the obvious reason being that the MA track flies over very high local terrain.07R on the other hand is much lower gradient as it goes over the sea, Peter.

[Manicured garden]

zlin77 + safelife + piratepete thanks a lot guys! Now it's more clear!

[whitelabel]

Ok now we mentioning these performance issues I have a question as well. Lets say you need to use the higher minima because the lower minima is not giving you the required performance. What if we descent below minima and for whatever reason we have to go around. Is our obst clearance assured?

[piratepete]

This is a good question and can only be answered either from your aircraft AFM charts otherwise your Runway Analysis service provider.Peter.

[B737900er]

In that case you would follow the engine out/bulked landing procedure.

Usually the min gradient is 2.5%, if you cannot make that then you cannot do the approach.

[HGVO]

Standard missed approaches require a minimum climb gradient of 2.5% if not otherwise indicated.
But airworthiness requirements for a twin engine aircraft only ask for 2.1% in CAT1 or Non precision conditions
(3 engines 2.4% and 4 engines 2.7%).
Only CAT 2/3 requires 2.5%. Therefore it makes sense to use the CAT 2 requirements for Landing Performance Calculations.
Balked Landings (Landing Climb) require no one engine out performance, only 3.2% climb gradient with all engines operative.
Therefore operators provide special balked landing procedures for performance critical airports i.e. INN.

[hph304]

In my outfit we use the efato procedure in case the ga clb gradient is below the required gradient.