Australian SID / Sup takeoff distance question

[BB8]

hello!

Im a kiwi pilot that is shortly about to do a bunch of IFR flying within Australia. Many of the smaller airfields within AUS don’t have SIDs, and I recall one of my colleagues saying the Supplementary take-off section of the RDS in ERSA could be used to figure out climb gradients for departure. I’ve scanned the ERSA, AIP, GPA and FIHA, and fear I may have missed the section that explains exactly how these can be used to work out a departure/climb gradient.

Is is anyone able to point me to the section in Aus pubs that explains it? I’m just a little unsure of the practical application.


thanks so much!

[john_tullamarine]

The two are unrelated but you can infer a few things ..

If the STODA is established by inclino survey, it will give you a straightout obstacle clear gradient surface. However, be wary, many are determined by calculation from, say, Type A data, and will only address a specific distance out from the runway head.

If you are looking at a turn, all bets are off as the STODA data only looks at a straight ahead flight path, unless otherwise specified.

I doubt that you will find anything in the rule books about using STODA data .. it is presumed that the basic definition provides the information needed for operations.

[Stu2d2]

ERSA RDS section (at the back contains the STODA information. The how to apply is found in ERSA intro page 22.

The catch is, depending on RWY code number, the survey area is only so long. Therefore another safety height will be required before the end as a turn is usually not available given rate of divergence.

[BB8]

Thanks John. I eventually managed to find the relevant section in the ERSA. It’s a pretty big gotcha that is only usually valid out to about 8.1nm meaning you have to be at MSA by then regardless.

Thanks again

[john_tullamarine]

Where the data can be useful is if you use it to run a simple trigonometric analysis to derive quasi-obstacles at the surface intersections and then you can use the lowest gradient scheduled from the final intersection.

As in, for instance, in this thread discussion (https://www.pprune.org/questions/162523-composite-runway-slope.html?highlight=STODA+intersections).

[glekichi]

What sort of aeroplane are you talking here?
If you're talking about using SID gradients on departure with all engines operating, then I assume piston twin?
If i remember correctly, generally, the practical idea was not to leave the circling area until MSA, i.e if required fly a couple of legs of the circuit, but MSAs are generally a lot lower in Australia than in NZ.
I think JT's expertise might be overkill for the scenario!