Aerodrome Obstacle Charts: Type A

[Cloud surfer]

Just to double check; the obstacle heights published on ICAO AOC: Type A...... they DO NOT include 35' (10,6m) obstacle clearance, or do they?

The reason I'm asking is that I'm finding discrepencies between "normal" state published charts of heights (non-aviation charts) and the ICAO AOC Type A obstacle heights publised for the same obstacles.

Any takers?

[john_tullamarine]

(a) no charts incorporate the NFP clearance .. would be a meaningless exercise

(b) the discrepancies are to be expected .. different accuracies and source data, etc. Type A is from a specific survey and probably is going to be the more accurate source of data.

[Cloud surfer]

Yes, you're right of course. It would make it very difficult to use performance charts with a 0/0 reference point.

(Call it wishfull thinking on my behalf; I just couldn't get the damn thing over the 5.2% net gradient the obstacle required with any reasonable payload....) Would have been nice to knock of 10,6meters....


;)

[john_tullamarine]

... as against knocking off a ton or two ... ?

[Cloud surfer]

Precicely.

:ugh:

[john_tullamarine]

... and you can't do a turn inside the obstacle for a better result ?

[Cloud surfer]

Regrettably no. Rising terrain.


:(