Multiple turns

28.10.2004

Submission:

Does PANS-OPS permit use of general departure schemes with multiple turns to direct aircrafts to specified waypoints?

If multiple turns are permitted during departure, how is the minimum allowable altitude/height over obstacles determined/calculated for such cases? For instance: departure routes with a turn designated at an altitude/height all distances to obstacles are measured from the bounds of the turn initiation area whereas for a turn at a designated "Turning Point" distances are measured from line K-K.


Pavel Samarin, R.I.S.K. Company AZERBAIJAN

Answer or Commentary:

(I.W.

As far as I know Pans-Ops doesn't specifically exclude multiple turns in a departure. However one does not see very many of them in an obstacle rich environment as they are rather hard to calculate.

I think it would be difficult to correctly design such a departure using turns at altitudes. In my opinion it would be easier to design a multiple turning departure using either turning fixes or waypoints as that way one has specific turn initiation areas from which to calculate the distance to climb to an obstacle. I suggest that one treats the second K-K line as an obstacle so as to determine the second dr distance (dr'').

To evaluate the distance to climb to the obstacle (refer following picture):

1st portion do

2nd portion dr + do

3rd portion dr + dr'' + do

and so on)