Cloud surfer,
Hmm I quite didnt get your point.
We have to differ between:
obstacle considerations within take off path such as:
¡§JAR-OPS 1.495
(d) For those cases where the intended flight path does not require track changes of
more than 15 DEG, an operator need not consider those obstacles which have a lateral
distance greater than:
„300 m, if the pilot is able to maintain the required navigational accuracy
through the obstacle accountability area, or
„600 m, for flights under all other conditions.¡¨
Or
¡§JAR-OPS 1.495
(e) For those cases where the intended flight path does require track changes of
more than 15DEG, an operator need not consider those obstacles which have a lateral
distance greater than:
„600 m, if the pilot is able to maintain the required navigational accuracy
through the obstacle accountability area, or
„900 m for flights under all other conditions.¡¨
And the way to determine the required Nav. Accuracy as follow:
The Required Navigational Accuracy is defined in AMC-OPS 1.495. It can
either be obtained via navigation aids, or by using external references in case of
Visual Course guidance (VMC day flights).
I would say the 2.2 is the explanation derived from 2.1.
However JAR and FAR are slightly different in handling this issue as follow:
JAR doesn¡¦t specify lateral separation from the obstacles within the funnel where as FAR does, namely:
¡§FAR 121.189
(d)(2) No person operating a turbine engine powered transport category airplane may
take off that airplane at a weight greater than that listed in the Airplane Flight Manual
[¡K] that allows a net takeoff flight path that clears all obstacles [¡K] by at least 200
feet horizontally within the airport boundaries and by at least 300 feet horizontally
after passing the boundaries.¡¨
If you are interested in detailed information please read ¡§getting to grips with aircraft performance¡¨ a document I would recommend to everybody. I have used a lot out of this DOC.
Read it your self you might understand it different way.
Cheers.
