View Full Version : Obstacles??

10th Feb 2008, 13:52
I was on a flight from Phuket and we took off from runway 27...
Pretty close to the end of runway 09 there is a beach and of course then
water. Are you limited then (performance wise)??
I mean when you takeoff from a runway you most could stop in case
of an engine failure, problem is does the ''beach and water'' limits the


10th Feb 2008, 19:06
This is just my thought..

water = nice and LONG clearway.

If there is a limitation, it would be for the runway length not the water.

I'd treat that as an obstacle only if I'm in a single piston.


11th Feb 2008, 09:51
Aha , Thanks for the help! :ok:

11th Feb 2008, 10:06
You could still be performance limited. The takeoff path must clear all obstacles but also comply with the 4 takeoff segments for FAR/JAR 25 aircraft.

The 4 segments has nothing to do with obstacles and must always be complied with even if the takeoff path is over water.

For a 2 engined aircraft the second segment is the most likely to be the limiting one. In that segment a 2 engined aircraft must, with T/O thrust set and gear up and the critical engine failed, be able to maintain a minimum of 2.4% climb gradient to a minimum of 400 feet.

The configuration changes for each of the segments and the climb gradient required depends on how many engines the aircraft has.

11th Feb 2008, 18:57
There is a structural limit weight limit set by the manufacturer, runway limits (accel/stop) and climb limits. (We'll skip the brake energy and landing weight limits.) Since the beach and water limit the length of the runway, they could affect your T/O weight.

17th Feb 2008, 04:55
If the water is relatively shallow, I agree that it equates to a "nice and LONG clearway". Also true for quite deep water, if there's good regulation to prevent large ships being in the take-off path. If the water is deep but there's no real regulation of shipping movements, the existence of a super-tanker, the QE2 or whatever, might well ruin your day.