NotaLOT
5th Jul 2013, 13:20
Dear All,
I could use with you specialist help on this issue. According to ICAO Doc 4444, for two consecutive departures:
"One minute separation is required if aircraft are to fly on tracks diverging by at least 45 degrees immediately after take-off so that lateral separation is provided".
I am assuming the aircraft are of the same wake vortex category, so wake separation criteria do not apply.
Is it possible (or practised) to apply 1 minute separation by providing only vertical separation between consecutive departures (i.e. both aircraft fly on the same track but the preceding one is launched at a steeper angle to ensure 1000ft vertical separation from the follower)? Alternatively, are there any means to reduce the 45 degree criterium for diverging departures?
I ask this in the context of simultaneous departures on parallel runways. If divergence of 45 degrees is required, then am I right in saying that is is practically impossible to achieve double the departure capacity of a single runway from a two parallel runway system (assuming the required runway separation for independent departures is in place)?
My thinking is that the second runway constrains the ability to diverge a departure towards it (since there will be other departures from that second runway that may conflict with departures from the first runway).
The requirement of ICAO doc on simultaneous parallel ops that parallel departures must also diverge at 15 degrees away from the extended runway centre line I guess further limits the choice of departure track.
Looking forward to your thoughts and suggestions (and corrections of my logic)!
I could use with you specialist help on this issue. According to ICAO Doc 4444, for two consecutive departures:
"One minute separation is required if aircraft are to fly on tracks diverging by at least 45 degrees immediately after take-off so that lateral separation is provided".
I am assuming the aircraft are of the same wake vortex category, so wake separation criteria do not apply.
Is it possible (or practised) to apply 1 minute separation by providing only vertical separation between consecutive departures (i.e. both aircraft fly on the same track but the preceding one is launched at a steeper angle to ensure 1000ft vertical separation from the follower)? Alternatively, are there any means to reduce the 45 degree criterium for diverging departures?
I ask this in the context of simultaneous departures on parallel runways. If divergence of 45 degrees is required, then am I right in saying that is is practically impossible to achieve double the departure capacity of a single runway from a two parallel runway system (assuming the required runway separation for independent departures is in place)?
My thinking is that the second runway constrains the ability to diverge a departure towards it (since there will be other departures from that second runway that may conflict with departures from the first runway).
The requirement of ICAO doc on simultaneous parallel ops that parallel departures must also diverge at 15 degrees away from the extended runway centre line I guess further limits the choice of departure track.
Looking forward to your thoughts and suggestions (and corrections of my logic)!