applying wake separation

[ALATOWER]

2 Wojtus

…thanks, U right I know what u mean…to be correct according to doc.4444 ICAO “at RWY-holding position should be 50m from RWY edge where RWY length is 900m or more” ….but I can give landing clearance at any distances from the RWY- 15 km, 9 km or 1 km. Providing safety separations between departing and landing a/cs we apply the wake separation and not issue line-up clearance if it less than established. So I asked about minima safety separation between landing and crossing RWY a/cs. What different from lining-up a/c preparing for take-off and crossing RWY? I hope we both understand that we talk about case except LVP. Our local doc. not prescribes it.

[jumpseater]

Vortex wake application is applied to the second, ie if its a two min dep separation and the preceding a/c departs at 18:29:29 secs, the subsequent a/c may not depart until 18:31:29 secs.
That's the way it's taught in all the colleges and that's the way it should be applied in the field.

I can confirm that's what I've been taught. Recently. When the nose wheel lifts on the first a/c, the clock starts eg 18:29:29. At college we were given 'fails' if we started the phrase 'cleared for T/O' before 18:31:29.

[Wojtus]

So I asked about minima safety separation between landing and crossing RWY a/cs.

Well, that's just the pure art of aerodrome control! ;D
Unless you have strict values published in your Manual, you're on your own judgement here. So it is all safe if you decide it is... until it's too short! Use the licence :)

What different from lining-up a/c preparing for take-off and crossing RWY?

A taxiing aircraft is not going airborne, so if you screw it up - just send approaching traffic for go-around and you're fine. But if we are speaking about departure/arrival separation - you have to consider the separation between departing a/c and a/c possibly executing a missapp. So the difference is huge.

[ALATOWER]

Thanks for discussing.

Cheer guys!