Apologies for my continuing confusion, but having re-read and re-read WTS in the MATS, Pt 1, I'm seeking two answers as listed below:
3.53 The wake turbulence separation minima in the table below shall be applied when aircraft are using:
1. the same runway; or
2. parallel runways separated by less than 760 m; or
3. crossing runways if the projected flight path of the second aircraft will cross the projected flight path of the first aircraft at the same altitude or less than 1000 ft below; or
4. parallel runways separated by 760 m or more, if the projected flight path of the second aircraft will cross the projected flight path of the first aircraft at the same altitude or less than 1000 ft below.
So it seems the magic departure WTS table applies to cross runways. What it fails to explain, however, is whether departures using cross runways are deemed intermediate departures or 'same position' departures.
So aircraft A departs the threshold of runway 25 and rotates before crossing the centreline of runway 35. Aircraft B can be launched from the threshold of runway 35 WHEN? Is it classed as an intermediate departure? If so, WHY? Where is the criteria for this laid down anywhere in the MATS?
3.62 For wake turbulence separation purposes, helicopters air taxiing across runways shall be considered to be a departure from that intermediate point of the runway.
Secondly, as mentioned previously, does the above statement refer to WTS before or after the helicopter in question? I.e. should there be 3 minutes WTS before the helicopter is allowed to cross, or should there be 3 minutes WTS between the helicopter crossing and the departure thereafter. Or would this indeed be 2 minutes instead of 3 minutes? I think the word 'intermediate' in this statement is hugely confusing as it draws the reader to thinking 3 minutes, the WTS associated with an intermediate departure. How does a crossing helicopter in any way form an 'intermediate' departure when an aircraft thereafter departs from the runway threshold?
Apologies for the lengthy questioning and perhaps confusion, but this is frustrating me somewhat.
