multiple runway independent paralleled departure

[caucatc]

Does anyone know the weather requirment for 3 or 4 paralled runways independent departure procedure ?

[caucatc]

Does anybody know it or any suggestion about this ????????:ugh:

[ramzez]

I don't think there are any weather requirements.

Doc 4444, 6.7.2.2
REQUIREMENTS AND PROCEDURES FOR INDEPENDENT PARALLEL DEPARTURES

Independent IFR departures may be conducted from parallel runways provided:
a) the runway centre lines are spaced by the distance specified in Annex 14, Volume I;
b) the departure tracks diverge by at least 15 degrees immediately after take-off;
c) suitable surveillance radar capable of identification of the aircraft within 2 km (1.0 NM) from the end of the
runway is available; and
d) ATS operational procedures ensure that the required track divergence is achieved.

[caucatc]

Thanks for your advice ,but here is the question: when aircraft departure from center runway ,it will drift to the left or right due to crosswind ,so we want to know if there is a regulation about when the wind is strong to a certain speed we should give initial TRACK rather than HDG .
I have seen once that when there was a strong wind ,the middle runway departre aircraft was almost on the upwind of the other runway!!!

[cossack]

The answer is in d) above. ATC ensure that divergence is assured. We do it here by issuing headings.

For example: Say you have runways 36L/C/R with a strong wind from the NW. If traffic from 36L normally flies 345', 36C flies 360' and 36R 015', you may need to use 340', 355' and leave 36R as 015'. If the wind is stronger just use more correction: 335', 350' and 015'. We normally leave the "downwind" runway uncorrected.

You can't just leave them uncorrected and some aircraft may not be able to fly tracks. There is no weather criteria or minima, its just a case of ATC noticing or more likely anticipating that divergence may not be assured and doing something to assure it.

Hope that helps.

[caucatc]

Ok ,I understood that ,but here is the question ,the wind is not same when aircraft in different layer ,it is complicated to let controller always focus on the heading .
Most of aircrafts come to BeiJing are Boeing or Airbus aircraft ,so sometimes we think if we should let aircraft dep from middle runway to maintain track 360 ???

[cossack]

I think you are over-thinking this. Its best to keep things as simple as possible. If you start introducing a track departure for one runway then headings for others, things will eventually go wrong. That's just the way things are.

How long are your aircraft from these runways going to be on these headings? One minute? Maybe two? They will need to turn on course and will likely do this after noise abatement (if you have that) at perhaps 3000 feet, yes? There may be different wind speeds and strengths but even if you have aircraft side by side from three runways they will all be affected by the wind in a similar way. Smaller aircraft will drift more and this will need to be taken into account.

We are trained professionals and should be able to foresee these variables and maintain a safe operation. Sometimes it is better to let controllers decide what is necessary to ensure separation at a particular time rather than have every eventuality covered by a rule in black and white.

[caucatc]

If you check BeiJing SID you will know we would like aircrafr dep from middle runway to maintain TRACK for 2 minutes at least ,currently we are using the RNAV for departure ,there is one waypoint that is only one minute after departure but we have found that pilots may made a mistake and turn to wrong place ,so we like to let aircraft maintain runway TRACK for 2 minutes and then vector join SID.
As you said aircraft will drift same even if they are side by side ,it seems right ,but what if aircrafts are in different layer ? How to make sure that the wind is still the same ? Normally aircraft from the east runway will turn heading 030 after maintain runway heading and climb to 900 ft ,they said it is their airlines' rule ,and if the middle runway departure aircraft drift to the upwind of east runway ,that will be a little bit dangerous.
I am not overthinking ,these did happen for several times ,we tried to let aircraft maintain runway track ,that recude the work load of departure ATC a lot .

[cossack]

Beijing looks like it has a very well laid out airport.:ok:

Do your departures normally depart from the closest runway to their parking or is it based on direction of flight?

Do you arrive and depart on all three runways (mixed-mode) at the same time?

There is no way of ensuring that aircraft in different wind conditions remain separated other than provide more than the minimum divergence on departure. I would think that aircraft on RNAV departures would have accurate enough track keeping that they would not be an issue. Non-RNAV departures would need vectoring to ensure separation.

[caucatc]

Yes ,normally departure from closest runway and both 3 runways are mixed mode ,except middle runway is only for departure in each morning due to dep aircraft rush hour.
RNAV is accurate enough ,but pilots sometimes made a mistake ,like there is one point named AA151 it is only one minute on upwind after departure ,we used to issued that point ,but pilot sometimes fly to west and made a mistake that is a potential conflict with aircraft dep from west runway.
Before we have RNAV ,we issue heading ,36L heading 330 ,36R heading 360 and 01 heading 060,but now we have RNAV 01 is initial heading 030,that made a dangerous conflict with aircraft from middle runway.