SID Speed Restrictions of less than 250Kt?

[cossack]

Does anyone know of anywhere where there is a mandatory speed limit on a SID used by jet aircraft of less than 250Kt? Not necessarily to the end of the SID but for the first say 10 miles of it.

My searches so far have yielded that at Amsterdam aircraft are required to fly at VR + 10-20Kt to 3000 feet for noise abatement, but what I'm looking for is speeds of less than 250Kt imposed to either assist in track keeping or for separation requirements.

Thanks

[StressFree]

Cossack,. .Try Cologne (EDDK) runway 14L, Norvenich 1F SID. This imposes a 220kt restriction on the first part, I flew it this morning in a 737 and as its part of the SID the FMS already knows about it so automatically flys it - clever stuff.

<img src="cool.gif" border="0">

[olivasnooze]

Many SIDs have speed restrictions in the early part of a SID 210kts is not uncommon.

[minuteman]

The LIFFY 2A from DUB has 240kt until overhead the VOR. About 13/14 track miles.

[Wino]

Bodrum turkey

Cheers. .Wino

[ironbutt57]

You might find that most sid's that incorporate a turning departure have a built-in max speed of 200 kts until established on the departure procedure....

[ 02 March 2002: Message edited by: ironbutt57 ]</p>

[Oliver James]

If memory serves...

I think the Gatwick right turns off 26L are restricted to 220k until established on the DET radial.

Point 4

[Warped Factor]

I thought Gatwick was a case in point as well, not just the right turns of 26L but the left turns off 08R as well.

On looking at the SID plates though, the only speed restriction mentioned is not above 250kts below 10,000ft.

A couple of examples....

<a href="http://www.ais.org.uk/uk_aip/pdf/ad/32KK0601.pdf" target="_blank">LAM SID</a>

<a href="http://www.ais.org.uk/uk_aip/pdf/ad/32KK0605.pdf" target="_blank">KEN SID</a>

WF.

[cossack]

Thanks.

There are it seems in the UK no SIDs with a published speed limit of less than 250Kt. Is this because the SID designers don't allow it or because they feel it isn't required.

In the examples given, are the restrictions for track keeping, airspace requirements or separation purposes? I realise that pilots may not be aware of the reason for the limit but any information or opinions would be of help.

Manchester's LISTO 1S departure turns right almost 100 degrees after less than a mile and a half, then right another 40 after another 3 miles. By this time most aircraft have not started to accelerate but some have and make a wide turn. The speed limit is the usual 250Kt below FL100. An aircraft flying wide and then rejoining can be caught up by one flying the correct track having departed after.

A question for Heathrow Tower types. If you have two aircraft of similar type on the same route one after another and your speed table says 2 minutes. How long do you really give? Full 120 seconds between rotations or 5 miles or what? Would you be able to reduce the time between same route departures if there was a lower speed limit on the SID? i.e. Speed control of departures.

It seems in the case of the Gatwick departures mentioned that the lower speed limit is unofficial and just used by the pilots to assist in track keeping rather than imposed in the design.

Any more thoughts?

[fireflybob]

In the case of a (fairly) early turn after take off involving a relatively large change of track, there is usually little point in accelerating prior to or during the turn since to do so wastes fuel and time.

Best to do the turn then accelerate.

[eyeinthesky]

In the case of the Gatwick LAM SID, for example, would I be right in thinking that if you were to accelerate beyond the 220kts mentioned then you might have trouble keeping the turn tight enough to establish on the DET radial by the required DME distance? Even if not, you would surely make a large turn, possibly heading SE rather than E to get back on the radial if your IAS was too high too soon.. .. .Just as an aside, the NDB procedure for Alderney gives a maximum speed of 110kts IAS. (I know it is an arrival, not a departure!)

[Not Long Now]

A few points:. .250kts max below FL100, wether on a SID or not, unless cancelled by ATC.. .Gatwick deps with 180 degree turns, speed isn't supposed to be cancelled by atc until turn complete to prevent deviation from noise routes. All deviations are automatically logged, and most result in fines nowadays, which airlines will try to blame on someone else, ie atc.. .Heathrow 2 minute deps, from the catching (TC) end are usually about 91 seconds. Generally fine, but a bit sporting last week with 270/9kts on ground and 285/48kts at 4000', get airborne, climb a little then hover and wait for one behind to catch you!. .Old point, but always a goody, A340 long haul dep speed often 190ks ish. Technically same group as 'real' jets. Nice. Also new DHC8 with go faster stripes, extremely slippery, almost caused a few embarrased looks as it overtakes BA46 ahead!

[cossack]

eyeinthesky. .That's what I'm getting at. Why should pilots determine their own speed to try to keep to a SID when it is probably known by the designer that it is nearly impossible to fly it accurately at 250Kt. Why not put an initial speed limit on the SID?. .. .NLN. .91 seconds probably gives you about 5-6 miles in trail and with similar climbers about 2500-3000 feet of vertical. Sounds good to me. . .I agree about the DH8D! We have in the same group as the RJ1H/146, Citations and Saab 2000. Seems OK in there...so far! <img border="0" title="" alt="[Wink]" src="wink.gif" /> . .. .If SIDs were speed limited to say 210Kt, could aircraft be departed closer together (5 miles rather than 2 minutes) and speed control gradually lifted to increase the departure separation? Since many aircraft climb at V2 + 10-20Kt to 3000 feet and they don't all reach 3000 feet at the same rate, then this would provide another way of keeping in trail aircraft separated more easily.. .. .Using this method you could have less time between departures and therefore be able to increase the departure rate. This would probably not help much at Heathrow where you have good early SID splits and lots of traffic on various SIDs, but at airports like Manchester where the SIDs are more track similar for noise reasons, it could be of great benefit.. .. .Is it feasible? Is it desireable? Any thoughts?. .. .(Spelling again!). . . . <small>[ 09 March 2002, 15:37: Message edited by: cossack ]</small>