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>