When you depart in a medium size or large jet and need to do, say, a 180 deg turn within a few nm of liftoff to track back to a departure pattern and the flightplan path, what sort of speed would you typically fly at so you don't bust ATC orders and the track? Is it realistic to set your IAS to something like 210 or 220 for the climbout--and keep your flaps out during such a maneouver-- until you are aligned with a straighter climb path?Just curious...Thanks!JS

Hi,The procedure will vary from one aircraft type to another, and also with local ATC procedure, but in general, it would be realistic to fly the following profile:Climb at V2+20 until Thrust Reduction Altitude, usually 1500' above the surface. Then reduce power to "Climb Thrust", lower the nose and accelerate to 250kt. Accelerate to enroute climb speed, usually between 270 to 300kt, once you climb through 10,000ft (in the US).The vast majority of the time, ATC will want you to accelerate to 250kt as quickly as possible. This is to make managing the departure streams easier. In fact, I'm fairly certain that ATC can't issue a speed restriction of less than 230kt to a departing aircraft (it might be 210kt). In any case, aircraft performance will always override any ATC issued speed restriction. For instance, a high gross weight 747 in a clean configuration may require 270kt during initial climb. ATC must accomodate that requirement because under certain conditions the 747 simply can't comply with the "250 under 10" rule.Hope that helps,NickEDIT: I forgot to answer your question regarding the flaps. Assuming the climb procedure I described above, aircraft configuration will not change from rotation up to thrust reduction height (except the gear, of course). Then as you accelerate to climb speed, you will retract flaps/slats "on schedule". Meaning, retract flaps to the next setting as you accelerate through that flap setting's maneuvering speed.

Just follow regulations basicly.. Under 5k, keep IAS at 205, under 10, under 250, under FL180, keep it at 290 or less. If your in a 747, i could turn it at 200 or so.. Basicly, just keep it at a safe spped, meaning above stalling speed.

Hi Chase,Are those numbers for an area outside the United States?I can't speak with any kind of authority on international airspace, but domestically within the US, the rules are pretty straight forward:Certainly the "250 under 10" rule is widely known. There is a also lesser known speed limit of 200kt within 4nm of the primary airport of a Class C or D airspace. And last, the speed limit while flying under any portion of a Class B Shelf is 200kt.I don't know of any speed restrictions that correspond to 205kt/5000ft or 290kt/FL180.There are a few more "rules" in place, but these can be modified if an operational benefit would result:Max Holding Speeds:MHA to 6,000ft - 200kt6,001 to 14,000ft - 230kt14,001ft and above - 265ktAnd last but not least, ATC imposed speed adjustments:For departing Turbojet aircraft, a speed not less than 230 knots. Mmmmm...legal mumbo jumbo. yummy. :-roll Of course, like I mentioned before, if the minimum safe speed for an airplane is higher than than the stated limit, then the airplame shall be flown at the minimum safe speed.Anyway, for all the time I've spent in the jumpseat of CRJ's, DC-10's, and the occasional MD-88, 767, etc., every single departure has had the same basic profile. Rotate and pitch for V2+XX at TOGA or FLEX thrust. Maintain V2+XX up to Thrust Reduction Height, set Climb Thrust then pitch for 250kt. See ya,Nick

Thanks to all so far for replies. Interesting data.My interest in this is because I have observed that the turn radius increases considerably doing something like a 180 deg turn at around 3-5 nm from liftoff depending on speed. I limit myself to IAS 220 for such turns because if I accelerate to 250 off the bat, the radius at higher speed puts me some distance off the flightplan track. It is partly the speed and partly the acceleration that does this. So I was looking for guidance on the best way to do this; or maybe I already am doing it the best way...?JS

JS,Maybe I've been looking at this the wrong way... Are you having trouble maintaining the prescribed lateral track of a charted SID/DP?If thats the case, then there may very well be some special climb profile spelled out within that procedure. For instance some airports with very strict Noise Abatement procedures may require that an aircraft must climb at V2+20 or the minimum manuevering speed in takeoff configuration for an extended period of time. This may or may not be combined with complex maneuvering to avoid populous areas. There are caveats to EVERY rule, so its very possible that you're trying to fly one of these highly tailored procedures.Can you tell us what specific departure you're trying to fly? That might help clear things up.Regards,Nick

Nick:Thanks for your note.I am doing a departure ex EGLL 27R/L for a flight to Rome, I forget the SID name (I am not too disciplined with published SIDs and STARs as I find many of them quite confusing, so I often customize them to suit my routing), but it involves a roughly 180 deg turn soon after liftoff heading west. It's that tight turn all the way around I am trying to hold at the right IAS to stay on track.JS