Flap retraction during climbout on a SID

[Driver 170]

I'm looking for some advice, Boeing does state in the FCTM

Immediate Turn after Takeoff - All Engines
Obstacle clearance, noise abatement, or departure procedures may require an immediate turn after takeoff. Initiate the turn at the appropriate altitude (normally at least 400 feet AGL) and maintain V2 + 15 to V2 + 25 with takeoff flaps.

If i'm above 400AGL and climbing out to D3.1 ISX, will i delay Flap retraction untill the turn is complete? My speed was above V2+15 white bug and i also reached my Acc Alt at 3000ft before the turn, my plane was acclerating and positive trend vector with increasing speed, i was F1 takeoff and retracted from F1 to up at the green 1 bug during the turn. I was going to delay the flap retraction untill the turn was complete and in level flight but wasn't sure if thats a good combo.

Also i did modify the speed for the turn to something more slower 220B/3000A to D5 BKY is this also good airmanship for a simmer so i can manage the turn alot better?


So any NG pilots or anyone like to give some sound advice on turns above 400AGL during SID turns and flap retraction?

Thanks alot.

[AerocatS2A]

I don't fly a B737, but we would commence acceleration at the acceleration altitude of 3000' and retract flap on schedule. Once clean we would continue acceleration to 250 knots. The question about staying slow for the turn would probably rely a bit on local knowledge. In my experience if a speed slower than 250 knots is required to achieve the turn radius depicted on a chart the lower speed is specified, e.g, "max speed 220 knots in the turn". Airmanship would normally dictate that unless there is a specific reason not to, you should get to 250 knots as promptly as your procedures allow so that the departure controller is dealing with aircraft all travelling at a known speed. In Australia it is a requirement to commence acceleration to 250 knots at 3000' AGL so that the controllers know what everyone will be doing.

I'm not really sure why you are looking at the immediate turn after take-off procedure. An immediate turn would be one where it says something like, "as soon as practical after take-off, turn left, track direct to GONZO". A turn at 3.1 DME is not even close to an immediate turn after take-off.

[Driver 170]

I was following the NADP1 for this SID out of EGSS. I found this in a FCOM, Enter max 220kts when no speed is specified in the FMC for initial turns on SID to assure track keeping. But in a busy place like london TMA the controller will want you climbing out alot faster and at the same speeds. But what do i know as i don't fly in the RW. Thanks for that advice and heads up

So if you haven't got an immediate turn after TO and you're above 400AGL, you can start a turn while retracting flaps?

[AerocatS2A]

So if you haven't got an immediate turn after TO and you're above 400AGL, you can start a turn while retracting flaps?

In general, as long as there's nothing specifically prohibiting it in the FCOM, sure. Check your copy of the FCOM for flap retraction speeds, it might have an increased speed to use if you are in a 30º bank.

Also, generally speaking, the sooner you can get the flaps up, the better your performance will be. The aeroplane flies a lot better once it is clean.

Hopefully someone with B737 specific experience can confirm for you.

[Driver 170]

Only thing it mentions is, limit bank angle to 15* Untill reaching V2+15.

I'll stick with what you said and i won't go changing speeds during DEPT unless it states it in the SID.

Thanks for your time and effort,

Regards.

[victorc10]

STN is noise sensitive and you should try and stick to the requirement to be on the BKY R171 by D8 BKY, a heavy NG (clean) will overshoot D8 BKY and not be inbound (351/R171 by D8 BKY). Your restriction of 220B is a good call, I used to put 210B at D5 and go around the corner at the up speed. Probably the only way to be on the required radial at D8 is with flaps extended depending on the weight. In the 5 years I was based at STN, only once did I have the pleasure of watching my collegue make the restriction at D8 (The response to a bet), I think we had F5 but can't remember.

[Driver 170]

Soon as i entered 220B the magenta brick road did shrink and became alot tighter and just kept my speed at UP speed for the turn D8 BKY. Soon as i was on the radial 171 i cancelled SPD INV and accelarated to 250. My flaps up speed was only 201kts as i was only going to EGPH and my GW was about 60t

Thanks for the help.