Take-off and then?
 

I have a question.. Once you start the take-off roll and pass V1 and Vr, what speed do you maintain in the big jets? Is it V2 + een increment and untill what altitude?

Great reference material here (757 specific), but will give you an idea.

http://www.757.org.uk/sops/sop2.html

We use v2+10 until 3,000' agl then pitch to climb at 500 fpm accelerate and clean up flaps to 250-280 kts (v2+100) until 10,000' in the US. After this we climb around 310-330 kts depending on weight and .82-.84 up to altitude. This is for 747 100/200.

If I'm guessing rightly, the original poster was referring to the Takeoff through to 'clean-up' phase, in which case it is V2+10 (for aircraft certified with V2min = 1.2 X Vs), or V2+15 (for aircraft certified with V2min = 1.13 X Vs).

The objective is to maintain optimum gradient during the early 'obstacle critical' phases of flight, thus these speeds are maintained until the higher of -

(1) The OEI Minimum Acceleration Altitude (MAA),

(2) The Company specified 3rd segment Altitude if above MAA, OR

(3) The altitude to comply with Noise Abatement requirements (typically 3000 feet).

Regards,

Old Smokey