V2 climb speed on 737/600

[Guest gjpollitt]

When taking off after rotating using FD and AutoThrottle why does my climb speed go up to around 180Kias when the AT has been set to V2 of 134 for example. I thought that the climb speed should be 134 then when AP is set the climb speed would be 154 (V2+20).Do I need to enable the Speed button?It makes for a messy climb as the aircraft has to slow down considerably to match the AT once the AP has been engaged.thanksGraham

[Mats_J 2]

Graham,During take-off and initial climb you have to pitch to stay within your speed limits. The A/T is in N1 mode which means it will set the N1 value from the FMC and expects someone else to manage speeds. ;-)Hope it helps,

[Guest gjpollitt]

excellent, thanks

[kmanning 12]

Hi Granam,Are you following the pitch using the flight director durning the climb? There's a magenta line that's usually at around 15 degrees. As the airplane accelerates, this line will move and you just follow that line using the flight director. When the pitch line merges with the flight director, your speed will be V2+20 knots or 154 knots. No, you do not need to press the speed button at this time. Just follow the pitch on the flight director. After reaching 1000ft, or it may be 800ft, push the nose over a few degrees and the airplane will accelerate. Do not exceed 250 below 10,000ft. If you're using VNAV, allow it to adjust speed.Ken.