V2+10

[QAVION]

Evening chaps....
Had a problem on a 747-400 a few weeks ago where the airspeed bug on the PFD didn't go to V2+10 on takeoff (it remained at V2 as set in the MCP airspeed window). I'm not sure if the V2+10 speed is purely a FCC-produced thing... or if it needs FMC input(like VNAV arming).
MCP's, FCC's and FMC's ground checked, satis., so that didn't help pinpoint the cause.

Should the speed go to V2+10 without VNAV arming?

Thanks.
Qavion.

[Cornish Jack]

Qavion
No problem there - if you didn't arm VNAV, the IAS window remains open and what shows in the window is what the bug will set to (or, for the purists, the speed to which the bug will set.) That speed window overrides anything else, apart from Min/Max speed protection, and even then, the bug remains at the window figure.
A lesson in egg-sucking for Grandmama - speed protection is NOT rpt NOT active in V/S mode.