diydrones/ardupilot — pull request #826 by priseborough (2014-02-07 08:12:53+00:00)
Title: AP_TECS : Allows accln launch detection without airspeed sensor

The 50Hz inertial speed rate of change calculation was not being run when no airspeed sensor was being used or available. This prevented accel based detection of hand launches without airspeed sensors fitted. This patch ensures that the speed rate of change is always calculated.