Copter-3.5.6-rc1 available for beta testing

Copter-3.5.6-rc1 has been released for beta testing. As with all betas, the firmware is available on and also through the ground stations. If using the Mission Planner please open the Install Firmware screen, click on the “Beta Firmwares” link, verify that the label below the icon has changed to “APM:Copter V3.5.6-rc1” and then push the icon.

The changes vs 3.5.5 are in the ReleaseNotes and also listed below.

  1. Safety switch fix to refuse presses once armed (BRD_SAFETYOPTION controls behaviour)

This change in the safety switch behaviour to protect against the possibility of a disarm in flight. There have been 3 verified cases of a sudden disarm in flight, 2 in plane and 1 in copter. In all three cases the Here+ RTK GPS was being used and in the two plane cases (at least) the switch had gotten wet.

The change (also demonstrated in the video below).

This change has already been released in Plane and Rover so we think it is low risk and will have a shortened beta period of perhaps only 3 or 4 days (assuming all goes well).

All feedback and testing is greatly appreciated!