Since the Blimp code is very new, limited failsafe behavior is currently provided and is expected to improve and evolve over time.
Blimp provides several failsafes which can be enabled or disabled:
RC loss via FS_THR_ENABLE, always disarms on any RC failsafe. “0” ignores RC failsafes
EKF Failsafe, when EKF is determined to be unhealthy, FS_EKF_ACTION occurs
Vibration Failsafe via FS_VIBE_ENABLE