The following have been extracted from ICAR Air Commission documents over the last 4 years or incidents witnessed.
- Physiological degradation caused by chest strop
- Casualty in strop loosing consciousness
- Roll out from hook
- Shock load breaking wire
- Attachment to rock-face/vessel
- Entanglement with gear (causing either attachment or unintended persons on winch)
- Blade strike hovering near obstacle
- Loss of visual references
- Accidentally hooked to weak harness point
- Winching starts with person unattached or partially attached
- Untethered hoist operator
- Hi-line attached to person or object on the ground
- Hi-line entanglement with person on winch
- Hi-line weak-link insufficient for large high-powered rotorcraft
- Tree blown down by hovering aircraft during winching
- Aircraft enveloped by descending cloud-base during winch operation
- Downwash causing fatal fall
- Accidental cable cut
So, is it risky? I think that's a yes.