Lifesaving Systems was made aware of a possible ring geometry interaction between the Petzl LEZARD and the 410 (series) D-LOK Hoist Hooks. During the review of a helmet mounted video of a cliffside hoist utilizing the LEZARD device, the below images were captured. These images show that the interaction of the connection ring with the gate/hook transition of the legacy D-LOK Gate can lead to an unintended connection of the LEZARD to the hook opening which may load both the hook and the LEZARD in an unfavorable position.
The operator reported being unaware that the condition existed until the video was reviewed and the above images were captured.
These images prove the point that if unfavorable position geometry exists between two connections, on a long enough timeline the condition may occur during field use.
Lifesaving Systems encourages caution and testing of all hardware interactions with any hoist device or hook to determine if unfavorable connections or instances of dynamic rollout may occur and further cautions operators who utilize the LEZARD with a legacy 410 D-LOK Hook to discuss the possible unfavorable interaction with aircrew. While the possibility of occurrence is small, it is still possible and should be discussed.
The updated D-LOK Gate (414 series) reduces the risk on unfavorable position geometry and dynamic rollout by fully guarding the release latches and through a patented ramping guard that tapers between the hook body interface and the gate.
Questions can be directed to email@example.com.
Images used with permission.