Evacuation Slide/Raft Daisy Chain Release for Stuck Loop Detachment
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Solution Overview
Problem
Daisy chained loops in evacuation slides/rafts for aircraft may become stiff from stowing, causing them to stick together and fail to automatically release without manual intervention during an emergency landing, especially in water landings.
Innovation Solution
A daisy chain release mechanism with release mechanisms such as straps, webbings, or cords, woven under the daisy chained loops, coupled to a release pin, which is pulled via a handle to uncouple the loops automatically.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If daisy chained loops are used to attach the evacuation slide/raft to the aircraft, then the attachment strength is improved, but the loops become stiff from stowing and stick together, causing automatic release failure
Solution Approach 1:
A release mechanism comprising a release pin and pull handle is introduced as an intermediary device between the daisy chained loops and the girt assembly. The release pin engages with the loops and, when pulled via the handle, forces the stiff loops to uncouple by overcoming their resistance through mechanical leverage, enabling automatic release without manual manipulation of the stuck loops
Solution Approach 2:
The system is designed to automatically release the daisy chained loops from the girt assembly through the release mechanism. When the pull handle is actuated, the release pin automatically pushes the loops apart and uncouples them from the girt, allowing the evacuation slide/raft to detach without requiring crew or passenger intervention to manually separate the stuck loops
2Reliability
If manual intervention is required to release the daisy chained loops, then the release reliability is improved, but the response time increases and training requirements increase
Solution Approach 1:
The release mechanism enables self-service operation where the system automatically releases the daisy chained loops when the pull handle is actuated. The release pin mechanically forces the stiff loops to uncouple from the girt assembly without requiring anyone to manually manipulate the stuck loops, ensuring reliable automatic detachment while minimizing response time
Solution Approach 2:
The release pin is pre-positioned to engage with the daisy chained loops in a ready state. The pull handle is positioned for immediate activation. When needed, the system requires only the preliminary action of pulling the handle, which then automatically executes the release sequence, eliminating the need for complex manual manipulation steps during the emergency
3Volume of moving object
If the daisy chained loops are made stiff for stowing, then the stowing compactness is improved, but the loops stick together and fail to release automatically
Solution Approach 1:
The release mechanism serves as an intermediary that bridges the contradiction between stiff loops for compact stowing and the need for automatic release. The release pin, when actuated by the pull handle, mechanically forces the stiff loops to uncouple by overcoming their rigidity, allowing the loops to maintain stiffness during stowing while still enabling automatic release when needed
Solution Approach 2:
The system changes the operational parameter of the loops from a static stiff state during stowing to a dynamic released state during deployment. The release mechanism facilitates this parameter change by applying sufficient force through the release pin to overcome the loop stiffness and separate the loops, transitioning them from a compact stored configuration to an extended operational configuration
Data Source
AI summary
An emergency evacuation slide/raft for an aircraft is disclosed herein. The emergency evacuation slide/raft includes a girt, a daisy chain assembly, a release mechanism, a release pin, and a pull handle. The daisy chain assembly is configured to couple the girt to a girt sleeve affixed to the aircraft. The daisy chain assembly comprises a plurality of daisy chained loops thereby forming a plurality of daisy chained loop couplings. The release mechanism is weaved under each daisy chained loop coupling of the plurality of daisy chained loop couplings. The release pin is coupled to the daisy chain assembly. The pull handle is configured to, responsive to being pulled, release the release pin and pull the release mechanism so as to uncouple the plurality of daisy chained loop couplings.