Aircraft Emergency Device Actuation Locking for Inadvertent Deployment
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Solution Overview
Problem
Existing aircraft emergency floatation devices lack sufficient security measures to prevent inadvertent deployment and ensure safe retention during normal flight operations while allowing reliable access and deployment during emergencies.
Innovation Solution
An actuation assembly with a rotatable actuation shaft, manually operated lever, safety locking system, and linkage assembly, including a bell crank mechanism and OTC spring system, to securely maintain the emergency device in a stowed position during normal flight and enable deployment upon activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a locking system is added to prevent inadvertent deployment, then safety and security are improved, but device complexity increases
Solution Approach 1:
The locking system is divided into separate functional components: access panel latches, bay latches, and an actuation shaft assembly with safety latches. This segmentation allows each component to perform its specific locking function independently, improving safety through multiple layers of security while managing complexity through modular design
Solution Approach 2:
The actuation shaft is rotated to the deployed position in advance during normal operation to pre-arm the system. This preliminary action prepares the locking mechanism for rapid emergency deployment while maintaining safety during flight, as the shaft rotation itself activates the safety latches that prevent inadvertent panel release
2Reliability
If multiple safety latches and locking mechanisms are implemented, then inadvertent deployment is prevented, but ease of operation deteriorates
Solution Approach 1:
Multiple locking functions are merged into a single actuation shaft assembly. The actuation shaft simultaneously controls access panel latches, bay latches, and safety latches through integrated linkage mechanisms. This merging allows one rotational motion to coordinate multiple locking and unlocking actions, improving ease of operation while maintaining multi-layer security
Solution Approach 2:
The actuation shaft serves multiple functions: it arms the emergency device by rotating to the deployed position, it controls the release of access panels through linkage to panel latches, and it manages bay latches. This multi-functionality consolidates what would otherwise require separate controls into a single universal actuator, significantly improving ease of operation
3Adaptability or versatility
If the actuation shaft is made rotatable for arming and deployment, then operational flexibility is improved, but risk of inadvertent activation increases
Solution Approach 1:
The actuation shaft is designed to be dynamically positionable with distinct armed and deployed positions. In the armed position (rotated but not fully deployed), the system is prepared for emergency use but safety latches remain engaged. In the deployed position, full release occurs. This dynamic positioning provides operational flexibility while the safety latches prevent harmful inadvertent activation during the armed state
Solution Approach 2:
The system provides mechanical feedback through the engagement of safety latches with the actuation shaft. When the shaft is rotated to the armed position, safety latches engage to provide tactile and visual feedback that the system is armed but protected. This feedback mechanism ensures operators understand the system state while preventing accidental full deployment
Data Source
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Figure 1A
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AI summary
Actuation assemblies for emergency devices (e.g., inflatable life rafts carried on-board an aircraft) are provided with enhanced (preferably multiple) levels of security to preclude inadvertent unlatching and/or deployment but also allow access to an on-board emergency device removably positioned within a device bay of the vehicle which is normally covered by an access panel. The actuation assembly may be provided with a rotatable actuation shaft, a manually operated actuation lever fixed to the actuation shaft so as to rotate the actuation shaft in response to movement of the actuation lever between stowed and deployed conditions thereof, and a safety locking system operably connected to the rotatable shaft and having a locked condition which prevents operation of the actuation lever to thereby maintain the actuation assembly in a safe mode during normal vehicle operation, and an armed mode which allows the actuation lever to be moved into the deployed condition thereof.