Aircraft Seatback Crush Zone Mechanism for HIC Reduction
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Solution Overview
Problem
Current aircraft passenger seat designs face a trade-off between weight reduction and safety, as they struggle to meet Head Injury Criterion (HIC) standards while maintaining seating capacity and comfort, often requiring extensive spacing or breakover mechanisms that limit seating arrangements.
Innovation Solution
The implementation of a passenger seat with a bezel and seatback that includes a slide mechanism and impact attenuator, which translates or pivots upon detecting emergency acceleration to create a crushable space, thereby absorbing impact loads and reducing head injury risk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If seat spacing is increased to prevent head contact during crash, then passenger safety is improved, but seating capacity is reduced
Solution Approach 1:
The bezel is translated forward and the seatback is reclined to a predetermined angle before impact occurs, creating crushable space in advance. This preliminary positioning of components allows the seat to absorb impact energy more effectively without requiring increased spacing between seats, thereby maintaining seating capacity while improving safety
Solution Approach 2:
The seatback and bezel are designed to be dynamically adjustable rather than fixed. The seatback can recline to different angles and the bezel can translate forward based on detected impact conditions, allowing the same seat structure to provide both normal seating function and crash protection without sacrificing seating density
2Reliability
If breakover mechanism is added to reduce head injury, then safety is improved, but device complexity increases
Solution Approach 1:
The breakover function is merged with the existing seatback recline mechanism. The same actuator that controls normal seatback reclining is used to pivot the seatback forward during crash events, eliminating the need for a separate breakover mechanism and reducing overall device complexity while maintaining head injury mitigation capability
Solution Approach 2:
The seatback mechanism serves multiple functions: it provides normal reclining for passenger comfort during flight, and it pivots forward to create crushable space during crash events. This multi-functionality eliminates the need for dedicated crash protection mechanisms, reducing complexity while improving safety
3Weight of moving object
If seat weight is reduced for efficiency, then fuel efficiency is improved, but safety capabilities are compromised
Solution Approach 1:
The heavy-duty crash protection features are activated only periodically when needed, not continuously. The actuators remain in a neutral position during normal flight, and only activate to translate the bezel or recline the seatback when crash conditions are detected, allowing the seat to maintain safety capabilities without the continuous weight penalty of permanently extended crash structures
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively increases the crushable space within the seat, improving head-impact criteria by absorbing energy and reducing the force of impact, thus enhancing passenger safety while maintaining seating density and comfort.
Implementation Method 1
an accelerometer configured to generate a signal in response to detecting an acceleration indicative of an emergency event
Implementation Method 2
the impact attenuator is configured to absorb an energy upon impact of the passenger with the bezel
Data Source
AI summary
A passenger seat is described which satisfies a head-injury criterion (HIC). To satisfy the HIC, the passenger seat translates or pivots one or more components of the seatback towards a passenger sitting behind the passenger seat. By translating and/or pivoting the components of the seatback towards the passenger, a crush zone for the passenger seat may be increased, thereby increasing the impact time and correspondingly decreasing the forces felt by the passenger.