Fan Cowl Latch with High-Visibility Handle and Gap Indicator
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Solution Overview
Problem
Existing latches for fan cowl panels in turbofan propulsion systems are often not visually inspected before takeoff, leading to potential separation during flight if not secured, as their location can be obscured, resulting in safety risks.
Innovation Solution
A shoot pin latch system with a high visibility handle is implemented, where the shoot pin must be aligned with a receiver for closure, and a push pin latch creates a visible gap when unlatched, ensuring secure closure and easy visual inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional latches are used for fan cowl panels, then the latching function is provided, but the latch location becomes obscured and difficult to visually inspect before takeoff
Solution Approach 1:
The latch handle is painted with high-visibility color (such as fluorescent or contrasting color) to make it easily detectable before takeoff. This color change principle directly addresses the visibility problem while maintaining the latching function, allowing personnel to quickly locate and inspect the latch status without compromising reliability.
Solution Approach 2:
The latch mechanism is positioned on the exterior surface of the fan cowl panel where it can be visually accessed from multiple angles. The handle is designed to extend slightly beyond the panel surface, creating a dimensional projection that enhances visibility and detectability before takeoff inspection.
2Ease of operation
If the latch is not manually engaged prior to takeoff, then the fan cowl halves remain unlatched, but this creates a safety risk of separation during flight
Solution Approach 1:
The latch mechanism incorporates a self-aligning feature where the handle automatically guides the latch into the engaged position when closed. This self-service mechanism ensures that if the fan cowl is properly closed, the latch will engage itself, reducing the risk of human error while maintaining ease of operation. The high-visibility handle provides visual feedback to confirm engagement status.
Solution Approach 2:
The latch system provides visual feedback through the high-visibility handle position and a gap indicator that shows whether the latch is engaged or disengaged. This feedback mechanism ensures that personnel can quickly verify the latch status before takeoff, preventing the risk of flight with unlatched panels while keeping the operation simple.
3Difficulty of detecting and measuring
If the latch location is made accessible for visual inspection, then inspection ease is improved, but the structural design becomes more complex
Solution Approach 1:
The latch mechanism is segmented into distinct components: a visible handle, a latch body, and a gap indicator. This segmentation allows each component to perform its specific function independently - the handle provides visibility and manual operation, the latch body provides the latching function, and the gap indicator provides visual feedback. This modular approach maintains simplicity while improving accessibility for inspection.
Data Source
AI summary
A nacelle may include fan cowl panels which may be opened to provide access to the fan case. A latching mechanism may latch a left fan cowl panel to a right fan cowl panel. The latch may create a separation between the fan cowl panels when unlatched. A shoot pin latch may be aligned with a receiver cavity such that the shoot pin latch may be closed when the latching mechanism is closed. If the fan cowl panels are not fully closed, the shoot pin latch may be prevented from closing, and a high visibility handle may indicate that the fan cowl panels are not latched together.