Flight Control Actuation Skew Detection via Deflector Biasing
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Solution Overview
Problem
Existing aircraft flight control surface actuation systems lack effective methods to detect faults or impairments before flight, particularly in redundant load path systems, where a failure in one actuator may not be promptly identifiable due to redundancy and external air-loads.
Innovation Solution
An actuation system with a detection device that includes a deflector and sensors to detect any deflection or skewing of the support frame, utilizing a biasing member to generate a force counter to the actuation mechanism's movement, ensuring fault detection even when the aircraft is on the ground without relying on air-loads, and integrating with existing skew detection systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple actuators are provided for redundant load path support, then reliability is improved, but fault detectability deteriorates
Solution Approach 1:
The support frame is segmented into multiple independent sections, each associated with a specific actuator. This segmentation allows the deflector to isolate and detect faults in individual actuators even when multiple actuators are operating, resolving the contradiction between redundancy and fault detectability.
Solution Approach 2:
A deflector is introduced as an intermediary element between the actuators and the support frame. The deflector translates actuator faults into detectable deflections of the support frame, enabling fault detection without compromising the redundant actuator configuration.
2Difficulty of detecting and measuring
If fault detection relies on air-loads acting on the flight control surface, then detection capability is improved, but detection availability deteriorates
Solution Approach 1:
The deflector is pre-configured to generate detectable deflections of the support frame in response to actuator faults, regardless of whether air-loads are present. This preliminary action ensures that fault detection capability is available both during flight and on the ground, resolving the contradiction between detection capability and detection availability.
3Strength
If the support frame is kept rigid and stable, then structural integrity is improved, but fault indication capability deteriorates
Solution Approach 1:
The support frame is divided into rigid segments connected by flexible joints or deflection zones. This segmentation maintains overall structural integrity while allowing localized deflections that indicate actuator faults, resolving the contradiction between strength and fault indication capability.
Solution Approach 2:
Different parts of the support frame have different mechanical properties: most sections are rigid for structural integrity, while specific sections incorporate deflectors or flexible joints that allow controlled deflections for fault indication. This local differentiation resolves the contradiction between strength and fault indication.
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
Enables prompt detection of actuation mechanism faults or impairments, ensuring safety by identifying deflections or skewing of the support frame, allowing for pre-flight identification and maintenance, even in the absence of external air-loads, thereby enhancing operational reliability and safety.
Implementation Method 1
the biasing member is resiliently deformable, e.g. elastically deformable
Data Source
AI summary
The present disclosure provides an actuation system for a flight control surface of an aircraft, having: a support frame for supporting a flight control surface, the support frame being configured to be mounted to an airframe structure of the aircraft for movement between a first position and a second position to operate and move the control surface; an actuation mechanism configured to effect movement of the support frame between the second position and the first position; and a detection device for detecting a fault in the actuation mechanism, the detection device comprising a deflector configured to deflect or skew the support frame away from or out of the first position in the event of a fault in the actuation mechanism.