Electronically Geared Elevator Pitch Control for Lighter Stabilizers

Solution Overview

Problem

Conventional horizontal stabilizers in aircraft are large and heavy due to the need for mechanical gearing, which increases drag and weight, limiting their effectiveness and flexibility in adjusting pitch control.

Innovation Solution

An aircraft pitch control system utilizing electronically geared elevators, where the movement of the horizontal stabilizer is synchronized with the elevator through electronic gearing, allowing for reduced size and weight, and enabling flexible gearing relationships based on operating conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If conventional mechanical gearing is used to coordinate stabilizer and elevator movement, then pitch control functionality is achieved, but the stabilizer size and weight increase

Engineering Contradiction:

Improvestabilizer weightVSAvoidmechanical gearing complexity

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent replaces mechanical gearing with an electronic control system that uses sensors to detect stabilizer position and actuators to coordinate elevator movement. This substitution eliminates the need for complex mechanical gear trains, directly reducing the weight and complexity of the pitch control system while maintaining the required coordination between stabilizer and elevator movements

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The pitch control system is divided into independent functional modules: position sensors for detecting stabilizer angle, electronic control units for processing position data, and separate actuators for moving the stabilizer and elevator. This segmentation allows each component to be optimized independently and eliminates the need for integrated mechanical gearing, reducing overall system weight and complexity

Inventive Principle:

Principle #1Segmentation

2Force

If a large horizontal stabilizer is used to produce desired aerodynamic effect, then pitch control effectiveness is improved, but drag and aircraft weight increase

Engineering Contradiction:

Improveaerodynamic forceVSAvoiddrag

Core Design Contradiction:

ForceVSObject-generated harmful factors

Solution Approach 1:

The patent implements a dynamic pitch control system where the elevator can actively adjust its position in response to stabilizer movements. This dynamic coordination allows the system to achieve the same aerodynamic effect with a smaller stabilizer by optimizing the interaction between the stabilizer and elevator surfaces, thereby reducing drag while maintaining pitch control effectiveness

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the pitch control by introducing electronic coordination between stabilizer and elevator. By controlling the elevator position as a function of stabilizer position through electronic signals rather than fixed mechanical gearing, the system can achieve more efficient aerodynamic performance with reduced stabilizer size, lowering drag

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If mechanically geared elevators are used, then coordinated movement is achieved, but flexibility in adjusting gearing relationships is limited

Engineering Contradiction:

Improvegearing relationship flexibilityVSAvoidmechanical constraints

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a dynamic pitch control system where the elevator can actively adjust its position in response to stabilizer movements. This dynamic coordination allows the system to achieve the same aerodynamic effect with a smaller stabilizer by optimizing the interaction between the stabilizer and elevator surfaces, thereby reducing drag while maintaining pitch control effectiveness

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the pitch control by introducing electronic coordination between stabilizer and elevator. By controlling the elevator position as a function of stabilizer position through electronic signals rather than fixed mechanical gearing, the system can achieve more efficient aerodynamic performance with reduced stabilizer size, lowering drag

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12409929B2Aircraft pitch control system with electronically geared elevator

Publication Date: 2025.09.09 BOMBARDIER INC

AI summary

Aircraft pitch control systems and methods are disclosed. In one exemplary embodiment, an aircraft pitch control system comprises a movable horizontal stabilizer and an elevator movably coupled to the horizontal stabilizer. The elevator is electronically geared to the horizontal stabilizer.