Aircraft Takeoff Trim Indication via Equivalent CG

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Solution Overview

Problem

Current systems for setting aircraft takeoff trim position are complex and prone to miscalculations, especially in large aircraft where multiple parameters are involved, often leading to errors that are only detected in extreme conditions, which can compromise safety and agility, particularly in military operations.

Innovation Solution

An automatic fly-by-wire pitch trim system that uses a flight control module to calculate and display the equivalent center of gravity (CG) trim position based on inputted takeoff trim settings, allowing pilots to easily verify the correctness of trim adjustments by comparing calculated and actual CG positions, and providing real-time feedback to correct errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If automatic fly-by-wire pitch trim system with flight control module calculation is implemented, then calculation accuracy and error detection capability are improved, but device complexity increases

Engineering Contradiction:
Improvetrim position calculation accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The flight control module automatically calculates the equivalent CG trim position using existing flight parameters (actual CG, flap position, slat position) without requiring additional manual input from pilots. The system self-verify by comparing calculated trim position with pilot-inputted trim position, automatically detecting discrepancies and alerting pilots to potential errors.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical trim adjustment verification with an automated electronic calculation and comparison system. The flight control module computes the equivalent CG trim position based on flight parameters and compares it with the pilot's inputted trim position, substituting manual verification processes with automated electronic validation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If multi-parameter trim settings are converted to CG-based equivalence, then ease of operation is improved, but loss of information may occur

Engineering Contradiction:
Improvetrim adjustment simplicityVSAvoidoriginal parameter data
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent introduces an equivalent CG trim position as an intermediary representation that bridges the pilot's simple trim input and the complex multi-parameter flight conditions. This intermediary value allows pilots to work with a single intuitive parameter (CG position) while the system maintains awareness of all original parameters (flap position, slat position, actual CG) for verification purposes.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system provides feedback by comparing the calculated equivalent CG trim position with the pilot's inputted trim position. If discrepancies are detected, the system alerts the pilot to potential errors. This feedback mechanism ensures that information is not lost but rather validated, maintaining data integrity while simplifying the user interface.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3441739B1Enhanced take-off trim indication
Publication Date: 2021.03.31 EMBRAER SA
  • EP3441739B1 patent drawingFigure 1
  • EP3441739B1 patent drawingFigure 2~3
  • EP3441739B1 patent drawingFigure 4

AI summary

A method converts an aircraft takeoff trim setting that would be a function of several parameters to a value that is a function of CG position only. In this way, it is possible to create a direct simple equivalence between Stabilizer angle and CG. The equivalent CG can be presented in real time to the pilot,