Propeller Feathering Torque Test During Aircraft Ground Phases

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Solution Overview

Problem

Existing propeller feather testing is manually conducted, which is inefficient and prone to false positives, and there is a need for improved automation and reliability in testing propeller feather functions.

Innovation Solution

An automated propeller feather testing system that monitors torque applied to a rotor shaft assembly, commands an angle change of propeller blades, compares post-angle change torque to an expected torque, and issues a pass/fail signal based on a threshold difference, allowing testing during aircraft ground phases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If manual propeller feather testing is conducted by pilot, then the test can be performed, but the testing efficiency is low and false positives occur

Engineering Contradiction:
Improvetesting efficiencyVSAvoidtest accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces manual mechanical testing operations with an automated electronic control system. The processor automatically commands propeller feathering based on trigger signals, monitors torque changes via sensors, and determines test results without manual intervention, thereby improving both efficiency and reliability

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

Solution Approach 2:

The system performs self-testing by automatically initiating feathering commands in response to trigger signals, monitoring its own torque changes, and evaluating test results without requiring external manual operation. The processor autonomously completes the entire testing sequence

Inventive Principle:
Principle #25Self-service

2Productivity

If automated testing is implemented, then testing efficiency improves, but system complexity increases

Engineering Contradiction:
Improvetesting efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The processor leverages existing multi-functional aircraft systems (torque sensors, propeller control mechanisms, flight data processors) to perform automated feathering tests, rather than introducing dedicated separate testing equipment. This approach maintains testing automation benefits while minimizing additional system complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the feathering control function and test evaluation function into a single integrated processor system. The same processor that controls propeller feathering also monitors torque changes and determines test pass/fail outcomes, merging multiple functions into one system

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4480813B1Automated propeller feathering test
Publication Date: 2025.12.17 PRATT & WHITNEY CANADA CORP
  • EP4480813B1 patent drawingFigure 1
  • EP4480813B1 patent drawingFigure 2A
  • EP4480813B1 patent drawingFigure 2B

AI summary

There is described herein systems and method for testing a propeller feathering function, including monitoring over time a torque applied to a rotor shaft assembly (24) operatively connected to a propeller (30) of an aircraft, commanding an angle change of propeller blades of the propeller (30) in response to receipt of a trigger signal generated upon initiation of a task or procedure performed within the aircraft, comparing, in response to the angle change being commanded, a post-angle change torque applied to the rotor shaft assembly (24) to an expected torque without the commanded angle change and obtaining a torque difference, and issuing a test passed signal when the torque difference exceeds a threshold and a test failed signal when the torque difference does not exceed the threshold.