Aircraft Propeller Thrust Reversal Synchronization Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current aircraft propeller control systems rely on pilot skills for thrust reversal, leading to human errors, asymmetries, and increased pilot workload, compromising safety and comfort during landing and taxing due to potential engine/propeller response delays or malfunctions.

Innovation Solution

Implementing a method to automatically synchronize the transition of propeller pitch to reverse thrust in opposite power plants, using a flight control system to check readiness conditions and disable reverse thrust if any power plant fails, ensuring simultaneous transition and preventing thrust asymmetry.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If automatic synchronization control is implemented, then thrust asymmetry is prevented and safety is improved, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flight control system continuously monitors the operational status of each power plant and propeller, comparing actual performance against commanded parameters. When asymmetry is detected or readiness conditions are unequal, the system provides feedback to prevent simultaneous reverse thrust transition, ensuring safety through active monitoring and correction

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The flight control system acts as an intermediary between the pilot's reverse thrust command and the actual propeller control systems. It receives the command, evaluates readiness conditions for each power plant, and only permits simultaneous transition when both are ready, thereby preventing thrust asymmetry without requiring direct pilot coordination

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If pilot monitoring and manual coordination is used, then pilot skills are utilized, but human errors and workload increase

Engineering Contradiction:
Improvepilot workloadVSAvoidhuman errors
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system enables self-service operation where the aircraft's flight control system automatically performs the coordination task that would otherwise require pilot attention. The system monitors its own power plant status and makes autonomous decisions about reverse thrust transition timing, freeing the pilot from monitoring duties while eliminating human error potential

Inventive Principle:
Principle #25Self-service

3Speed

If thrust reversal is allowed without synchronization check, then response time is reduced, but thrust asymmetry and yaw moments are generated

Engineering Contradiction:
Improveresponse timeVSAvoidyaw moments
Core Design Contradiction:
SpeedVSObject-generated harmful factors

Solution Approach 1:

The flight control system performs preliminary evaluation of readiness conditions for each power plant before executing the reverse thrust transition. By checking engine speed, propeller RPM, and control system status in advance, the system ensures both power plants are ready simultaneously, preventing yaw moments while maintaining rapid response capability when conditions are met

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3018054B1Method for controlling an aircraft propeller system during thrust reversal
Publication Date: 2019.01.02 AIRBUS DEFENCE & SPACE SAU
  • EP3018054B1 patent drawingFigure 1A~2
  • EP3018054B1 patent drawingFigure 3A~4B

AI summary

The present invention refers to a method for controlling an aircraft propeller system during thrust reversal, wherein it is checked whether each power plant is ready for the transition to negative pitch, and where the propeller transition to negative pitch is controlled from a flight control system such that, only when both power plants are ready for the transition to negative pitch, the flight control system instructs the aircraft propeller system to reverse thrust. If a power plant failure is detected before a thrust reverse order is received, then the flight control system is informed of that failure condition, and then the flight control system will disable the thrust reverse operation as long as the failure condition remains. The method of the invention improves the aircraft controllability during landing operations, reduce pilots workload, and to improve passengers comfort during landing and taxing.