Synchronized Reverse Thrust Control for Multi-Engine Propeller Aircraft

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Solution Overview

Problem

Multi-engine propeller aircraft experience undesirable behaviors like yawing due to unsynchronized transition from forward to reverse thrust, which is complex and prone to pilot error in traditional methods.

Innovation Solution

A system with first and second engine controllers that communicate to ensure synchronized blade angle transitions for propellers, commanding reverse thrust only when both propellers' angles are beyond a predetermined threshold, eliminating the need for central arbitration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional pilot coordination methods are used for transitioning propeller blade angles, then reverse thrust can be produced, but the system is complex and prone to pilot error leading to unsynchronized transition

Engineering Contradiction:
Improvesynchronization of reverse thrust transitionVSAvoidcomplexity of control coordination
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each engine controller independently determines its own propeller blade angle and monitors the other engine's status, eliminating the need for external coordination. The controllers autonomously evaluate whether reverse thrust should be produced based on local conditions and communicated blade angle data, making the system self-regulating and reducing coordination complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The engine controllers exchange blade angle information and use this feedback to determine when reverse thrust conditions are met. Each controller continuously monitors the other's blade angle status and adjusts its own reverse thrust production accordingly, ensuring synchronized transition through continuous information feedback

Inventive Principle:
Principle #23Feedback

2Productivity

If unsynchronized propeller blade angle transitions occur, then reverse thrust production begins, but yawing and other undesirable behaviors result

Engineering Contradiction:
Improvereverse thrust production capabilityVSAvoidyawing and undesirable aircraft behaviors
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The engine controllers first exchange blade angle information and evaluate whether the predetermined conditions for reverse thrust are met before actually commanding reverse thrust production. This preliminary verification ensures that both propellers are ready for synchronized transition, preventing yawing caused by unsynchronized blade angle changes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system prevents harmful yawing behavior by proactively ensuring synchronized blade angle transitions before reverse thrust begins. The controllers verify blade angle synchronization in advance and only permit reverse thrust when both propellers are properly aligned, thereby counteracting the potential for undesirable aircraft behaviors before they can occur

Inventive Principle:
Principle #9Preliminary anti-action

Data Source

PatentEP4101769B1Reverse thrust in multi-engine propeller aircraft
Publication Date: 2024.04.10 PRATT & WHITNEY CANADA CORP
  • EP4101769B1 patent drawingFigure 1
  • EP4101769B1 patent drawingFigure 2A
  • EP4101769B1 patent drawingFigure 2B

AI summary

Herein provided are methods and systems for producing reverse thrust in a multi-engine propeller aircraft (100), comprising: obtaining, at a first engine controller (222) of a first engine (212) of the aircraft (100), a first power request for the first engine (212) for producing reverse thrust; determining, at the first engine controller (222), a first blade angle for a first propeller (214) coupled to the first engine (212); obtaining, at the first engine controller (222) and from a second engine controller (272) of a second engine (262) of the aircraft (100), a second power request for the second engine (262) and a second blade angle for a second propeller (264) coupled to the second engine (262); and when the second power request is indicative of a request for producing reverse thrust and when the first and second blade angles are beyond a predetermined threshold, commanding, via the first engine controller (222), the first engine (212) to produce reverse thrust based on the first power request.