Aircraft Reverse Thrust Rating for Variable Landing Deceleration

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Solution Overview

Problem

Existing aircraft powerplants provide a predetermined amount of reverse thrust during landing, regardless of the actual need, which can lead to inefficiencies in deceleration and potential discomfort for passengers.

Innovation Solution

A method and system for controlling reverse thrust in aircraft powerplants by determining a reverse thrust rating based on various aircraft and powerplant parameters, such as speed, weight, runway length, and deceleration rate, to adjust propeller speed, blade angle, and engine torque, allowing for customized thrust levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a predetermined amount of reverse thrust is provided at maximum reverse thrust position, then the aircraft can be slowed down effectively, but the deceleration efficiency is reduced and passenger comfort deteriorates when the predetermined thrust exceeds the actual need

Engineering Contradiction:
Improvedeceleration efficiencyVSAvoidpassenger comfort
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent implements dynamic reverse thrust control by transitioning from a fixed predetermined thrust level to a variable thrust system that automatically adjusts based on real-time aircraft parameters (speed, weight, runway length, deceleration rate). The control system continuously monitors these parameters and modifies the reverse thrust output to match actual deceleration needs, thereby improving both deceleration efficiency and passenger comfort.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the thrust parameter from a static predetermined value to a dynamic value that varies according to aircraft operating conditions. By calculating the required reverse thrust as a function of multiple parameters (aircraft speed, weight, runway length, deceleration rate), the system optimizes thrust delivery to match actual requirements, avoiding both excessive and insufficient thrust scenarios.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If a predetermined amount of reverse thrust is provided irrespective of actual need, then the control system is simple to operate, but the system lacks adaptability to different landing conditions

Engineering Contradiction:
Improvecontrol simplicityVSAvoidadaptability to different landing conditions
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The control system performs self-adjustment by automatically calculating and modifying reverse thrust levels based on sensed aircraft parameters without requiring manual pilot intervention. The system monitors its own operating conditions and autonomously optimizes thrust delivery, combining operational simplicity with environmental adaptability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system incorporates feedback mechanisms by continuously monitoring aircraft parameters (speed, weight, runway length, deceleration rate) and using this information to adjust reverse thrust output. This closed-loop control enables the system to adapt to different landing conditions while maintaining ease of operation through automated decision-making.

Inventive Principle:
Principle #23Feedback

3Reliability

If maximum reverse thrust is applied to ensure sufficient deceleration capability, then the deceleration margin is adequate, but engine and aircraft wear increases due to excessive thrust application

Engineering Contradiction:
Improvedeceleration marginVSAvoidengine and aircraft wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system applies the principle of partial action by delivering only the necessary portion of reverse thrust required for safe deceleration rather than consistently applying maximum thrust. By calculating the precise thrust needed based on current aircraft parameters, the system avoids excessive thrust application and its associated wear while maintaining adequate deceleration margins.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3741665B1Method and system for operating an aircraft powerplant
Publication Date: 2025.12.24 PRATT & WHITNEY CANADA CORP
  • EP3741665B1 patent drawingFigure 1
  • EP3741665B1 patent drawingFigure 2
  • EP3741665B1 patent drawingFigure 3

AI summary

In methods (300) and systems (200) for operating an aircraft powerplant (100), one or more powerplant or aircraft parameters indicative of one or more conditions at landing or during an approach to landing are obtained. A reverse thrust rating is determined based on the one or more powerplant or aircraft parameters. Reverse thrust of the powerplant (100) is controlled based on the reverse thrust rating when reverse thrust is requested.