Aircraft Engine Mounting via Segmented Thrust Reverser

Solution Overview

Problem

Conventional turbofan propulsion systems with inner fixed structures present challenges in accessing attachment features for ground support equipment during engine installation and removal, as the thrust reverser design does not easily expose these features, hindering efficient engine handling and maintenance.

Innovation Solution

The method involves a nacelle design with separate bifurcation panels and movable portions that hinge independently, allowing for the use of standard ground support equipment to attach to the IFS support, enabling easy access and handling of the engine by coupling hoists and cables to the IFS support's attachment features, even when the thrust reverser is open.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the thrust reverser is designed with an inner fixed structure that does not hinge open with the translating sleeve, then the structural integrity and aerodynamic performance are improved, but the accessibility to attachment features on the engine case deteriorates

Engineering Contradiction:

Improvestructural integrityVSAvoidaccessibility to attachment features

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The thrust reverser is divided into separate components: the translating sleeve that hinged open and the inner fixed structure that remains stationary. This segmentation allows the translating sleeve to provide access to attachment features while the inner fixed structure maintains structural integrity and aerodynamic performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The inner fixed structure serves as an intermediary element that provides attachment features for ground support equipment while maintaining the aerodynamic envelope. It acts as a mediator between the need for structural integrity and the need for accessibility during engine installation and removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the translating sleeve and inner fixed structure are connected and hinge open together, then the accessibility to attachment features is improved, but the structural complexity and aerodynamic performance deteriorate

Engineering Contradiction:

Improveaccessibility to attachment featuresVSAvoidstructural complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The thrust reverser is divided into separate components: the translating sleeve that hinged open and the inner fixed structure that remains stationary. This segmentation allows the translating sleeve to provide access to attachment features while the inner fixed structure maintains structural integrity and aerodynamic performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of having the inner fixed structure hinge open with the translating sleeve, the design inverts the approach by keeping the inner fixed structure stationary and allowing only the translating sleeve to hinge open. This provides access to attachment features while maintaining structural integrity.

Inventive Principle:

Principle #13The other way round (Inversion)

3Productivity

If attachment features are provided on the engine case, then the ease of engine installation and removal is improved, but the difficulty of accessing these features during maintenance deteriorates

Engineering Contradiction:

Improveengine installation and removal efficiencyVSAvoidaccessibility during maintenance

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

Attachment features are provided on the inner fixed structure rather than the engine case, allowing ground support equipment to be attached in advance before the engine is installed. This preliminary attachment enables efficient engine installation and removal while maintaining accessibility during maintenance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The inner fixed structure serves as an intermediary element that provides attachment features for ground support equipment while maintaining the aerodynamic envelope. It acts as a mediator between the need for structural integrity and the need for accessibility during engine installation and removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP3696095B1Installing or removing aircraft engines

Publication Date: 2022.03.16 ROHR INC

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AI summary

A method (400) for removing an engine (200, 300) from a pylon (240, 340), wherein a forward engine mount (382) of said engine (300) is attached to a forward pylon mount (384) of said pylon (240, 340) and an aft engine mount (382) of said engine is attached to an aft pylon mount (430) of said pylon (240, 340), the method comprising: coupling a forward hoist (362) and an aft hoist (364) to said pylon (240, 340, 410); coupling one or more forward cables (366) to said forward hoist (362) and to forward attachment features (239) on an inner fixed structure (IFS) support (231, 331, 420) of said engine (300);detaching said forward engine mount (382) from said forward pylon mount (384) and detaching said aft engine mount (382) from said aft pylon mount (430), lowering said engine onto a trolley (440); separating said cables from said attachment features on said IFS support; and transporting said engine (300) on said trolley (450).