Rotary Wing External Cargo Hook Direct Load Path

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional external cargo hook systems for VTOL rotary-wing aircraft either induce undesirable stresses on the airframe due to an indirect load path or require a large opening in the aircraft belly to accommodate swinging loads, compromising structural integrity and efficiency.

Innovation Solution

An external cargo hook system with a lower frame interface to accommodate longitudinal and lateral loads and an upper frame interface adjacent the main rotor system, utilizing a tension member to transfer tension loads directly through the aircraft cabin, minimizing airframe-induced loading and optimizing structural performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional belly mounted cargo hook system is used, then the cargo hook is located within a lower belly portion of the aircraft airframe, but the indirect load path parallelograms the frame and places undesirable stresses on the airframe

Engineering Contradiction:

Improvecargo hook locationVSAvoidairframe stress

Core Design Contradiction:

Ease of operationVSStress or pressure

Solution Approach 1:

The patent transitions from a conventional lower belly-mounted cargo hook to an upper portion cargo hook system, changing the spatial dimension of load application. This dimensional shift allows the load path to traverse directly through the airframe's upper structure to the main rotor system, avoiding the parallelogramming effect and undesirable stresses associated with lower belly mounting.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Stress or pressure

If a frame structure is located within an upper portion of the aircraft cabin, then a more direct load path is provided, but a relatively large opening in the airframe belly is required to accommodate pendant motion

Engineering Contradiction:

Improveairframe stressVSAvoidairframe opening

Core Design Contradiction:

Stress or pressureVSArea of stationary object

Solution Approach 1:

The patent employs a dynamic tension member system that can flex and move within the aircraft cabin to accommodate pendant motion during cargo operations. This dynamic capability allows the upper portion frame structure to provide a direct load path without requiring a large fixed opening in the airframe belly, as the tension member adapts its position to accommodate operational movements.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If a large opening is made in the airframe belly to accommodate pendant motion, then the opening can accommodate cargo operations, but structural integrity is compromised

Engineering Contradiction:

Improvecargo operation capabilityVSAvoidairframe structural integrity

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The patent introduces a tension member as an intermediary element that transmits loads between the upper portion frame structure and the main rotor system. This intermediary allows cargo operations to proceed with adequate adaptability while avoiding the need for large openings that would compromise airframe structural integrity, as the tension member can accommodate motion without requiring structural openings.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS8636250B2External cargo hook system for rotary-wing aircraft

Publication Date: 2014.01.28 SIKORSKY AIRCRAFT CORP

AI summary

An external hook system for a rotary-wing aircraft includes a lower frame interface which accommodates longitudinal and lateral loads and an upper frame interface. A tension member is mountable between the lower frame interface and the upper frame interface to transfer tension loads between the lower frame interface and the upper frame interface.