Aircraft Inflatable Float for Rotor Water Landing Protection

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Solution Overview

Problem

Aircraft rotating elements, such as propellers and tail rotors, face challenges during water landings as they risk coming into contact with the liquid surface, potentially causing damage and instability, and existing buoyancy systems do not adequately protect these components.

Innovation Solution

The aircraft is equipped with a buoyancy system featuring an emergency inflatable float that surrounds the rotating elements, deploying in an inflated position to prevent contact with the liquid surface, while allowing the blades to remain operational for anti-torque functions and enhancing stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rotating element is positioned to perform anti-torque function during landing, then the aircraft can maintain stability and control, but the rotating element risks coming into contact with the liquid surface causing damage

Engineering Contradiction:
Improverotating element protectionVSAvoidcontact with liquid surface
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a float as an intermediary protective element between the rotating element and the liquid surface. The float is positioned to surround at least a portion of the rotating element and makes contact with the liquid surface first, preventing direct contact between the rotating element blades and the water, thus resolving the contradiction between maintaining operational position and avoiding damage.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The float is deployed in advance before the rotating element would contact the liquid surface. The float is positioned and configured to extend below the rotating element, creating a protective barrier that activates before any potential contact occurs, allowing the rotating element to maintain its anti-torque function without risk of water contact.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the float is deployed to protect the rotating element, then contact with liquid surface is prevented, but the float may be caught and torn by the rotating blades

Engineering Contradiction:
Improverotating element protectionVSAvoidfloat structural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The float is designed with non-uniform thickness, having a greater thickness at the front portion (facing the direction of rotation) and a smaller thickness at the rear portion. This local quality variation allows the front, thicker portion to withstand the impact and shear forces from the rotating blades, while the rear portion provides buoyancy. The differential thickness distribution optimizes both protection capability and structural resistance to blade contact forces.

Inventive Principle:
Principle #3Local quality

3Stability of the object's composition

If the float surrounds the rotating element, then stability on liquid surface is improved, but the device complexity increases

Engineering Contradiction:
Improveaircraft stability on waterVSAvoidbuoyancy system structure
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The float is constructed as a flexible, collapsible structure that can be stored in a compact state during flight and deployed when needed. The float comprises a flexible material shell that can be inflated or expanded to provide buoyancy and protection. This flexible shell design provides the necessary stability and protective function while maintaining a compact, simple storage configuration, thus improving stability without permanently increasing device complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents contact between rotating elements and the liquid surface, reducing the risk of damage and improving the aircraft's stability on water, while maintaining the functionality of the blades and power transmission chain.

Implementation Method 1

a buoyancy system including an inflatable float arranged in the fairing to avoid interference between a liquid surface and the blades during a water landing

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Implementation Method 2

the float improves the stability of the aircraft on the liquid surface

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP2586705B1Aircraft equipped with a buoyancy system of a rotating element
Publication Date: 2014.04.16 EUROCOPTER FRANCE SA
  • EP2586705B1 patent drawingFigure 1~2
  • EP2586705B1 patent drawingFigure 3~4
  • EP2586705B1 patent drawingFigure 5~7

AI summary

The aircraft (1) has a rotating element (10) provided with blades (11) that come into contact with a liquid surface during sea landing. A shroud (15) partially surrounds the rotating element and comprises a float (20) that is inflatable by a buoyancy system to prevent the blades from making contact with the liquid surface in an inflated position. The shroud comprises a lower portion (16) that faces ground when the aircraft rests on the ground. An inflation unit (50) deploys the float into an inflated position before a landing position. The rotating element is designed as a standard rotor or a propeller.