Rotorcraft Autorotation Entry Assist for Low-Inertia Main Rotors
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Solution Overview
Problem
As rotorcraft become larger and more complex, the transition into autorotation after engine failure becomes challenging due to lighter main rotor blades with less inertia, requiring faster and more automated recognition and implementation of autorotation entry to ensure safe landing.
Innovation Solution
A fly-by-wire system that monitors engine failure and automatically adjusts the main rotor pitch and rotorcraft attitude to maintain a target RPM, engaging an autorotation entry assist process by generating commands to control flight characteristics, even if the pilot is not manually controlling the rotorcraft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If lighter main rotor blades are used to reduce weight, then weight is reduced, but inertia is reduced making autorotation entry more difficult
Solution Approach 1:
The system uses the rotorcraft's own sensors and flight control computer to automatically detect engine failure and execute autorotation entry commands, making the system self-rescue without requiring external assistance or perfect pilot reaction
Solution Approach 2:
The patent replaces manual pilot mechanical control with an automated fly-by-wire system that uses electronic sensors and computer-generated commands to control flight surfaces, enabling faster and more reliable autorotation entry
2Ease of operation
If manual pilot control is used during autorotation entry, then pilot judgment is utilized, but reaction time is insufficient for safe autorotation
Solution Approach 1:
The system continuously monitors engine parameters and prepares for autorotation entry in advance by having the flight control computer ready to immediately execute commands upon detecting engine failure, eliminating pilot reaction delay
Solution Approach 2:
The system uses sensors to continuously monitor engine operation and main rotor RPM, providing real-time feedback to the flight control computer which automatically adjusts flight controls to maintain target RPM during autorotation entry
3Productivity
If automated autorotation entry assist is implemented, then autorotation entry speed is improved, but system complexity increases
Solution Approach 1:
The flight control computer performs multiple functions including normal flight control, engine failure detection, and automated autorotation entry assistance, making the system multi-functional without adding separate dedicated hardware systems
Solution Approach 2:
The patent combines the autorotation entry assist functionality with the existing fly-by-wire flight control system, merging multiple functions into a single integrated system rather than adding separate independent systems
Data Source
AI summary
A rotorcraft including a main rotor, flight controls connected to the main rotor the main rotor, a plurality of engines connected to the main rotor and operable to drive the main rotor, a main rotor revolutions per minute (RPM) sensor, and a monitoring system operable to determine an engine failure of the plurality of engines. The monitoring system is further operable to engage an automated autorotation entry assist process in response to at least determining the engine failure and according to the measured main rotor RPM, where the automated autorotation entry assist process comprises the monitoring system generating one or more rotor RPM related commands according to at least a target main rotor RPM and the measured main rotor RPM, where the automated autorotation entry assist process further comprises controlling the one or more flight controls according to the one or more rotor RPM related commands.