Aircraft Flight Guidance Mode Switching for Engine-Out Airspeed Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During take-off and go-around maneuvers, aircraft airspeed decay below safe operating values occurs when a single engine failure happens while in altitude capture vertical guidance mode, posing a critical safety issue due to the inability to control airspeed through thrust, especially in integrated Automatic Flight Control Systems where pilot intervention is not feasible.
Innovation Solution
A computer-implemented method and system that transitions the aircraft from altitude capture mode to a flight level change mode, automatically maintaining airspeed at target values by adjusting pitch, thereby preventing airspeed decay, even when a single engine fails, by using a processing unit and memory with executable program instructions to detect engine inoperative conditions and adjust vertical flight guidance accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If the flight guidance system switches early from takeoff mode to altitude capture mode to achieve target altitude, then the time to reach target altitude is reduced, but airspeed decay below safe operating values occurs when single engine failure happens
Solution Approach 1:
The system dynamically transitions from altitude capture mode to flight level change mode based on detected engine failure conditions. This dynamic mode switching allows the system to adapt its control strategy - using thrust-based airspeed control in normal conditions and pitch-based airspeed control in engine failure conditions - thereby resolving the contradiction between rapid altitude capture and airspeed safety protection
Solution Approach 2:
The system changes the control parameter from thrust (in altitude capture mode) to pitch attitude (in flight level change mode) when engine failure is detected. This parameter change enables airspeed control through pitch adjustments instead of thrust, preventing airspeed decay while maintaining the ability to reach target altitude, thus resolving the safety-time contradiction
2Reliability
If pilot intervention is required to prevent airspeed decay during engine failure, then airspeed safety can be maintained, but crew workload and operational complexity increase
Solution Approach 1:
The flight guidance system automatically detects engine failure conditions and self-corrects by transitioning to flight level change mode and controlling airspeed through pitch commands. This self-service capability eliminates the need for pilot intervention during critical engine failure scenarios, maintaining airspeed safety while reducing crew workload to acceptable levels
Solution Approach 2:
The system continuously monitors engine operating parameters and provides feedback to detect inoperative conditions. This feedback mechanism triggers automatic mode transition and pitch-based airspeed control, ensuring safety without requiring continuous pilot monitoring or intervention, thereby resolving the contradiction between safety and ease of operation
3Extent of automation
If integrated Automatic Flight Control System is used, then automation level is improved, but the system cannot provide airspeed protection during engine failure in altitude capture mode
Solution Approach 1:
The integrated AFCS dynamically adjusts its control strategy based on flight conditions and engine status. By implementing conditional mode transitions from altitude capture to flight level change mode, the system maintains high automation while adding the capability to provide airspeed protection during engine failure, resolving the contradiction between automation level and protection capability
Solution Approach 2:
The flight guidance system is designed to perform multiple functions: normal altitude capture, engine failure detection, and pitch-based airspeed control. This multi-functionality allows the integrated AFCS to maintain high automation while providing comprehensive airspeed protection across different failure scenarios, resolving the contradiction between automation and reliability
Data Source
AI summary
Methods and systems for providing vertical flight guidance for an aircraft. Vertical flight guidance for the aircraft is provided by an aircraft computer in an altitude capture mode for commanding the aircraft to capture a target altitude. At least one engine inoperative condition is detected by the computer, while in the altitude capture mode. In response to detecting the at least one engine inoperative condition, the computer causes an automatic transition (e.g., no pilot action on a flight level change (FLC) pushbutton on a flight control panel) of the vertical flight guidance for the aircraft from the altitude capture mode to an already existing mode that is flight level change with modified control parameters and provides vertical flight guidance in the flight level change mode for commanding the aircraft to capture the target altitude while maintaining airspeed of the aircraft substantially at a target airspeed.