Aircraft VNAV Descent Re-Engagement Using Calculated Intercept Parameters
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Solution Overview
Problem
Aircrafts face inefficiencies in manually controlling descent profiles, leading to fuel wastage and delays due to deviations from preplanned paths, as aircrews struggle to adjust altitude and speed to re-engage the ideal descent profile without violating restrictions.
Innovation Solution
A method and system for engaging a vertical navigation descent (VNAV/DES) mode in a flight management system (FMS) that retrieves a preset VNAV profile, calculates intercept parameters based on current flight path angle and vertical speed, and displays these parameters to aircrew for acceptance, allowing the aircraft to automatically intercept the desired descent path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If manual control is used to adjust descent profile, then aircrew can make real-time adjustments to meet the profile, but fuel efficiency decreases and delays occur due to deviations from preplanned paths
Solution Approach 1:
The system pre-calculates and stores optimal descent profiles including altitude, speed, and path parameters before the descent phase. This preliminary preparation allows the aircraft to follow an efficient predetermined path without requiring manual adjustments, thereby reducing fuel consumption while maintaining operational flexibility.
Solution Approach 2:
The system continuously monitors actual flight parameters (altitude, speed, position) and compares them with the preplanned descent profile. When deviations are detected, the system provides feedback to guide the aircrew back onto the optimal path, ensuring fuel efficiency is maintained while allowing necessary manual corrections.
2Adaptability or versatility
If manual control is used to adjust descent profile, then aircrew can respond to changing conditions, but delays occur due to difficulty in re-engaging the ideal descent profile
Solution Approach 1:
The system provides continuous feedback on descent status, comparing actual position with the ideal profile. This real-time information allows aircrew to quickly understand deviations and make precise corrections, reducing the time needed to re-engage the optimal descent path while maintaining adaptability to changing conditions.
Solution Approach 2:
The descent profile and correction parameters are pre-calculated and stored in the system. When deviations occur, the system already has the optimal correction path ready, eliminating the time required for manual recalculation and enabling rapid re-engagement with the ideal descent profile.
3Loss of energy
If automated VNAV/DES mode is engaged, then fuel efficiency improves and delays are reduced, but system complexity increases requiring calculation of intercept parameters
Solution Approach 1:
The system automatically calculates intercept parameters, determines optimal descent paths, and guides the aircraft without requiring complex manual computations by the aircrew. The automation handles the complex calculations internally, reducing fuel consumption and delays while the interface remains relatively simple for the user.
4Productivity
If automated VNAV/DES mode is engaged, then operational efficiency improves, but ease of operation decreases requiring acceptance of calculated intercept parameters
Solution Approach 1:
The system pre-calculates intercept parameters and descent profiles before they are needed, so that when the aircrew needs to engage VNAV/DES mode, the parameters are already ready for acceptance. This eliminates the need for complex real-time calculations and maintains ease of operation while improving productivity.
Data Source
AI summary
Methods and systems are provided for engaging a vertical navigational descent (VNAV/DES) mode of a flight management system (FMS) for an aircraft. The method comprises retrieving a preset vertical navigation (VNAV) profile for a descent path of the aircraft that is stored in the FMS. The current flight path angle (FPA) and vertical speed (VS) of the aircraft is determined and intercept parameters are calculated to intercept the preset VNAV profile with the VNAV/DES mode of the FMS. The intercept parameters are calculated based on the current FPA and VS and displayed to an aircrew member of the aircraft on a visual display device. The aircrew member is allowed to accept the intercept parameters with the VNAV/DES mode of the FMS.