Aircraft Engine Control Computer In-Flight Latch Logic

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Aircraft engine control systems face restrictions in mode change due to unintended latching when an engine is restarted in flight, leading to inefficient fuel consumption and thrust imbalance between engines.

Innovation Solution

The engine control computer includes a latch operating section that determines whether the aircraft is on the ground or in flight, preventing latching during flight and updating the reference altitude to ease mode change restrictions, allowing for appropriate mode selection and thrust balance between engines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the reference altitude is updated to an altitude in the air when the engine is restarted in flight, then the latch is activated at a predetermined timing, but the mode change is restricted until a predetermined altitude difference is secured with respect to the altitude in the air, leading to unintended latching

Engineering Contradiction:

Improvelatch activation reliabilityVSAvoidmode change flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The in-parking/in-flight determining section performs preliminary determination of the aircraft state before the latch operating section activates the latch. By detecting whether the aircraft is in flight or on the ground in advance, the system prevents the harmful effect of unintended latching during flight, allowing reliable latch activation only when appropriate (on the ground).

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The in-parking/in-flight determining section acts as an intermediary between the engine restart detection and the latch activation. It mediates the latch operation by conditionally allowing or blocking the latch based on the aircraft state, thus resolving the contradiction between reliable latch activation and mode change flexibility.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the latch is activated during flight after engine restart, then the latch remains active until a predetermined altitude difference is secured, but fuel is uselessly consumed and the change to appropriate mode is restricted

Engineering Contradiction:

Improvetakeoff stabilityVSAvoidfuel consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary determination of the aircraft state (in-flight or on-ground) before activating the latch. By preventing latch activation during flight, the system avoids the harmful effects of unnecessary fuel consumption and restricted mode changes, while maintaining reliable latch functionality during actual takeoff operations on the ground.

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

Instead of activating the latch whenever the engine is restarted regardless of aircraft state, the system inverts the logic by activating the latch only when the aircraft is determined to be on the ground. This inversion prevents harmful latch activation during flight while preserving the beneficial latch function during takeoff.

Inventive Principle:

Principle #13The other way round (Inversion)

3Ease of operation

If the latch operates without determining aircraft state, then the mode is latched into Take off mode during takeoff until predetermined altitude is secured, but the same latching mechanism causes unintended restrictions when engine is restarted in flight

Engineering Contradiction:

Improveautomatic mode controlVSAvoidmode selection freedom

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The latch operating characteristics are made dynamic by conditioning the latch activation on the aircraft state determined by the in-parking/in-flight determining section. The latch function adapts its behavior based on whether the aircraft is in flight or on the ground, providing automatic mode control during takeoff while preventing unintended restrictions during in-flight engine restarts.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the in-parking/in-flight determining section to control the latch operating section. The determination result feeds back to enable or disable latch activation, creating a closed-loop control system that automatically adjusts latch behavior based on aircraft state, thus resolving the contradiction between ease of operation and mode selection freedom.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS10081438B2Engine control computer of aircraft, and aircraft

Publication Date: 2018.09.25 MITSUBISHI AIRCRAFT

AI summary

The invention deals with the restriction on the mode change of an engine due to latching in the case of restarting the engine that has stopped in flight. A FADEC that controls an engine of an aircraft in accordance with a mode, includes a latch operating section that latches the mode, and an in-parking/in-flight determining section that determines whether the aircraft is on the ground or flying off the ground. The latch operating section operates when the in-parking/in-flight determining section determines the aircraft is on the ground, and does not operate when the in-parking/in-flight determining section determines that the aircraft is in fight.