Rear-Mounted Engine Aircraft Tail Plane Airflow Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft with rear-mounted engines face inefficiencies in control surface performance and increased drag during take-off and landing, particularly when engines are mounted at the back, leading to potential ground impact risks.
Innovation Solution
The configuration of mounting engines on top of the horizontal tail plane, with an inner fixed part and two outer movable parts, allows both to be partially subjected to engine airflow, enhancing control surface efficiency and reducing drag by utilizing the airflow for trimming and minimizing ground impact risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If engines are mounted at the rear of the aircraft, then the wing can be kept clean and noise is reduced, but control surface efficiency deteriorates and drag increases
Solution Approach 1:
The invention converts the harmful engine exhaust flow into a beneficial resource by positioning control surfaces (elevator and ailerons) in the exhaust path. The exhaust flow actively blows over these surfaces to enhance their aerodynamic efficiency, transforming what was previously waste or harmful flow into a useful trimming mechanism that reduces drag during takeoff and landing.
Solution Approach 2:
The invention moves the engines from conventional wing-mounted or fuselage-mounted positions to a rear-mounted configuration above the horizontal tail plane. This spatial repositioning in the vertical dimension allows the engine exhaust to directly impinge on the control surfaces, creating a new aerodynamic interaction that enhances control efficiency while maintaining the benefits of rear-mounted engines.
2Object-affected harmful factors
If engines are mounted at the rear of the aircraft, then a clean wing is achieved, but drag increases during take-off and landing
Solution Approach 1:
The engine exhaust flow, which would normally represent energy loss and increased drag, is redirected to blow over the control surfaces. This active use of exhaust flow creates a beneficial aerodynamic effect that enhances control surface efficiency and actually reduces overall drag during critical phases of flight such as takeoff and landing.
Solution Approach 2:
The control surfaces utilize the engine's own exhaust flow as a resource to enhance their performance. The system is self-servicing in that the engines provide their own exhaust flow to blow over the control surfaces, eliminating the need for additional external systems or energy inputs to achieve enhanced control efficiency.
3Adaptability or versatility
If engines are mounted at the back of the aircraft, then rear-mounted configuration is achieved, but risk of engine ground impact increases
Solution Approach 1:
The invention positions the engines in the vertical dimension above the horizontal tail plane rather than mounting them lower on the fuselage or wings. This vertical elevation creates additional clearance between the engines and the ground during takeoff and landing rotations, reducing the risk of ground impact while maintaining the aerodynamic benefits of rear-mounted engines.
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
This configuration improves control surface efficiency, reduces drag significantly, and eliminates the risk of engine ground impact during take-off and landing, especially for aircraft with long fuselages and rear-mounted engines.
Implementation Method 1
both the inner fixed part and the outer movable parts are at least partially subjected to the flow coming from the engines when they are in use
Data Source
AI summary
An aircraft with rear mounted engines, comprising a vertical tail plane and a horizontal tail plane, in which the engines are mounted on top of the horizontal tail plane, such that the horizontal tail plane comprises an inner fixed part attached to the fuselage of the aircraft, the inner fixed part comprising an elevator, and two outer movable parts, each one of the outer movable parts being located at each side end of the horizontal tail plane which is furthest away from the fuselage of the aircraft, such that both the inner fixed part and the outer movable parts are at least partially subjected to a flow coming from the engines when the engines are in use.