The engine mount is responsible for directing all the forces from the hood, aircraft engine, propellers, and other installation units to the main aircraft’s structure. The engine mount must be capable enough to bear and deal with the flight load and absorb the vibrations from the engine and the propeller. Moreover, an engine mount must be able to compensate for the thermal deformation of the aircraft’s engine and provide relaxation to the structural assembly and disassembly.
The following blog post explains various aspects of a light aircraft’s engine mount to understand the mechanism better.
Also Read: 5 Crucial Things To Remember About Aircraft Engine Mounts
What Is An Engine Mount?
An engine mount can be best explained as the foundation of the plane that connects the main body and the engine of the aircraft. It serves more purposes like connecting the fuselage, suppressing, absorbing and distributing the vibrations equally throughout the aircraft structure to aid in a smooth flight.
An engine mount is a sturdy precision-based metal structure that needs to balance out the whole weight of the aircraft during various torque requirements.
The Structural Scheme Of An Engine Mount
The structure of an engine mount depends on the type of aircraft engine and the propulsion layouts. Modern aviation experts follow the trend of having a quick detachable propulsion system; this design helps to replace the engine on the aircraft in less time during repair and maintenance activities.
In most turbojets suspension takes place using separate support units, rods, brackets, and special units located with the engine’s mountings.
These structural components are made mechanically with heat-treat aluminum, special steel, and magnesium alloys. This is usually done by hot stampings, forging, and castings. Getting into the details of commercial aircraft could turn this blog into very complicated content. So, without going into further depth let's just say that the commercial turbo air jet engine is mounted on pylons out of the craft’s wings.
Engine Mounting For A Modern Commercial Jet
In propeller-driven aircraft the engine is mounted using a spatial rod system, beam plus rod combinations, and support belt rings. This system has a special feature of strong and powerful shock absorbers to mitigate the heavy vibrations induced by the engine and propeller.
Engine Mount Systems For Small Aircraft
The engine mount system for a small aircraft has a simple mounting system with the following components.
- Barrier wall for fire
- Aircraft engine
- Engine mount system (frame rods)
- Engine mount beam-rod system
- Engine mount brackets
- Fuselage part
- Engine mount bolts + rubber dampers - mounting pads
Engine Mount Analysis Steps
The first step in the structural analysis of an engine mount is to determine the load. Remember that all the loads are acting all in one and need to be managed accordingly. Typically, the following loads act on an aircraft;
- The engine weight action including all the overloads
- Propeller thrust while incorporating the required margin of safety
- Torque reaction from the engine, also including the margin of safety
- Load forces induced by the propeller and engine gyroscopic movements
All these loads are distributed and exerted on the engine and propeller through the crankcase. These then react at the engine mounts fittings and then are finally submerged at the mounting pads.
Generally, the engine is considered a rigid body with inertia, torque, thrust, and gyroscopic forces. All these loads are derived at different locations in the crankcase. To simplify engine mount strength analysis all the engine loads are brought to a single focal point that is known as the ‘engine focal point’.
About Acorn Welding
Acorn Welding is one of the leading names in the aviation welding industry. We are your one-stop shop for high-quality aviation exhaust and engine mounts. We are Canada's largest aircraft exhaust and engine mount repair company, as well as the world's largest radial and vintage aircraft exhaust repair company, we serve clients all over the world. Learn more about Acorn Welding.
For industry-standard aviation welding repair and the maintenance of high-quality aircraft parts, contact us today.
