This is the fuselage portion of a RC Aircraft. It is how the model looks like without the wings, tail assembly, landing gear and motor-propeller attached.

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ENGINEERING DISASTERS: THE RUSSIAN FLYING FORTRESS
While Americans are renowned for wrapping up their works in the quickest ways possible, Russians follow a motto of “stay strong till you last”. Characterized by the robust nature of their engineering, Russians always believe that a machine should be judged by the number of years it lasts and not the performance. At a time when scientists all around the world were engaged into miniaturization, Russians still thought that “Big is the way”. Back then during WWII, aircrafts were designated based on their purpose in a battle. There were bombers, cargo aircrafts, reconnaissance, fighters and what not. The need for a multipurpose flying machine was a big matter. So the Russians came up with the idea of an aircraft that would cater to all these needs together.
The failure of the Russian K-7 Flying fortress is a classic example of the fact that addition rule does not work out during all situations. It means that taking out the individual perks of all the aircrafts and assembling them into a single one with hopes of churning out the maximum level of destruction is not a good idea. Altough it took decades to realize, aircraft engineering itself was at a nascent stage and experimentations were still at large. The fortress was a very product of this addition rule. It was an amalgamation of every category of weaponry one can think about. It could have been named as a “machine gun with wings”.
To talk about the specs of the aircraft, this gigantic monster was a nightmare for its enemies. The wingspan of the craft was a whooping 132.5 metres, a length which is almost double the length of a modern-day Boeing 747 aircraft. With an estimated cargo carrying capacity of more than sixty eight tonnes, it could practically carry tanks and armored vehicles. Imagine a tank being dropped from mid-air right into the middle of the battlefield. The fortress was to be propelled by as many as twenty propeller engines. The weaponry attached to the flying giant is what really made it a “giant”. The flying fortress had two heavy rail guns at the tail section of the fuselage. These two rail guns were further backed by a dozen gunner positions. As a strategic bomber, it had a housing capacity of 8.5 tonnes of droppable weight. Statistically more than a hundred paratroopers could have been accommodated at a time.
It crashed, on the first attempt of takeoff itself. With a payload of much less than what it was designed for. Considering the size of the craft, it was not even possible to build another prototype!

This is a simple design of an octacopter. There are four arms, each holding two propellers up and down.

FUSELAGE OPTIMIZATION FOR AERODYNAMIC LOADS DURING FLIGHT
THE MAIN OBJECTIVE OF FUSELAGE OPTIMIZATION IS FOR THE FOLLOWING PURPOSES:
[1] During flight, the entire fuselage of the RC aircraft is subjected to loads (dynamic). These aerodynamic loads affect the fluid flow boundary around the entire plane, which can affect the governing factors of flight like lift, drag, stalling angle, cruise velocity.
[2] The distribution of aerodynamic loads around the fuselage can affect the control surfaces. The roll rate for a certain angle of aileron deflection at a certain angle of attack is fixed. These loads can affect the angle and deflections. Hence it is necessary to know these load distributions.
[3] The fuselage shape must be made keeping the aerodynamic loads in mind. The no of support structures to be added: gussets, bulkheads, stringers, Longerons are calculated based on the pressures at each point.
GENERAL FLOWCHART FOR DEIGNING OF AN AERIAL VEHICLE
WHAT DOES OPTIMIZATION INCLUDE?
The optimization process consists of the following stages, chronologically.
Preliminary design sketch
Aerodynamic mesh panel
The surface of the design is divided into a number of panels. An equation of the flow potential at the surfaces and velocity potential at the intersecting points is done. The load due to the pressure
distribution is directly related to the potential at these mesh panels. The unknowns are grouped under a single matrix of co-efficient. They can be further extended as a system of linear equations which when solved help in calculating the disturbance potential and then the individual velocities at these points. These velocities can be used to find the aerodynamic pressures. Having multiplying these with area of a single mesh, the forces can be calculated. Using a coupling method between the aerodynamic model and structural model, the forces can be added as parameters to the structure to calculate the displacements on the fuselage. Accordingly, the sizing of the fuselage can be done to determine the necessary shape.
AERODYNAMIC PANEL MESH
Calculation of aerodynamic loads at each point
The loads are present at each mesh of the surface. The aerodynamic pressures are found out as a
function of the mesh area.
Structural sizing to reduce these loads
At a certain angle of attack, attitude, acceleration of the aerial vehicle, a flight condition is calculated by taking the load factor into account. These variables are then put into account and the resulting deflection required for the control surfaces are calculated. This is termed as the trimmed condition of the aircraft. The trimming may also include more design parameters, each of which is added as a constraint and subsequently coupled with the load factors to repeat the above process. These are the static and trim loads.
During dynamic flight conditions, the velocity potential and flow potential shifts around turbulent regions or gusts. The procedure for calculation of the aerodynamic loads is similar, where the boundary conditions are assumed to be harmonic in nature and the singularities considered for a solution to the equations are doublets (Multiple solutions for a single constraint equation).
Every dimension is taken as a displacement constraint. The no. of load cases for the entire structure is taken into account. Since each dimension is affected by all the loads, these values are multiplied to get the total number of constraints. In the first case, 5 dimensions have been considered for constraint. 50 load cases have been determined. Therefore,
TOTAL CONSTRAINT= DISPLACEMENT CONSTRAINT X LOAD CASES = 50 X 5 = 250
Structural design (adding of support structures)
The design variables for the fuselage are stringers (thickness, length), skin cross section, skin thickness, position of bulkheads at the centre part of the fuselage. More the support structures more will be the design variables. The idea is to reduce the mass of the aircraft and place it exactly where the aerodynamic loads will be the maximum during static and dynamic flight conditions. The support for the rear end of the fuselage can also be determined depending on the bending. The shear forces acting on the walls are similarly taken into account. Apart from the minimization of mass, another objective is to keep the manufacturing ease in mind. The final dimensions for the fuselage structural components must not be difficult to build and the assembly should be easy.
Structural FEA.
Finite element analysis of the final structure of the entire RC aircraft is done.
DIFFERENCE BETWEEN A FEA DESIGN AND AN AERODYNAMIC DESIGN. NOTE THE SPLINES IN THE AERODYNAMIC MODEL WHICH DENOTE THE OPTIMIZATION
SOFTWARE:
LAGRANGE is a software which is used for Multidisciplinary Design Optimization (MDO) of aircraft
structures.

Gyroscope is a basic component used for navigation in ships and also in aeroplanes it is an important device as with its help the stability of the body and its motion can be known. Here in this pdf its various properties and how it's used has been explained in detail and simple way.

This was a question posted in quora. I posted my opinion based on my outlook on both of these streams. Whether one is better than the other depends on what is being considered as a common criteria for comparison.
Let's start with scope. A person graduated with a mechanical degree can very well have opportunities to work in the aerospace sector. The aerospace sector is multidisciplinary and people from electrical, coding and other background can easily find work. But the other way is not so. An aerospace engineer is only familiar with the mechanical aspects related to aircrafts. You cannot expect this guy to easily get a job in a heavy machinery industry, for example.
Next grade of comparison is payscale. It is obvious that aerospace is a better paying field compared to field. Here I am talking about the average salary per annum for both the fields. There may be mechanical jobs which pay more than a specific aerospace job. But on an average, aerospace job gets you more bucks.
R and D. Once again this is a tough comparison. Both of the sectors are undergoing numerous innovations over the years. In case of mechanical, there are certain specific fields where R and D is more concentrated than other types of industries. For example, R and D in the automotive fields is much more compared to other types of fields. But for aerospace, every sub-sector is under constant Research and Development.
Job vacancy is a big issue. And mechanical easily exceeds aerospace in terms of available job numbers. This is primarily because mechanical is a broad field. It can be divided into marine, automotive, heavy machinery, thermal, tooling, power plant, and hundreds of sub fields, each of them having numerous opportunities. Aerospace is only aerospace. To be more precise, aerospace is a specialization field of mechanical itself.
So you can see the comparison. Better is a relative term. The grounds of comparison matter a lot. So choose your interest carefully, and don't regret later!

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