Helicopters are marvels of the modern age. With their ability to take off and land vertically, and to carry enormous loads, helicopters have become the backbone of many civilian and military operations around the world. But, how are these vehicles made?
The first element of a helicopter to be manufactured is the airframe. Similar to the frame of a car, the airframe is the rigid skeleton on which all of the other elements of the helicopter will be laid. Generally, an airframe is made of lightweight metal tubing This tubing can be bent to exacting dimensions, but is still lightweight and rigid enough to remain strong but not so heavy as to keep the vehicle from achieving flight. Wherever these tubes meet, they are generally welded together and reinforced with plates or brackets called “gussets.” The tubing and gussets are chemically cleaned and treated to prevent corrosion, welded together, then inspected for flaws before moving on to the next steps.
At this point, sheet metal is added to the airframe to create both shape and mounting points for other parts of the assembly. A honeycomb shaped composite material called the “core” is then applied to create a lightweight insulation between interior and exterior body parts. This will help to prevent temperature change inside the cabin and block out some of the outside noise. The hollow structure of the cores also helps to reduce weight. Lightweight composite or fiberglass panels are then applied on top of the cores to create the exterior skin of the helicopter. Once dried and shaped, paint and trim may be added to the exterior in order to protect it from wear an to meet various aviation identification and visibility requirements.
The Engine, Transmission, and Rotors
At this point, the helicopter is merely an empty shell with no means of flight. Thus, an engine, transmission, and rotors must be added. Modern helicopters use turbine engines rather than the piston type engine one would find in an automobile. However, a transmissions sends mechanical power from the engine to the rotors in the same fashion a transmission in a car sends engine power to the wheels. It is also at this stage that it is extremely important that the helicopter be within a temperature controlled warehouse.
The rotors on the top and rear of the helicopter, arguably the most identifiable feature of any helicopter, are then added. The rotor blades are usually made of sheet metal with a composite layup applied and shaped over the top. Each rotor is given a slight teardrop shape along its horizontal access that resembles the wing of an airplane and for the same reason. This shape gives each blade lift and drag, just like an airplane’s wing does, and allows the spinning blades to carry the helicopter into the sky. The tail rotors use a similar principle to help steer the vehicle left and right.
Final Assembly and Inspection
Once the entire helicopter’s primary parts are assembled, the finishing touches can be applied. These include seats and cargo features, electronics, canopies, doors, windows, etc. After all of the systems have been installed and the helicopter is in its final form, it must undergo a rigorous inspection process. The vehicle is inspected and tested thoroughly on the ground, and then taken for test flights to ensure that nothing changes when the helicopter is in use.