What are the physical principles that govern the flight of a helicopter? To find out, we climbed aboard theAW139 helicopter of the State Policeone of the most advanced in circulation. It is a means twin-engine from 15 seats designed for search and rescue with over 1000 units in service in the world.
Helicopter Physics: Here’s How It Fly
A helicopter flies thanks to different concepts than an airplane. Let’s simplify to the max: an airplane has wings that generate lift, that is, upward thrust. This is generated if there is a forward thrust and for this reason airplanes take a run-up to take off and need engines, which have the role of pushing the airplane forward. The helicopter take off vertically and from here you can already understand that it works quite differently. The helicopter is in fact equipped with three main controls
The Collective
The collective it’s theblade inclination which allows to give the thrust upwards. So when the pilot wants to take off or climb in altitude, he increases the inclination of the balls, the angle of incidence; instead if he wants to descend in altitude, he reduces the inclination.
The Cycle
Then there is the so-called cyclic which allows you to tilt the entire rotor in one direction. To be clear, when the helicopter starts moving forward, what actually happens? There is no engine pushing from behind, but the rotor tilts forward and therefore the thrust generated by the blades is not only downwards but also forwards. This is true for any direction.
The pedalboard
And then there is there pedalboard that allows you to direct the helicopter, just like a rudder, and it acts on the tail rotor. And here we understand what the propeller at the back is for, which is fundamental: if it were not there, the helicopter would start to spin on itself. To avoid this, something is needed to counteract the rotation; and this is why helicopters have a tail. The tail is like a lever that counterbalances that unwanted rotation. In other words, if there were no problem with this uncontrolled rotation, helicopters might not have a tail.
So, to fly a helicopter, to put it simply (but as you can imagine, it’s all more complex), you need to control the collective, the cyclic and the pedals.
The characteristics of the AW139 helicopter
The helicopter we turned on it is a AW139long 16.62 mtall 4.98 m and has a main rotor with 5 blades of 13.38 m diameterwhile the tail rotor of 2.7 mIt is equipped with two turbine or turboshaft engines, a variant of the jet engine, from 1700 hp eachwhich in this case are Pratt & W which are the most powerful engines ever mounted on a medium-sized helicopter. It can reach a maximum speed of 306 km/h (165 knots). This is one of the most advanced helicopters in service with the Police, in fact this helicopter is equipped with a very powerful gyro-stabilized video camera called FLIR capable of stay balanced regardless of the helicopter’s movements.
