Our helicopter (Helimed 56) is built and operated using a complex combination of Science, Technology, Engineering and Mathematics. These aspects are equally important to our operations. In fact: NO STEM, NO HEMS!
Our four helicopter blades are made from modern composite materials and are aerofoil shaped (just like an aeroplane wing). The shape of the blades causes the air to flow faster across the top of the blade and slower underneath the blade. This difference in speed results in a difference in pressure which generates LIFT; enough to lift 2.9 tonnes of helicopter into the air. Each blade supports 25% of the weight of the helicopter.
The instruments in our H135 helicopter are presented using the latest generation glass cockpit. This is made up of a number of liquid crystal display (LCD) screens. They are known as smart multifunction displays. They are “smart” because if any screen fails, the information from the failed screen will automatically be added to another screen so very little is lost.
The helicopter is powered by two Arrius 2B3 engines. Normally they share the task of powering the helicopter but each one is capable of providing enough power for flight, should the other one fail. We use powerful gas turbine engines; a kind of jet engine. The jet exhaust from each engine is used to drive two turbines at the back of the engine. The turbines drive the rotor blades through a complicated system of gears and driveshafts.
At the start of each flying shift, the pilot is required to use a selection of graphs to work out how well the helicopter can be expected to perform that day. One example is how much weight the aircraft will be capable of carrying (it changes according to the temperature and air pressure each day). This is vital information because it will determine how much fuel can be carried, while still leaving enough spare weight to carry a patient. A typical graph is shown here.