Pressure Switches in Aerospace Applications
In aviation, pressure switches are used throughout the airplane and in nearly every system of the aircraft. They trigger the flight controls and flight instruments, they are throughout the fuel and engine system, and they are also used to keep the cabin comfortable and safe. Even the pilot seat is equipped with a pressure sensor that senses if the pilot is sitting in the chair. The aircraft is covered with pressure switches automating all these systems to make the airplane functional and economical.
Importance of Pressure Switches
In modern commercial airplanes, pilots completely rely on pressure switches and sensors to fly the airplane. Some types are located on the outside of the airplane and are used to determine altitude, airspeed and how the aircraft is flying. For instance, in situations where the aircraft is not level in the air, pressure switches help a pilot prevent side slipping.
In addition, airplanes are designed with hydraulic systems to power the movable surfaces on the plane’s exterior. These systems use pressure switches to actually move the surface of the plane to turn, maneuver and land. With the landing gear, a pressure switch will sense the pressure from the weight of the airplane and trigger certain flight controls such as reverse thrust.
Separately, determining airspeed and measuring outside air pressure can help airlines run airplanes more economically as well. Air speed must be accurate in order to prevent unnecessary loss of fuel and to function the airplane. Too slow and the plane stalls. Too fast and the airplane burns excessive fuel.
Another obvious key area, engines completely rely on pressure sensors and switches to move fuel throughout the engine system and problems can arise if the fuel system is over or under pressurized. Think of what happens in a car engine when a pressure hose has the slightest crack. The car may stall or not even start. A jet engine is a hundred times more complex than a car engine and not enough fuel and air pressure could make the jet engine fail. Maintaining a proper fuel-air mixture and igniting it is what creates the engine thrust and the whole operation is dependant on knowing the proper inlet pressures, and then having proper safety responses to overpressures or low pressures.
Pressure switches are also used when testing new airplane designs. Engineers will strategically place pressure switches and sensors to monitor the plane’s performance during a flight test, and if anything is not right with the pressure, then the engineers know the plane may need a redesign.
Overall, pressure switches are important because they allow the flight crew to operate the plane safely, and without them, modern aviation could not be possible.