How To Start an Aeroplane
Im not sure whether u guys have been to the prohibited area in KLIA - the end of the runway (kompleks bunga raya)? Yea, it's prohibited to enter and drive on the road parallel to the runway. The sight of seeing a life plane rolling on the runway is exhilarating, in addition of being so near to it. BUT there's the possibility of being stopped by police cars doing their rounds. Be careful.
Ever thought of today's topic? How to start an aeroplane engine? Is it similar to cars where we insert the keys and crank the engine? Do u need to step on fuel pedals to rav the engne?
Answer is no. Aircraft engine starting is totally different from automobiles. There's no key, and there's no fuel pedal. A car takes bout 3 seconds to crank, but an aeroplane takes 30 seconds.
Cut-off view of a turbine engine.
Some might think, Do Pilots lock the plane like we lock our car? ahahha... answer is no again. The reason is because who would want to steal an aeroplane when u most probably will be gunned down by security officials even before stepping into the plane?
Furthermore, why would someone wanna steal a plane when he doesn't even know how to fly one. So, dun be so futuristic by thinking that planes have remote control locking system. Dit Dit! hahha...
Before starting an engine. The aircraft engineers will do a pre-flight check according to a check-list. After clearing the check-list, the aircraft engineers sign the papers and certify that the plane is fit to fly. Then, the Pilot comes and take over the plane.
The Pilot now does the same thing(double check), do a pre-flight check around the aircraft, checking for foreign objects obstructing the engine inlet and stuff. Then, he will get back to the cockpit and both Captain and Co-pilot are ready to start the engine.
Firstly, Pilot will turn on the MASTER SWITCH, which turns on all the electrical stuff. Cockpit will light up and LCDs will show information on the engine. After turning on the master switch, next will be the Auxilliary Power Unit(APU) switch.
APU is at the back of the plane.
APU is a small engine located at the back of an aeroplane, normally used for engine starting only. So the APU produces a high volume of air and ducts/send these compressed air all the way from the back, through the wings, and finally to the engine. This air is used to turn the huge and heavy fan blades of the engine.
When the blades are turning, it sucks in a sufficient amount of air from the atmosphere into the engine. For combustion(explosion) to occur, there are 3 things to be met. Combustion = Air + Fuel + Heat.
Big planes have 4 engines; smaller ones have 2. Nice pic, btw!
Now that we have air in the engine, we need heat. Following that, Pilot turns on the ignition switch.
Ignition switch is the circuit that sends around 20,000 volts of energy to the igniter unit (spark plug for automobiles). This high energy causes a high intensity spark and produces a tremendous high heat. The spark is quite alike the camera's flash, just that it's 10 flashes in 5 seconds. Your eyes will hurt if exposed too long.
Lastly before combustion occurs, Pilot turns on the fuel pump switch. Once on, the boost pump will pump fuel into the Fuel Control Unit (FCU), which meters the appropriate amount of fuel needed for starting.
Walaaaa! the high heat burns the fuel/air mixture and brings the engine to self-sustaining speed/idle speed. At this point, it is critical for the pilot to observe the Exhaust Gas Temperature (EGT). A normal engine start will bring the EGT to let's say 680F (depending on aircraft type). If the temperature shoots to 700F, the pilot has to shut off the fuel into the engine immediately, to cut off the engine.
EGT = Exhaust Gas Temperature
Some other information that are displayed on the LCD.
There u go, a successful 30 seconds long engine starting. Hope u guys learnt something new bout planes today. Just wanna share the info i have with everyone :)
*note: for ppl who are from the aviation industry, this is just a simple explanation to my friends for easier/better understanding. Pls do not judge. I know there are other ways with complicated steps to start an engine. your patience is appreciated, thank you.