Why do you need to press so many buttons to start a plane? Can’t there be just one button to start everything in sequence automatically?
In: Technology
There are two points to this. If you are thinking of an old 172 airplane the main reason is it’s from the 50s level technology. Sure improvements have been made but those carburetor piston engines need you to manually control fuel flow (more to do with airplanes encountering different air pressure at altitude which requires the fuel mix to be adjusted). Its old reliable technology but had a bit more human input.
New engines that have digital controls are mostly just push button start. A computer takes care of everything just like your new car. Might be 3 switches, battery then fuel pump on then flick the starter and boom engine running. Separate switches for these things to be able to isolate them in emergency or just because they are not always needed.
The rest of the time taken getting into the air is running checklists to ensure everything is running properly and if you are going IFR flying getting the clearance from ATC can also some time be a longer wait.
The aircraft can be in the air very quickly if you need to and skip the checks. For example when I was on a red alert stand by for fire fighting we had to be airborne in less than 5 minutes from getting the call. As we are waiting at the look out tower for 8 hours a day we clearly are not sitting strapped in all day waiting so some of that 5 mins is just getting in. To make sure the aircraft is ready I ran the full checklist at the start of the day and basically just did the bear minimum checklist to get into the air. Typically in around 45secs to a minute to have the helicopter cold to airborne. In this case I’m trusting my previous full checklist and the aircraft hasn’t been out of my sight all day. For less critical flying we do have turnaround checklists that ignore many items on the first start of the day checklist to get airborne quicker. Compared to flying IFR where more items are critical that they work so longer checklists I might be 10min on the ground before departing.
Pilot here. In a sense, a lot of the larger planes *are* “one button starts”, in that when everything is configured correctly, you simply turn a knob or push a button and the start sequence happens automatically.
The major difference between larger planes and cars is that, while cars can be started simply by the power from the battery alone turning over the engine, supplying fuel from the fuel pumps, and powering the spark plugs all at the same time, jet engines take a lot more “oomph” to turn over. They are far too heavy and need to turn at thousands of revolutions per minute before they gain enough speed to compress the air and begin the combustion process. Hence they are started with pressurized air rather than an electrically driven starter.
This air is typically supplied by a smaller jet engine in the back of the plane called an Auxiliary Power Unit which is small enough that it *can* be started with an electric motor. This smaller jet engine outputs enough pneumatic pressure to drive the larger jet engine and begin the combustion process. However, when it is broken or disabled, they can be started on the ground with a huge cart that is basically a giant fan that blows air into the engine and can get it going fast enough to begin the combustion process. If you have one engine running, it can also supply the air to the other engine. And in the *extremely* unlikely event that you lose *both* engines *and* the APU in mid-flight, the airplane can pitch down and glide fast enough to use the air blowing through the engines to start the combustion process. Pretty cool, right?
So in a way, when everything is working correctly, most larger airplanes are started with a two-button process- start the APU, then start the engines. The reason the airplane is so “configurable” and has so many buttons is primarily for troubleshooting and manually tweaking the systems in the event of a mid-air emergency. Unlike a car, when your engine quits or starts to overheat or something else, you can’t simply pull over and coast to a stop. You need to be able to isolate the affected systems and toggle them on or off as necessary. Also, if a giant computer controls all the systems and the computer itself has a problem (*cough* 737 MAX *cough*) you want to make sure you can manually and directly control the individual systems. Boeing takes the majority of the blame for the MAX design, as well they should, but there was a lot that went wrong on the pilots’ end of those crashes, too.
If your car malfunctions/breaks down while driving, you can take it to a mechanic, or get a tow. If it’s a plane that’s flying, you have to fix it before you die.
When flipping all those switches to start the plane, you’re not just turning things on; you’re making sure they work. If you find a problem, you can isolate its location; then either attempt to fix it, or abort the flight: thus preventing said problem from crashing your plane.
Think of it like a Velcro shoe and a laced shoe.
The Velcro shoe just takes 2 steps: pull out taut and bring in the other direction.
A laced shoe requires adjusting the strings and pulling taut, crossing and looping under, creating a loop. Then it’s winding one strong around the other, creating a gap, pulling through, and tightening while making sure it doesn’t come undone at the end.
Both do the same thing, keep the shoes on your feet, but one is more complicated, gives more control to you, and is much more stable and reliable!
Some good and really bad answers here. I’m an expert in process control, and to black and white answer your question, there is no technological reason why this is not possible today
There technology is currently in use across many processes and industries across the world, and relatively simple to program and still keep the pilot at the front of control.
On start up, the pilot would need to be retrained to observe a start up report in case of any anomalies and likely they would still 4 eye check that all systems are functional as intended.
Whether this should happen would be a purely human factors discussion. It could be argued that a less manual start up sequence may cause disengagement of pilots, but the counter argument would be that a program can do the task quicker and with magnitude lower errors. An interesting discussion anyway but from you question, yes it’s possible.
I am no plane expert, but imagine as a Pilot, suddenly your plane is showing one warning light, and you don’t have anything else except one start button
Latest Answers