How Do You Start a Plane?

Starting a plane is usually not as easy as starting your car, there is often much more involved. Though it differs between aircraft, how do you start a plane?

How you start a plane depends on the type of aircraft, but there’s a general procedure to go through. In just about any aircraft, you’ll do the following: check the electrical systems, adjust fuel and throttle, power up the electrical components, get fuel to the engines, and fire the engines up.

Starting a plane is much more involved than getting in and turning the key. At least most of the time. And although the process will slightly differ from plane to plane, you’ll learn the key aspects of the procedure that you’ll need to use on just about any plane out there. From single-engine turboprops to big-time passenger jets, we’ve got you covered.

Everything that you read in this article comes from our own experience of starting — and flying — all kinds of different aircraft over the years. We’ve also discussed the general starting procedures of various aircraft with other pilots to come with the comprehensive information you see below.

‍How To Start A Plane

Starting a plane is (usually) not as easy as starting your car. You likely get in your car every day to drive to work or to take the kids to school. And it’s super easy to start, right? You just get it, turn the key, and you're good to go. Or on some more modern cars, you just get in and push the start button and it fires right up. For aircraft, both smaller planes and passenger jets, the startup procedure is typically much more involved.

That said, starting a plane is different from plane to plane, but especially from class to class of plane. By that we mean, starting a small, single-engine aircraft is going to be different than starting a commercial airline with jet engines. But at the same time, there will be some general similarities in getting both types of planes started.

So let’s dig a little deeper and take a look at the general procedures for starting a plane. We’ll first start with smaller aircraft, and much of the information will be similar to passenger jets, so we’ll go into a bit less detail on those. The main difference — although there are certainly many — is the types of engines between the two planes and how they’re actually started.

All that said, strap in and let’s take a look at how to start a plane.

Small Aircraft

Some of the information regarding starting small aircraft, especially the first few paragraphs before we get to actually starting the engines, pertains to larger aircraft as well. Of course, some of the actual steps involved and some of the systems will be a little different, but the general ideas are similar among most planes.

Check Electrical Systems

The first thing you’ll want to do when you’re starting your plane is to check a couple of different aspects of the electrical system(s) to make sure that everything is operating as expected. The first thing you’ll want to take a look at is the circuit board, which has circuit breakers for all the main aspects/components of the system. Ensure that none of the breakers are tripped, meaning that the corresponding component will not receive power.

If the breakers are all in the correct position, check to ensure that the master switch for the plane’s avionics system is turned OFF. You’ll want these systems to be turned off when the engine eventually fires because the surge in electrical voltage could potentially lead to damage.

Adjust Fuel and Throttle

The next thing you’ll want to do is check and adjust the fuel and throttle selectors and levers. First, start by adjusting the fuel selector valve on the floor of the cockpit to BOTH. This will ensure that the engine will take fuel from both wings simultaneously throughout the flight so that you don’t have to manually switch between wings and keep the fuel levels equal.

Next, open the throttle about halfway (roughly ¼ of an inch) to allow for a small amount of airflow to enter the engine. The throttle lever will typically be black, but sometimes it might be white. Located nearby, pull the red mixture knob all the way out to cut off the flow of fuel to the engine to mitigate the risk of an electrical fire.

Power Up Electrical Systems

Once you’re sure the fuel mixture is cut off (from the step above), you’re safe to start turning on some of the major electrical systems. This is super easy to do, and in this step, we’re just referring to turning the master switch to ON. Do NOT confuse this with the avionics master switch from before, which should remain OFF! Flipping the master switch on will turn on electrical power to most of the aircraft and you’ll hear some things kick on.

Get the Fuel Going

Now that the electrical systems are up and running, it’s safe to allow fuel to enter the engines. Push the red lever from before all the way in now, which will put it in “full rich” position and allow the flow of fuel. Depending on how cold it is out, you may also need to pump the primer a few times to make sure there’s enough fuel for the engine to start. The primer puts atomized fuel directly into the cylinders to make it easier to start in less than ideal conditions.

Make Sure You’re Clear and Fire it Up

Finally, it’s time to fire the engine up!

It’s important to check around the plane, especially up near the propeller and around the back. Once you’re sure that everything is clear and nobody is close to the plane, you can engage the starter and let it fire up. During this process, you’ll also want to make sure you have the brakes engaged so that the plane doesn’t start trying to creep away once it gets going.

And that’s it — your plan should be running and you should be good to go!

Passenger Jets

As alluded to above, much of the same information is needed when it comes to starting a passenger jet as for a smaller aircraft. The things that you need to check before firing it up — fuel, throttle, electrical systems, switches, etc. — all remain largely the same. Of course on these massive planes, these systems will typically be larger and potentially much more involved, but the general ideas remain the same.

Let’s branch off and see how starting jet engines on passenger jets is much different than starting smaller engines on private aircraft, that’s where it really gets interesting.

Get the Turbine Blades Inside the Engines Spinning

Unlike the smaller turboprop engines or piston engines found on smaller aircraft, planes like passenger jets and other commercial airliners use jet engines. These engines have blades (or turbines) inside them that spin at high rates of speed to move air through them. To get these engines started, the first thing you need to do is get the blades themselves turning before any fuel gets added so that there can be more than enough airflow inside the engine.

If fuel is added too early, combustion can begin prematurely and damage can occur. To get the blades turning, jets typically come equipped with an Auxiliary Power Unit (APU) located in the tail of the plane. The APU is a much smaller turbine engine that produces enough extra air to start turning the blades inside the two (or 4) main turbine engines. Once the turbine blades get spinning and pulling enough air through, the engines can finally be started.

Starting the Jet Engines

Once the air pressure from the APU gets the blades inside the jet engines spinning fast enough, the system will automatically start adding fuel to the engine — this process happens in one engine at a time. The engines usually have two ignition points that produce a spark to ignite the air-fuel mixture. This process is actually similar to how a spark plug works in a piston engine, like the one in your car or one of the smaller ones found on private aircraft.

As the engine really gets going, it will continue to build pressure and spin faster and faster until it reaches its normal idle speed. As it begins to bring enough air and pressure in on its own, the APU will stop feeding air to it and the engine will be able to keep idling on its own. After it’s up and running, the remaining engine(s) can be started up in the same way.

The only major difference for the remaining engines is that they can be started in the exact same way as the first one, using the APU to get the blades spinning. Or, the already-running engine can be used as the source of high-pressure air to get the subsequent engines fired up. Interestingly, this second process is exactly what’s done mid-flight to attempt to restart a failed engine if one happens to go out during the flight.