Single Engine vs. Twin Engine Planes – Pros and Cons

Spend a day in an FBO in the US and you’re bound to hear this conversation. It usually goes something like: “I would fly a twin over a single any day. They are safer, faster, and will haul just about anything you throw at them.” To which the single engine pilot usually responds something like, “I’m sure you would, but you can’t afford the fuel, that extra loading negates the safety factor, and assuming you do load it to the POH, the extra fuel stops mean we are going to get there at the same time anyway.”  

In 2016, there were around 1,019 new piston powered airplanes delivered worldwide. Of those only 129 were multi engine pistons. Why this disparity, especially if, as our first pilot stated, multi engine aircraft are safer? If you’re looking to buy an aircraft, it may be helpful to know the advantages and disadvantages of single engine and multi engine planes.

Single-Engine Planes

Let’s begin with singles. For starters, single engine planes are typically less complex. This is true when it comes to maintenance, repair, and even flying itself. There are typically fewer controls, a simpler fuel system, an easier to deal with electrical system, and one fewer engine to monitor. One engine can mean fewer, and smaller, problems down the road.

Fuel consumption is a big deal in aviation, especially when fuel prices seem to be on an ever-ending climb. Back in the 70’s, the height of the twin engine era, you could easily get a gallon of avgas for $1.50. Today that same gallon will likely cost you over $5. More engines equal more fuel, and that extra fuel means higher costs. You will be hard pressed to find a multi engine plane that operates for as cheaply as its single companion.

Flying a plane is ultimately a battle against gravity. That means that the less weight you have, the better. That extra engine can give you a lot more power, but that power comes at a cost, which is weight. Single engine planes are almost always lighter than their multi engine aircraft counterparts.

Perhaps the biggest negative of a single engine plane is that, in some cases, it is not as safe. When your engine quits, you are a glider. This can make finding that perfect place to land not only a necessity, but one you must embrace with haste. A multi engine airplane on the other hand, if properly loaded, can give you that extra time you need to land safely. With a single engine airplane you have no redundancy to help should something go wrong.

Multi Engine Planes

Multi engine aircraft make up for some of that extra fuel with extra speed. Multi engine aircraft are almost always faster. The extra power of an additional engine mean they usually climb faster too, and that can be a big deal when your trying to find some smooth air or get out of a tight space.

That leads to the next major pro, planes with two engines are safer for the most part. When one engine malfunctions, you have another engine to keep you in the air. Even the best maintained engine can fail, and that second engine gives you a backup.

There is a paradox here, however. Data has shown that bicycle riders who wear helmets are in more crashes than those who eschew safety gear. People may feel that the added protection allows them to take more risks. The same thing is true of multiple engines. Some pilots may feel that the second engine gives them license to engage in risky behavior, when you should always be cautious. Light twins can lose up to 80% of their power when an engine fails. If you’re overloaded this will likely mean you just have one more engine to fly you to the scene of the accident.

As part of this, pilots need additional training. Pilots undergo up to on average around 10-15 hours of additional flight instruction to get a multi engine rating. A pilot will also need to understand multi engine aerodynamics and operations.

When it comes time for an annual inspection that second engine starts to hurt. The added complexity of a cross feed fuel system, along with two sets of everything else, equates to some hefty bills. Beyond the annual inspection, when you start approaching TBO, you will quickly understand why there are fewer twin engine planes.

Two engines may or may not be better, but they are for sure more expensive. Two of anything will always cost more than one to replace, and aircraft engines usually only last around 2000 hours between major overhauls.

And that’s what it usually comes down to, cost. Multi engine planes, when operated correctly, should be safer. They are almost always faster. Assuming a light passenger count, they can often fly further. But at the end of the day they are going to cost you more. More to own, more to fly, more to learn, and more to maintain.

There are pros and cons to both single engine and multi engine planes. Depending on your mission and budget, either could be the perfect fit. For this reason it is a good idea to ask the experts, consider your options, and think about what you will need the plane for.

If you have any questions about various types of planes, ask the pros at Aircraft Sales. We are professional pilots, aircraft owners and aviation enthusiasts. We have a passion for planes and pilots and we want to help! While you’re here, check out aircraft for sale on our site.



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