What is Jet Engine and how does it work ?

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The power of a jet engine is equivalent to that of 28 Formula-1 racing cars. No wonder the grease monkeys and thrust junkies at KLM Engine Services are crazy about them.

General Electric’s GE90-115B, with a diameter of 3.25 metres, generating 115,000 pounds of thrust, is currently the biggest in the world. You’ll find these big boys hanging under the wings of KLM’s Boeing 777-300s, which are easily recognisable because they are all named after world heritage sites, such as the Yellowstone National Park.

You’re in an aircraft taxiing to the runway. You stop momentarily. Then you hear of the swelling roar of the engines, the aircraft vibrates as it accelerates, pushing you back gently into your seat. The scenery whips by faster and faster until you leave the ground. You’re airborne! All of which would be impossible without the powerful engines.

When you buy yourself a new car, the manufacturer recommends that you should have it serviced regularly. It’s up to you, the owner, to decide whether you heed this advice. But that’s not the case in aviation.

Maintenance, checks, modifications – they’re all mandatory. Airworthiness authorities like the FAA or EASA closely monitor KLM and other aircraft operators to ensure that all maintenance is done on time and as instructed.

And whereas car maintenance is based on distance driven, aircraft maintenance is based on flight cycles and hours flown.

Engine life is measured in flight hours and flight cycles. One cycle = one take-off + one landing,

So, a one-way flight from Amsterdam to New York amounts to around 8 flight hours and 1 cycle (i.e. one take-off in Amsterdam + one landing in New York). A roundtrip between Amsterdam and New York would amount to 16 hours and 2 cycles.

Every engine must undergo minor or major maintenance after a set number of flight cycles. This varies depending on the engine type. For instance, the CF6-80E, which powers KLM’s Airbus A330s, requires major maintenance approximately every 7,300 cycles and minor maintenance every 200 to 400 cycles.

Our “garage” is as big as six football fields, approximately 40,000 square metres.

KLM has its own maintenance department and its own Engine Shop where jet engines are maintained and overhauled. There’s a reserve engine for every type that KLM operates, which means they can be immediately replaced if maintenance is required. Our technical crews can replace an engine in around 24 hours.

The engine that has been removed for maintenance – the “dirty engine”, as we call it – is carefully packed and transported to our Engine Shop. Depending on the engine type and the required maintenance, it will be as good as new and ready for flight after 50 to 60 days. It bears mentioning that KLM Engine Services also services engines for other airlines.

That’s an interesting question, but it’s surprising difficult to answer. Most aircraft are fully equipped with engines when purchased, so you could say it’s a package deal. And then there are so many different types of engines, which each have their own thrust rating. Say what? Thrust rating, but let’s leave that for another blog. Roughly speaking, an engine can cost anything from 12 to 35 million dollars.

It always gives me goose bumps when the gentle roar of the engines starts seeping into the tranquillity of the cabin. But the engines only really come to life during take-off, pushing you back into your seat as the aircraft accelerates on the runway, and then you’re airborne. Engines are probably the most striking and impressive part of an aircraft. So much so, that I wanted to know more about these fascinating powerhouses and decided to do some research.

Measuring 3.43 meters in diameter, the General Electric GE90-115B is the biggest engine in the KLM fleet. These big boys power our Boeing 777-300ERs, which are the biggest twin-engined aircraft in the KLM fleet. These engines generate 115,000 pounds of thrust, which makes them the “World’s Most Powerful Commercial Jet Engine”, according to the Guinness Book of World Records.

Our B777-300ERs spend almost 16 hours a day in the air. It is important to keep track of this because the engines must be regularly maintained. Operational deployment is measured in flight hours and flight cycles. Each cycle consists of a single take-off and landing. Our B777s complete 1.9 flight cycles per day, on average.

Maintenance varies per engine type. The GE90-115B, which powers our B777s, goes in for a check-up multiple times per year. A major overhaul is done after the engine has been operational for about 750 days. Minor maintenance is conducted in between the bigger checks. In short, the engines get plenty of attention to keep them in perfect running order!

KLM has its own Engine Shop where engines undergo maintenance. KLM has a reserve engine for every type it operates, so that engine maintenance can be carried out while the aircraft remains operational. An engine can be replaced within 24 hours.

Engines are fully disassembled when they’re overhauled. On average, a jet engine consist of around 40,000 parts, which means this process can take 50 to 60 days. I can only imagine how many diagrams they need! After a full overhaul, the engine is as good as new and ready for many thousands of kilometres in the air.

Aircraft engines are very costly. Because airlines always buy their aircraft with the engines attached, it’s difficult to say just how expensive they are. And the price varies per engine type, of course. Roughly speaking, prices range from USD 12 to 35 million.

An aircraft engine reaches temperatures of up to 1,400 degrees Celsius (2,552 degrees Fahrenheit) in the hottest part of the engine, where compressed air is mixed with fuel and ignited.

It’s one thing to wrap your head around the physics of the Wright brothers’ plane, but how do you generate enough power to sling a 350-ton Boeing 747 into the air and keep it cruising at 1,000-plus kilometres (640 miles) per hour? These extraordinary powerhouses are fascinating, even to those who work with them on a daily basis, which is why we’d like to share some facts about jet engines with you.

That’s an interesting question, but it’s surprising difficult to answer. Most aircraft are fully equipped with engines when purchased, so you could say it’s a package deal. And then there are so many different types of engines, which each have their own thrust rating. Roughly speaking, an engine can cost anything from 12 to 35 million dollars.

To generate electricity, some powerplants use 100-ton gas turbine engines fuelled by natural gas. Residual heat can be used to boil water for a secondary steam turbine.