[woofa.express]

This is to follow the story on the PT6 Gas Turbine / Propellor engine and the earlier story on fuel. My son (Moo) wrote it (for the Model A Forum) after departure from Hong Kong and transmitted it to me on arrival Toronto. His Model A is the one featured on my avatar. The picture of the A350 is from the internet.


The Modern Jet engine.

The Rolls-Royce Trent XWB-97 aircraft jet engine, is a powerful high by-pass modern jet engine. Two of these underwing engines, powers the latest Airbus aircraft, the A350-1000. They each can provide up to 97,000lbs of thrust. The engine comprises of 3 compressor turbine assemblies (LP, IP, HP). Each turbine operates it’s associated compressor via a shaft. The Low pressure (LP) compressor is the first stage that you can see, where the air enters the engine intake. This fan compresses the air, with most of it by-passing the engine to provide thrust. A small amount of this compressed air enters the core where it is further compressed by the Intermediate and High Pressure compressors. This high compressed air will then enter the combustion chamber where it is mixed with fuel and ignited. As the air leaves the combustion chamber with this added energy, it is allowed to expand through the turbine stages HP, IP, LP which drives it’s associated compressor. The hot expanding air is returned to the atmosphere, out of back of the engine via the exhaust cone. Each stage of the compressor/turbine, have varying number of smaller compressor/turbine blade stages to optimise the flow of the air through the engine. Some of the engine air flow is bled off to pressurise the aircraft and to mechanically drive components on the accessory gearbox; like supplying the aircraft electrical system.
On the A350, 2 of these Trent XWB-97 engines, provides a maximum take off weight of 316 Tonne (316,000 kg). With the basic weight of a typical A350 being approx 149T, this calculates to a possible payload of 167T. On a recent flight from Hong Kong to Toronto, I took off with 257 people on board and a payload of 54.4T (passengers, baggage, cargo). It had a flying time of 14hrs 27min and flew at M0.85 with an average tailwind component of 59kts, over the 14,630 km journey, averages 1010km/hr, burning 125,280 L of fuel. That equates to a burn of 856L/100km for the payload. This can be further broken down to approximately 3.3 L/100km or 1.57 L/100km/passenger with baggage.

So as you American readers don't feel slighted I'll get an article written by a Boeing pilot on the engines powering a Boeing 737.