This high power ground run was performed after a routine visit to the hangar for a maintenance check (called a 4A check). Performing the run allows us to check that the engine and it's auxiliary equipment are operating normally and there are no fluid leaks from filters that have been replaced.

Rolls Royce Trent 1000
Type: Threeshaft high bypass ratio (1110.8:1) turbofan engine
Length: 4.738 m (186.5 in)
Diameter: 2.85 m (112 in) (Fan)
Dry weight: 5,765 kg (12,710 lbs)

Compressor:
Single stage LP, the Fan (N1),
Eightstage IP (N2),
Sixstage HP (N3)

Combustors: Tiled Annular combustor

Turbine:
Singlestage HP (N3),
Singlestage IP (N2),
Sixstage LP (N1)

Maximum thrust: 72066lbs (This Trent 1000G)
Overall pressure ratio: 52:1 (TopofClimb)
Thrusttoweight ratio: 6.189:1
Cost: Approx $16.25m per Engine


Random Facts:
• Each of the 66 HP turbine blades makes 800horsepower at takeoff, that's 52,800hp just to drive the HP compressor.
• Fan tips reach 900mph, HP turbine blade tips can reach 1200mph
• At takeoff the Fan munches through 1.25tonnes of air per second
• Combustion temperature is 2000c, the combustion chamber material melts at 1300c (it doesn't due to cooling)
• Although heavier, a 787 is half as loud as a 767
• The Trent 1000 engine has around 18,000 individual components and 35,000 parts.

The Vapour and Vortex:
I'm going to explain it as best I can in simple terms, for anyone who might be interested. So please don't think I'm insulting your intelligence if you already know some of the content. Here goes.

Air can suspend a certain quantity of water vapour within it based on the temperature of the air. The hotter the air, the more water can be held. The amount of water suspended in the air is known as relative humidity, it is the percentage of water in the air compared to the maximum it can hold for the temperature at the time.

Now, say the air was 25degC with 70% humidity, if we dropped the temperature to 20degC and the water content stayed the same, then the humidity would rise to 95%. At 19degC the humidity would be 100%, this is called the dewpoint. At the dewpoint the air can no longer hold all the water within it and so some is condensed into liquid water droplets that you can see as mist.

When the pressure of air (or any gas) is decreased its temperature also decreases. At the engine intake the air pressure is lower than ambient as the fan is acting like a big vacuum cleaner, so the temperature lowers and the humidity rises.

On certain days, when the humidity and temperature of the air are just right, the drop in pressure at the intake lowers the air temperature to below the dewpoint. The cloud and vortex are then visible. The vortex was there before, you just couldn't see it.

As for why the vortex forms in the first place, that's a much more complicated subject. It has to do with the updraft caused by the intake, the direction the wind is blowing, the fan spinning, and fluid dynamics. These are outside the limits of my knowledge I'm afraid. Thanks for watching!