@@bruno80292 Commercial engine tech here. I garantuee you the tip clearance between the fan and the casing is either 1mm or less. 2mm at most. While the engine is running that is. Believe me. It would blow your fucking mind if i could show you how close those blades are to scraping at the case at speed. (Theres a scrapable, destructible material on the casing around the fan just incase of that. It indicates when work needs to be done on it.) With turbine engines, *clearance. is. everything!* The less tip clearance you have anywhere in your engine, the less air slips by unused, and the better your engine will perform. The compressor blade clearances in the ge9x/ge90 most likely range between 0.5 mm and 1.5 mm depending on blade wear and thermal expansion wear on the casing.
I love how you can feel the ground vibrate sometimes when the GE-90 starts up. Best sound out of all the heavies I see at work. The 787 and A350 engines are nice too but the deep vibrations of a GE-90 cannot be beat.
Starting Engines during boarding? Probably if you fly with gulag air. Usually the planes are starting the engines if there is no person near to the plane/engines
@@arnabnath8428nah 777x has it. Also airlines arent going to waste their time and money on replacing their current fleet of 747's and a380's with those engines due to long term cost(cuz its 4 of the big bastards you have to put on them, so double the engines double the cost). Not to mention the 747 has to have taller landing gear because the engine is so god dam big it has to be angled😂 in order to fit. Its all about efficiency
This is the engine speed when you just landed, the reason why the plane is not moving because it's on brakes and there are some objects that wont let it go.
Can you imagine a 777 with GE90-115 in August 1949 next to a Comet? The engine was wider than the fuselage of the Comet and had 475% more power than the Comet's four engines combined and VERY quiet by comparison.
I remember waiting for flights inside New York JFK and Rome Fiumicino. Those GE90 starts are so beastly loud that they are one of the only things you can hear loud and clear inside the terminal. Might be the greatest jet engine type ever created.
*HA!* You ain't heard nothing yet. This is what's called "ground idle." This is the weakest setting the engine can run at while supplying power to the aircraft systems. Probably like 15%-20% power.
Until passed by its derivative, the GE9X, the GE90 series held the title of the largest engines in aviation history. The fan diameter of the original series being 123 in
heard one starting up at LAX. i was in the parking garage outside the terminal and the sound reverberated through the entire garage. i knew instantly what it was
Nothing better than hearing the kids crying and nervous flyer's faces when that rumble echoed through the ENTIRE cabin...it was glorious to operate on them
As an aircraft mechanic for over 35yrs years what blows me away is the fact that the 737 sitting in the hangar behind and to the right, has a fuselage diameter approximately the same diameter as the engine cowling of the triple seven!
I've only ever been on board A320s, 737s, Dash 8s and a museum Concorde so it's extremely hard for me to grasp how absolutely huge those engines actually are
@@zacharysylvester8349 i watched a documentary about 9/11 and how they hurried the oresident bush with his staff to AF1 and how they were hauling ass out if the airport like a bat out of hell. Apparently they had to alternate fighter jet planes to escort it around the skies because it was going to fast the jets were burning fuel just trying to keep up. I did some digging in around snd i found out that for them to burn fuel at that ratem the airforce 1 had to be going over 550 mph. Which is shocking for a 747. But i think AF1 have a top speed of mach .90 I know. But who are yo dictate to the airforce i suppose. Its all hersay for now. But I do know that current airforce one utilizes two 787 engines for the inner ones and larger engine size of 757-300 for outer. That i k ow for a fact. I spotted airfoce one 1 2 years ago and I didn't believe how massive the 747 engines were. I know what typical 747 engines are. And typical they were not.
@@aky19832001 Wrong. The VC-25A uses four CF6 engines, while the VC-25B uses four GEnx engines. And the C-32 uses two RB211 engines, while the other plane uses CFM56 engines.
Believe it or not, most of the resistance comes from the compressed air in the HP stages of the compressor. But once it's connected power wheels get going, it's a totally negligible force.
How come at 1:30 it sounds like the engine stops ramping up but then the sound comes again a second later at higher pitch? Have noticed several times when flying in a 777.
@@CaptainTransit U mean initially a starter motor and bleed air is used to start the engine to some RPM then the fuel is introduced which further spools up the engine to IDLE rpm right ??
This is a sound I won’t forget as a passenger- on the older British Airways 200ERs I remember, you can literally hear the plastic paneling of the cabin rattling as the engine howls on startup
That is the Auxillary Power Unit, or A.P.U. for short, running in the rear of the aircraft. It's basically a gas turbine engine that produces electricity and hydraulic power, and also can supply pressurized air to start the engines. Pilots typically leave it on so they can start their engines without needing a Ground Power Unit (or G.P.U. for short).
@@davecrupel2817 oh i understand now.....that was also something that I wanted to know actually....i thought it was like a mini turbo engine like that on a military aircraft
@@SSaugaCriss Usually if there is a fault with an IDG and your company's MEL (minimum equipment list) allows you to defer the defect. The engine must be at or above idle speed to enable a disconnect via the overhead switch. Disconnecting energizes a solenoid and opens a clutch in the IDG.
@@SSaugaCriss 777 has a pneumatic starter so it must have an air source for ground start. Either APU, ground start cart or doing a X-bleed from the other engine.
You're a little light, Stephen. More than 100 F1's combined. The GE90's strength is commonly measured in pounds of thrust but it equates to over 100,000 horsepower. GE90-115 fun facts: 9'7" in diameter, weighs 18,000 pounds (although the carbon fiber fan blades only weigh about 1200 pounds combined), cost $40 million apiece and on a test stand, it's been pushed to over 125,000 pounds of thrust, making it the most powerful jet engine in existence. Two of these big boys can shove a 700,000 pound aircraft through the air at 550mph for 10,000 miles.
The best sound in the world imo. It sounds amazing in video, but it's nothing compared to being inside the actual aircraft during takeoff. This is a beast.
I hear these things spooling up on the cargo side of O'Hare from the last place where I lived. That low 1:10 BWOOOOOOOOOOOOOOOOOOOO sound is very therapeutic especially late at night.
