This video is more awesome than people may realize. This video captures the following visual information I have not seen in other videos. First, it shows clearly how the air flow volume is actually only a thin cylinder around the spinning fans. Most pepole don't realize that air hitting the engine does not go through the engine even close to the center. Second, it shows how this particular kind of engine has not one but two coaxial counter-rotating shafts. Three, it clearly shows the angle of the compressor blades (I mean the moving blades) and the stator blades (the fixed position blades along the outside). Fourth, the second and third features combined allow you to imagine how the air flows from the forward exterior fan, gets pushed through and will start spiralling, and the *spiral* flow from the front engine fan then meets the first row (part of first stage?) of compressor blades at a *low* angle of attack (the blades are efficiently moving through spiraling air like a wing). I always wondered how the blades were not acting like a wall pushing air. It's because the air coming at them is spiraling and not racing straight in. This reduces the angle of attack, so the compressor blades don't create turbulence (or stall). Then you can imagine (yes, you need to imagine) how the first row of blades starts reducing the spiral flow, so the next row of blades needs to be angled to face more of an axial than spiral flow. This continues through the compressor stage. The video does fail to mention there are two stages (or three? if you count the front blade?). From what I call the first stage, the air still has some spiral motion, and the second stage of blades then rotates in the opposite direction from the first, allowing the blades (like before) to meet the air with less angle of attack. This allows for reduced turbulence/stalling while allowing the blades to do more work. Again, the fans have less and less angle as you go from front to back. All while this is happening, look how very little space the air is moving through. It gets smaller! Now, an engine working at a steady speed always has a steady amount of air mass moving through it (lets say pounds per minute). Each slice of the engine has the same flow rate. Where I pointed out the cylinder gets smaller, the mass moving through has less space, so it must be more dense. That means it *must* be at higher pressure (unless you could magically cool it to reduce the pressure). So, you see the air must be flowing through at higher and higher pressure. Then, when it gets past the second stage (second set of fans), the flow is allowed to expand where it meets the fuel. NORMALLY, expanding air flow reduces the pressure. However, the fuel is ignited at the expansion point. The heat is just like an explosion - it prevents the pressure from dropping. So, you go from a narrow, high-pressure flow to an expanded area with similar pressure. Note - the pressure is NOT greater in the combustion chamber than right upflow. If it were, the flames would move forward. No, the pressure actually DROPS in the expanded flow in the combustion chamber but not much. However, although pressure keeps dropping from final compressor fans to combustion, the ENERGY/work put into the air dramatically increases due to the burning fuel that is preventing the pressure drop in the expanding flow volume. Then, this air is once again squeezed through a narrowing opening, speeding it up and meeting the exit stage of the turbine. (I don't know the terminology.) I may sound rambling, but my point is - I have not seen a video that allows you to see the moving parts this way. I am especially stunned I did not know (a) how narrow the air flow cylinder is and (b) that the engine has counter-rotating shafts, one poking through the other. Cool!
@@vagabond630 this man just spent the good part of a day detailing his opinion on this, and you ask HIM why there are turbines? Watch the video dumbass
@@untrust2033 fuck you man, I wanted to know If there are turbines, won't there be energy loss? The velocity of the gas ejecting out would be reduced. But then again is the thrust actually produced by the exhaust? or the thrust is actually produced by the fan sucking in the bypass air and this fan is powered by the turbines?
Very cool. I didn't know the blades turn in opposing directions... I've seen these engines in museums cut open to see inside, but I couldn't figure out how the things don't just shoot flame out of both ends!
So lemme get this straight, a Jet engine is basically a recoilless rifle and a turbo conjoined to make continuous combustion a reality. I thought these engines were much more complicated than regular combustion engines but it seems I was wrong; they seem much simpler than a regular car/truck engine!
Yeah, they're really not conceptually complicated. The difficulties in the development of the jet engine were more about the comparatively advanced material science and manufacturing side.
This is all amazing, but I still also love even more watching a simple afterburner take-off and feeling it rattle my bones! :-D Well, I guess I can't do that anymore. I only served a brief time and I am not near SR-71s or other AB-equipped jets that are taking off. (OK, nobody is near SRs taking off anymore, but one time I had a single privilege of witnessing that.)
@@BrunoBoy3913 - I saw mine at Beale. I was with a small summer contingent of USAFA cadets that stayed there a couple of days. Operation CONUS was the name of the program I was in. Small groups of cadets were sent to tour various groups of three bases for two weeks. My group was Beale, McClellan, and Travis. (A few years later I ended up serving at Travis as a lieutenant in the Travis 22nd AF Ops center Weather Support Unit, plus doing flight line wx briefs and forecasting). I remember touring the Beale maintenance facilities and one airman animatedly expressing his passionate hate about how often his uniform got wet from all of the leaking fuel and hydraulics, plus all the laundering required! That was kind of funny. He and some others were not fond of the Marysville area. What did they want, New York City? That's life in the AF for most people. So, we got to see a daytime takeoff of a U2 and a takeoff of a Blackbird, plus a sit in the simulator - but it was off and a few things were covered up. The sim was cool and lame at the same time. Us cadets were a little bummed, as we had heard from others how they were given flights in F-15s or at least cool sim rides at their respective bases. We ended up riding in KC-135 that refueled a Blackbird. We each joined the boom operator for a bit. That was a special treat. How many people get to do that? I think the ride doubled up refueling F-16s as well, or maybe that was another tanker ride. It is still amazing (to anyone not in a coma) how superior the Blackbird was to anything else that ever flew high and fast.
I would like to understand : how axes are interconnectet / or not ? Which turbin moves the fan ? Why the last turbin is spining in opposite direction of the big fan ?
Viewers out their i would like to know the program used to come up with the animations in this video clip, I will be grateful from your positive response.
@@nicholasaquino5160 Yeah flying an aircraft does not mean you know a jet engine, with all due respect. I work for GE and have worked for CFM / Safran in the past. here is a tip : noise leads to vibrations and losses making engine inefficient. in lay man's term. An old inefficient engine would make noise.
Just contact Pratt & Whitney, I cannot guarantee they will sell an individual engine however. It will also be rather pricey. It's not some magical thing that's impossible to obtain, like the other two comments suggest.
if you put a tesla coil on the cone of a jet engine, would it create plasma as it was sucked into the engine for more thrust? also would it pull hydrogen out of the air that would com-bust as it went threw engine? since electricity is used to pull hydrogen out of water and there is moister in the air?
That would not really be functional, and certainly not practical. The Tesla coil would be more trouble than it's worth, quite possibly screwing with all the other electrical systems on the craft, and shielding that would be too much work to make it feasible. It would not create a noticeable (if any) boost in performance. Many aircraft engines (both jet and piston) run better with colder air intake. And even flying through a cloud would not give a reasonable amount of hydrogen using such a method. Oh and final point, just having a random amount of hydrogen going into the engine will completely ruin fuel efficiency, because the air/fuel mix is perfectly balanced for maximum power with minimal fuel. Adding varying amounts of hydrogen will throw off the fuel/oxygen mixture from the air, negating any benefit.
The bypass ratio is about 10, but the thrust ratio os always lower. The actuall ratio depends on speed, thrustsetting and altitude. But typically in cruse something like 5 or 6.
Impressive stuff, but let's forever remember that without Sir Frank Whittle, English inventor of the jet engine, none of this would be possible. As an Air Commodore, the RAF will be forever proud of Frank.
if the blades at the front are rotated by the blades at the rear through a shaft when compressed air is ignited then how come there is compressed air already in the chamber during engine start up when front blade is at rest? sorry dumb question
It's not a dumb question. A jet engine is a bit like a car engine with regards to starting it. Both types of engines require being spun into motion first to get them going. A car uses an electric motor to spin it and start it. Jet engines use a small turbine that drives the turbo-compressor assemblies through a gearbox and drive shaft. High pressure air is driven through the starter turbine from an air source like the APU or an external starter cart. The starter spins up the engine to a minimum RPM to get it started just like in a car.
Hans Eco because the exhaust air is typically moving much faster than the aircraft is capable of, therefore the exhaust will basically be like a tire on the ground during a burnout, not very efficient. The bypass air moves AT MOST 650mph in the duct.
It's more efficient if the speed that the air is being ejected at roughly matches the speed of the airplane. A turbofan engine is actually a hybrid between a propeller airplane and a turbojet. The fan does most of the work low and slow. Then the core does most of the work up high and going fast because the ejection speed of the core is higher than the fan.
The animation suggests air takes a helical path through each stage but reverses through each successive stage. Why is that, counterspin that reduces torsion?
The most efficient engine is one that spits out a stream of air at almost the same velocity of the external airstream. So if your plane flies at 560 mph, a high bypass engine will dump air out the back at just below the speed of sound.
Path Finder, there isn't a starter motor, the APU supplies compressed air. A motor would be ineffective (fans are EXTREMELY MASSIVE - using a motor would take a long time to start the engine).
kinda like in your car where air comes in the where the spark plugs spark and gas is sprayed as a mini bomb make the pistons move up and down thats the thrust to push and make camshift go
Thank you! Finally an animation that shows the propellers rotating the right way.
This video is more awesome than people may realize. This video captures the following visual information I have not seen in other videos. First, it shows clearly how the air flow volume is actually only a thin cylinder around the spinning fans. Most pepole don't realize that air hitting the engine does not go through the engine even close to the center. Second, it shows how this particular kind of engine has not one but two coaxial counter-rotating shafts. Three, it clearly shows the angle of the compressor blades (I mean the moving blades) and the stator blades (the fixed position blades along the outside). Fourth, the second and third features combined allow you to imagine how the air flows from the forward exterior fan, gets pushed through and will start spiralling, and the *spiral* flow from the front engine fan then meets the first row (part of first stage?) of compressor blades at a *low* angle of attack (the blades are efficiently moving through spiraling air like a wing). I always wondered how the blades were not acting like a wall pushing air. It's because the air coming at them is spiraling and not racing straight in. This reduces the angle of attack, so the compressor blades don't create turbulence (or stall). Then you can imagine (yes, you need to imagine) how the first row of blades starts reducing the spiral flow, so the next row of blades needs to be angled to face more of an axial than spiral flow. This continues through the compressor stage. The video does fail to mention there are two stages (or three? if you count the front blade?). From what I call the first stage, the air still has some spiral motion, and the second stage of blades then rotates in the opposite direction from the first, allowing the blades (like before) to meet the air with less angle of attack. This allows for reduced turbulence/stalling while allowing the blades to do more work. Again, the fans have less and less angle as you go from front to back. All while this is happening, look how very little space the air is moving through. It gets smaller! Now, an engine working at a steady speed always has a steady amount of air mass moving through it (lets say pounds per minute). Each slice of the engine has the same flow rate. Where I pointed out the cylinder gets smaller, the mass moving through has less space, so it must be more dense. That means it *must* be at higher pressure (unless you could magically cool it to reduce the pressure). So, you see the air must be flowing through at higher and higher pressure. Then, when it gets past the second stage (second set of fans), the flow is allowed to expand where it meets the fuel. NORMALLY, expanding air flow reduces the pressure. However, the fuel is ignited at the expansion point. The heat is just like an explosion - it prevents the pressure from dropping. So, you go from a narrow, high-pressure flow to an expanded area with similar pressure. Note - the pressure is NOT greater in the combustion chamber than right upflow. If it were, the flames would move forward. No, the pressure actually DROPS in the expanded flow in the combustion chamber but not much. However, although pressure keeps dropping from final compressor fans to combustion, the ENERGY/work put into the air dramatically increases due to the burning fuel that is preventing the pressure drop in the expanding flow volume. Then, this air is once again squeezed through a narrowing opening, speeding it up and meeting the exit stage of the turbine. (I don't know the terminology.) I may sound rambling, but my point is - I have not seen a video that allows you to see the moving parts this way. I am especially stunned I did not know (a) how narrow the air flow cylinder is and (b) that the engine has counter-rotating shafts, one poking through the other. Cool!
can you explain me why are there turbines?
@@vagabond630 this man just spent the good part of a day detailing his opinion on this, and you ask HIM why there are turbines? Watch the video dumbass
Wow! Maybe you can re-narate the video. Your in-depth observation is what I needed.
@@untrust2033 fuck you man, I wanted to know If there are turbines, won't there be energy loss? The velocity of the gas ejecting out would be reduced. But then again is the thrust actually produced by the exhaust? or the thrust is actually produced by the fan sucking in the bypass air and this fan is powered by the turbines?
bruzote you mentioned everything Except the FREQUENCY of the compressed air. ;)
The sound effects helped me understand better, thanks Pratt & Whitney!
Very cool. I didn't know the blades turn in opposing directions... I've seen these engines in museums cut open to see inside, but I couldn't figure out how the things don't just shoot flame out of both ends!
Thank you pratt & whitney..only video that has made sense..now I understand jet engines
This was a really well animated video and it was very easy to understand thank you!
I like bow P&W put what is basically an equivalent of 'buy my merch' at the end ))
That made so much sense. So glad I could learn this!
One of the most educative adverts I've seen in a while
Fantastic video. Thank you!
The trick to higher fuel efficiency? An amazing gear.
Haha 😂
Thanks for making it so simple.
"an amazing gear" ok
Considering this video is an advertisement for their new planes it's no surprise they've dumbed stuff down so anyone can understand it.
fucking awful lol
Planetary would be too confusing here.
That's all you need to know... Lol
😂 😂 😂
Explanation is really clear!
Beautiful explanation.I understood the jet engine concept clearly.Ty and keep it up.
Keep it up? they have been supplying engines to legendry aircrafts for decades
1:24 me after Taco Bell
Jackal lol
lol
I am the 69th like, so please don’t like exept if you are going to like this comment up to 6.9K
@@doapin6240 after opening the page I see like counter is 69, don't worry I won't change it
lol
I really liked the video, thanks!
Thank you very much, I'm just studying the principle of jet engine compressorsk. Thank you for show me this close look.
Thank you 🙏🏼 I love Pratt & Whitney ❤ amazing video
i can watch vids like this all day
Why so hyped and the music does my head in, what good does that do.
anything that works on action reaction philosophy will work wonders until physical limitation comes in. this is why i love this
I already knew how they work but I enjoyed watching it anyway. Good video
hi there. can I use 10 seconds of this clip for educational purpose in my own language?
So lemme get this straight, a Jet engine is basically a recoilless rifle and a turbo conjoined to make continuous combustion a reality.
I thought these engines were much more complicated than regular combustion engines but it seems I was wrong; they seem much simpler than a regular car/truck engine!
i agree its much simpler than a car engine just that there are alot of blades spinning to compress the air sucked in
There are WAY less moving parts, which results in smoother operation while being simpler.
Yeah, they're really not conceptually complicated. The difficulties in the development of the jet engine were more about the comparatively advanced material science and manufacturing side.
This is all amazing, but I still also love even more watching a simple afterburner take-off and feeling it rattle my bones! :-D Well, I guess I can't do that anymore. I only served a brief time and I am not near SR-71s or other AB-equipped jets that are taking off. (OK, nobody is near SRs taking off anymore, but one time I had a single privilege of witnessing that.)
I did too. I was stationed at Beale AFB where nine of them were kept. Watched from the flight line. Bone rattling amazing
@@BrunoBoy3913 - I saw mine at Beale. I was with a small summer contingent of USAFA cadets that stayed there a couple of days. Operation CONUS was the name of the program I was in. Small groups of cadets were sent to tour various groups of three bases for two weeks. My group was Beale, McClellan, and Travis. (A few years later I ended up serving at Travis as a lieutenant in the Travis 22nd AF Ops center Weather Support Unit, plus doing flight line wx briefs and forecasting). I remember touring the Beale maintenance facilities and one airman animatedly expressing his passionate hate about how often his uniform got wet from all of the leaking fuel and hydraulics, plus all the laundering required! That was kind of funny. He and some others were not fond of the Marysville area. What did they want, New York City? That's life in the AF for most people. So, we got to see a daytime takeoff of a U2 and a takeoff of a Blackbird, plus a sit in the simulator - but it was off and a few things were covered up. The sim was cool and lame at the same time. Us cadets were a little bummed, as we had heard from others how they were given flights in F-15s or at least cool sim rides at their respective bases. We ended up riding in KC-135 that refueled a Blackbird. We each joined the boom operator for a bit. That was a special treat. How many people get to do that? I think the ride doubled up refueling F-16s as well, or maybe that was another tanker ride. It is still amazing (to anyone not in a coma) how superior the Blackbird was to anything else that ever flew high and fast.
Hi @Pratt & Whitney , may I know what kind of software are you using for this animations ?
Pratt & Whitney J58 May I know how it works that engine and how to rebuild it 👍?
A very useful video. Thank you!
Freaking amazing video . Thanks 👏👏
Pratt & Whitney -- Dependable Engines, Enduring Freedom.
Annoying music, but interesting nonetheless.
studies show you retain more when listening to music
@@cwr8618
Studies are also wrong sometimes, because the music was certainly distracting and annoying in this video.
@@AlainHubert easy tiger, just sharing a thought
eh, didn't mind it much, but you have a point
I mean that's YOUR opinion.. I enjoyed it and the video. Thanks for sharing your comment..
One of the best and simple explanation
Another question, where is the rotating assembly suspended? And how are the bearings cooled?
Best explanation I’ve seen.
Best explanation i ever had on jet engines thank you
tego the best to oni ci tutaj nawet nie powiedzieli ;)
Best explanation so far!!
Please loose the irritating music. Good video.
@Hull's Production's yes
@Hull's Production's lol
Get rid of that horrible music & just let the boy talk!
Seconded.
It helped me focus
This is the best explanation so far ❤
what made the turbin spin?
Hey please look into the issues of neo 320 engine failures . 2 weeks ago another indigo flight.
Fantastic video, kindly make more and more PW videos...
So what percentage of total thrust is made up by the turbofan vs. the jet turbine?
this has the best 3d animation than other videos
I would like to understand : how axes are interconnectet / or not ? Which turbin moves the fan ? Why the last turbin is spining in opposite direction of the big fan ?
Best explanation!
Yea, but it is still unclear to me how do those engines start.
Extremely Intriguing
Thanks for this educational video
Informative
Fantastic music in the background and also smart and to the point explanation.A Dey❤❤❤
Can you tell me which software to use to simulate?
Viewers out their i would like to know the program used to come up with the animations in this video clip, I will be grateful from your positive response.
Nice video very good explanation..
Thanks for video
Very good video. Helped me!
Bring back the LOUD JT8D's. That's how a jet engine should sound"❤
Wht nonsense. You have no idea what a jet engine should be like
No maybe flying since 1984. Nahh" I Probably forgot more about a jet engine then you'd know!!!!!!!
@@nicholasaquino5160 Yeah flying an aircraft does not mean you know a jet engine, with all due respect. I work for GE and have worked for CFM / Safran in the past. here is a tip : noise leads to vibrations and losses making engine inefficient. in lay man's term. An old inefficient engine would make noise.
Pratt and Whitney is my favourite engine manufacturer
where can I buy one of this new jet engines, they look amazing
deep web
Just contact Pratt & Whitney, I cannot guarantee they will sell an individual engine however. It will also be rather pricey. It's not some magical thing that's impossible to obtain, like the other two comments suggest.
How does it start? thanx, good video. ...... I have been wondering that all my life3.
"An AMAZING gear" lmao what, the revolutionary secret to fuel efficiency has been an amazing gear all along
Good explanation & clear animation,keep up
Awesome bro!
Can I use your video on my channel for educational purposes? I will share my audience by sending them to your channel to view the full video!
I like ur video love u bro
Pratt and Whitney made the sr 71 what it was. Legendary
What type of bearing and lubricant being used, can you please tell me.
The background music is so amazing any link for the site or artist ?
Rugrats - theme song
Repeat after me...Tur-bine, Tur-bine...Sikhs wear turbans.
In Britain it sounds like he's referring to the Sikh head dress...it's amusing...
What? Dude I know he’s got like a tiny Brituish accent or something but no. That’s really not how say it, at least not in American English.
Ok that was really stupid and random. Dont know what point you're trying to make here.
@@MAK3212 The point that hearing Americanised English can be funny and annoying at the same time to people who actually speak English?
You take the blonde, I'll take the one in the turban! ruclips.net/video/SrAs4xnFOZc/видео.html
At least this one got the rotation of the fan right
Thank you Uploader and my sweetheart Angel KD 😘 😘😘💕👩❤️💋👨👌 👌
what energy rotate those blades ? how the blades get initial velocity ?
Thanks to pumping air by smaller turbine in rear of plane, that starts thanks to electric motor.
The video is awesome. Please what is the artist/sight name of the background song, playing on the background? It is very nice.
Yes, everything is like squeezing a balloon..
Which part of this engine is grounding all the NEOs?
if you put a tesla coil on the cone of a jet engine, would it create plasma as it was sucked into the engine for more thrust? also would it pull hydrogen out of the air that would com-bust as it went threw engine? since electricity is used to pull hydrogen out of water and there is moister in the air?
That would not really be functional, and certainly not practical. The Tesla coil would be more trouble than it's worth, quite possibly screwing with all the other electrical systems on the craft, and shielding that would be too much work to make it feasible.
It would not create a noticeable (if any) boost in performance. Many aircraft engines (both jet and piston) run better with colder air intake.
And even flying through a cloud would not give a reasonable amount of hydrogen using such a method.
Oh and final point, just having a random amount of hydrogen going into the engine will completely ruin fuel efficiency, because the air/fuel mix is perfectly balanced for maximum power with minimal fuel. Adding varying amounts of hydrogen will throw off the fuel/oxygen mixture from the air, negating any benefit.
What's the ratio of the thrust produced by the core exhaust air and peripheral exhaust air?
The bypass ratio is about 10, but the thrust ratio os always lower. The actuall ratio depends on speed, thrustsetting and altitude. But typically in cruse something like 5 or 6.
thank you!
"A Kind of super gasoline" seems to be confusing the engineers here.
...and the bypass air also expels most of the water you get from storms etc rather than it going through the turbine.
Impressive stuff, but let's forever remember that without Sir Frank Whittle, English inventor of the jet engine, none of this would be possible. As an Air Commodore, the RAF will be forever proud of Frank.
Sir Frank was a true visionary, like fellow Englishman Alan Turing who created the programmable computer.
Great explanation👍
I'm sold! So where is my " buy one and get one free" button?
That's good information 💯😍
The direction of rotation of fan is opposite of direction of rotation of turbine with same spool? is that correct?
Very good video my friend!!! but i was wondering how the fan is powered?? By electricity or by fuel??? Anyway keep up the good work!!
Both the fan and the compressor are powered by the _turbine,_ which is powered by the hot, high pressure gas produced in the combustion chamber.
czyli, krótko mówiąc, ani prąd, ani paliwo nie porusza tymi urządzeniami ;) bardzo, ale to bardzo interesujące@@fromnorway643
fantastic explanation
Wow well explained👏👌
what source rotate the turbine fans ?
if the blades at the front are rotated by the blades at the rear through a shaft when compressed air is ignited then how come there is compressed air already in the chamber during engine start up when front blade is at rest? sorry dumb question
Actually the apu provides compressed air for the startup, then the engine powers itself
It's not a dumb question. A jet engine is a bit like a car engine with regards to starting it. Both types of engines require being spun into motion first to get them going. A car uses an electric motor to spin it and start it. Jet engines use a small turbine that drives the turbo-compressor assemblies through a gearbox and drive shaft. High pressure air is driven through the starter turbine from an air source like the APU or an external starter cart. The starter spins up the engine to a minimum RPM to get it started just like in a car.
Question: why is it better for the secondary air to move slower than the air coming out of the exhaust?
Isnt it more efficient for the secondary air to move quicker since it helps produce more thrust and cools the combustion chamber?
Hans Eco because the exhaust air is typically moving much faster than the aircraft is capable of, therefore the exhaust will basically be like a tire on the ground during a burnout, not very efficient. The bypass air moves AT MOST 650mph in the duct.
It's more efficient if the speed that the air is being ejected at roughly matches the speed of the airplane. A turbofan engine is actually a hybrid between a propeller airplane and a turbojet. The fan does most of the work low and slow. Then the core does most of the work up high and going fast because the ejection speed of the core is higher than the fan.
i get it now. Thanks guys and safe skies!
The animation suggests air takes a helical path through each stage but reverses through each successive stage. Why is that, counterspin that reduces torsion?
Please make a video of pressure cleaner.
Very impressive!
Pretty badass! Slow down the fan for more thrust & better efficiency. Who'da thought!😉
The most efficient engine is one that spits out a stream of air at almost the same velocity of the external airstream. So if your plane flies at 560 mph, a high bypass engine will dump air out the back at just below the speed of sound.
I understand. Very good.
GREAT VIDEO
Nice explanation.
I love my company. We, the dependable people with dependable engines.
the thrust force acts opposite to the engine so it can lift with max velocity
Great video.
How does the front fan begin to pull the air in if combustion is at the back?
Josh Holden hi my friend
There's a starter motor usually, it rotates the front fan until the engine becomes self-sustaining.
The back blade is connected to the front blade by a shaft
Josh Holden o
Path Finder, there isn't a starter motor, the APU supplies compressed air. A motor would be ineffective (fans are EXTREMELY MASSIVE - using a motor would take a long time to start the engine).
kinda like in your car where air comes in the where the spark plugs spark and gas is sprayed as a mini bomb make the pistons move up and down thats the thrust to push and make camshift go