One important correction, N1 rotation begins before fuel is introduced. When the N2 shaft is spun by the starter, it will suck air through the engine, which will turn the N1 shaft at a low speed. This rotation must be confirmed before fuel is introduced, as lack of N1 rotation could indicate a seized engine.

@JxJAVIATION

3 жыл бұрын

Thank you for the information!

@muzzafariqbal4648

Жыл бұрын

@@JxJAVIATION Thank you for jet engine start steps.

@Echo_Lima

Жыл бұрын

thank you very much

@Heisenberg2K

Жыл бұрын

Thank you, I have always wondered about that. Thanks for explaining.

@iulianstoican1119

Жыл бұрын

Good explanation, I was wondering how N1 starts, now I know...

Where has this video been my whole life? I've watched so many videos just to understand this but they all deviated. Thanks a lot. Good video.

@JxJAVIATION

3 жыл бұрын

You're very welcome! Please do Watch other videos on my channel as well.

@Sanctustormentor

3 жыл бұрын

You should also watch this one. It is also as good kzread.info/dash/bejne/ea6cxtqMo9K6YMo.html

You nailed it! This is so good I chose to use it in my classroom of aircraft mechanics students.

@JxJAVIATION

3 жыл бұрын

WOW! Thank You. A PLEASURE!

I’m an A+P who no longer works in the industry so I really appreciated that you did not call this a jet engine but a turbo fan. Most high bypass engines have a twisted arrow on the inlet so the crew can verify the correct rotation before initiating ignition and fuel. Thanks again!

@JxJAVIATION

Жыл бұрын

You are Welcome! Check out my other videos as well!

@majestikstyle

Ай бұрын

I am confused. This isnt a jet engine?

@powerwagon3731

Ай бұрын

@@majestikstyle It’s not a true jet engine It’s a turbine which uses a series of compressor blades mounted on wheels in the convergent duct thus compressing the air. After which fuel and ignition are introduced in the hot section driving another series of blades in the divergent duct mounted to a common shaft that also drives the compressor section. A high by pass fan is also used for thrust around engine case . A true jet is much simpler in design.

Thanks so much for the info, nobody out there explaining “how a turbine works” shows how the turbine starts or accelerate. Thanks again ❤️

@JxJAVIATION

2 жыл бұрын

You are Welcome! Check out my other videos as well!

This Video would be WAY BETTER with out the robot voice

@stankakol5195

3 жыл бұрын

Very true. That robot voice sucks.

@jevanmcfarlane16

2 жыл бұрын

True

@captainemerald7308

Жыл бұрын

False

@Mongoliantreecow

Жыл бұрын

Forreal, if you take pride in what you do you should be confident in speaking your knowledge

@outerrealm

Жыл бұрын

He doesn’t give a $hit because he’s too lazy to bother.

Thank you. As a flight sim enthusiast I really wanted to understand the N2 importance initially and why N1 is important later for most of the flight. You nailed it.

@JxJAVIATION

3 жыл бұрын

Thank you mate!

@KingdaToro

Жыл бұрын

Think of it this way: N1 is your thrust, and N2 powers your systems. The N1 shaft has many more turbine stages, in order to extract as much energy as possible from the jet exhaust and use it to run the fan. That's where most of your thrust comes from. The N2 compressor gives you bleed air, which runs your AC, anti-ice, and engine starters. The gearbox linked to the N2 shaft runs a generator and a hydraulic pump.

This is the most crisp and on the point explanation of turbofan engine start i have ever watched. Thanks a ton for your work. Liked and subscribed.

@JxJAVIATION

3 жыл бұрын

Thank you so much! :)

@gowdsake7103

Жыл бұрын

With a shit computer generated voice ? WOW

One of the things I did on pushbacks, before I give the pilots permission to start. I notice the wind. A strong rear wind would turn the fan blades in the opposite direction. If the wind is really strong from the rear, I would alter the angle in order to prevent a hot start.

@JxJAVIATION

3 жыл бұрын

That's very interesting information! thank you! :)

@Charlesrangerover

3 жыл бұрын

I want to learn this

@hugolafhugolaf

Жыл бұрын

What is a hot start? Very interesting!

@As_A________Commenter

Жыл бұрын

It’s always refreshing to work with push back crews who have that kind of situational awareness

@As_A________Commenter

Жыл бұрын

@@hugolafhugolaf in order to make more power, engines must get hotter. We measure this heat by the temperature of the gasses that are exhausted out of the engine, known as exhaust gas temperature or EGT. During an engine start, the EGT is monitored to not exceed a certain value before the engine is started and stabilized. If it does exceed this value, that is known as a hot start.

Thanks, I dont know why so many videos skip how to initially get the turbine spinning, that's what I needed to know.

@JxJAVIATION

3 жыл бұрын

You are Welcome!

Thank you very much for sharing this information, you took away the darkness of my ignorance.

@JxJAVIATION

3 жыл бұрын

Glad it was helpful!

Really great explanantion. Thank you. My lecturer insist us to watch this vid, does not have any regret at all. 🔥🔥🔥

@JxJAVIATION

3 жыл бұрын

You are welcome! This has definitely made my day today. Thank you. Do watch my other videos as well and please share. :)

You're videos are so educational thank you for sharing!

@JxJAVIATION

3 жыл бұрын

thank you for watching!

Thanks, Stephen Hawking, that was super education!

@JxJAVIATION

2 жыл бұрын

Thank you so much man! Made my day!

@egregiousqueef7781

2 жыл бұрын

@@JxJAVIATION ... al. EducationAL. But also a super _free_ education, so I guess it kinda fits! I just had to replace a torque converter on a car and there are similarities, that's how I arrived at your video. Plus TheFlightChannel is like super addicting, and also super sad and frustrating Thanks again! I'm all about making days!

@JxJAVIATION

2 жыл бұрын

@@egregiousqueef7781 Great to have you onboard! Check out my other videos as well. As you mentioned its free aviation education! :)

Beautifully explained... Looking forward for more videos!!! 💯

@JxJAVIATION

3 жыл бұрын

Thank You so much! Please do share the videos! and Watch my other videos as well!

@jasminderpinder

2 жыл бұрын

I have to agree. Your clear and easy-to-understand explanations together with the fantastic animations are first rate! Well done and thank you.

This video just solved one of the biggest doubts i had as aplane enthusiats. Thank you very much, and you've gained a new subscriber :)

@JxJAVIATION

2 жыл бұрын

Thank You so much and WELCOME! Check out some of my other videos as well!

@lewismuange3786

2 жыл бұрын

What were you doubting if I may ask

@CheapBastard1988

Жыл бұрын

@@lewismuange3786 Well I understand why many people are wondering what is right, as I've seen multiple TV shows telling it wrong. I even remember the startup sequence being described as "compressed air pushing down the pistons" in "Ultimate Airport Dubai". Which is of course laughable.

AWESOME video The diagrams are very easy to understand and the slow-rate voice really helps to follow the explanation. Thank you

@JxJAVIATION

3 жыл бұрын

You are Welcome!

2:59 finally a video explaining what started the engine! Most videos just start with "air is sucked in" lol

@JxJAVIATION

2 жыл бұрын

Cool! :)

very neat, concise and clear presentation

@JxJAVIATION

3 жыл бұрын

Thank You!!

This was a huge help, best one I've seen. Well done!

@JxJAVIATION

2 жыл бұрын

Thank you so much. Do check out my other videos as well!

absolutey FANTASTIC! thank you!!

@JxJAVIATION

Жыл бұрын

You are welcome. Check out my other videos as well

You are the MAN!! This video is the best ever!

@JxJAVIATION

3 жыл бұрын

Thank you so much!!

Superb demonstration

@JxJAVIATION

3 жыл бұрын

Thank you so much!

Sir this video, i like most. Marvelous video. Thank you sir.

@JxJAVIATION

3 жыл бұрын

thank you and welcome!

Very straight forward, excellent explanation, thank you! /ATPL student

@JxJAVIATION

Жыл бұрын

Thank you! Check out my other videos as well! Could be useful!

thanks a lot for this video....crystal clear

@JxJAVIATION

3 жыл бұрын

You are welcome!

Oh thank you so much for this info.

Nice work! Very helpful!

I'm fascinated with aviation and always learn something new everyday. Thanks 👍

@JxJAVIATION

6 ай бұрын

Thank you! Check out my other videos as well!

The accessory gearbox is like a drive belt on the cars. It drives the fuel pump and the oil pump and the hyrdaulics. It is driven by the Hp turbine. So to drive the Hp turbine itself we can drive this gearbox itself.

@JxJAVIATION

3 жыл бұрын

That is a good explanation!

Impressive, easily understandable

@JxJAVIATION

3 жыл бұрын

Do watch my other videos as well!

Super informative and im looking forward to more videos 🙂

@JxJAVIATION

3 жыл бұрын

Thank You!!

Thanks good explanation.

@JxJAVIATION

3 жыл бұрын

Thanks for watching!

GREAT PRESENTION. I enjoyed the video fully. Thanks for sharing ✈️🛫

@JxJAVIATION

2 жыл бұрын

Thanks for watching! Do Check out my other videos as well!

@aircraftmaintenanceinsider

2 жыл бұрын

Of course

There’s always a portion of magic in the procedure nobody has ever fathomed

@JxJAVIATION

10 ай бұрын

That is the beauty of it!

Very clear explanation 👍

@JxJAVIATION

3 жыл бұрын

Thank You!

Most find qn answer how jet engine starts.....thanks man

@JxJAVIATION

3 жыл бұрын

No problem!

Great explanation sir ! It's just mind-blowing awesome...

@JxJAVIATION

2 жыл бұрын

Thanks a ton! :)

Very nice explanation, it is easy to understand it. Thanks!

@JxJAVIATION

3 жыл бұрын

Glad it was helpful!

great video, thanks

@JxJAVIATION

3 жыл бұрын

You are Welcome!

Its 2020 and flight schools still teaching trash. Best way to teach airplane systems is either with real airplane opened or watching videos like this from someone that really knows his stuff.

@JxJAVIATION

3 жыл бұрын

Thank You! It really means a lot!!

Great explanation. Thank you.

@JxJAVIATION

2 жыл бұрын

You are Welcome!

I am exciting this video. This is so good I chose to use it in my classroom of aircraft mechanics students

@JxJAVIATION

Жыл бұрын

Thank you so much! Do check out some of my other videos as well!

Some jet engines now start electrically. On the 787 they have what are called VFSG for Variable Frequency Starter/Generators. The starters are also the generators once the engine runs on it's own.

@JxJAVIATION

Жыл бұрын

Yes, just focused on the Pneumatic Starter

@rael5469

Жыл бұрын

@@JxJAVIATION Love the video.

@CheapBastard1988

Жыл бұрын

And each engine has two VFSG's (as does the APU).

@louvegas1048

Жыл бұрын

Good point. And most business jets.

Very good explanation 🙏🙏🙏

VERY NICE WAY TO TEACH, IMPRESSIVE THANK YOU SIR FROM PAKISTAN

@JxJAVIATION

3 жыл бұрын

Welcome!! :)

Good stuff. Thanks 👌

@JxJAVIATION

3 жыл бұрын

Thanks for watching!

Thank you.Help me a lot

@JxJAVIATION

3 жыл бұрын

You are welcome! Please Share and Watch my other videos as well

Your videos are so educational thank you for sharing.....

@JxJAVIATION

3 жыл бұрын

Welcome & Glad you like them! :)

Excellent. Complete & concept educate. Thanks 😊

@JxJAVIATION

Жыл бұрын

Most welcome 😊

I m in love with this channel

@JxJAVIATION

2 жыл бұрын

Thank you!

Thank you so much for this video

@JxJAVIATION

2 жыл бұрын

You are so welcome!

Great video thanks man

@JxJAVIATION

3 жыл бұрын

Glad you enjoyed it

Really great and to the point explanation

@JxJAVIATION

Жыл бұрын

Thank you! Do check out my other videos as well!

Thanks for the details 🙏

@JxJAVIATION

Жыл бұрын

No problem 👍

Just loved it, so easy now.

@JxJAVIATION

2 жыл бұрын

That's great!

Great explanation, very helpful

@JxJAVIATION

Жыл бұрын

Glad it was helpful! Check out my other videos as well!

Splendid job!

@JxJAVIATION

2 жыл бұрын

Thanks Mate!

Very well explained!

@JxJAVIATION

Жыл бұрын

Thank you!! Do check out my other videos as well!

Thank you so much! , so informative and short

@JxJAVIATION

11 ай бұрын

You're welcome! Check out my other videos as well!

Thank you for sharing 🤝🏻

@JxJAVIATION

2 жыл бұрын

You are Welcome 👍

The video is so much useful an understandable then others, the voice is robotic or not, it is more important that talks slowly and gives the listener some gap to digest the information, thank you so much for the video

@JxJAVIATION

3 жыл бұрын

Glad it was helpful!

Very good explanation...thanks

@JxJAVIATION

Жыл бұрын

Welcome!

As an important point with regards starting a turbo fan engine. The air starter for the engine is fed low pressure high volume air. A popular understandable mistake is that the starter is fed high pressure air. The air pressure is generally around 45 psi. The volume of air supplied is what provides the energy to drive the air starter.

@JxJAVIATION

10 ай бұрын

Yes that is a very good point! Thank you for sharing!

very educative. Thank you Rgards

@JxJAVIATION

Жыл бұрын

Glad you enjoyed it

Very informative n Interesting..🛫🛫

@JxJAVIATION

Жыл бұрын

Thank You. Check out my other videos as well! and please share!

@philiptm1243

Жыл бұрын

@@JxJAVIATION Sure..Regards..🛫🛫

Great video.☺️ I just subscribed to ur KZread channel.☺️

perfect animation :) love from Pakistan

@JxJAVIATION

2 жыл бұрын

Thanks man! Love from India! :)

Great vid and very informative.

@JxJAVIATION

Жыл бұрын

Thank you!

Superb well explained

@JxJAVIATION

3 жыл бұрын

Thank you! Do watch my other videos as well

Very well explained Sir

@JxJAVIATION

Жыл бұрын

Thank you! Check out my other videos as well!

Good explanation!!

@JxJAVIATION

2 жыл бұрын

Thanks!

The _shaft_ from the accessory gearbox does not disengage from the N2. The gears in the starter unit disengage from the shaft. The shaft is still required to drive the accessories.

@JxJAVIATION

Жыл бұрын

Did some research: The shaft which drives the accessories is separate from the shaft that is used to start the engine.

@ImperrfectStranger

Жыл бұрын

@@JxJAVIATION Engine type? The N2 (or N3) shaft drives the accessory gearbox (permanently attached) on most engines. There are various components attached to the gearbox: Hydraulic pump, EEC power generators, fuel pump, electrical generator and starter motor. i.e. The starter motor is mounted on the gearbox (CF6, RB211, CFM56, etc). You said that "the shaft from the N2 starter unit disengages from the N2 shaft" and the graphic in the video shows the accessory gearbox shaft disengaging from the N2 rotor. What actually happens is that the starter disengages from the gearbox. According to your graphic, all the accessories would stop working.

Thank you,information.

@JxJAVIATION

3 жыл бұрын

You are welcome

Awesome 🙏💎 work

@JxJAVIATION

Жыл бұрын

Thank you!

Thank you so much the detailed explanation but can you please provide more information about accessory gear box and its way of operating and stopping mechanism .

@JxJAVIATION

3 жыл бұрын

You are Welcome! Noted and will do a video on the AGB soon!

wow u are amazing, god bless you mr😻

@JxJAVIATION

2 жыл бұрын

Thank you so much 😀

Nice I understand the others I never got it ,

@JxJAVIATION

3 жыл бұрын

that''s great

Awesome!!!!! :D!

Thanks a lot ... more informative Vedio

@JxJAVIATION

Жыл бұрын

Thank you! Please check out my other videos as well!

Super explained , sir aabout N1. And N 2 shaft because of I knows one main shaft and one another and well explained about N1 and N2 shaft connections ,

@JxJAVIATION

3 жыл бұрын

Thanks and welcome! :)

Did you miss the sequence of the 3 rubber bands ? Thanks , simple and we'll put. It sure beats 24 volt starting motors and ring gears.

@marcwolf60

3 жыл бұрын

I was expecting.. "Next press the switch to release the Hamsters in to the rotating wheel"

Very. Informative

@JxJAVIATION

Жыл бұрын

Glad it was helpful!

On the C-17 (pw2000 engine) the ignition is left on. It’s turned off as part of the cruise checklist and then turned back on in the descent checklist. This is so that the engine has less chance of flameout at critical stages of flight.

@JxJAVIATION

10 ай бұрын

That's right. A very good point!

@simsch97

8 ай бұрын

I think that is quite normal for almost all turbofan or jet engined aircraft. Boeing aircraft definitely have it and I think Airbus too.

Great video ! I’m wondering what happen to the airstarter after the starting cycle is complete ? Do the ground crew take it off ? Isn’t it tricky since the turbine of the airstarter still has a lot of inertia even thaugh it has been disconnected to the N2 shaft ?

@JxJAVIATION

3 жыл бұрын

The air starter unit is not removed by the ground crew. This is because, when the aircraft is in flight and the engines were shut down and need to be restarted, the air starter may be required to restart the engine.

@Binette96

3 жыл бұрын

JxJ AVIATION oh so the pressure that flows in the airstarter during flight is enough to start back the engine !? Waw Thanks a lot for your accuracy in your videos and for taking time to share this knowledge with simple terms ! Hope to see you doing well on youtube it is really well deserved !

@JxJAVIATION

3 жыл бұрын

​@@Binette96 Thank you, and Welcome! Please do Watch my other videos and Share the videos as well

@Greatdome99

3 жыл бұрын

The starter attached to the engine gearbox (about 6" in diameter and about as long) has an overrunning clutch like your car. At some point during the start sequence, the clutch disengages, the starter valve is shut off.

@reymaulion2667

3 жыл бұрын

@@Greatdome99 You are right Sir.. maybe you are acft engineer or A&P instructor.

very GOOD

@JxJAVIATION

3 жыл бұрын

Thank You!

Personally, I Think The Robotic Voice ADDS To Value Of This Long Overdue Explanation.

@JxJAVIATION

3 жыл бұрын

WOW! Thank You!

What a video thank you so much. I just want to request from you, can you describe accessory gearbox duty basically?

@JxJAVIATION

3 жыл бұрын

You are welcome! Will make a video on it soon!

easy to under stand tq

@JxJAVIATION

6 ай бұрын

Thank you! Check out my other videos as well!

Thank you

@JxJAVIATION

Жыл бұрын

You're welcome! Check out my other videos as well!

Hai i just want to clarify that the HP air opens HP valve then it passes through air stater unit before entering to AGB. From AGB it is coupled to N2??

@JxJAVIATION

3 жыл бұрын

the HP valve opens and this allows hp air to flow to the air starter unit. the air starter is housed inside the AGB. the coupling is from air starter/agb to N2

@Greatdome99

3 жыл бұрын

Starter Valve (electrically activated)->Starter->Overrunning clutch->Gearbox->driveshaft to HP spool (via bevel gear). The engine control unit (EEC) controls start sequence of the engine fuel and ignition.

@vilttu82

3 жыл бұрын

@@JxJAVIATION Starter is not housed inside the AGB, it is connected via shaft to gearing inside the AGB.

Can you tell me N1 shaft & N 2 shaft are two independent module which are disengaged during start up or N 1 shaft & N 2 shaft are coupled permanently (single shaft)

@JxJAVIATION

3 жыл бұрын

N1 and N2 shaft are 2 separate shafts and are not coupled mechanically. The aerodynamic forces cause these shafts to rotate. So basically they are always disengaged mechanically.

So when the engine starts, is that the rumble noises u hear when ur being pushed back?

@JxJAVIATION

10 ай бұрын

Usually one of the engines is started during pushback!

@Soapy_Water06

10 ай бұрын

@@JxJAVIATION oh ok

Thanks, very interesting! How does the APU start? electric? What is the pressure of the air needed for starting? Something like 10 bar or more to 100 bar?

@JxJAVIATION

3 жыл бұрын

You are Welcome! The APU uses an electric motor for starting. The air pressure required for starting the engine would be less than 5 bar.

@wasserdrucker6227

3 жыл бұрын

@@JxJAVIATION thanks!

@bobelaviador

3 жыл бұрын

@@JxJAVIATIONindeed, I cannot imagine a electric starter to a GE90, I just cannot conceive it

@sjmunoz

3 жыл бұрын

@@JxJAVIATION 5 bar is enough for making the HP shaft turn ?

@Greatdome99

3 жыл бұрын

@@bobelaviador The 787 has starter-generators

We don't know exactly where, when airplanes begin but i believe there is a wire to connect the engine to start.

@JxJAVIATION

10 ай бұрын

Some engines need wire, pipes, tubes etc

thanks

@JxJAVIATION

2 жыл бұрын

You're welcome!

Thanks

@JxJAVIATION

Жыл бұрын

Welcome!

Cool👌👌👍👍🙏🙏

@JxJAVIATION

2 жыл бұрын

Thank you!

The graphic appears to be a 787. I worked on the 787 Common Motor/Starter Controller, which was the 1st all electric start of an engine of its size; otherwise the information is mostly consistent with other turbine engines I've worked on.

@JxJAVIATION

9 ай бұрын

On the 787 there is an electric starter, but I was giving an idea about the air starter unit!

Thank you for jet engine start steps. I have a question, burning chamber is at high pressure as compared to compressed air entering it - in flow line and due to generation of product gases. What is the scientific answer? Is it high velocity? Engr. Muzzafar Iqbal.

@JxJAVIATION

Жыл бұрын

Because of the fuel air mixture being burnt in the combustion chamber the pressure increases.