Excellent explanation! The jet engine is an amazing invention. I recently flew back from Dubai, direct to Seattle, 15 hour flight, on an Airbus A-380. The endurance and lift those engines deliver day in and day out is just incredible. Hundreds of passengers and all their luggage. Inside the aircraft, I could hear the engines, but just barely. Have to respect the engineers that design these engines.

@andydouglas2108

3 ай бұрын

Yes Sir, it is an amazing age in which we live! Long may it last👍

I was a gas turbine tech in the US Navy. The engine starting sequence was one is the most challenging topics to explain to junior technicians. This video simplifies kindergartens it. Thanks you!!

@Negev-Israel

2 ай бұрын

Do you know why they use an air starter instead of an electric starter?

@twwc960

20 күн бұрын

@@Negev-Israel In the past, electric motors and generators were heavier than the components used to carry the high pressure air (called "bleed air") from the APU or engine to where it is needed. Improvements in motor and generator technology have changed this balance, and newer aircraft, such as the Boeing 787 dreamliner, use electrical starters and virtually eliminate the use of bleed air in all their systems.

@ChapaLipar

14 күн бұрын

We use air starter instead of electrical starter for many reasons. The first one is that an air starter of an A320 or B737 is a 150 HP turbine. An electric equivalent would be heavier and you have to carry it for all the flight when you only use it for less than 1 minute. Also an electric starter would require energy that you find in heavy batteries. Same thing. The weight to power ratio is not in the advantage of the electric starter. As described in videos the APU which is a small turbo engine is started by the battery of the aircraft or a ground cart when available. But when power is required the electric solution is too heavy yet 😊

@Negev-Israel

14 күн бұрын

@@ChapaLipar makes more sense

@ChapaLipar

14 күн бұрын

@@twwc960yes it’s true. On bigger aircraft such as 777 they use alterno-generators which are used as electrical motors during start and as generators during the flight, providing electrical power to the aircraft. They are heavy but they replace the generator and the starter. That provides a weight benefit over two separate systems.

Why do I find the sound and sight (and smell in a real setting) of a jet engine starting up so satisfying? Thanks for this walk-through.

@energeticvids

5 ай бұрын

Agreed. It's a full orchestration of sounds also including the ding, ding-dong of chimes, pumps and motors and constant 400Hz electrical hum. I even featured that start-up sound in one of my music videos. /watch?v=U1Q5KohVfsw

@iTz_JLAR

3 ай бұрын

Here's an engine start for you. Best sounding engines I've ever worked around kzread.info/dash/bejne/poKA3JaBoNaxgbg.htmlsi=5l3I10u_hWmzoMdW

@Alirezarz62

2 күн бұрын

Because you know how much engineering and thought went into this beautiful piece of machinery to work flawlessly

Using one engine to start another is a cross-bleed start. It's only done if the APU is down, since the engine providing the starting air needs to be throttled up significantly, using a lot more fuel than the APU. This is done after starting the first engine at the gate with a "start cart", an external air source. Normally, the APU starts both engines, then is shut down once both engines are running.

@user-bc5qz3mt5h

5 ай бұрын

My understanding is that there are many variables at play here which will determine the starting procedure that (commercial) pilots use. Options e.g.: APU bleed air to start both engines separately, an APU start for one engine to then cross-bleed another, and ground-cart air used in place of an APU for engine starting. If an aircraft is going to be sitting around after taxiing away from the terminal, waiting for take-off permission, it can be more economical to start a single engine via the APU, shut-down the APU to conserve fuel, and then shortly before take-off, cross-bleed to start the other engine. I always thought it was pretty much up to the airline policy to determine whether it's an APU or cross-bleed start for the final engine...

@KingdaToro

5 ай бұрын

@@user-bc5qz3mt5h Unless there's a single-engine taxi procedure in place, you'd normally start the APU and shut down both engines if you're going to be sitting still for a while. On a 737NG, for example, the APU will burn 240 lb/hr under load, but a single engine at idle will burn 850 lb/hr while putting out the same amount of electricity as the APU and significantly less bleed air.

@foofghtr

5 ай бұрын

Cross Bleed Start was a new Airframes Change in 1986 when I was in VF-101 for Tomcat training. Before that the huffer and power cord had to stay connected until both engines started.

@memcrew1

5 ай бұрын

I was looking for this comment. The APU is used to start both engines. A crossbreed start is usually done if the APU is not available.

@chacehart7286

5 ай бұрын

The 737 starting procedure-Aft left fuel on, APU start, APU bleed on, selector switch to engine 2, engine 2 start switch to GRD, wait for 25% N2, fuel selector switch behind throttles all the way up. Repeat process for engine one. APU does all of the work.

One of the best explanations out there. Students need teachers like you

Thanks. The explanation is simple and straight forward. Just in case the starter system fail, the pilot need to engage the clutch pedal, put to second gear, ask ground crew to give a little push to the aircraft, and pop the pedal..😄

@HitMeWith

5 ай бұрын

Haha! The absolute fail safe method 👌

@OrianaBiggs-xz1oq

5 ай бұрын

Bloody true, sounds like you fix what pilots break😂

@OrianaBiggs-xz1oq

5 ай бұрын

PS when I did my apprenticeship on Beechcraft, I have been ask a question similar to that. 😂

@ImperrfectStranger

5 ай бұрын

If second gear doesn't work, try reverse (thrust) 😜

@planaproject

5 ай бұрын

The cool thing about this procedure is that its in flight!

Absolutely fantastic description on the air-starter clutch.

@HitMeWith

5 ай бұрын

Glad it was helpful!

Good video, very accurate. I spent 43 years in the aircraft design industry, and was always impressed by that start-up sequence.

I’m thankful for all these smart people moving humanity forward. Imagine what we will come up with in 50-100 years.

I've always been curious about the specific sounds an airliner jet engine makes during startup. Now, I've finally learned what that particular sound is just before fuel injection in the main engine: it's the speeding up of both pressure shafts. Each shaft has a different RPM and can sometimes go out of harmony with each other.

@ChapaLipar

14 күн бұрын

In fact, during the start sequence it’s mainly the air exiting the starter and the HP compressor spooling up that you hear. When the starter provides the maximum HP speed, around 20% of the maximum, the LP spool ( Fan in the front and low pressure turbine in the rear) are only rotating at 4-5% of their maximum by the air going out of the engine. So you don’t hear it. When fuel and ignition are turned on you may hear a little clic noise (and if you can see the back of the engine, a small fume) and then you hear the engine spooling up to idle ( around 60% of the maximum) the GE90 of the B777 has a double annular combustion chamber which gives a specific growling noise when the ignition begins until it stabilizes at idle. This shows that the engine is not designed to run in this condition. It’s a little weird, but it’s perfectly normal. Then everything becomes quiter.

First video on this topic that actually combines every element of the startup into a easy to follow package!

God the sound of the engine starting up is a pure eargasm!

4:40 you got the engines mixed. Left engine is #1 and right engine is #2

@zolo111

25 күн бұрын

Yup, looking from back to front, count engines from left to right. Great video though.

With the exception of misidentifying engines 1 and 2, this was an informative video. Engine 1 is always the one on the left wing.

@markburckhard553

3 ай бұрын

I noticed that, too. Good eye.

0:40 "By a large onboard battery" Commercial jet technician here. Its only marginally larger than the battery in your car. Though they throw out twice as much voltage. And there are two of them in narrowbody jets, and 4 of them in most widebody jets.

Great overview, just one comment from an engineer at Rolls-Royce: the fuel is not self igniting due to the high air pressure, you need a sustained flame in the combustion chamber. So if you have a flame-out you need to re-ignite.

@m3photo726

4 ай бұрын

Yep. That’s the case for diesel.

@symbionese2348

4 ай бұрын

Thank you. I jolted when he said that, too. What he should have said is that the engine sustains combustion in the correct direction. Yes?

@PeterNGloor

3 ай бұрын

The ignition is switched on when it's time to light the fuel, then the flame burns like on a welder's torch. But I understand that in certain weather conditions the ignition is set to continuous in case of a flame-out.

@ChapaLipar

14 күн бұрын

@@PeterNGloor that’s correct. In normal circumstances during engine start you use only one of the two igniters. If the engine start fails, then you make a second attempt with ignition selected on ‘both’ . When the engine is spooling up to idle, the starter disengages and the ignition is switched off. During the flight in severe conditions like heavy rain, ice, or freezing temperatures on the ground when landing the procedure is to turn the ignition on to prevent any flameout.

@ChapaLipar

14 күн бұрын

And in ‘continuous’ position the ignition is on for both igniters.

Iv been searching for videos like this since I was a child. But never found one. This was very educational and fun to watch. Make more please

The SR-71 used an external V-8 engine, connected thru a driveshaft, to the engine. Once started, the shaft was removed. On the KC-135R, it has two large APUs on board, so it can start multiple engines at once.

@M3dicayne

5 ай бұрын

So the Blackbird wouldn't be able to even start its engines without on any other airfield than that with that kind of engine?

@robertheinkel6225

5 ай бұрын

@@M3dicayne correct. It could only land where full support is available.

@Bellboy40

4 ай бұрын

Actually, the start carts for the SR71 had two 400 hp Buick engines connected together to start the jet engines. Later on the start carts used two 460 hp Chevy 454 ci engines. Those engines had to be revved up to their red line to spin the jet engines over fast enough to start. Those things sounded awesome when they were spinning up to start the jets. Link to video of start cart in action: kzread.info/dash/bejne/fJ6Y27Opdbi_qqw.html

It is very rare for engines to be started from another as you need to spool up to gain the 40 psi needed. It is only the HP spool that is driven. The LP rotates as the airflow generated by the rotatating HP drives its turbine. The 20% mentioned is HP speed as you only need to check you have rotation of N1. Other than that good description.

@dehypnotizerz

5 ай бұрын

Yup! Actually, I haven't heard about rotating the LP fan during the start-up.

@stephenholland5930

5 ай бұрын

You would only use bleed air from the first engine to start the second engine when doing a cross-bleed start. This would be required when the APU was unable to supply bleed air, and a ground airstart unit is used to start the first engine.

@ChapaLipar

14 күн бұрын

@@stephenholland5930 or if you have to restart an engine in the air. As the APU is generally turned off.

Thank you . This is the best illustration video about aviation technicals I’ve watched!

Thanks. I always wondered how airliners started their engines. Very informative and easy to understand.

One of the best videos explaining this.

This was super interesting. I always wondered what those sounds were when I'm waiting for my plane to take-off. Now I know. Thanks HMW! Love this channel - subbed

@HitMeWith

5 ай бұрын

Glad you enjoyed!

@philipgotay7314

4 ай бұрын

closest thing to riding a fighter jet, except for the catapult launch...😊

Thank you for the lesson!❤

As a passenger I have always wondered what the sounds were as the engines made as they (spooled) up and now I know , thank you very much !!!

@joesimonetti

4 ай бұрын

Same here...was a pretty cool illustration...

Loved this video! Thank you

Just found your channel. Really enjoyed it, and I hope you do more as they are genuine and honest as well as interesting and informative. Thank you

Thank you! love that you included the startup sounds also.

I learned so much in 5 minutes here that I've never known.... thank you! fascinating!

Didn't realize it was that complex. Thanks for teaching us.

Thats one of the best videos on KZread. A great thanks to the creator🎉

VERY professional presentation with clear audio and without irrelevant jargons. Diagrams are to the point and step by step logical approach. hope you do another video on all the sounds we typically hear within the cabin during the flight. Thanks

@twwc960

20 күн бұрын

That annoying crying sound is the baby in the seat behind you.

really enjoyed your explantions - just great !

GREAT INFO. FOR US OLD PROP PILOTS. I KNEW THE PROCESS IN THE OLD 707 DAYS. I HAVE HEARD THIS NEW PROCESS MANY TIMES. NOW, I KNOW WHAT I HEAR. THANKS.

I loved this video - thanks!

At 2:48 there is a minor suggested change. It's not the pressure of the air that ignites the incoming fuel. It's the existing flame in the chamber. An excellent video. Nice job.

I have been looking for explanations as to where the sound comes from during startup. Thank you for making such an amazing and educative video.

This is 10/10 content, very nice explanation. Thank you

Amazing. I always thought that first sound was the first engine starting. Now I know it's the APU. And I remember that deep grumble when the engine is fired up from my last flight.

@KoolHandJuke

4 ай бұрын

I thought the same exact thing! 😅

@KoolHandJuke

4 ай бұрын

That low grumble is awesome. The power gets the old testosterone flowing. 🤜💥🤛

@ChapaLipar

14 күн бұрын

The low grumble is very noticeable ina B777 with GE90 engines. It sounds like the engine is not willing to start a new business day 😊 Just like me with the alarm clock on monday morning 😖

Awesome video. I learned so much from it.

I work on cars and always wanted to know how jet engines start but never got to researching it, after this amazing video I now understand exactly 👍

I already knew how they start. So I watched this to waste my time. but I learned something new today and that is what do the different type of sounds created by the engine mean. Thanks so much!

@meischill921

5 ай бұрын

u got a like btw

Most excellent ! I didn't know all of these steps before. Gorgeous. Aarre Peltomaa

Very useful video and adds to my knowledge about airplanes

Thanks for a great video! Now i know how it works!

Spot on video! Thanks for the lesson!

That was an excellent explanation.

For our maintenance engine runs we use the APU for both engines. I’m certain the pilots usually do the same. A cross bleed engine start is done when the APU is inop. The first engine is started with a high pressure air cart. (In the Navy we called them huffers). Then they start number two with cross bleed. Great video!

Amazin explanation. Thank a lot.

Cool video! But we start the second engine exactly the same as the first one, so with the help of the APU. A crossbleed start, where you use bleed air from the other engine instead of the APU, is only used when the APU is unserviceable. The rest of the video is very accurate!

Very fantastic description vidéo of starting jet engine

Nicely explained.

Very clear info thank you 🎉🎉❤❤

Excellent, thank you.

That was fantastic!!!! The use of graphics really helped me understand the physical process of the engine working. Excellent work!!

I have been waiting for someone to make this video. Thanks man👊🏾

Very good sir. Subscribed!

Very interesting video. Thanks!

Best explanation I've ever seen

Thank you so much for your excellent explanation. Waiting for more videos

i am liking the FLOW in enunciation

Excellent video, thank you. Concise explanation and description.

Thanks a lot for the piece it's interesting to note the plane also uses the clutch.

Great video, hope to see more

terrific video,,always luved the jets

Thanks!! I work at LAX and LOVE LOVE LOVE watching the engines start when we push back. I do the mechanic headset sometimes and instruct the pilots when it’s clear to start engines Right to Left on a 777, or 4,3,2,1 in a 747. 🎉 ✈️ 😎

@kevingould6725

4 ай бұрын

It’s even better when you get to carry out engine tests. Last test on a Tornado engine set up test is The Slam . We take the engine from idle to combat through afterburner. We slam the throttle from idle position to combat and the computer does its magic. We still have control of the engine via the throttle.

Very nice video. Well explained for beginners like me, who are aviation enthusiasts. Thanks for sharing.

Now I know how those engines whine first and then roar; fascinating sequence of startup!😘🤷‍♂

finally figured out what makes the rumbling sound, as ground staff i love it

@PeterNGloor

3 ай бұрын

the older jets with a smaller bypass ratio sounded different. They spooled up much faster, the onset of fuel burn was very audible, and there was no rumble as on today's big engines.

Learnt something; cheers

Awesome thanks !

Great Work. Easy to understand

Interesting!! V he Ave heard these sounds from outside znd ad a passenger. Now I know what all the sounds are. Thanks!!

Very good explanation

This was very interesting! You should not leave such a long gap between delivering videos - you do a great job! Subed.

that was sick!

Great explanation. Nice to watch.

Excellent explanation, I was aware of the basics but not the use of a centrifugal clutch

@Osmone_Everony

5 ай бұрын

Same

Oh Yeah... I think we'll be seeing and hearing a lot more from this channel!! At least I hope so! Excellent production in all ways: camera, B-roll and audio all great! A very interesting topic, well-demonstrated, brilliantly detailed with diagrams and a good script. In My Opinion. An easy: subscribe, like, notifications on and a comment for the creator. YES - more like this please!

Thank you for your super simple yet very easily to understand video

I’ve read wiki pages and seen many videos of how plane engines start and finally I have a sort of surprising and informative answer. Thank you very much!?😁

Great video...I've been around aircraft for years and never knew this information. Well done..

Engineering... Its what makes the world work! Gotta love it. And...High Fidelity. Good movie and...great track when he hits that play button. American treasure, Stevie Wonder and I beleive when I fall in love. Great....great track!

Omg I never new it had a clutch amazing

Perfect explanation complemented by outstanding visual graphics.

Best explanation I’ve seen 👍🏻🇬🇧

Thanks 🙏

Thank you 🙏.

Always wondered how it was done, now I know. Thank you so much.

Cool video, thanks!

Cool ...... Thank you ! .....

Cool, thank you

Wow. That was awesome. Thanks

Excellent.

Nice one, thanks!

Such a great video

Nice and simple. Now i'd like to hear about how a JFS system works different.

Great video 🎉

Very cool !!!

Good information