Want to start a jet engine? Here's how...
Note: this video was created after I had already posted dozens of videos where we start and test jet engines. People were asking how it's done, exactly.
If you are one of those very few people who are complaining that I don't start it up here... well, you need to be a bit more aware of what's all around you. Jeez.
I have posted hundreds of jet engine test videos... many with afterburner, so have a look at them.
This is a GE LM1500/J79, and it is the real thing. No RC, no GPU; a real turbojet that took the F-104 to Mach 2.5, and made the F-4 into the most versatile jet fighter ever.
Index of all videos: members.iinet.net.au/~tgard/
Thanks so much for this video. ALL other "how-does-a-jet-engine-work" videos ignore this very important starting point, leaving viewers ignorant. Well done AgentJayz :)
I was totally confused on how the jet engine starts initially by what powers the turbine to rotate.. Now its clear that only with external air supply... Thank u very much
When I worked on the SR 71 in the 1960s, it was really fun. Our start cart had 2 Buick 401 Wildcat V8s with open headers. My ears are still ringing.
I guess you're the expert, but the books I've read say the engines were 455s.
Hardly an expert, and it's been 50 years. I have read that the Buicks were swapped out for Chevy 454s in the mid 1970s. What I do remember is how exciting it was to pull down on that throttle and hear that J 58 come to life. If you did it wrong the pilot could get very upset. The probe could drop out on a 'hanging start' and everything had to coast down. They had a tanker to catch! I really enjoy your channel. You are the undisputed expert!
30 years in aviation on the ramp side.. worked with everything from jt3/4 's to cfm's to rb211 to pt8's and the venerable DARTS. have heard many starts but this explanation was excellent. . sucke squeeze bang blow..
Man ! u r the best Turbo machinery guy on KZhead ! I don't know if ur father or brother is a turbojet engineer or not but the exposure u have to turbojet engines is HUGE and what takes u to the next level is ur willingness not to JUST share it on KZhead for views but to share it in a clear cut novice manner ..... Awesome , keep it up !!!
Why would anyone dislike this video? There's nothing to dislike. Straight forward and simple! Total opposite of the actual engine shown!
Yeah simple... we start a jet engine with a jet engine.
HI AgentJayZ et al, I'm neither a pilot or aircraft mechanic, but I really enjoy your channel and learning how turbojets (and turbofans) are put together, how they work, are rebuilt, and maintained. As a child I spent many hours at a grass runway with my Dad. He was a private pilot and had served in the US Air Force as an aircraft mechanic. He even towed home a Taylorcraft one time (wings off and the tail wheel in the car trunk), put a new skin of ceconite on it, and sprayed it bright yellow, right there in our home garage. I must have inherited my flight genes from him. I also subscribe to Mentour Pilot and enjoy the cockpit side of the story too. Captain Petter just did a piece on 12/6/2019 titled "Sucked into a Jet engine?". Since we're all interested in jet engines, I thought you and your subscribers might enjoy watching that one particularly if you've not seen it yet. It's over at: kzhead.info/sun/n5yIYbqPZHaBdKc/bejne.html Thank you and your team again for the dedication to your profession and sharing your knowledge and enthusiasm! Regards . . .
The SR-71 was started with a cart that had 2, 454 CI, super high performance Buick engines mounted on it. Both engines worked simultaneously to rotate a large gear extremely fast. The gear turned over the jet engines until they started and ran by themselves. Pneumatic start carts like the one seen here, just weren't strong enough to crank over an SR-71 (J-58) engine.
The engines were stock 455 wildcat Buicks. Each engine was started individually. There is one of these start carts on display, along with an SR-71 that you can sit in, at the Boeing museum in Seattle.
@@AgentJayZ later on they used 454 engines
Douglas Oakley Buick didn’t make the 454 though, Chevy did
@@bigdaddy7119 You're right. Sorry. I meant to say "455 wildcat engines." My mistake. It's been over 40 years since I worked on the SR-71. Thanks for the correction.
super cool! having autism and loving engines of every type and researching about them and how they work, I found this video extremely informative and satisfying to watch. Thank you
I love your videos so much! Thank you for taking the time to do these.
This video is so educative you have no idea. I had to go to the library on a friday night to suffice my curiosity. Thanks for the content!!
The biggest difference I noticed between starting an older engine like a JT3D and a newer one like a CFM56 was that you had to talk to the CFM56 during the slower start process. The JT3D started like an old Chevy Six and the CFM56 seemed like it needed coaxing, encouragement and patience. Both great engines in their own right, though. Some folks might also be interested in hearing about a cross-bleed start.
So, now I got to know how engines start with the help of bleed air of the APU in commercial jets! Thanks for the video!
I can see this quickly becoming one of my new favorite KZhead channels. Just this one video alone (although I understood in principle before I got here) was excellent. Well described, sir! Thanks, and subscribed! :)
Clear and concise. Than you for taking the time to explain it all.
Your videos are brilliant and always very enjoyable to watch!
Dang, and I thought he was going to start the engine
Need... to ... open... eyes, and click... just one... of his... engine... test run... videos...gasp! Hundreds of 'em...
AgentJayZ hello I’m Michael Milburn I live in wayland mi. I like your videos on those jet engines it’s a interesting learning thing you show us I’m wondering if you can send me a memberbilia such as that one hooded sweatshirt you wear in some of the videos my address Is 1175 eagle drive wayland mi 49348 apt 104 if you can do that that will be ausome my wed address is Michaelmilburn75@ Gmail.com thanks bro you rock keep up the good work
Yjhjg
Your video's are great, Thanks for taking the time to make them.
Great video, very informative. I always assumed that the turbine was spun by the second method you mentioned, I also thought that bleed air from the APU was also used. Just goes to show, there is always something new to learn.
bleed air from the APU is often used yes... but the APU is itself just a turbine engine hence then it becomes the first engine to be started by other means.
Finally found the right video, been searching how does the engine starts but couldnt find the appropriate video, thanks man🙏
For other mysteries, try putting the subject into the search bar on my channel page. Might have made a video on it already.
Once again, I really appreciate your videos. Learning all this stuff took my fear of flying away. Educational. Thank you
Airliners rarely use ground air starter unit or engine cross bleed. Only when APU is unservicable or not practical to use. Each engine is started by APU bleed air.
Thank you for this video. I was waiting for this kind of explanation for a while. Finally, you made it clear.
Very Nice Explanation, I struggled to know how does it actually starts OR what makes a front big fan to rotate. Got the answer. Thanks!
What an informative video. Its always great learning about machines that we use everyday and take for granted. Thanks for the upload
we started our aircraft off the aux power unit, which was a small turboshaft on the aircraft. we only used the ground cart for maint. the apu started from hydro pressure
Thank you for all your time posting this and all your videos
Great vid, explained a lot more than I initially intended to learn. Thanks!
very nicely done video. I am a master auto diesel mechanic and I never knew how a jet engine started. Thanks for the info.
Well that explains the answer a pilot gave me years back when I asked how a jet engine was started. He said "With a running jet engine". In a way, it seemed a lot like the egg vs chicken debate for an answer. lol Thank you for this explanation. Imagine for a moment if these engines were started via pull cord somehow. "Who wants to start the jet?" 123 NOT IT! lol
ME 262 had a gas engine starter...
Always wondered what makes turbines spin in the first place. Thanks for clearing this up.
I just asked you a question about this on another video VERY INTERESTING I am very surprised a jet engine can not start under its own power I assumed they used onboard electric motors powered by batteries to spin the turbines up to that initial idle speed. Some of the best videos I have ever seen on KZhead. Thanks again
Ray here, N1 is gas producer speed in a split shaft engine. This is an engine whose exhaust gas 'blows' or pushes the power turbine blades around, the power turbine (N2) drives the external connected load. This is standard arrangement in helicopter and small industrial style machines under about 1MW. The term 'multistage' refers to the number of compressor and turbine blade discs in the engine. A typical small industrial may have 7 stages of compression blades followed by 3 turbine stages.
Started LM2500 many a time with bleed air from the GTG, Using the auto start mode done manual start when the PM book called for it. (didn't know they made an LM1500. (Mississippi gulf cost, USA)
The GEnx is electric start. There is no bleed air and no air turbine. The accessory gearbox drives a generator. This generator also functions as an electric motor to turn the high pressure shaft for starting the engine. Electric power is provided by one of two Lithium Ion batteries or by the APS5000 APU.
great video I always wondered how they start those things on the tarmac.
Thanks for the videos! We love em here in NY!
I worked at test cell at nellis afb....ran the engines for the f15 and f16 jets....a lot of fun and noisy....how he started this was the same way...
Good presentation, you deserve being commended for your presentation. :)
I been watching you tube to understand the process of jet engine working, non as good as this THANK you for this
Excellent video. I was guessing how you did it until now. Thought it was an electric motor but now i know ))
Totally an aviation nut myself! Dis guy right here always watch the plane video from here with my rock playlist crancked to 11. Metallica, Delta Parole, ACDC etc. AWESOME!
Nice informative video! Thanks!
Great information. So easy to understand. Great job.
Who’d have thought when I used to work with you at TCT I’d be watching you years later on KZhead!
Such a great place to escape from!
This took me back to my flight line days, Thanks
Excellent explanation. Igniter box energized 500 rpm, Around 1500 rpm fuel on ignition start, at around 3000 rpm minimum self-sustaining rpm, starter off, 5000 rpm idle. Do those figures vary much with other engine models or with turbo fans?
Really clear explanation!! Thanks for sharing!
Thank you so much ! I know also that Orpheus engines equipping the Fiat G 91 uses cartridges because it is, or was, an attack airplain for troup support that could land and take off in rugged terrain and not need any assistance from a compressor . Could you explain how these cartridges work ? Thanks in advance !
Great video, man! 🙌
Wow! Very informative! Thanks.😀 brother.👍
LOL - Ok, I don't want to argue, you obviously know a lot more about this than I do. I did go on to watch several more of your vids, and if you watch a number of them, the things I found a little hard to follow in this one iron themselves out a bit. I agree that starting a piston engine is quite different, my point was you could compare and contrast. ...And thank you, by the way, these are very interesting vids.
Worked with Pratt & Whitney Gas Turbines and the newer General Electric LM6000 Gas Turbines. At one power plant that was pretty isolated, we used high pressure natural gas instead of air to start the engines.
Surely you need some air? Oxygen is still needed to combust in the LM6000?
No, stinky... he is describing an engine that uses an air turbine starter, like the one shown here. But instead of using compressed air, supplied by a compressor or start cart... the ATS is powered by the natural gas in the pipeline/well, which is already at high pressure. Using the gas as a source of power for the ATS, it does get exhausted as uncombusted natural gas to the atmosphere, so it's not exactly environmentally friendly, but it does work, and it reduces the amount of equipment needed at the installation. These engines run for long periods of time when used in industrial settings (often many months non stop), so startups are infrequent.
@@AgentJayZ busted I was being stinky
that was really helpful, thank you! now i can finally start my jet engine
Right on man, thanks for the response. Just one of those things I've wondered about. I actually watched your video on the electric starter generator. Pretty interesting. It's funny they're using that technology again on the 787s. Now I wonder if anyone's ever made an air starter to double as a compresser to provide aux air instead of bleeeding from the engine. That would be cool.
Perfect mate, exactly what I was looking to understand.
The only reason I'm here is to see and hear a jet engine starting.. But thanks, now I completely understand the principle
Hi I'm studying Aircraft Maintenance at Centennial college in Toronto. You're videos are very helpfull!
great, thanks for the explanation, it all makes sense now. it wasn't easy to understand how gross thrust tests could be done just from the theory. The engine actually needs a small push
I was thinking the other day this exact question. Thanks for explaining
Agent J, Thanks for your vids. They are exactly what I look for when looking for jet/turbine engine inner workings. I haven't checked all your vids but do you have a heli or turboshaft vids.
We called the jet engine starter in the Navy a huffer. I worked on Pratt & Whitney tf30 p408.
Always good to hear from someone who was there, in the days when these things were in their prime.
@@AgentJayZ Thanks for compliment I worked on A 7 Corsair IIs during the Vietnam war. With VA 155. Involved in operation linebacker and linebacker 2 that brought the North Vietnamese to the bargaining table.
I really like your videos. They are very detail explained and very informative. I like a lot to learn about jet engines and you are the guy that know how to talk about it. Just one question: As a jet engine is the machine that push the airplane in the air why when you are testing it in the hangar it does not move from it's mounting fixture?
That was neat and informative. Thanks for posting.
thank you sir for your such an interesting information you give us i respect you a lot for such good things you deliver us thanks again .
Excellent job, thanks for the video.
Another valuable and informative video - Thanks!
it was one of the most amazing explanation about starting a jet engine thanks ^_____^
:: "WRONG" ::end Terminator quote:: .... But seriously, as an engineer working in the aviation industry (for a company that manufactures many of the engines you are demonstrating here) I have learned so much from your videos. It's tough not getting to see most of things that I work on up close and personal. Your videos have been serving to fill that void. Thanks and keep up the great work. Maybe I will get to visit some time.
dude that was exactly what i wanted to know, straight to the point. that one gets a like
“And we don’t like bangs”. The understatement of the century.
keep making these videos. i love it and learned alot 😀😀
Exelente video, all clear and understood
Hey Mr. JayZ, Big thanks to you
Watching this before I go to work because I'm a painter and decorator and need to know these things........
Great explanation 👍👍 👍👌
Cool stuff, thanks! Is there a video where the mechanics and the use of the adjustable stator blades of the compressor is shown and explained? I've watched it operate in "The Big Engine - the GE LM2500" but there wasn't any explanation around it.
Their purpose is explained in Compressor Stall...
@@AgentJayZ Thanks, I will look it up!
So if this was a commercial jet, the start cart would be the APU and the output air switch is the bleed air used to start the engine?
Replaced three lm1500 turbines with electric motors. North slope Alaska. Had one come apart during the project....
Thanks for responding to my questions.
Brilliant video! Thankyou so much!
Kaboom,instead of bang. Thank you. I learn so much thru your videos
The airlines use bleed air from the APU to start the engines. If the APU, or the bleed from the APU is inoperative, we use a start cart to start the first engine, and then cross bleed start the other engine(s).
Yeah, I think we covered that. Ten years ago. But you are absolutely correct, sir!
@@AgentJayZ You are welcome (sincerely). My comment was for non-aviation types who might have been watching this video. Not everyone watches every video you create.
@@oscarb9139 Thank you veey much, I need such information as Im studying for tests.
@@mashedtomato2079 Sure thing. What tests?
@@oscarb9139 Airframe and Powerplant licenses
I've been in a Boeing 737-800 that used a cross bleed start. This was probably due to problems with the APU as the first engine needed a compressor for start, After push back with the first engine running the aircraft increased in thrust which shook the aircraft for a few seconds until the second engine wind milled. I knew exactly what was happening and enjoyed understanding just how much thrust is needed to to transfer 30 psi to the other engine.
Thanks for video! Could you also explain, what is "hot start"? There is also an option with electric starter, as on H1-bell helicopter for example, is this scheme still used somewhere?
not all jets have electric starters
This is SO COOL! Thanks so much for sharing :-D
Very interesting video, I've always wanted to know how a jet engine starts.
I find your videos very interesting, I like to hear about RPM, pressures, temperature and all those details that I don't know and only imagine. One question about this video, what happens to the starting turbine after the jet engine starts? it keep turning as long as the engine is running or somehow it disengage and stop after the air house is disconnected?
Hey just curious, how often is an external start cart actually used for initial starts during regular aircraft use? Don't most modern airliners have onboard battery power to start the apu which can in turn be used to start all the engines?
Good vid - always wondered how they got cranked up.
Excellent video!
We wanted to hear it Start
That is in all of my many, many engine test run videos...
This is such a nice video!
You are a talented tutor, thanks for the instruction.
@AgentJayZ Oh, I didn't know that, thanks for the info! Are turboprop starts different, or is it essentially the same-air, ignition, and fuel? I know that torque is involved with turboprops.
your videos rock.. thanks for sharing..
hey folk, great video, tks for post it!
Sir, about the gear box for the other accessories, does the rotor transmit the power back to the angle drive connected to the starter motor or onto a separate shaft?
I was always curious of how this starting thing works! Thanks a TON. just curious...when do they use the ground power unit (GPU) for starting...(is it fed into the small yellow gas turbine engine which you showed in video?)
At the airport in my town, all the aircraft use electric start for their engines. The ground power units are of two types: one is basically a transformer that converts grid electricity to the required power for starting the aircraft. I'm sure it's switchable, but a common format is 30VDC. The other type of GPU I see used is a cart with a small diesel engine used to turn an electrical generator. The whole thing resembles a powerful welder, and I'm sure it has variable formats of output. Electric start is more common now, because aircraft engines are using smaller, more efficient cores, and electric motors have become much more powerful than they were fifty years ago. This video might have been better titled "How we start vintage jet engines in our test cell"
@@AgentJayZ Thanks so much for infusing your knowledge to us! you are the BEST
I maybe completely wrong but most jet airliners have an APU (Auxiliary Power Unit) that is used to spool up their engines. The APU again if I'm not mistaken can also assist in relight should an engine flame out in flight. Although if just one engine flames out the remaining engines can be used to power the dead engine back to life if possible. I'm not saying all jet aircraft are that way but most modern heavy airliners are to my knowledge.
You are not wrong. The engine in our start cart is the same as the APU in a Boeing 727.