The only reference I personally have is being fairly close to a 13-14000 lb high bypass fan during mx runs and we're still probably looking at orders of magnitude of a difference in noise I really appreciate your time and effort to produce these videos, and I appreciate the business allowing it! Cheers, RD
Normal person: Whats it like standing next to a jet engine? Engine Mechanic: It's air shattering, thunderous, violence. Like being viciously punched to death. Normal person: Oh my god that sounds awful. Engine Mechanic: (While giggling internally) It's freakin awesome.
super vid here with J79's at work, Goodbye 302sq F-4 OJIRO PHANTOMS having seen so many of jays vids i can picture the look of the bare engine as i watched them flying.. thanks to jay
Do you guys have a backup genorator there? The reason I ask is this place seems fairly remote, and what happens if the power went out during a test. The other thing is you have a huge volume of fuel there, so I would think its feasable to have a small genorator of some kind, whether its a propane engine or a turbine like the Solar GS-350.
We are off grid at our test cell. We generate our own power. All the controls have UPS power. It has never failed. You never can say never, but so far... a 100% reliability.
I worked on the J79 in F4s. You are right that nothing can describe what it feels like with 2 engines running all 17 stages of afterburner when you are doing engine trims. Your heart won't even beat right.
On another note, I saw a video last week of a special railroad locomotive with a turbojet engine mounted on it with a special "nozzle" on it meant to blow snow off the tracks. The engine looked and sounded like it might have been a RR Spey. The engine didn't have any protective shroud over it and it looked like it had a pronounced waist in the middle. Seeing that made me wonder if you have ever serviced equipment repurposed for that configuration. It is because of your videos that I had any sense what kind of engine I was listening to. Thank you for all the wonderful sights, sounds and insights you share with us. My life is richer for it.
Not a Spey, but usually they are ancient centrifugal compressor engines, and fairly rare, because it was finally re-discovered that (news flash): jet engines do produce a lot of heat, but their main purpose is to produce thrust, and that plays hell with the ballast on a railway...
@@AgentJayZ Thanks for the response. Wow, I've never heard of that type of engine before. Maybe if you're inclined you could tell us a little bit about them (centrifugal compressor engines) some time. P.S. Stay safe, making videos shouldn't require wearing a hero's hat and getting pummeled with rocks. We love you man! We want you to save Jay for another day!
I know at air shows, low passes by twin engined fighters is almost bowel loosening. And the B1 Lancer at low level is extraordinary. It sneaks up, then WHAM.
Any chance you could pull out your white board and tackle the basic physics of the difference in thrust mechanics between sub sonic and super sonic thrust? Sorry, I had a difficult time wording that question so I’m not sure if it makes sense. But if I was standing next to you when you were describing the con-di Nozzle I would say, “ hey, what’s the physics of that?”
I'm not at all sure that I understand exactly what you are asking, but here is an edited cut and paste of what I posted about the convergent-divergent nozzle in a discussion in AgentJayZ's previous video. I'll start with the engine at maximum ‘dry’ thrust (military power in US terminology?). The nozzle is closed, with the ‘turkey feathers’ (we call them ‘’petals’ in the UK) forming a simple convergent final nozzle. For US readers, consider an F100 or an F110 engine and the appearance of the back end of an F-16. The difference between the outer and inner diameters of the closed nozzle is quite noticeable and there will be a rearwards load on it. This is as a result of the jet pipe pressure acting on the projected area (outer diameter minus inner diameter) of the nozzle. That's why, personally, I don't like the term 'propelling nozzle'. Now when the afterburner lights up and the nozzle opens up to become con-di, the engine conditions typically remain exactly the same, so its internal loads are obviously unchanged and the jet pipe pressure remains essentially the same. The physics state that the increase in thrust is as a result of the increase in velocity of the exhaust gas, courtesy of Newton’s Second Law, but what load changes actually occur in the final nozzle? Firstly, the outlet area of the nozzle is increased, so that there is less projected area of the convergent section for the jet pipe pressure to act upon and the rearward load on it is reduced. The gas velocity at the nozzle ‘throat’ is sonic (ie, at the local speed of sound). However, the speed of sound in the hot exhaust gas is much higher than the 760 miles/hr for the speed of sound in air that you might be thinking of. At 600degC, it's around 1,300 miles/hr, which is about the temperature of the turbine outlet, so it will be even higher downstream of the afterburner. The divergent section of the nozzle is still a nozzle (not a diffuser), because it is a supersonic nozzle, and there is a radical change in the physics and aerodynamics of a supersonic flow. The divergent section is, therefore, accelerating the hot gases even more and there is a forward load on the divergent section. The resultant increase in thrust, which is transmitted to the engine mountings via the jet pipe, is therefore produced as a result of a reduction in the rearward load on the nozzle and the creation of an additional forward load. Sorry, but I’m not in a position to put any actual numbers to these two loads, but, for example, the result is an increase in thrust from 11,905lb ‘dry’ to 17,835lb in afterburner for a J79-GE-17, according to Wikipedia.
Oh well, look, I understand what it its to study. But I like to participate in this channel. Jay himself often responds to comments, and I like that. I think he is a good teacher. I think that is one of the reasons he does this. If he chooses to respond I will get an opportunity to see it explained in a way that you may not get in a text book. That is why I ask. No need to get nasty. Sincerely Dr. Seth
Nice! Yall got that engine tuned to perfection. Afterburner flame looks really smooth and clean, even compared to a lot of newer engines. Getting a fire to burn so perfectly under any conditions is hard enough, so I can’t even imagine how much hard work goes into calculating, designing, building, testing and fine-tuning an afterburner assembly.
I was an ammo guy working on the flightline. The noise is no joke. Probably the loudest thing I've heard is being at the end of the flight line directly underneath an F-15 doing combat takeoff. You can feel it in every nerve, every bone in your body. It's not just the noise. In some cases I would wear hearing protection and I still couldn't hear anything for a couple hours.
I'm just a car guy. But, I still watch this channel because learning about how jet engines work, how they're fixed and designed is still really fascinating. I'll never get a chance to work on one, so this is the closet I'll ever get. Really enjoy the content and the thrust action 🍻
Noise so loud you think you are gonna die from it? Not enough. Exhaust so hot it would literally melt the flesh from your bones? Still not enough. Giving the thing ammunition to throw around the whole property? Just right.
@@AgentJayZ Believe me sir, I would like nothing more than to be there, asking silly questions, watching what goes on, trying to stay out of the way, and experiencing the tests live in person.
To know it's 20psi was actually just as interesting to know as it was amazing to watch. It's hard to get these numbers, especially for vintage engines.
Thank you for taking one in the face for OMFG AFTERBURNERS! Never gets old. I bet you get asked this question a million times, but do your neighbors ever complain? Or are you far enough out in the bush that it doesn't matter?
I love the "get away" part 😂. Netherlands air force used to fly the starfighter. I have only seen the Italians fly, and one Norwegian 637. Best sounding plane ever made. I hope we will see one fly again in the Netherlands. Dont you guys have that engine? Love your videos ❤
The microphone can't begin to register the sound level. I live 3 miles (4.8km) from a military aircraft manufacturing plant and a little over 2 miles (3.2km) from a military base. Even at that distance, the deep rumble and roar when the engines are tested are loud enough inside my house to make sleeping nearly impossible. Good that they don't do that near bedtime.
Try hearing 2 of those on full AB for 2 years straight. We actually got numb to it but would turn our heads when we heard something different. They sounded really good in the 104 starfighters
I worked at Orenda in the early 80s...I fondly recall watching in the test cells the J-79, and J-85 engines going through their engine run-ups...A team from the NRC came to Orenda, to film in high-speed, what happened when a large object was thrown into the intake...
Agent J Zed, is the fuel for the turbine gaseous propane, or are you burning kerosene. When the afterburner went back to stage 1, you could see a blue flame which would make me think you were on Propane. The nozzle (we call them Turkey Feathers) has an air gap between the burner tube and the nozzle. In flight, does bypass air (or air that does not enter the turbine) get routed through the gap to help cool the nozzle and give additional air to the after burners? I am really surprised that the test cell does not have a blast fence about 100 meters away from the back of the test cell to direct the jet stream up so you would not have a gravel storm when the turbine is at max power. I am significantly worried that if I put my Kia Soul with the 1.6 liter engine in the cell and revved the engine, the exhaust gas may rip huge sections of earth away. I mean, really, a 1.6 liter at 5000 rpm must have an thrust of at least 10 kilo's roaring out the pipe :-)
This engine is running on JetA-1 liquid kerosene fuel. The ID of the fuel line is about 1.75 inches, and the boost pump supplies it to the engine at about 25 psi. Like a low pressure fire hose.
Listen to your instincts. Your head is basically a can of jello and sound pressure levels that high could very well produce displacements large enough to cause a brain bleed or worse. Don't risk it. I've often held my breath watching you guys lean over the engines in operation, making adjustments, wondering if one had a cato of a disk, or a blade failure what would happen. I know that those sorts of things are usually contained, but considering the physics involved, the test cell is a mighty small place, even in the control room, I wouldn't consider it "safe". I've spent most of my life around industrial equipment and even the little stuff can get you. I once was in in tiny (as in nowhere to run) underground room under a aluminum rolling mill at Alcan and we had to pressurize 5 freshly rebuilt 18" diameter x 14'h piston accumulators to 5000psi. I'll never forget the sound and sheer terror each time the pistons groaned as they moved. I remember thinking about being a spot on the wall if even a line blew off or an o-ring failed. What you guys do is every bit as scary. I'd suggest a scattershield or blanket, but it would probably only become a secondary projectile if the worst happens. I guess that's another good reason to be so careful with assembly, not only do the aircraft pilots/passengers trust their lives to your work, you're personally right there the 1st time it comes to full power. When you think of things in this light, it explains a lot of the seemingly overcautious practices followed in the assembly of these incredible machines. Stay safe!
Cut my mechanic teeth on USAF F-4D's with J79's. Spent many hours on the run/trim pad... tailhook engaged in a ground harness, while running in full afterburner. We would run at night. The show was amazing. And, yes... the sound and shear power of this engine needs to be seen and felt to really appreciate such technology.
WOW! Awesome video! Thanks! Judging from the size of that engine, A F104 Starfighter is basically an engine with a cockpit, a pair of wings, landing gear, and not much else?! Haven't seen the raw power of that engine displayed any better.
My dream would be to work with you. That would make me the happiest man on earth. I don't know the technicalities of jets but I learn super fast !!! You have the greatest job on earth. I am happy for you.
I wish the camera mic, and/or my speakers were up to the task of portraying this sound. Having seen F15s take off from RAF Lakenheath in England its a utter JOY the power of afterburner noise
You know when you are in a club... next to the speaker towers... you pants are vibrating against your shins, and you can't hear somebody, even if they yell in you ear? It's about a hundred times that loud. I actually was a DJ in a rock club in the 80s...
I love the term “fire breathing monster”, it reminds me of sitting with the GE tech rep during ground school at Shaw AFB in the ‘70’s just marveling at the sense of raw latent power of even an inert J-79. May I propose a science experiment I believe only you would be nuts enough to carry out? What would it look like if you rigged a fuel nozzle from a jet engine up on an outside fixture, pressurized it with jet fuel same as it would be at full rated thrust and ignited the resulting mist? Assuming you didn’t burn down your entire shop in the process, it would be a fascinating demonstration of the sort of energy being released in a turbine engine and provide a visual sense of what is ordinarily happening invisibly inside the engine and would reveal the flaming heart of your fire breathing monster! I still fly but there’s no other thrill quite like that of going outboard and forward on the throttles of an after burning engine!
Now I’m loving the cap in the first instance!👍🇳🇿 but what’s not to like about fighter jet engines!!!! Strap that baby on. Great way to clear the driveway of snow. Hate to think how much that test costs. Is this the same beast they put in the F16? I’ll go do my homework. Loving your work. I won’t tell the greens about the carbon emissions 😉.....oh! 2 of them side by side in the F4...ok double awesome. Sorry P&W. 2xF100 In F15 next level
There is one that crashed in the country where I live. I’ve been there many times to find parts of the plane. But I have used your videos to try to identify any pieces to the J 79‘s of the plane. The parts and pieces are not nearly as pretty as the J 79‘s that you have on your show as they are mangled twisted and broken like they were made of twigs. I have only been able to find one piece of a rotor with four mangled fins still attached and by the size of the fins I would say that they are maybe from the 15th to 17th rotor of the cold end. I have to say thank you very much for your great videos as they are much appreciated.
dude I have had this same idea. I would love to see something like that, here is an idea BUILD ONE hahahahahahahahahaha. Hey I'm up for turning wrenches 😁
IIRC, that's the type of powerplant that the Lockheed F-104 Starfighter used ( en.wikipedia.org/wiki/Lockheed_F-104_Starfighter ) or at least the same family.
4:26 "Probably physically not harmful..." When you have to qualify this with a 'probably' I immediately think its a bad idea :) Also the gravel bouncing around like popcorn was pretty interesting!
So. if the gravel wasn't the best idea, how long before you bore hold through to the Southern Ocean? LOL! (Maybe try concrete :) Great vids as always, thanks.
you have not heard after burners till you had experience a sr 71 close up with 9 of 15 stages lit up on take off. both engines. and on a runway check detail.... while a F-16 scrambles past you off said runway. FUUUN !!!!!!!
Try roasting the marshmallow over the jet pipe just forward of the nozzle via the radiant heat. Safer, and hopefully it won't taste like jet A when it's done.
Been a while since I've been here. Looks like the winter has been kind to you. The engine start-up (from inside exhaust) was interesting. Thanks for another great video. I've missed my regular AgentJayZ/Jet City fix.
All those poor, innocent, unsuspecting little air molecules just minding their own business when WHAM they get sucked up and body-slammed down this huge hot chaotic piece of serrated, bifurcated metal machinery, then being sprayed all over with that slimy smelly jet fuel like that.,..NO WONDER they got so hot! [HOP HOP HOP!]
All hail the high priest of jetwash! I have stood in front of the works of the great masters of art, sometimes for as much as 5 minutes but when I am at an air museum I usually have to be physically retrieved from the static engine displays! I don't know if it's beauty in the form of fitness for purpose or whether it is the display of the pure excellence of the craft of the machinists, fabricators and design engineers. I am however always completely transfixed and that is when they are not running. Start em up and for me it is just transcendental.
@AgentJayZ you always go on how indescribable loud afterburner is. Last year I happened to be at the CIAS in Toronto at one of the small islands at the city. And by coincidence it was the turning point of all the fighter jets. I vividly remember when one F22 turned overhead, probably 100m above us with afterburner. Earth shattering and air ripping is really the term to use here. I can only imagine how violent this must be, if you stand right next to the engine.
I saw an F22 in Reno, and it could have been my vacation ears, but it seemed by much louder, snappier, and angrier sounding than I was expecting. Nice plane.
I still believe the Spirit to be the most body-intense sensation I've ever been to close too.. took off right over our heads and pulled up hard. (Taking off at military base. Not an air show) The ground was shaking and rocking. The sound was low and thundering. I don't think I've ever gone out of my way to overly express pride in America, but at that moment I felt like I had been saved and reborn by "the church of murica." Baptized in jet fumes.
The microphone on the camera and the computer speakers can´t ever repeat the enormous thunder from a jet engine on full afterburner blast and our ears are also to weak to hear it and tell the tale afterwards.
