The Howling J79 Turbojet Engine

[@needleonthevinyl]

Afterburning is actually how modern diesel emissions are kept clean. The particulate filter (DPF) gathers the carbon smoke particulates over time until its full. When the DPF gets full, a fuel injector opens that sprays fuel directly into the exhaust stream and burns it all off. As its afterburning (DPF regeneration), it generates a ton of EGT which is why you see venturis built onto diesel truck tail pipes. The venturis help to keep from burning the paint off the vehicle next to it during regen.

[@AgentJayZ]

I've often wondered about those exhaust tips.

[@gjpmrekkers]

Principal by gasgenerators (jet engines): extra mass flow( power) Newton’s law F= M x a!

[@gjpmrekkers]

I was 18 years working in the airforce as an engine mechanic. I started with J79 and J85 mostly on the platform and runup for troubleshooting! Later on i went to the testcell for over 3 year testing de F100 pratt & w! This testcell was build bij FN Belgium and was a that time the most sufusticated testcell in the world! Many testcell workers were jealous! After 18 years i started as an engineer for the T701 (GE) and worked on this program for an other 10 years. This is the reason why I am a follower of this youtube channel

[@AgentJayZ]

Welcome to Jet City!

[@zaktabak4460]

This is the sound I grew up with! Starfighters were all over the place and our Dutch 104s used these howling J79s!!! Really miss this sound!

[@DaveWrightKB9MNM]

I watch these videos and I get chills because they are so powerful and sitting on a test stand, I’m surprised they don’t break themselves loose. I think the howling is what makes the engine seem to be alive.

[@gooniac33]

All of the starfighters that I have seen had the flame always lit. I remember seeing that when I saw the German Air Force fly at Moffett in the mid 80s and the other shows where the starfighters were as well. The videos of the italians with theres have the ignitors lit too... nothing cooler than a howling F-104 pass!! Sounds like a space ship!! Thanks for sharing this burner action!!

[@AgentJayZ]

Use the link at the very end for more fun.

[@planekrazy1795]

Along with the Vulcan howl and the Hunter Blue Note the Starfighter Howl is among the coolest jet noises there are. An honourable mention to VC10's idling.

[@bowser515]

I agree completely, look up also four of the new SU-57's flying over Moscow. They sound almost haunting...

[@makecba]

Jeremy Clarkson has a book called I know you got a soul. This thing should certainly be in it. It roars, purrs, screeches, and cries. God damn, what a beautiful piece of engineering.

[@scottminshall6420]

The -11 was a F-104 Engine, I worked on the -15's in the RF-4C, and a little time on the -17 in the F-4G model, J-79 is a great engine! I do miss the sound, all of ours were the low smoke engines, as far as the torch ignitor goes on your engine, that is supposed to shut off when you come out of burner, so you guys got something going on there. I have had hard lights on the burner in the test cell and let me tell you it gets your attention real quick! Great video keep them coming.

[@christinadaly7743]

How come AB won't ignite without the spark ? not enough oxygen in the exhaust ?

[@JosevanEijl]

As far as I know in the J79-11 the torch ignitor is always om. Here is a video of Dutch starfigters departing for a mission. As you can see is the torch ignitor already on. kzbin.info/www/bejne/mGSlqn5_osSgqbM

[@AgentJayZ]

Not enough heat in the exhaust. That's the reason the torch ignitor was developed.

[@johnramberg1928]

On the F-104, the J79-GE-11 Torch Igniter is always operating. After engine start, there is a torch ignition test switch that is pushed before the hydraulic bay door is closed to ignite the torch. If this isn't done during post start, the torch will ignite during the first afterburner ignition and stay lit thereafter.

[@scottminshall6420]

@@johnramberg1928 Interesting, learned something new.👍

[@rickblackwell6435]

I was in Cold Lake Alberta in 1981. The walkway behind the Startfighters was close enough to feel the heat and a tiny bit of wind from the engines. I loved how they smelled and sounded. Great fun.

[@insanereindeer4081]

It's very cool to see what a rebuilder does to test jet engines, vs what a manufacturers does. Having the chance to freely roam DOD funded test cells, it's just so much of a different operation, but without you, I would not have known what they were actually testing.

[@jimporter7602]

Worked in the F 4E engine shop at Homestead AFB 69-70 -17 engines. F 104s at Homestead had -19 engines. Then Udorn Thailand 70-71. -15 engines RF 4C and F 4Ds, only went to the test cell a hand full a times. First time at the test cell at Homestead was 4 weeks out of engine school, wanted to show what i was in for ,got put 10 feet away from a AB engine run it was a eye opener. Did have ear protection

[@AgentJayZ]

Excellent. Sort of secret... the "overseas" version we often work on is the J1-E, which is basically a -17 that nobody talks about...

[@j007pace]

Just when I think I don't need to watch this video because I've watched so many of your videos over so many years but I watch it anyways and boy oh boy am I ever glad I did. What a remarkable test run video. I know I've said it multiple times over the years but many many thanks for taking the time and effort to film what you do in share it with us here on KZbin

[@welltell.]

I am glad this jet engine was a screamer and a smoker and not a moaner and a drinker...

[@slidey1788]

At up to 90 gallons a minute, I'd wager she's a drinker

[@edwardarruda7215]

Closed my eyes and pictured F4s taking off.

[@zapfanzapfan]

That is a substantial aeolian feature you have created there.

[@elwoodzo]

I had to google that - good vocabulary 😀

[@mikes9939]

I think the engine came from an F 4, they used the starter in the front of the engine. Also I was stationed at a pilot training base in west Texas during the Vietnam war and we had many Phantoms come in and out on their way to various places doing ferry flights. I worked in the GCA radar unit that was out among the runways and the control tower would always let us know we had one coming in to land. We could spot the plane miles away just from the black smoke, way before you could even see the plane itself. The smoke problem was very bad on the early engines. When descending into dangerous territory the pilots would put one engine into stage 1 afterburner and pull the other engine back onto idle. The afterburner nearly eliminated the smoke and the other engine at idle did not produce any. This kept the signature of the plane cleaner and made it harder to see. The Phantom was a big plane anyway and easy to spot. We loved having them come in and they were fun to watch take off as our radar unit was only about 300 feet from the edge of the runway where our radar unit was and we would stand outside and watch the show. Our base had T 37's and T 38's flying all day every day during the week so we had our fill of jet engines.

[@AgentJayZ]

This is great info, from someone who was actually there. Thank you for this!

[@kimalexander4083]

@@AgentJayZ Military J-79's used two different starting systems. The Airforce used a turbine starter attached to the gearbox which used low pressure air around 45psi. The Navy version used a turbine impingement starter system which was a ducting attached to the turbine case and blew air onto the second stage turbine wheel and used 75psi.

[@AgentJayZ]

Oh, we've got a few air impingement turbine cases lying around. I would like to see that system in operation.

[@FlyingHighVeteran]

I worked the RF-4C's out of Bergstrom AFB, remember doing full AB runs in the hush house. First time I did it being next to that much raw power was a humbling experience. I got around allot during my career--A10 Thunderbolt, RF-4C, F-15 C, D & E, F-16, RQ1 Predator & Transient Alert.

[@AgentJayZ]

For many folks, you were living the dream.

[@FlyingHighVeteran]

@@AgentJayZ I enjoyed it overall there were many long 12+ hour nights on the flightline fixing aircraft. The last 7 or 8 years though was doing the adult supervision gig--which definitely had allot of ups and downs.

[@AgentJayZ]

I have great respect for you guys who were there, doing the real stuff, in country. Your stories of your experiences are absolute gold. If you sat down in front of a camera, and told stories, I would be interested, and tell all my viewers about it.

[@tweed532]

Nowt better than a good howl and a few bags of soot out the back. Here in UK I have been lucky enough to witness a ground run howl of the preserved Avro Vulcan XF588 'Spirit of Great Britain' and its RR Olympus 202 engines.... Unforgettable.👍😎🇬🇧

[@grahamj9101]

The Vulcan howl has made the hair on the back of my neck stand up at air shows on a few occasions over the years. Of course, the howl is a product of the intake, not the exhaust system. As a Foundation Guardian, I hope to get up to Doncaster and hear that howl once more, before I get too old. However, my real bucket list wish, having seen two Lancasters in the air over England in 2014, would be to see two Lancasters in the air again.

[@jreid641]

Very cool! Spooky howling and black smoke.

[@dfb1111]

That would clear snow from my parking lot quite nicely!

[@batman1169]

For fun add a few small wind turbines in the field! Great 👍 video!

[@mdouglaswray]

Amazing. I had no idea you could put hell in a bottle.

[@guyh3403]

Amazing to hear (and see) the instant throttle response!

[@GarageSupra]

ahhh yess the blue note, a thing of beauty

[@carstuff4260]

I cant help but watch all of your videos.

[@sharg0]

I still use the earmuffs my father used when he worked on the RM8 used in the SAAB 37 Viggen (derived from Pratt & Whitney JT8D-1). I got them when he retired as motor engineer from SAAB in -95.

[@zapfanzapfan]

RM8 has a deep booming voice, different from other fighter engines. Maybe it's the relatively high bypass ratio.

[@sharg0]

@@zapfanzapfan Yes that's correct if I don't misremember. It also keeps the sound down a bit.

[@brabhamfreaman166]

AaaaaaaawwwwwweeeeeeSOME!!! Thanks for all of it Jay!

[@uzairbukhari99]

I remember the last j79 afterburner video. The engine had an amazing sounds. Had it saved on my playlist 😊

[@Andrew-13579]

I wish there was smellivision. 😀. I miss that jet smell. I can still remember the howling sounds of F-4 Phantom II’s making PAR approaches to NAS Miramar in the 1970’s to early 80’s, especially at night. It seemed sort of two-toned as either the pilots varied the throttles or some sort of automatic power compensator varied the throttles. Someone once told me the sound was caused by their engines’ variable stators. A sad, haunting sort of howl. Must have been the F-4B/N’s. They had the J79-GE-8’s with the short exhaust nozzles. They always left a “nice” smoke trail, too…sometimes a couple miles long.

[@Andrew-13579]

At about 8:34 and again at 8:49 I can hear that howl like I used to hear it from F-4’s, from a couple miles away. A nice long howl from 24:08 to 24:35. The F-4’s would howl like that almost all the time at approach speed with gear and flaps down…I think the flaps were “blown” with BLC hot air from the engine compressors, too. A couple other military jets that used the afterburning J-79’s were the Navy A-5 Vigilante (by the 70’s mostly known as the RA-5C supersonic photo reconnaissance) and the Air Force’s B-58 Hustler, which used 4 of them.

[@Andrew-13579]

Could you give us a video of the J-79 (or other engine), from close-up to the front, to capture the sound from idle to shutdown, all the way to zero RPM? It won’t be very exciting, but just to show how long it takes a J-79 to spin down to a stop and the sounds it makes doing so. Does it make a chattering sound as it gets below a few hundred RPM? Is that from the compressor blades rattling?

[@homefront3162]

My Dad was an F-4 Pilot

[@Andrew-13579]

As the engine spins down from idle, I can hear 4 or 5 overlapping crescendos (might not be the right term) or cascades from high pitch whistle to lower pitch. I wonder if those are sounds from the various front stages of the compressor blades passing air to their stators, with such close spacing, each with a higher “voice” than the stage in front of it. The higher the RPM, the higher the pitch, probably up above hearing range at times. And the variable incidence stator blades maybe causes resonance at various incidences and RPMs…thus, the howl…just guessing. Thank you for the videos! …and do I have that right, many of the front stages of the compressor have stator sections that vary their incidence in unison? Probably one of you other videos explains this?

[@AgentJayZ]

I've done that a few times, but I will include in my next J79 vid. Coming soon.

[@jimporter7602]

Worked on J 79-17 and -15s at Homestead AFB and Udorn RTAFB 69-71 only got to the test cell for about a dozen engine runs

[@USNVA11]

Blades of grass behind the workshop: “ oh shit, here we go again …… “

[@AgentJayZ]

In response to a J79 video years ago, a viewer said they hoped I died because I was killing so much grass... ... ...

[@USNVA11]

@@AgentJayZ - LOL 🤣

[@CaptainSpicard]

@@AgentJayZ Was it Hank Hill?

[@apollorobb]

i love the j79 sound in an aircraft when they pour the beans to it thats an iconic sound

[@chartphred1]

Pretty amazing video, that AB certainly clears up the smoke. Awesome sound, love it. Thanks 😁

[@Mrsournotes]

Now that’s an engine sound! Fantastic.

[@kimalexander4083]

The torch igniter originally was on all the time. This made the aircraft easier to see during the night(here I am). A powerplant change made it operate only when the afterburner was selected.

[@tulku1]

Thank you for great Film , i love that 😎

[@TheAllisonV12]

Tanks for making the earth now rotating a bit faster. ;-)

[@imagecrafting]

He could be making it go retrograde depending on which direction he's pointed

[@reab8286]

And To Think The F4 Phantom HAD 2 of these..OMG SOOO GOOD..Thanks JAY Z!.

[@wickedcabinboy]

Thanks for your quick response. Felt stupid after asking the question so I deleted hoping you wouldn't see it. Again, thanks for your videos, they are always interesting and extremely informative.

[@michaelogden5958]

As might have been said in the 80s... "Shmokin'!!!" Although the term might not have been a descriptor of a jet engine on a test stand. Even so... cool video!

[@DeliveryMcGee]

I forget that's not a road going through the test shed, that's just scoured down to bedrock by jet exhaust.

[@AgentJayZ]

Jetwash alley is tortured ground...

[@micstonemic696stone]

@@AgentJayZ Jetwash alley must enjoy cannabis, as is often stoned, LOL

[@tubehellcat]

While screeching and smoking might be less beneficial to the environment, it's hugely beneficial to enjoyment 😁 Like having chocolate cake for dinner, not healthy but so much fun!

[@barrywest3758]

Ah, the ole J79-GE-15 and 17s . The good old days. Yes in the air force in early 1985 we started replacing the main fuel control units and other parts on the 17s to vastly reduce the ole smoke trails. Little too late tho.

[@AgentJayZ]

The low-smoke conversion contains different design fuel nozzles and updated combustor liners. Nothing else. You can see both of these compared compared to the pieces they replace in my video series called Fuel nozzles, and my series called combustor liners.

[@mfbfreak]

Well damn! The hurricane factory is making local hurricanes again!

[@danielramirez8661]

love it!

[@jacklav1]

That protractor guy needs a mirror and a pair of binoculars.

[@High_Alpha]

It was common for fast jets of this era to use min burner in enemy territory to avoid leaving a big trail to point you out to the bad guys.

[@imagecrafting]

I was wondering the same thing

[@frommarkham424]

So that's what 5.5 tons of thrust looks like...

[@AgentJayZ]

In AB it's a little over 9 tons.

[@MechWizzard]

Does the smokey exhaust gas cause any carbon buildup in the turbine blades?

[@AgentJayZ]

When we disassemble the engines, they don't have any carbon anywhere except the inside of the exhaust tail cone.

[@zigwil153]

Any chance of a timestamping the startup process based on the sounds? I always wondered what is going in the engine creating those different pitches.

[@AgentJayZ]

A few years ago, I made a video somewhat like that : Jet Start with Commentary

[@zigwil153]

@@AgentJayZwill watch. thank you.

[@dtiydr]

17:44 Can you stand there with full afterburner even with the best of earprotection? Ok the answer came a little later: not for any longer duration as I thought, since no ear protection is enough for that.

[@planekrazy1795]

The torch igniter thing could be very common. There is a video of Italian Starfighters leaving a German base, as they taxi out (making many wonderful noises) all show the torch igniter burning away. None of them had been up to afterburner. Maybe there is a Norwegian, Italian, Dutch, Danish or German 104 engineer that can tell us more.

[@oscarzt1652]

what a massive crater behind your test cell!

[@dbeasleyphx]

Why does it sound different (howling) than other jets?

[@SpringDivers]

Ah! I'll never forget the smell of JP-5 in the morning.

[@tensecondbuickgn]

Seriously cool. It's amazing how certain setups create such a wicked sound. I watched your video on how the petals are responsible? On a much smaller scale, I recently updated my turbocharger from an old Garrett TE-60 to a newer and more efficient Precision 6262 and it's so much quieter 😕. My Buick used to turn heads driving down the road because it sounded like a Learjet with the Garrett lol. I wonder if that's in the efficiency of the Precision's turbine blades?

[@miconn99]

awesome video loved it

[@TechGorilla1987]

It's kind of cool to see a couple of dames up close to the enclosure immersed in the magnificent jet-ness. Hot chicks and hot jets go hand in hand.

[@turbofanlover]

That was absolutely spectacular. And I continue to be impressed with just how good that Orenda engine looks. Any idea when it's going to be back in a Sabre?

[@AgentJayZ]

The owner just purchased a Sabre that is in crates, and has been stored for a while. I am guessing it will be flying in about a year. I will be there for the commissioning, for sure!

[@micstonemic696stone]

@@AgentJayZ It would be great it you can cover this, the full story start overhaul to wheels up

[@micstonemic696stone]

I now have Patreon AgentJayZ for this Orenda next hospital stay I will watch complete overhaul, when I feel better it is so boring in there, I have successfully linked my phone with my 10" tablet, it was horrible and cold in there during covid

[@AnarchistAaron]

So I should decat my car and stick an afterburner on it for improved economy and emissions?

[@isaacsrandomvideos667]

“Improved” actually gonna use that one now lol

[@_Max_Headroom_]

Reminds me on Avro "Vulcan's" -Sound of death- over the falklands...

[@user-bg4cy9rx4w]

Speaking of Avros, This Makes Me Curious about how the Iroquois is doing. I haven't seen all the videos on the channel but It looks like the last updates on it were many years ago now. If AgentJayZ Reads our posts, I'm wondering are there any future plans for it?

[@AgentJayZ]

It is still in storage, and I will give updates as progress occurs.

[@TechGorilla1987]

Could you speak sometime about the water injection engines that the US military used> The huge black smokers!

[@Chainsaw-ASMR]

12:00 - Worlds most badass dragonfly!

[@AgentJayZ]

Depth of field compression by a long-focus lens. That little guy was 50 yards away from the engine.

[@imagiro1]

12:00 Is the dragon fly also working for you?

[@AgentJayZ]

We try to avoid showing or discussing our cybernetic projects. Exhaust gas monitoring. No, we certainly do not have anything to do with, and do not have access to, any examples of microelectronic-insect hybrid technology. Never heard of it, actually.

[@imagiro1]

@@AgentJayZ Understood - I never saw anything! 🤫

[@AgentJayZ]

Excellent. You've got a bright future in the aerospace and aero(blank) industry.

[@grahamj9101]

@@AgentJayZ So, does this mean that those two little dragonflies, which settled on the Armco barrier next to me on Friday, when I took a breather during my walk, might have been keeping me under surveillance?

[@zapfanzapfan]

@@grahamj9101 Something from the NHS black budget ;-)

[@YouNameItGaming]

Great video as always, this has me wondering if there was any extra efficiency picked up with the later smokeless combustors.

[@AgentJayZ]

None.

[@YouNameItGaming]

@@AgentJayZ cheers for the response, and keep up the great work

[@marianmusic7221]

@AgentJayZ I've seen the video in which you talked more about the differences between the two "cans", but I do not remember you talking about the differences in power output and consumption. Is there any difference between the two "cans", beside the smoke? Or along with the "cans" design changes there were other changes also, and a direct comparison is not possible? Thanks for sharing your passion with us!

[@AgentJayZ]

The Low smoke cans are also called Long Life cans. They do last longer in industrial engines. The Low smoke cans do not produce any more power, and the do not improve fuel consumption. The "smoke" is actually particles of unburned carbon, which is not really pollution. It is environmentally inert. It does look bad, though.

[@alisonfox7318]

Does anyone have any ideas as to what the oxygen content of the exhaust gas is and what is the efficiency of the afterburner at burning fuel? I believe that combustion chambers / cans are above 90% efficient (I seem to remember that RB211 combusters where 99.9% efficient)

[@arktossgaming5936]

I belive the exhaust gas still contains around 75% of the oxygen that went into the engine

[@ASJC27]

The amount of residual oxygen in the gas after the main combustor depends on the specific engine. The hotter it burns - less oxygen is left. In the case of the J79 about 75% of the oxygen is unburned in the main combustor, leaving a lot of oxygen available for the afterburner. On the other end of the spectrum, the F135 in the F-35 burns about 72% of the oxygen in the main combustor, so only ~28% is left over. But the F135 is a mixed flow turbofan, so a lot of "fresh" oxygen is added when the core flow is mixed with the bypass flow, so it still has plenty of oxygen available for its afterburner.

[@tech270154]

how much fuel does it consume for one stand test aprox, ? very nice vid , many thanks

[@AgentJayZ]

You will enjoy this video, and all the info in the description: Testing a GE J79 with afterburner

[@frankhollein7093]

I always wondered if this fuel rich setup was done on purpose, to help extend the life of the cans and turbine blades? Maybe Temps were too hot back then, so they ran a little richer.

[@AgentJayZ]

It's not fuel rich. There is no mixture control. Just like a candle or a camp fire, the combustion of fuel in a jet engine takes place in an environment where there is a great deal of excess oxygen. Most importantly, these are not piston engines.

[@anthonyglee1710]

So cool! Leave the mic tape off, sounds way better! 😉

[@midbc1midbc199]

Is this how you shovel the driveway

[@SolarWebsite]

Moving around that running engine at very close range, surely the sound pressure must be so high that no hearing protection can prevent all hearing damage? Or is it not as bad as it seems?

[@TeemarkConvair]

i've been under wing of B-52 during multiple engine runs and the throttle bursts are beyond "hearing", the sound rattles your insides, almost to making one think of vomiting..

[@AgentJayZ]

"all hearing damage" is mighty dramatic language. And don't call me Shirley. No damage occurs, but your body will not allow you to stand near the engine when in AB.

[@SolarWebsite]

@@AgentJayZ OK, sorry about the language, it's a a field I know next to nothing about. I just thought the noise levels next to a running jet engine might be so high that some hearing damage might be unavoidable, even when wearing hearing protection. I only know my dad is quite deaf from driving 70s/80s trucks for 20 years, having essentially sat on top of a large noisy diesel engine before sound insulation became a thing.

[@grahamj9101]

@@AgentJayZ That was Leslie Nielsen's line: corny - but funny.

[@stonelaughter]

When you engage reheat, and increase thrust to max reheat, does the RPM of the turbine/compressor combo change? i.e. does the extra burning at the rear increase exit energy of the exhaust, forcing a need for an increase in intake air? Or does RPM remain at 100% dry and all the extra burning in the jetpipe only affect JPT and EGT?

[@AgentJayZ]

It's an afterburner. Everything happens after the gases have left the core engine. No effect, except for a few seconds of slight EGT rise. JPT is measured by the nozzle area controller. Of course there is a rise in JPT when it's full of fire as opposed to when it's not.

[@mbmann3892]

that brings my to a question I always wanted to know. What makes the GE T-34 (A-10 engine) sound so unique. ?

[@SkyhawkSteve]

I think it is due to being a modestly high bypass turbofan engine. The fan makes the whining noise that is fairly unique among smaller jets like this.

[@AgentJayZ]

I think the whistling noise of a TF34 is coming from the turbine.

[@dfb1111]

Is there a maximum amount of time the engine can stay in afterburner or is it a function of EGT and time?

[@AgentJayZ]

It's a function of how much gas you got.

[@dfb1111]

@@AgentJayZ Great answer!

[@deereboy8400]

Wow. Thanks.

[@ShuRugal]

Speaking of AB flameout: The F-14A had a problem with AB flameout at low airspeed. The NATOPS manual actually prohibits takeoff with AB because the chance of one engine flaming out and creating massive assymmetric thrust was deemed unacceptable. All takeoffs in the Tomcat were to be performed at mil power.

[@AgentJayZ]

The TF30 turbofan had a short service career, due to its tendency to suffer from compressor stall.

[@johnramberg1928]

You may be mistaken on the no A/B takeoffs in the F-14A. Per the F-14A NATOPS right in front of me, for an afterburner takeoff(field ops), both A/B's must be confirmed lit (nozzle position 2) before brake release. Carrier ops can also be accomplished with full A/B on the F-14A and most were.

[@johnramberg1928]

@@AgentJayZ The TF30 actually had a long service career and is still flying 56 years after the first TF30 flew in the F-111. The last USN F-14A (TF30) flight was in 2004 and the Iranians are still using it in their F-14A's. The original TF30-P-412 in the F-14A had lots of problems. P&W worked some out with the -414 in 1977 and it got a bit better with the -414A in 1982 but they were still a dog of an engine.

[@ShuRugal]

@@johnramberg1928 interesting, I could have sworn the Tomcat was not permitted to use AB for takeoff. Good to have my misapprehension corrected.

[@AgentJayZ]

I'll accept that you know more about that engine than I do. The Iranian F-14A's, have long been non-functional, haven't they? I really should be limiting my comments to the subject of this video, namely the J79.

[@robertborchert932]

Nice! I'm early tonight. JayZ, back in the day at MCAS El Toro, I remember the howl of these Phantoms. The smoky combustors! You captured that unique howl very well, sir! Is the howl induced by a standing wave in the combustors? Good times. There are few things cooler than that run up to afterburner after the crew mounts an engine. I'll never forget that characteristic wooo-oooo sound! Fantastic. VMFA 531, the Grey Ghosts!

[@AgentJayZ]

The howling noise seems to be associated with the exhaust nozzle. We have tested engines with the standard (old) combustor liners but with the new design nozzle, and they don't howl.

[@eddean6663]

I was told the Air Force cut the spray bars off to get all of the fuel in the afterburner.

[@AgentJayZ]

Yess... I have also been told they cut the wings off the F-35 to make it go faster... Yess...

[@eddean6663]

@@AgentJayZ that's what I was told at Evendale, Oh when I worked there. And yes we made the spray bars. And the low smoke combusters. But by that time J-79s were out of production and it was spares.

[@TonVerkleijT3]

Brilliant, what a brute force! A former fighter pilot in the Netherlands said he loved this engine more than the F16 engine he flew after the F104's where decommissioned, due to it's sheer ongoing power. He had no complaints about the older J79 engine and its howling noise. By the way, will this engine fly agein in a restored F104 in the future? And did newer J79's not howl or smoke? Regards, Ton

[@AgentJayZ]

This engine will be installed in an aircraft. I've made a series of vids on combustor liners. You might enjoy searching my channel page for them.

[@SupremeRuleroftheWorld]

so, afterburners are good for the enviroment?

[@AgentJayZ]

Actually, the black "smoke" is unburned carbon particles, which are completely harmless. But when burned to "clean up" the exhaust, they form carbon dioxide, which is not completely harmless. Sometimes what looks nice can be very dangerous... oh, how true!

[@WarblesOnALot]

G'day Jay, Well mate, the Engineering and Mechanic-ing and Spanner-Twizzling showcased hereinat is definitely Top Class. However, as it happens, at this point in History..., in light of the latest Reports by the International Energy Association (more or less a Union or Club for Fossil Fuel Extraction, Refining, Marketing Companies) and the latest Reports from the UN's Intergovernmental Panel on Climate Change...; it won't be long before this kind on Non-Essantial (Vanity Project) burning of Refined Transport Fuel will be either outlawed, or taxed out of existance. Always assuming that the Bat-Eater's Lament Virus doesn' render it a moot-point by shutting down the Industrial EcoGnomic Activity required to generate the Cashflow needed to permit sufficient "Profit" to be scooped-out as to enable anybody to be rich enough to be able to afford to commission such work, on such delicately complicated Machines - simply for the Fun of owning a working example and playing with it. You're like a high-priced specialist Vetinarian to Aero-Mechanical Dinosaurs... A fully working Personal Jet Engine appears to be similar to an Atomic Warhead ; they're wildly complicated, horrendously expensive, incredibly easy to get wrong, catastrophic when they do malfunction, and one has to be very Very VERY Skilled and clever and experienced to put one together...; but, only a Lunatic would actually WANT one of the things. It's a very beautiful "White Elephant", and if I owned it I would be busting myself to sell it for whatever anybody might offer - least I get stuck with the thing when it becomes a "Stranded Asset" and Storage Costs for it become an issue. We live in interesting times, And the Thymes - they be A' Changeling... The halcyon dayze of being able to fly in the Sky, for the fun of it ; are rapidly drawing to a close. Such is life, Have a good one.... Stay safe. ;-p Ciao !

[@donaldstanfield8862]

Hahaaa, sadly, sounds apt! Hope not, though!

[@WarblesOnALot]

@@donaldstanfield8862 G'day, Well, check it out..., 2030 is only 8 & 1/2 years away..., and to cut Atmospheric Fossil Carbon Emissions by 50% in that time..., either Refined Transport Fuel will become either illegal to burn recreationally, or too expensive to set fire to for anything less than matters of imminent Life & Death. And after that, it will all get worse. Because ever since President Eisenhower started worrying about Greenhouse Effect & established NOAA in the 1950s..., the Busyness As Usual Lobby from the Chamber of (the Horrors of) Commerce have worked unrelentingly to convince every CONSUMER on Earth to ignore ALL the Science - in the interests of Profit Maximisation during the next Fiscal Year. So, it isn't as if we don't richly deserve what's coming down the Pipeine at us. Tough Tittty for the Youngsters though ; their Parents & Grandparents & Great Grandparents having conspired for decades to steal the Kids' Playlunch, Lunch, and Afternoon Tea, eaten the bloidy lot - and then burned down the Family Home while seeking the Insurance Payout - while neglecting to have paid the Premiums on any sort of Insurance Policy before burning the World. It would be hilarious, were it not a True Story. Such is life, Have a good one... Stay safe. ;-p Ciao !

[@todddembsky8321]

Hello Special AgentJulietAlphaYankeeZulu I know that you have answered this a gabazillion times, so -- are you running LP, Gaseous Propain, or Jetgrade Kerosene during the tests? Next question -- how far in front of the bell housing does the danger suckage zone (new word "Suckage") extend? I keep seeing the engineer pass in front of the bell housing while the turbine is at or near military power, however because of the zoom lens, I cannot tell if he is 1 meter or 10 meters in front of the bell housing intake. Great video, love the reheat pictures. Looks like I am staring into hell. Is the reheat or afterburner, flame holder in a protected, subsonic housing? Thank you very much for bringing us with you in the videos.

[@AgentJayZ]

Jet A1 is on the side of the delivery truck. My video called Is Testing Jet Engines Safe addresses the subject...

[@andrewhofmann5453]

Please do us all a favor and NEVER aim your test stand westward. We cant risk the J79 slowing the rotation of the earth. :)

[@TheSound0fLegends]

Is it the airframe that increases the howl effect? I ask as the J79 Phantoms I never recall hearing howl like the Starfighters

[@brianoz2brn976]

You may have heard it from a greater distance, and distance attenuation is higher at higher frequencies ?

[@brentdennard6722]

I’ve heard the star fighter a couple of times howl like one of those two distinct resonance frequencies in this video, they must’ve had they’re own design of nozzle for the F-104. I had thought it was something on the aircraft whistling... interesting. Sounds like you’ve got an f-104 engine here

[@charlottejet4338]

That was awesome 😊 🇬🇧

[@AgentJayZ]

I was hoping to be able to make you say that. Smirk.

[@charlottejet4338]

@@AgentJayZ I'll say it again. Ah hem... THAT WAS AWESOME! 😁🇬🇧

[@callen6893]

When the engines are finally installed into what ever they may go in are they completely ready to go? I mean are no further adjustments needed or does a person such as yourself go out to the location and do some checks to the engine as installed?

[@AgentJayZ]

Industrial engines sometimes have some adjustments made, but not usually necessary. Aircraft engines are treated as new, and no adjustment is necessary.

[@freindimania11]

At one point it felt like its gonna take the shed and fly away.

[@drthik1]

Would be fantastic to be neighbors with Agent JayZ and hear these engines rip

[@0623kaboom]

ok 2 minutes intro and noise disclaimer done ... BRING ON THE NOISE lol .. kind of like sitting in front of a speaker tower at a KISS concert ... not the best place to be BUT fun still lol

[@0623kaboom]

yup the afterburner or reheater thrust tends cause flameouts so leaving an ignition source running during it mitigates it by relighting the exhaust as needed ... the flame out tends to happen as the veins on the exhaust cone are transitioning from closed to open ... even the main combustion chamber will have at least one chamber running a spark igniter to avoid flame outs there by keeping one can lit which will relight the others if needed ... . i wouldnt expect the torch to be on UNTIL the re heat has been engaged ... sure its only a few pints of fuel but thats a few pints of fuel for other things like dog fighting or loitering etc .. not much BUT for each tank of fuel a few more seconds can mean being refueled and a dead stick landing being forced upon you ..

[@0623kaboom]

oh that channel behind the test shed ... is it a planned feature or is that all dug out by tests .. I assume planned to lessen launching fine bits down the field and causing harm or damage ...

[@AgentJayZ]

There is no such thing as a main combustion chamber. There is a combustion section that contains ten individual liners in this engine. It has two spark igniters, and they are not sparking when the engine is running. They are also not sparking during operation of the afterburner. "the afterburner tends to cause flameouts" incorrect. Never seen it happen, and in modern fighters, never heard of it. Thanks for watching, but I will be keeping a close eye on your false information.

[@zakp.2759]

@@0623kaboom do you know what you're talking about? the igniter doesn't stay on just in case the engine flames out...i think you need to learn a little more.

[@kennethsalomonsen6244]

I wonder if this J79 is for the Norwegian 637??

[@kennethsalomonsen6244]

kzbin.info/www/bejne/rZW4fJh6rrOHaJo

[@inakig.4079]

@AgentJayZ I'm curious about: - how much fuel did you approximately burn in that run with AB - is there any MCT rpm or N1 setting - is there any limit of time at which AB should be turn off before melting/destroying anything (maybe called AB MCT🤔) Love your videos and explanations, keep on it! 💪

[@AgentJayZ]

1) Already answered in comments several times in this video, hundreds of times throughout my channel. Too much effort to find? You are entitled to your opinion, of course. 2) What does MCT mean? What does setting mean? We measure the rpm of the engine. When we give it more fuel, it goes up. When we give it less fuel, rpm goes down. 3) The afterburner needs to be shut off before the aircraft runs out of fuel. It will not damage anything. "MCT" is an excellent example of jargon, which impairs communication.

[@CertifiedIndustryProfessional]

@@AgentJayZ I believe he means maximum continuous thrust, but as you say, this is an example of non universal jargon that slows communication.

[@AgentJayZ]

Wow, It must have really taken a huge effort for you to actually type out the words in "long" form. I can see why a lazy person wouldn't bother... I was actually guessing it meant something like maximum speed turbine, which is equally stupid. If you are at maximum thrust, is that any different from max continuous? And please explain how. The only engines I have seen that use a setting called max continuous are non afterburning turbojets, and the term means "cruise" or 93% rpm. above that is military (97% 20 minute limit) and Takeoff (100% 5 minute limit). So now we see how much confusion can be caused by laziness.

[@inakig.4079]

I'll omit acronyms next time, I thought native-english speakers loved them... 😏 Yes, I meant what is often called "max continuous thrust" or max operating time at a given RPM. (probably a more common term in commercial turnofans rather than turbojets you deal with...). Thanks for replying.

[@thunderchief2004]

Very cool! I notice that the -19 version have a lighter blue afterburner flame compared to this -11 version: is the EGT somewhat different?

[@AgentJayZ]

Same EGT, but less soot is produced by the lo-smoke cans. And burning particles of soot will radiate an orange glow, like campfire sparks do.

[@sanfranciscobay]

My question is How much fuel does a J79 burn in MIL Power AND MIL Power witb Full Afterburner, 2 separate numbers. Here is a comment from the youtube channel Diesel Thunder Aviation where he is a Mechanic on a F4 Phantom in the United States. "Per the manual, each engine will consume between 800 - 1,400 lbs per hour at idle. At 6.7 lbs per gallon, that translates to 119 - 209 gallons per hour for one engine, or 238 - 418 gallons an hour with both engines idling. The variance is tied to the ambient air temperature. Cruise power is generally 4,000 - 8,000 lbs per hour, per engine. In gallons, that is about 1,194 - 2,388 gallons per hour (both engines combined). In afterburner (at sea level), each afterburner can consume between 19,800 and 27,600 lbs of fuel per hour. That's 2,955 - 4,119 gallons an hour per engine. One thing to also factor in is that the engine core is running at MIL power when the burner is engaged so the total fuel burn is engine core + afterburner. These J-79's sure are thirsty!" The below text is from my comment from the GE Manual about fuel burn from his comment from the manual. Here is the math on gallons per minute for both engines combined. Idle. 4-7 gallons per minute. Flight Cruise. 20-40 gallons per minute. At $5 per gallon, that's $100-200 per minute. MIL Power and Full Afterburner. 49-68 gallons per minute.

[@AgentJayZ]

I get asked that a lot. A few of my videos mention fuel consumption. Have a look at "Testing a GE J79 with afterburner". I've put fuel consumption info in the info section.

[@sanfranciscobay]

@@AgentJayZ Will do. Thankyou.

[@sanfranciscobay]

@@AgentJayZ I went to your video and this is what I found in the description: "Fuel consumption is about 35-40 gallons per minute at full dry power, and the afterburner adds about 50 to that number."

[@AgentJayZ]

Thank you for repeating what I did in fact write... and of course checked before sending you there.

[@robertbinder106]

F-15s have (had) afterburner blowouts from time to time. I witnessed one while the aircraft was in flight at a airshow in the late 1980s. Also, here is a video of one: kzbin.info/www/bejne/oqSrZJR4fdl9psU And another: kzbin.info/www/bejne/g4amg2qspph7q8k

[@boomer9900]

Nice footage. I was wondering how much fuel the combustors use vs the fuel the afterburner injectors use? Always enjoy your videos.

[@AgentJayZ]

Fuel use is progressive all the way from idle to full dry (40 ish gallons per min), and then to full AB (another 50 gpm added on top). Pilots always have one eye on the fuel gauge!

[@ASJC27]

At full wet, the afterburner on the J79 burns fuel 2.5 times faster than the main combustor. So fuel consumption at full afterburner is 3.5 times higher than at military thrust.

[@AgentJayZ]

Whatever. We measured it at 37 gpm mil, and 87gpm full AB. Real data, unconcerned with whatever anyone publishes anywhere.

[@ASJC27]

@@AgentJayZ That's interesting. Janes specs mil power consumption at 26 gpm. I looked at an F-4E flight manual that I have access to, and it specs 26-28 gpm. I believe you got what you say you got, but I wonder what could cause this discrepancy.

[@zapfanzapfan]

@@ASJC27 US gallons vs Imperial maybe?

[@18robsmith]

Do you test run on LPG or Jet-A ?

[@AgentJayZ]

Our test cell has facilities for both. This is a J79-11 aircraft engine.

[@arcburn3364]

No dragon flies were injured during this test.

[@AgentJayZ]

Actually, that's true!

[@imagecrafting]

Ok Zulu, how much fuel (your choice of pounds, gallons, whatever) and what type did that particular test run use, and how much did that fuel cost?

[@AgentJayZ]

We started with a full 1000 gallon tank. We used half of it in about a half hour of running at various power settings. If you are looking for specific consumption, you'll find that in the descriptions of my other J79 videos.

[@imagecrafting]

@@AgentJayZ nope, that's exactly what I wanted to know. Thanks! :)

[@isaacsrandomvideos667]

still goin!

[@pinkdispatcher]

About the torch igniter: This educational video (kzbin.info/www/bejne/l3zZap-pmdGhbac in German) seems to imply that at least at the German Luftwaffe (one of the largest F-104 operators), the torch igniters were lit after engine start on the ground. The voice over says, "After the first technician has switched on the torch igniter, the second technician must make sure that it is actually burning. Thus the pilot knows that he can operate the afterburner at any time." Maybe there are/were different procedures.

[@AgentJayZ]

I have today consulted with a crew chief for the USAF in Vietnam, concerning the J79s in the F4 Phantom II. He says definitely the torch igniter is off unless AB is selected. The valve to the fuel supply of the torch opens at 8 psi, and the AB fuel is delivered at 400 psi. With age and heat, the valve can stick open. Think about it, a flame constantly in your tailpipe is a beautiful signal at night for enemy pilots, and all 24 hours for heat seeking missiles. It's a malfunction.

[@pinkdispatcher]

@@AgentJayZ Thanks for the reply, that makes sense. Maybe what's shown in the video is just a functional check of the torch igniter, and after verifying that it works, it is turned off again. It would be strange that it would have to be turned on by a technician on the ground.