The Air Starter - Turbine Engines: A Closer Look

The Garrett air turbine starter. We take one apart, and video one in action starting a large turbine engine. In the process we see some things that have not been noticed before...
Once the engine has been started, there is a clutch to disengage the starter. To see more about that, have a look at my video called "the Starter Ratchet Clutch"

[@AgentJayZ]

Every time I work on my GM 2500 4X4, I realize how spoiled I am, and how tough you frontline melonfarmers really are. You guys do the hard work, day in and day out, and you get my respect for that.

[@danilorosich]

You have a turbine, driving a turbine, to start another turbine. I love aerospace technology....

[@Fat_Ninjah]

Also a manual for the manual for fixing the aircraft XD

[@samuelpeter9636]

its called turbine craze

[@saveflatearth-now4490]

the first runs on compressed air then compressing that there and feeding is into another turbo or giant turbine or jet engine which took a long time to get-spun up to the right speed but once there needs no fuel

[@fryncyaryorvjink2140]

What came first, the turbine or the turbine?

[@yudjy3286]

😂

[@barumman]

I like your honesty in admitting to not tightening the bolts, very interesting videos, thank you

[@perrooceaniko2005]

i have nothing to do with air engines but is very interesting anyway ... I always learn something ...

[@jaishetty8586]

No where on earth would someone let you see , teach and understand such complicated things except here. thank you.

[@michaelteeple8704]

You are a real mechanic when you can see and admit room for improvement or fault on your part. Much respect to you cause its way to easy to defer blame or just ignore it all together. It happens all the time and teaches nothing good.

[@JorgeMartinez-bs7rw]

My respects for pointing out the Starter shift on a KZbin video with over half a million views! Very professional! Love it!

[@StratMatt777]

Your videos are fantastic! Nobody else provides content like this! Thanks!

[@chuksanthony6665]

thanks

[@aftab4579]

Admitting flaws and mistakes really makes you Great. Excellent presentation 👏👌

[@ROCKSTARCRANE]

Perhaps the finest produced video I have seen yet. This is what You Tube should be about; educating people and not sensationalizing garbage.

[@SpotTiger]

How very professional to admit a fault. That was very honourable and I admire such attitude. Well done. 👍

[@ROCKSTARCRANE]

Perhaps the finest produced video I have seen yet. This is what You Tube should be about; educating people and not sensationalizing garbage. And yes, that is the sound I remember hearing on my first ride in a Boeing 707 in 1960....like a large cat howling.

[@chad.williamson]

Awesome videos. They open up a world few of us get to see. Jet engines are amazing! And I like your honesty about the starter mounting...refreshing these days.

[@philhmp4231]

Like a responsible professional. Always looking for issues to improve on. Well Done

[@AgentJayZ]

Electric and hydraulic starters are used on some of our tests. I've posted videos. The combustion gas cartridge starter is something we've never dealt with, but there is a video out there of a Canberra bomber having it''s engines spun up that way. Air-impingement on the turbine is another way. We have not used it, bit some of our engines have the manifold installed. The system is discussed in a couple of my videos.

[@jonremmers7723]

I like your hands down aproach "ok that´s how we do a better job next time". With that constant learning mindset one learns through the whole life. Once you get arrogant and stop observing you also stop learning. Now we can all learn from your vid. No matter if we are turbocharging an old Nissan or whatever.

[@MichaudDaniel]

It takes a man to admit his mistakes, I really enjoyed this video.

[@asicerik]

I am always impressed with your videos. What is routine to you is black magic to most of us. Very cool.

[@P61guy61]

Great video. I'm happy to see threat and error management at work and your control of ego in the interest of safety. Conscientious adherence, professionalism, and education all in one. Thanks.

[@bpj443]

Thanks for the insight. Awesome videos and outstandingly produced and edited! Keep up the good work, I know there's thousands of us gearheads who really love this peek into a little seen world.

[@EricLaspe]

These videos of yours are great! I'm a computer engineer, but I've always been fascinated by aircraft and the incredible forces their parts are engineered to harness. I really appreciate you sharing the hows and whys of the things you're working on. Thanks for your great work. I'm sure your videos are inspiring to kids... hell, they kinda make me want to change careers. :)

[@jettoymaker]

Enlightening, informative, insightful and considered...everything that a worthy education is built around. When I started to play jets here in Australia back in the late 70s, none of this information was available, let alone so brilliantly laid out and exposed for the pure delight of filling the void in my knowledge. It is pure gold handed out by Santa himself :) Where were you AgentJayZ when we were growing up in the dark? We thank you for the brilliant light of the valuable, engaging and concise information you share.

[@AgentJayZ]

+jettoymaker Thanks! I was making models of aircraft, never dreaming I would be working on their engines someday.

[@chrishenniker5944]

+AgentJayZ has anyone put this to the exhaust manifold of their car and made it a turbocompound engine?

[@AgentJayZ]

It is not designed to take combustion exhaust to its inlet. It would melt if used as a turbocharger. and it has no compressor. It is an air turbine, shaft output device. Its max input temp is about 500 degrees F If you could get around all that, it's way too big for a car engine.

[@heathfiedler]

lol sorta figured as much i was thinking about if you could rig it up as a supercharger like setup with a belt drive instead of exhaust.

[@cmans79tr7]

I noticed that you cut the camera before we could ensure that you finished "torquing the nuts to specs", but i was surprised that there wasn't a notch in the mating surface between the starter and the engine to ensure full engagement. I was also surprised to hear of "self locking" nuts in an aviation environment, especially when you just showed us a view of the wire-locked screws. I guess the lack of positive engagement in the mating surface and lack of wire-locking the nuts is a sacrifice made in safety for quick- change capability? When you started the huffer my antennas went up at 6:11 when that hose started turning. Have those things ever blown off and hurt sombody? Also thanks for posting this is great. Oh, BTW does the starter freewheel after the engine starts? One more thing, have the engines ever backfired, turning the starter backwards and blowing it off?

[@aaron8862006]

What a professional. I love this stuff. I wish I had a turbine engine that needed repairing, I'd seek you out right quick.

[@transformer889]

Couple of years ago we were departing John Wayne airport, in southern California on a MD 90, but the pilot could not get the APU started, the ground crew brought in a huge air compressor and attached the air hose to the left engine through a special duct and got the engine started. Now I know what the air starter looks like, thanks

[@sahltysahil]

Great stuff Jay, no one really bothers if everything turns out to be safe in the end. Keep up the good work.

[@Parker-di7ef]

I know this is an older video but I learned a bunch! Today I Air started a T-38 with an air start. Since it has two engines, you have to switch the valve with a wrench next to where the hose attached. My goodness is it loud! I always thought the air just blew into the turbine and spun up the fan, not though another turbine and gearbox assembly. Thanks!

[@AgentJayZ]

Excellent. You know... the J85 is a turbojet, so in the standard terminology.. it does not have a fan.

[@jeylful]

Excellent video! I really liked it, in particular seeing the starter running because as you said, it is normally hidden. Thanks for posting this! Jorge.

[@mapleleaf4ever]

Thanks for finally solving the mystery of how Air Start works. Always wondered that as I've operated those carts for a long time starting JT8s etc as a Ramp Agent.

[@algladyou]

all these designs and the craftsmanships. Mankind has gone so far. I doubt if all engineers and books disappear that we can make these.

[@SternLX]

Well... that start up took me back to the good old days on the flight line at George AFB when it was still an AFB with F-4's. Home of the Wild Weasels.

[@bakedhorsefly]

I'm a student in a AMT school an very much enjoy your video's. My instructors use them as well from time to time. Keep up the good work.

[@bradzee9947]

I was running a PW2040 one night and my operator says "hey, it's not starting". So we let everything spool down and cool off for the 2nd attempt. This time the operator says "we got some sparks here". So we aborted the 2nd attempt and went out for a look, and the starter was lying on the floor with the hose still connected!! Needless to say, the starter ate itself from the no-load speeds!! How fast?? No idea. It looked like the clamp was not tight and or not aligned properly. Expensive boo boo!! P.S> awesome video!!

[@tonyroulston1244]

I wish that event was recorded.

[@AgentJayZ]

+brad zee The axial flow starters we tested in a video I made few years ago were thankfully designed to produce zero torque just before the reached maximum safe rpm. The testing procedure is to run them unloaded and record the speed attained.

[@remylopez2408]

Hello Agent Jay I was in the United States Air Force and I was a crew chief on F-4 Phantoms I remember we used to have two different types of starters air research and sunstrand? We also used to use cartridge starts which were very interesting but getting to your starter the starter’s on Air Force J-79s were mounted on the accessory drive case however on the Navy and Marine Corps jets they were mounted straight to the turbine section which required a higher pressure air there and lied the problem I had to go to El Toro Marine Corps air Station twice to change starters because they hooked up the wrong air and it not only sheared the starter shaft but it also completely destroyed the starter Anyways thanks for the videos sure do enjoy them and brings back memories

[@AgentJayZ]

Great story! The F-104 has the same air starter as the F-4, but is mounted in the center fairing of the inlet. It drives the main rotor directly. Both of those starters require a lot of air at 30 psi. The air impingement starting system is a manifold around the turbine, which feeds air at over 200 psi to nozzles the blow directly on the turbine. I have witnessed one of the 30 psi starters hooked up to 150 psi. It worked, but made the most horrible screeching sound. I don't think it was very happy!

[@remylopez2408]

@@AgentJayZ I got a question for you since you worked on F104s when I was stationed in Germany they would come to our base and the thing that interested me was you could see the pilot light for the afterburner section yet on the J 79’s on our Phantoms didn’t have that feature

[@AgentJayZ]

Yes, I've seen it many times. The torch igniter, for providing a positive ignition source for the afterburner, is a small enclosure with its own fuel nozzle, controlled air supply, and ignitor plug. It is energized only at full 100% rpm, and only when the throttle is pushed past full into AB. When we test our J79-19s, used in later Starfighters, the torch ignitor is out until it is activated when needed. I have seen a lot of different vintage clips of Starfighters taxiing, and they all have the torch ignitor on. Is it a malfunction? I doubt it. Is it a workaround, performed by the ground crew, because of pilot requests? Is this normal for the earlier dash numbers of the J79 used in the early F-104s? I honestly can't tell you. We need an F-104 crew chief to let us know for sure. I know there are some of them out there...

[@garman1966]

I was going to ask if the starter spun constantly while the engine was running but thankfully read the intro first. I'll look at that starter ratchet clutch video. Thanks for the great videos!

[@eloyex]

i am ALMOST able to fix a turbine after see so many chapter from this guy ....... hahahaha !!!!!! funny weird guy .... i like the videos indeed ....

[@thspamed]

I cannot wait to start working on aircraft engines, i find them facinating and wonderous pieces of engineering

[@brett8090]

I saw the starter torque around and had to rewind to see it again. Very interesting stuff, sudden torque in a turbine sounds strange and looks even more so. Very cool to see.

[@MachineKing]

Wow i spotted the mistake like you said, Man learning all this little by little makes me more comfortable of getting into this career path! What makes me admire this Job is the Safety!

[@xBrahx90]

I like how u analyzed the video at the end great job. Safety is number one!!(:

[@ZaidEssopPlayzIke5163]

damn this is one of the most interesting videos ive ever seen

[@JBLewis]

I've been watching the river boat and AI-25 videos, and watched this one randomly. I think it's cool that by putting the camera where you normally could never put yourself, you were able to learn something new. So we, your audience, get something out of the video, and you got something out of the video!

[@bobbypaluga4346]

I remember boarding (1990-ish) an America West flight at ALB for PHX while they were rebuilding the airport in Albuquerque. Without a real gate we just followed a chain link fence to board. The pilots started the 737-200 using a full air start which filled the interior with smelly dusty air. A TWA pilot who was seating ahead of me launched himself into the cockpit, the door was open in those days until we took off. The TWA pilot believed he was smelling smoke, and it was explained to him, "No, just dusty stale air".There were no start carts of TUGs, it was like flying I the dark ages, because of the rebuilding taking place. That was the first and only airstart I have experienced.

[@olusesanfesobi5219]

Yeah!!!! I love that sound. All systems go!

[@stanpatterson5033]

I noticed the lock on the hose that wasn't quite tightened down properly, but didn't notice the starter twisting home before the 6 bolts stopped it. Good to shake everything down, and then re-torque all fasteners anyway, but yes, it never hurts to re-check your work, just in case you missed something *before* firing up the big guns. Fine work on the video.

[@wkuntjoro6130]

Great videos with great details......real things here.

[@markwhitson]

Thanks for sharing this--I'm doing an installation of an air starter on an old JT8D tomorrow, but it's only for a school project so there'll be no run-up afterwards. I always enjoy your videos.

[@AgentJayZ]

How about a short video of before, and after. Us aircraft geeks gotta see!

[@markwhitson]

I took a little clip and I'll upload it later--it's just 2 hairs short of humiliating. It's like singing in front of Simon Cowell on American Idol, but your video certainly gave me a solid heads up.

[@Angry.General1461]

Is that the same as an APU???

[@markwhitson]

No, it actually isn't. This is a pneumatic starter. It can work with the APU whereby it takes airflow from the APU and uses it to start a given engine. Thanks for your question.

[@salemcripple]

As an automotive mechanic. I'm jealous of how accessible everything is on a jet engine :-)

[@AgentJayZ]

The slotted holes are there so when you want to change starters, you don't have to put 6 bolts and 6 washers... somewhere... while you do it. In a busy repair area, this is very smart. Yes, there is a one way ratchet clutch, and a high speed centrifugal disconnect device.

[@deathbykitty1954]

I used to rebuild and test air turbine starters. We tested them in an explosion proof cell. If I were you, I would stay as far away for that engine and starter as possible when firing it up.

[@lekoman]

It's like a gigantic air wrench. Neat.

[@AgentJayZ]

Actually, turbochargers are the bottom rung for Garrett. They make APUs for airliners, and they make them for start carts. Ours is a Garrett GTC85. Garrett makes a very popular and reliable turboprop engine, the TPE331, which starts at 500 Hp and up... They also make a very popular and reliable turbofan engine for business jets. It was designed in the early 1970s and it has a geared fan.

[@Automotive.Master]

Many respect for the man who respect the truth 🙏

[@RaivoltG]

If you don't think that was one of the best sounds ever created, you might want to check yourself for a pulse! You sure have some cool toys! Great video and channel!

[@fryode]

Troubleshoot, update, and improve... most companies prefer to rest on their laurels. What you are doing is a Good Thing.

[@sheikhabrahim3463]

I don't have the right words to express how priviledged I am to see this piece of technical info.There were so many details to learn there.I have always wanted to be an aircraft mechanic.Thanks for your time,patience and the sharing.Are you an A&P instructor?You have the touch to teach.Cheers from Guyana.

[@Chuck9901]

Very interesting. Thanks for filming and sharing!

[@desperado1670]

The best video i ever found on youtube,you gave me the answere,and i asked my self for years.....what the hell starts the Jet engine as first...now i know...thank you very much.

[@rickey5353]

I believe I find Agent JayZ's vocabulary as interesting as his working knowledge of all things turbine.

[@singletrackmatt]

Im like all the other guys, love learning stuff. I love to be your friend but you might hate it. I'd wouldn't stop asking questions about the entire turbine until I thought I new something about everything on the unit. Great video!

[@hamsterminator]

Thankyou very much for this video. Am doing a type rating and it helps enormously to be able to visualise these elements.

[@chartphred1]

Interesting video. Also glad you noticed that the starter moved in its mounting position. I noticed that when you first re-mounted the starter motor that you didn't appear to rotate it as much as I thought it should before doing up the bolts - if you watch the video closely it's subtle but easy to see how the amount of rotation put on the motor as its being slid on was not equal to the length of the slotted holes... but hey all good you picked it up in the video later. So no harm done. Love the sound of those engines though.

[@thaiexodus2916]

It would help to explain to non -engineer types why turbine engines have such odd starters. That the average car draws a massive amount of current from the battery to get the engine to turn over about 200 RPMs. But with a turbine engine you have to get it turning well over 1000 RPMs with a load that is many times that of a car engine and the load increases dramatically the faster it turns. That equates to a very exotic electric starter or another power source. Hydraulics are sometimes used but with the older turbines the small lightweight air powered 'motor' with a remote air supply was the easy, cheap and lightweight way to go.

[@AgentJayZ]

The hufffer or start cart does not supply exhaust gas to the starter on the big engine. It has a large bleed valve on the compressor, and through that it supplies about 85 pounds per min of air compressed to about 25 psi through the discharge hose to the air turbine starter on the LM1500.

[@krugtech]

For some reason it reminded me of my first turbocharger turbine. it had an afterburner that was lit my a spark plug neon sigh transformer. The weird thing is the afterburner would screetch like hell at certain fuel settings and when it did the ceramic in the sparkplug would start to rotate clockwise at about 20-30 rpm. We saw the HT lead whipping around and though it was a gas leak blowing on it, then we saw the words CHAMPION spinning like a barber pole. Crazy awesome forces.

[@ShannonSmith4u2]

Fabulously done.,as usual, thank you for clear simple descriptions.

[@GeneralG1810]

Mate awesome channel, I had a basic grasp of gas turbine but it's good to see the finer details thanks a lot

[@cowboycapitalrealty]

Thank you for your video's!!! GREAT info. AND from Canada!!! :-) miss you all!

[@Rainhill1829]

Fascinating, did not know Garrett was into aero mechanisms.

[@Nyck461]

AgentJays; I really like your videos. They are very well done and full of explanations making easy to understand better how jet engines work. Jet engines are not my job but repair CNC and PLC machines. I like a lot to see how these amazing engines work and your videos give a detailed step by step explanation. Congratulations for your job.

[@nicholascrespo9003]

Cool, never got to use an AGPU. Our aircraft had APUs, so we were hands off at start up.

[@terlinguabay]

Ouch. Glad you spotted the starter displacement.

[@craigtate5930]

What a cool looking mechanical contrivance

[@JasonWaterfalls13]

Excellent vid!! Amazing stuff to watch for gearheads :). Also, I love that Garrett is my name. Its respresented by such an excellent company and products! I just saw the Thunder Over Michigan air show and after that seeing jet aircraft fly, every other man made vehicle/machine just seems unimpressive...its awesome!!

[@proffessasvids]

Lovely stuff JZ xx

[@texNoz]

Yes, I see those all the time.... I was walking to my car and tripped over one of those in the driveway. I've got a drawer full of those too.. I'VE NEVER seen one of those...

[@sharoz6300]

Finding this channel was the best thing that happen to me as a student pilot. Can you show from where air from APU is introduced in air starter unit?

[@JamesYoung61]

You have to be self critical or you'll never learn from mistakes and committing them to YT lets the rest of us know that you're on the case.

[@pavelavietor1]

hello, on the hose cam lock i use dock tape all way around the aluminum nozzle over the cams to keep it from pooping open, and i have seen velcro been use the same way hope this will help you .Nice video thanks for posting

[@AgentJayZ]

@NoWattz There is a one way clutch that prevents the LM1500 from driving the starter. You can hear it ratcheting on shutdown in my other videos of engine tests. As far as the starter driving the engine, there is no slipping or catching up. The starter output is a nice, smooth application of torque because it is generated by air passing through the starters turbine. It's a lot of torque, but there are no shock loads...

[@beefgoat80]

I repair watches. It's funny how every so often, no matter how many times you've preformed a particular task (follow a checklist, etc.), you bork something and don't find out until you've put the damn thing together. That, and some movements just love to put up a fight. 🤷 Lol

[@justinclark9258]

Nice honestly... a rare trait.

[@jordananderson4710]

that's cool, wish you would have shown the engine burn but oh well off to another video!!

[@AgentJayZ]

@foxrider80807 The J79-17A is an aircraft engine, and my experience with it is in removing all the external accessories to make an LM1500, so I'm not the best guy to answer this question, but I'll check the manuals. There is a large drive pad at the rear of the gearbox, about 14 inches in diameter. To that pad, in some aircraft, is attached a large electrical generator, weighing a couple hundred pounds. It supplies electricity for all needs, except running the afterburner ignition.

[@cjmech9156]

Wow this man.. admitted his mistake.. Thats how you know he is a good technician

[@AgentJayZ]

The air in the hose can be over 300 degreesF, and duct tape would just make a sticky mess. It's a temporary connection that has never popped ( or pooped ) open. The connection moved in this video only because the cams were not locked all the way in.

[@brhc]

We use Natural Gas at 35psi to start the LM1500. The V-Band on the inlet and exhaust side of the starter can leak some during starting. With air a small leak isn't a problem but with gas it can be. So we found a small amount of silicone will seal it up. Now, what that guy had was a bit excessive. :)

[@TyphoonVstrom]

As soon as I saw the Airesearch plate on it, I thought what a nice engine driven supercharger an air starter would make. Already has it's own reduction drive too.

[@AgentJayZ]

+Sideslip Only problem with that idea is that a turbine is not a compressor. They do the exact opposite job. If you look closely, the difference is more obvious when you compare a wind turbine with a propeller. The two are opposite and not interchangeable.

[@southernwaytransport]

Very cool! I always wondered what made that "wind through the trees sound". I'd love to see more about how a turbine works and is put together.

[@AgentJayZ]

+JaDo Steele If you look at my channel, you may find a few...

[@AgentJayZ]

I talk about the starter clutch mechanism in my questions videos #4 and #8. Crash engagement to me would mean attempting to start the engine while it was still turning, possibly from a failed start attempt. It would work, but you'd be risking breaking some parts.

[@AgentJayZ]

The starter has no oil pump, and a small amount of oil in its casing that lubricates the reduction gear in the classic "splash" fashion. It's meant for short duty cycles, and is very highly stressed. I think the braided line is a vent, to allow any fumes from the highly stressed oil to be vented into the exhaust of the starter.

[@reactor4]

I've always wondered how jets started. Thanks!

[@spock7945]

great insights indeed and SALUT! to your perfectionist mind-frame that you notice and acknowledge even ye slightest of odds!

[@AgentJayZ]

It contains its own supply of turbine engine oil..350cc of Mobil Jet2. It's splash lubricated, without a pump or filter. We change the oil for every test run,

[@AgentJayZ]

There are no cylinders. The only thing vee-shaped is the arrangement of drive pads for pumps and other accessories we don't use. All the gears are coupled together the way gears are coupled together; the teeth intermesh. What's the fluid flow region? If you mean airflow into the engine, I hope I've made it clear that the radial drive shaft is inside the strut. We have many drawings, and I have over 180 videos now. As always, I suggest you watch all of them.

[@AgentJayZ]

There's a ratcheting, one way mechanism that wil not let the engine drive the starter. There is a small amount of drag in the mechanism, so in my videos where I show the starter on rundown, it is turned by the engine. When the engine is running, another feature of the mechanism is that the ratchets use centrifugal force to completely disengage from the engine.

[@AgentJayZ]

@uTube486 The operator of the big engine is in the control room with the computers and the controls. The start cart is operated by another person directly from its own control panel. The start cart guy follows signals given to him by the operator in the control room. There are other methods of starting, such as electric and hydraulic, both of whiich have been shown in my other videos. There are a couple of other ways I haven't had experience with.

[@jdmk20aek]

still love all your videos !!!!!!!!!!!!!!!!!

[@rwashi]

Once again that´s nice.. Learnig alot

[@AgentJayZ]

Huffer is slang term invented in the American military... by people who know that it's not an air pump. It's a small gas turbine engine with a large capacity to "donate" bleed air from its compressor. The proper term is GPU for ground power unit, or even better, its real name is the Garrett GTC 85-70. ... Maybe I should have been a bit more detailed in the info section, eh?

[@Skyisnotalimit]

The engine of my black angel bike has that construction. Nice!

[@AgentJayZ]

As I have mentioned before, aircraft with jet engines normally fly with the ignition in the "off" position. An ignitor box, which provides the energy for the spark, typically is rated to run for two minutes, and then must cool down for 20 minutes. You'll see in my spark test videos that the ignitors give off a massive spark...many thousands of times more powerful than an automotive ignition system.