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.
I also noticed the starter shift and the hose link and was a bit surprised but that is a teachable moment. Thanks for the look inside. I've been using these for decades but never saw the internal workings before. Good job.
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
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.
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.
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.
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.
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.
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.
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.
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?
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.
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.
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.
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.
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
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. :)
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!!
+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.
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.
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!
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!
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.
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!
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.
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.
Hi AgentJayZ, in videos of F-104s starting up I've noticed that the pilots give a hand signal to the ground crew (sort of a "chopping" motion) at around 35-40% RPM, which I assume means to shut off the air supply from the cart to the starter. Got me wondering about the point at which air is cut off to the starter. Is it cut off when the ratchet clutch disengages to prevent the starter from spinning up to too high of a speed, is it to prevent excess wear, is it because the engine has reached self sustain speed, or is it for some other reason? Sorry if it's a stupid question but I couldn't find an answer. What would happen if the starter wasn't shut off and was just allowed to run all the way until the engine reached idle?
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.
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.
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.
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.
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.
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!
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!
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
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!
@@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
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...
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.
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.
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.
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.
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
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.
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.
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...
@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.
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.
@michaelcrowe1 You should watch my latest starter video... in which I reassemble the planetary reduction drive. In it I discuss and show the one-way sprag clutch that prevents the engine from driving the starter. Newer engines have a different system that disengages the starter completely above a certain rpm, and acts like a one-way ratchet below that rpm.
@ROCKSTARCRANE I answered your other comment before reading this one... ... and you've got a pretty good memory; it must scare the heck out of your friends ! Thanks for the comment.
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.
>What if I land at a remote location where no air supply is available ?? >Once the engine get started is there a one-way clutch bearing on this shaft or it stays turning ?? Thank you Agent JayZ
@JetAce08 The start cart does have a larger than necessary compressor, and supplies extra, or compressor bleed air to its discharge hose. This is not bypass air. By convention, that term refers to air that is always passed around the core of a large axial flow aircraft engine by a larger than necessary first stage or two of the compressor. Sounds like nitpicking, but that's the way the terms are used.
I saw three things, the things you mentioned and it seems as though there may be some seepage at the starter housing gasket. Maybe that's air turbulence and some water or oil on the outside of the starter?
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!
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!!
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.
Fascinating, did not know Garrett was into aero mechanisms.
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okey, probably a stupid question. BUT, where do the air come from when its on the plane? is that from the APU (if thats what its called) that are allmost all the way back of the plane?
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.
My understanding was that self locking nuts should only be used once, particularly in aerospace applications. So I am a little confused by the keyhole slots on the mounting that enable the starter to be removed without taking them right off.
One thing I've always wondered: what disconnects the starter from the jet once the jet is turning? Or does that starter get driven nonstop by the engine at super speeds via the gears during operation?
Can you comment on the size of those bolts? 1/2"? Sure is scary seeing that turn on there. Might have been a little loose, but still must be an incredible amount of torque. Those bolts dont look that small either. Any idea the rated speed?
Hey, 6:09 is normal this movement or aren’t tightened correctly?......you said something about this in the final, but I don’t understand, maybe that’s all ok 👍🏻
Does the turbine and gears in the air starter continue to rotate once the turbine motor starts, or does it disengage since it is no longer needed? To save wear and tear, I would think, it should disengage, but something tells me that it continues to rotate since it might make it more complex to have a disengaging unit.
Since i have never had any exposure to jet engines and have no clue as to what things cost do you think it is possible to throw in some cost of items that you are presenting and how much labor costs so we have a better idea of the scale of what we are watching?
Does the starter disengage or does it spin the whole time the engine is running? (Disregard that question, I will watch the video you reference further down) But I do want to ask, are all air start carts turbines?
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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.
I also noticed the starter shift and the hose link and was a bit surprised but that is a teachable moment. Thanks for the look inside. I've been using these for decades but never saw the internal workings before. Good job.
You have a turbine, driving a turbine, to start another turbine. I love aerospace technology....
Also a manual for the manual for fixing the aircraft XD
its called turbine craze
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
What came first, the turbine or the turbine?
😂
I like your honesty in admitting to not tightening the bolts, very interesting videos, thank you
i have nothing to do with air engines but is very interesting anyway ... I always learn something ...
Your videos are fantastic!
Nobody else provides content like this!
Thanks!
thanks
No where on earth would someone let you see , teach and understand such complicated things except here. thank you.
I am always impressed with your videos. What is routine to you is black magic to most of us. Very cool.
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.
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.
My respects for pointing out the Starter shift on a TH-cam video with over half a million views! Very professional! Love it!
Admitting flaws and mistakes really makes you Great. Excellent presentation 👏👌
How very professional to admit a fault. That was very honourable and I admire such attitude. Well done. 👍
Perhaps the finest produced video I have seen yet. This is what You Tube should be about; educating people and not sensationalizing garbage.
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.
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.
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.
Like a responsible professional. Always looking for issues to improve on. Well Done
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.
+jettoymaker Thanks! I was making models of aircraft, never dreaming I would be working on their engines someday.
+AgentJayZ has anyone put this to the exhaust manifold of their car and made it a turbocompound engine?
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.
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.
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?
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.
damn this is one of the most interesting videos ive ever seen
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.
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.
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.
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.
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
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. :)
all these designs and the craftsmanships. Mankind has gone so far. I doubt if all engineers and books disappear that we can make these.
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!!
I wish that event was recorded.
+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.
What a professional. I love this stuff. I wish I had a turbine engine that needed repairing, I'd seek you out right quick.
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.
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.
Great stuff Jay, no one really bothers if everything turns out to be safe in the end.
Keep up the good work.
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!
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!
Excellent.
You know... the J85 is a turbojet, so in the standard terminology.. it does not have a fan.
It takes a man to admit his mistakes, I really enjoyed this video.
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.
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!
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.
I like how u analyzed the video at the end great job. Safety is number one!!(:
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.
Hi AgentJayZ, in videos of F-104s starting up I've noticed that the pilots give a hand signal to the ground crew (sort of a "chopping" motion) at around 35-40% RPM, which I assume means to shut off the air supply from the cart to the starter. Got me wondering about the point at which air is cut off to the starter. Is it cut off when the ratchet clutch disengages to prevent the starter from spinning up to too high of a speed, is it to prevent excess wear, is it because the engine has reached self sustain speed, or is it for some other reason? Sorry if it's a stupid question but I couldn't find an answer. What would happen if the starter wasn't shut off and was just allowed to run all the way until the engine reached idle?
Answer incoming, in video form...
@@AgentJayZ awesome, looking forward to it!
I cannot wait to start working on aircraft engines, i find them facinating and wonderous pieces of engineering
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.
Thank you for your video's!!! GREAT info. AND from Canada!!! :-) miss you all!
Mr Bill is warming up the engine??
OOOOOO NNOOOOOO!!!
Mate awesome channel, I had a basic grasp of gas turbine but it's good to see the finer details thanks a lot
Fabulously done.,as usual, thank you for clear simple descriptions.
Great videos with great details......real things here.
Thankyou very much for this video. Am doing a type rating and it helps enormously to be able to visualise these elements.
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.
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.
How about a short video of before, and after. Us aircraft geeks gotta see!
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.
Is that the same as an APU???
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.
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!
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!
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
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!
@@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
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...
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.
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.
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.
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.
Very interesting. Thanks for filming and sharing!
Cool, never got to use an AGPU. Our aircraft had APUs, so we were hands off at start up.
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
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 ....
Ouch. Glad you spotted the starter displacement.
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.
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.
Yeah!!!! I love that sound. All systems go!
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...
@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.
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.
great insights indeed and SALUT! to your perfectionist mind-frame that you notice and acknowledge even ye slightest of odds!
@michaelcrowe1 You should watch my latest starter video... in which I reassemble the planetary reduction drive. In it I discuss and show the one-way sprag clutch that prevents the engine from driving the starter.
Newer engines have a different system that disengages the starter completely above a certain rpm, and acts like a one-way ratchet below that rpm.
@ROCKSTARCRANE I answered your other comment before reading this one...
... and you've got a pretty good memory; it must scare the heck out of your friends !
Thanks for the comment.
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.
>What if I land at a remote location where no air supply is available ??
>Once the engine get started is there a one-way clutch bearing on this shaft or it stays turning ??
Thank you Agent JayZ
1) you are stuck. but there are many supplies of air, including another aircraft sometimes.
2) yes. see my vid called Starter Ratchet Clutch
@JetAce08 The start cart does have a larger than necessary compressor, and supplies extra, or compressor bleed air to its discharge hose.
This is not bypass air.
By convention, that term refers to air that is always passed around the core of a large axial flow aircraft engine by a larger than necessary first stage or two of the compressor.
Sounds like nitpicking, but that's the way the terms are used.
I saw three things, the things you mentioned and it seems as though there may be some seepage at the starter housing gasket. Maybe that's air turbulence and some water or oil on the outside of the starter?
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!
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!!
I've always wondered how jets started. Thanks!
It's like a gigantic air wrench. Neat.
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.
Fascinating, did not know Garrett was into aero mechanisms.
okey, probably a stupid question. BUT, where do the air come from when its on the plane? is that from the APU (if thats what its called) that are allmost all the way back of the plane?
Troubleshoot, update, and improve... most companies prefer to rest on their laurels. What you are doing is a Good Thing.
The engine of my black angel bike has that construction. Nice!
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?
Glad to see it tightened up although it was loose. Vibration from the CLAMP mounting caused this. See Brad Zee reply below.
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.
What a cool looking mechanical contrivance
My understanding was that self locking nuts should only be used once, particularly in aerospace applications. So I am a little confused by the keyhole slots on the mounting that enable the starter to be removed without taking them right off.
As an automotive mechanic. I'm jealous of how accessible everything is on a jet engine :-)
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.
+JaDo Steele
If you look at my channel, you may find a few...
the pursuit of excellence is its own reward.
the start cart is a small turbine is it not?
we used something like it in the us army.
One thing I've always wondered: what disconnects the starter from the jet once the jet is turning? Or does that starter get driven nonstop by the engine at super speeds via the gears during operation?
Can you comment on the size of those bolts? 1/2"? Sure is scary seeing that turn on there. Might have been a little loose, but still must be an incredible amount of torque. Those bolts dont look that small either. Any idea the rated speed?
Hey, 6:09 is normal this movement or aren’t tightened correctly?......you said something about this in the final, but I don’t understand, maybe that’s all ok 👍🏻
Does the turbine and gears in the air starter continue to rotate once the turbine motor starts, or does it disengage since it is no longer needed? To save wear and tear, I would think, it should disengage, but something tells me that it continues to rotate since it might make it more complex to have a disengaging unit.
"something" is steering you wrong.
Please see my video " starter ratchet"... or something like that. Cheers!
Does the starter disengage when the engine is running or does it stay spinning?
+7.3 IDI Diesel It disengages. I have made a video called "Starter ratchet clutch"
Since i have never had any exposure to jet engines and have no clue as to what things cost do you think it is possible to throw in some cost of items that you are presenting and how much labor costs so we have a better idea of the scale of what we are watching?
Does the starter disengage or does it spin the whole time the engine is running? (Disregard that question, I will watch the video you reference further down) But I do want to ask, are all air start carts turbines?
I've got a video for you; it's called the starter ratchet clutch, or something very close to that.