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+Tim Engel What a nightmare it would be, possibly do damage as well, I think I would just go home and cry if that happened.

***** Check out my vid called Orenda 14 in the Sabre6 ...

+boomer9900 Got a whole series on Combustor liners. Also several videos in the playlist called Your Questions Answered dealing with exactly the subject you've requested. There's a kind of index there.

+AgentJayZ thanks, I'll have to back up and look at those vids again. Index, here i come.

jfan4reva I work for me, I run the shop. It would be great but my boss can be a jerk!

LOL! I hope he isn't so big a jerk that he won't take you out for a beer after a long day ;)

It's a silicone O-ring. The temp it will see is maybe 300F, so the material is more for its softness. The air pressure it will seal against is about 90 psi at maximum.

ratride1 I am fairly sure it's a 2007 or 2008 model of the Marin Point Reyes. I got it from the used rack out front of Reds Shreds bike shop in Williams Lake, BC. They are really nice there, and you should visit them when you go there to ride the hundreds of miles of trails right around this town in the foothills of the rocky mountains.

Arthur Lejawka They are drain lines. After shutdown, if any fuel leaks out of the fuel nozzles, it drains out, so there is no fire hazard at the next start-up.

superdau Your second sentence describes it well.

petestowne If you stand a barrel full of water on its end, it will never just fall over. Same idea, only larger and heavier.

+AgentJayZ yeah, that makes sense of course. Thanks!

It's pretty heavy. It would be about as easy to knock over a 55 gallon drum full of sand

Oh Ok, so its pretty stable I used to hang out with my Dad at the hangar, he was a aircraft mechanic he passed away last week :( I work nightshift and enjoy watching your videos, im no mechanic but find jet engines fascinating. Cheers From Aus

gundamm5 The parts under the most stress, and the ones most frequently replaced, are the combustor liners and the turbine nozzles, also called the NGVs. It should be remembered that each engine design has its own pattern of wear, and these generalities apply to the GE LM1500.

Michael Carroll I had 'em on, and never thought to take them off. No real reason.

No. There is a problem with using a carbon or graphite based marker on steel blades, as the heating could cause diffusion hardening and an increase in the likelihood of a crack forming, but steel blades are rare, and we don't use such marking devices...

BTW, great videos. I love the educational component.

With two cranes to horizontal, then on stands on a trailer, or into an engine shipping container for shipping. Here's what they look like ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eXskgcu7I1A.html

Elan Jacobs Yes. The Iroquois made a quest appearance at the FSJ air show. People seemed interested.

***** The ten was for multi-engined aircraft, like the CF-100, and the fourteen was for the single engine Sabre series of Canadian built F-86 air frames. For single engine use, there are more backup systems controlling the fuel. Also the 14 was more powerful by a thousand pounds of thrust or so, It has a two stage turbine, while the 10 has a single stage, like the J47. Structurally they appear so similar that one is tempted to use the 14 manual for reference, yet they are different enough to make that a bad idea...

AgentJayZ Thank you for such a deeply insightful and informative answer! I wish I had caught the 2 turbine thing. I should have seen that.

+ladams00 YA! I second that if its possible

ladams00 Great vid!!!!!!!!!!!!!

ladams00 No

ladams00 Heck, I'd like to see it tested when it's *snowing or raining* outside. That would be cool seeing the snow or rain swirling around. C'mon, Agent J make it snow.

Cooll Asice We are still working on controlling the weather.

louigi600 It's more about the stuff than the dust. Much like everything in life.

I take a look inside a T-58 that was damaged from excessive heat, similar to a hot start, in a video called Bad news, good news with a T-58.

+Hein Joubert (Hein-ZA) I'll take the liberty of answering this, having worked on one of the few engines, the Olympus 593 in Concorde, that was capable of supercruise. This term is commonly used in industry to denote supersonic cruise without reheat/afterburner. You are quite correct in stating that the exhaust velocity of a jet engine must always exceed the forward speed of the aircraft to produce thrust. If the jet velocity equalled the forward speed, then propulsive efficiency would be 100percent, but there would be no thrust! The 593 had a convergent-divergent nozzle and a reheat/afterburner system, but this was used only during transonic acceleration. There was a project design for an uprated 593 with an enlarged LP compressor that would not have needed reheat, but it would still have had a con-di nozzle. There was nothing special about the 593 as a turbojet, other than its size and the fact that it had to be designed to cope with an intake air temperature of 127degC in supercruise at 58,000ft. Perhaps you're tempted to ask why the 593, being a turbojet, didn't become an industrial gas generator, like its predecessor, the Olympus 200? The answer is, it very nearly did, but the project was cancelled with at least one development engine running and design well under way.

+grahamj9101 Thanks grahamj9101, so you basically just need a very big engine capable of supplying the mass flow rate and turbine outlet pressure as I understand (since the turbine outlet temperature is fixed and will drop as the gasses accelerate through the nozzle). Would supersonic flow out of a J79 or similar turbojet without an afterburner be possible, by adding a smaller converging diverging nozzle for interest sake?

+Hein Joubert (Hein-ZA) You've posed a very good question! You don't necessarily need a "very big engine", just a big enough engine, in relation to the aircraft - and you are on the right lines thinking in terms of mass flow. I'm no performance engineer, just a retired engine designer, so I'm doing some revision in answering. The pressure ratio of the Olympus 593 at 15.5:1 wasn't much higher than that of the J79 at 13:1 and supersonic flow from a 'dry' J79 with a suitably sized con-di nozzle should, therefore, be theoretically possible. However, we need to understand what 'supersonic flow' means in this context. What it doesn't mean is a flow velocity of over 768mph or 1,126 ft/sec, which is the speed of sound in air at 20degC. The speed of sound in the hot exhaust gas is directly proportional to the square root of its absolute temperature in degK (or degR for US readers): so let's do some rough and ready maths (sorry, but I am a Brit!). For an EGT of, say, 600degC, I make the local speed of sound in the exhaust gas as over 1,325mph. If you add on the temperature rise with reheat/afterburning, then the local speed of sound will be considerably higher. That is why reheated engines such as the Avons in the RAF's Lightnings and the Speys in the UK's Phantoms, both of which had variable (but not con-di) nozzles that could not produce a supersonic flow, could nevertheless power their respective aircraft to well over 1,000mph.

Hahaha, Yesssss, it's wonderful when something makes such clear scene. Its funny because i know the theory but did not piece everything together. I wrote a thermo-fluid dynamics exam today, we are currently doing converging diverging nozzles, normal and oblique shock waves, stagnation conditions, reheat and fanno flows ect. Very interesting stuff.

+Hein Joubert (Hein-ZA) I do not wish or mean to be patronising, but I do not necessarily know the technical background and knowledge of individual subscribers. Consequently, I try to give answers that can be more widely understood.

+Tracy Reed It happens - I've done such things a time or two in the days when I could work on my car, for instance. And, if I recall correctly, AgentJayZ has told us that he doesn't have repair and overhaul manuals for this engine, which would give him a step-by-step procedure.

mtnbiker310 It's about what one can expect from a PR media department. Really great old photographs, some of them mislabeled, and a great story featuring a few facts compounded with a lot of errors, and some plain old spelling mistakes. Great for PR, but misleading and useless for anyone interested in what really went on.

+mtnbiker310 At least it gives some credit to Frank Whittle, who really was s**t on by the powers-that-be in the UK at the end of the War (WWII, that is).

SirDeanosity Did you miss the part where I explained there are no instructions? There are no instructions.... Over.

AgentJayZ And maybe... proof-read your condescending comment before hitting that blue button...

SirDeanosity If at first you succeed, move on to the next step.

Ah... have a look at a couple of my videos: So you want to work on jets How I got here Another way to get there ... There's a search feature on my channel page.

***** Either of those options is possible, and it is up to the owner to decide whether greater performance or longer life is the goal. For industrial engines, the increased service life at the rated power output is usually the reason for adding the thermal barrier coatings.

KJ6EPL No tiny cooling passages. Plus, even If they were packed in sand, part of the skills of a fitter/technician/builder/mechanic is to ensure they are installed correctly, without damage or contamination.

13megaprime What the heck is an afterburner disc? That point in time would be when the engine is not running.

I'm talking about the LM2500 first stage blades...

Arthur Lueck Every part that goes into an engine is inspected.

Vasileios Koutsovoulos The O-rings are made of silicone. A standard part available through a hydraulic supply house.

Thanks

MrShobar No.

spowyou No pit in the new shop. Ladders and cranes it is!

+Corey Straker From my very limited experience, air bearings are extremely high precision devices and their surfaces have to have a very fine finish. When I was an apprentice in the 1960s at Bristol Siddeley Engines, Coventry, the company made air bearings for the nuclear industry and they were assembled in a clean room. There are those in the aircraft engine industry who envisage the use of active magnetic bearings, but having done some work on them, unless and until there is some major advance in electro-magnets, they will be heavier and have a much lower load capacity than rolling element bearings.

waterlover30 I found out about it from the news. Nobody I know felt anything.

+Braeden Hamson Many designers (like me) did apprenticeships or traineeships that included placements in engine assembly shops and we did think about the engine fitters, as we would be called into the build shop if/when there were problems. These days, there are more formal processes, such as 'design for manufacture' and 'design for assembly', which are intended to do what they say. Lockwire or safety wire has been a 'no, no' on new designs for many years, thank goodness: the sharp ends aren't good for the fingers.

***** To the best of my knowledge it prevents the metal it is coated with from getting hot.

***** From our experience with ceramic coated industrial turbine blades, it never cracks or wears off. It makes the blades immortal.

***** You were the first to answer the bonus question correctly!

Yeah I remember you saying something along the lines of the worst thing you can hear is the song a dropped bolt plays as it tings off all the turbine blades.:)

+Ducksauce It depends on how 'hard' a ride the coating gets. In base load industrial operation, as AgentJayZ suggests, it should last almost for ever. However, put it in an engine that gets a lot of thermal cycling, it can become eroded and sometimes spall off in patches. I know it as thermal barrier coating (TBC): it is a barrier and not a total insulation, so it cannot stop the coated parts getting hot. In the case of the LM2500 HPT1 blade, it will reduce the metal temperature significantly, by acting as an external insulation layer, with the blade being cooled internally, plus some external film cooling from the rows of small holes either side of the blade leading edge. The beneficial effect on an uncooled aerofoil will be more of a second order. It will reduce the thermal shock and it should reduce the peak metal temperature, to give a more uniform temperature gradient both chordwise and spanwise. And yes, there could even be a small reduction in the average metal temperature, with the TBC reducing the heat flux into the aerofoil and allowing the blade root or vane platform to act as a heat sink.

Nighthawke70 Once I figured out the correct procedure, no special tools were needed, and it was quite straightforward. Thanks for the concern, though!