Jet Engine Spool Engineering

[@lindakavinsky3502]

Another educational video. Quite interesting to novice like me.

[@StigAviation]

Glad you enjoyed it!

[@jgaffney6]

Great video learned a lot. 👍 Thanks for your time !

[@StigAviation]

No no no. Thank YOU for your time and being here.

[@ashrafshadid5870]

Good mechanic keep learning, your channel always teaches me it’s very useful video thank you Stig

[@StigAviation]

Even myself, even after all these years, I am still a student, and always will be a student of Aviation. I will always do my job and keep on studying to become a better mechanic for tomorrow.

[@mikecappa1094]

It makes me comfortable knowing such a knowledgeable and caring and committed individual is taking care of the engines that fly me across oceans and continents. Thank you for your dedication to the craft. Millions appreciate you !

[@StigAviation]

Thank you for the kind words. I appreciate you.

[@jonbradshaw3385]

I would love to see one of these engines up close!

[@StigAviation]

There are a few museums that you can visit that have these engines on display, I highly encourage you to check them out.

[@aviatordiego4769]

Yes indeed, many museums let you get up close with the airplanes and engines, definitely worth the research.

[@jonbradshaw3385]

@@aviatordiego4769 thank you! I will definitely check into one that I can go to.

[@ruirodrigues6956]

Absolutely amazing your explanation ...

[@StigAviation]

Thank you very much sir.

[@aaronchandler2380]

Oh, now you brought a tear to my eye… the JT8. She put a lot of food on my table over the years… I miss her.

[@StigAviation]

Same here my friend. Same here. I think I lost count on how many I hung and dropped from aircraft such as 727s and MD 80s, not to mention the upgrades for the hush kit we used to do, well that was a nightmare. 😅

[@aaronchandler2380]

@@StigAviation I know all about them hush kits, i “absolutely,positively “ do… if you know what I mean. Great videos too my friend!

[@sheldonbattle1935]

I'm involved in the manufacturing of mainshaft bearings for all these customers and engines. It's fun hearing and seeing the names JT8D, GE90, Pratt NEO, LEAP and many other programs we support, incredible engineering.

[@StigAviation]

Thank you for all the incredible work you do to develop these engines

[@bmused55]

The JT8D was EVERYWHERE. It is as important to the history of civil aviation as the Comet or the 747. My last JT8D powered flight was on an AA MD82 from DFW to JAX. I sat right on front of the No.2 engine. Oh man, that scream and whine. I miss it. But my favourite of all is the RB211. NOTHING sounds like it at take off power. That buzzsaw sound is music. It was also an important engine in aviation. My last RB211 flight was a BA 747-400 from LHR to DFW. A glorious concerto of four RB211's

[@StigAviation]

Indeed, the RB 211 was iconic, matter fact if you look closely and listen closely, you can actually hear its remnants in the V2500 engine. Even though it’s not a triple spool, but it still has that distinct buzz saw noise.

[@vorlonb3]

loved that stig thanks for taking the time to explain it.

[@StigAviation]

My pleasure. Thank you for watching

[@DavidGlover555]

Awesome video Stig! I buy parts for the engines of one of these Manufacturers and learning more about the technology is just insane! Keep the videos coming! Love them as an Avgeek!

[@StigAviation]

Right on! Thank you for enjoying and always learning 👍

[@Notmahfoozkhan]

Thanks a bunch for the video , really enjoyed it.

[@StigAviation]

My pleasure! Thank you for watching

[@seanmcerlean]

Awesome Stig.😊

[@StigAviation]

Thank you! Cheers!

[@jay-1172]

I finished electricity last week. Just started General Aviation maintenance. Aircraft drawings and graphs so far.

[@StigAviation]

Study well Jay. It’s gonna come in handy when you actually start working

[@hugostiglitz47]

You're my hero Stig. Cool vid🎉

[@StigAviation]

I’m no hero. Just a wrench my friend. I’m just happy you enjoyed the video. Always appreciate your support

[@gumnaamaadmi007]

Loved the trip back in time, Stig! Just as I loved the smoky, noisy take-offs of early 737s fitted with the JT8Ds. They were soon hush kitted, but I am not sure it made much of a difference :)

[@StigAviation]

Oh, i used to install those hush kits, it didn’t help at all. It was still earth shattering loud. 😂🤣

[@paoki4everole]

Another good old bulletproof engine is the J79-GE-10. I did my apprenticeship on one of these last year assisting the engineers to its assembly. 12000 and something pieces. What an experience

[@StigAviation]

I bet you learned a lot

[@paoki4everole]

@@StigAviation I did! Another question. I have an interview with the sit manager for a line maintenance mechanic. Could you give any examples of what questions are they gonna ask regarding the technical part?

[@bryandunawey]

Great video as always

[@StigAviation]

Glad you enjoyed my friend. 👍

[@ScapoloMichael]

Triple spool vs geared dual spool is the hot topic these days. Both about the same weight. Dual spool has a smaller radius of the shafts and this has benefits with compressor tip speed, although compressors are fast anyway. Also, a triple spool whilst better than a normal dual spool for fan speed still isn't as good as a geared dual spool, as the third stage turbine can only be physically made so slow, whereas the geared engine can have the fan spin even slower than that. 'course, the big issue with gearboxes is their potential to grenade the whole engine. They're small yet have to channel the kind of horsepower that could easily propel a ship. Lots to go wrong, so lots to get right. It'll definitely make the job of the maintenance engineers even more interesting in future

[@StigAviation]

You’re starting to see a trend where technology is kind of hitting a wall at this point, they are getting to a point where they exceeding the speed of sound for the blade, rotation, and speed. It’s going to be interesting in coming years of what they developed.

[@ScapoloMichael]

@@StigAviation I'd like to see intercooling of compressor air between stages, and maybe even recuperation of exhaust heat to preheat stage two compressed air before combustion. Both were already under study 20 years ago but haven't been tested yet full scale. There's other ideas like active cooling for the turbine cooling air that's bled off the compressor, instead of using it hot, variable diameter compressor cowls that can shrink or expand with the temperature of the blades, massively widening the engine's efficiency across the powerband, and other stuff, including the sexy variable pitch fan idea. All chasing a percentage or two of extra efficiency. All of it needing 99.x% reliability. What I really wanna see, but it might not be practical, is a contrafan. With a two stage front fan spinning in opposite directions, the second one smaller and faster, and the shroud around it tighter, precompressing the air before it reaches the first stage compressor (which can now have fewer stages) and giving the fan thrust of a much bigger, heavier fan with the low drag of a smaller one, plus smaller fans can spin faster without supersonic blade tip issues. It could be a triple spool with the first fan on the third stage turbine and the second, faster fan on the second stage compressor turbine, or a dual spool with a gearbox. It would be expensive and heavy even with composite fans and fan shroud, so best for long haul engines. And it might turn out to be shit 🤣

[@StigAviation]

@@ScapoloMichael how about we think into the past and get inspiration from there, why have all these moving parts, think, scramjet, think ramjet, how about no moving parts and figure out a way to optimize compression. But I’m just thinking out loud 😂

[@ridewitharko]

Love & support from India 🫡

[@StigAviation]

Thank you very much, cheers from LAX

[@TheBeagle58]

Nothing sounds better than the RB211 on take off roll, other than the GE90😁 and that's the new kid on the block in comparison lol! The next GE for the 777-9 is the next best thing, modern day.

[@StigAviation]

The GE9x is going to be incredible. 👌

[@TheBeagle58]

@@StigAviation Back in the 70's, the landings used to be as fun as the take off and rotate for the engine sounds. When they reverse thrusted, it was exciting 🤣😂🤣. Today, it's so different with noise abatement tech and such. Still, the reigning champion, on an overcast weather day is the Rolls. The way they chop up dense air, is like no other and you need not look for the bird, the sound has its own unique signature. The DC9/ mad dogs, also had this reputation with loud crackling from the exhaust. My goodness. That and the flame throwing that came from the 707's. Talk about a great time to be around aviation.

[@voytekcyvr1936]

I am happy to see such a marvel of technology, thanks. Just wonder what will power those flying machines in the future.

[@StigAviation]

Technology will probably get to a point where we will minimize components, it will be more efficient with less moving parts, think scramjet, or ramjet.

[@Gavin7177-xq4pb]

🔥

[@StigAviation]

👍

[@theLeftHandedDog]

I've read that most internal combustion engines in cars are only about 30 % efficient at best, which is one of the reasons electric cars--which I think are close to 100% efficient--are transforming that industry. I'm not sure how efficiency is measured, but I'm wondering how efficient these jet engines are? Do we have figures on that? Thanks.

[@StigAviation]

Efficiency is a bit above my pay grade in regards to actual numbers and figures, that’s more of engineering and manufacturing level data. But from what I understand and read, efficiency is somewhat calculated of longevity and economic values (fuel economy, component reliability, maintenance costs)

[@njjeff201]

Thanx again Stiggy ✈️

[@StigAviation]

Any time!

[@hellcat9165]

after your last video I just had to subscribe, could not wait till the next vid and here we are. thanks bro =) keep it up

[@StigAviation]

Awesome, thank you! I appreciate you being here and enjoying.

[@Bruins77Fan]

Our GTF engines have taken some heat...but the kinks will be worked out...its concept and design are incredible.

[@StigAviation]

It truly is incredible design. I appreciate that but what I don’t like is that PW likes to hide everything under the core. You want any maintenance done you have to open the whole thing up. I’m more partial to the CFM family. Much easier to work on.

[@andreweppink4498]

Trouble is GE's gonna have to bite the bullet and go to a reduction gear setup like Pratt & RR. No two ways about it. Running fan blade ends greater than supersonic is just nuts. Very inefficient. Engines with reduction gears are also much quieter, and smoother.

[@StigAviation]

You are right on that, they are reaching as stage where they need more innovation and new technology. We will see what comes in next generation of these monster engines.

[@dankuettel5063]

The JT8 was even used in the SAAB Viggen

[@StigAviation]

Very interesting. I didn’t know that. Thank you for the knowledge.

[@outrageousexistence]

My current A&P school has a retired fedex boeing 727 on display, powered by three JT8D engines. One of the engines was taken out of the plane, as well as the APU for teaching purposes. I really love that thing! so interesting. unfortunately, when they transported the plane down to my school, it was “too heavy” to land at the nearest airport 100 feet away. (it wasn’t too heavy) so they took the wings off the plane and shipped it down here. none of the hydraulic or electrical equipment works because they cut it out.

[@StigAviation]

I’m curious what school this is. And that’s unfortunate they did that. I wish they gave you the whole aircraft intact

[@outrageousexistence]

@@StigAviation Arkansas-State university mid-south. it’s near Memphis Tennessee !

[@martinross5521]

Really interesting to see these up close, Stig. Was the RB-211 developed for Concorde? I’ve noticed in Royal Navy vessels too. Hope the Ultra Fan becomes available soon!

[@Iwishiwasflying]

747

[@martinross5521]

@@Iwishiwasflying Wikipedia says the L1001 Tristar was the first user, also in 747s

[@Iwishiwasflying]

@@martinross5521 valid point but the 747 lasted longer than the Tristar. So one could infer that the 211 was more for the 747 aka 743 and 744

[@ScapoloMichael]

They tried the first composite fan, Hyfil. Shattered in the birdstrike test. Rolls Royce nearly went bankrupt coming up with a traditional alternative, had to be bailed out by the UK taxpayer. Lockheed was therefore late with the L1011 which doomed the plane to low sales. Rolls were so traumatised they haven't used composite blades since, until the Ultrafan, which will also have a gearbox.

[@StigAviation]

From what I remember, the RB 211 was specifically created for the L1011 , also the classic 747.

[@andrewdavy9921]

Hi I love all your videos you're a genius, Are you looking forward to the Boeing 777x coming into service?

[@StigAviation]

Thank you Andrew. Yes indeed I’m looking forward to seeing the 777x advancements , I’m not sure if my carrier will be purchasing them tho.. seems like we are more invested into the 787 fleets for wide body aircraft. Nonetheless I’m still excited about the new 777 and its subsystem architecture.

[@andrewdavy9921]

@@StigAviation I always see the American Airlines 777s at London Heathrow especially the ones going to LA, have you ever been over here to England?

[@StigAviation]

@@andrewdavy9921 many years ago.. but I’m way over due for a visit. I’ll fly there soon

[@PRO-PLANE]

Diesel ??)))

[@StigAviation]

Jet A is basically very refined Diesel. It has a higher flashpoint.

[@PRO-PLANE]

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