737 Powerplant

[@MikeSierra8282]

Sir, your content is absolutely fantastic. As a 737 TR student myself I think it's the great way to organize the knowledge. Thank you, I've just shared it with my TR mates

[@ChrisBrady737]

Glad to hear it was helpful. If you are new on type you might also find my book useful.

[@MikeSierra8282]

@@ChrisBrady737 absolutely. I am going to purchase it soon

[@telescope64]

A comprehensive overview of the various aircraft and engine models,very interesting useful information.Once again many thanks to Capt C.

[@ChrisBrady737]

Thank you for your kind words

[@hzgl]

You have the best voice of a narrator!

[@ChrisBrady737]

Thank you, I appreciate your kind comments

[@balazsegressy3788]

Some more information about the Dual Annular Combustion Chamber engine version. The DAC engine was basically the prototpe of the TAPS (Twin Annular Premixing Swirler ) combustion chamber/fuel nozzle design. The reason the DAC engines did not become popular (actually the engines were refitted with traditional SAC combustion chambers) is the high vibration/ and high temperature loading of the low pressure turbine blades. During power changes/transient modes when some of the nozzles were switched on/off the LPT blades had increased vibration and uneven temperature loading as a result of the gasflow pulsation and temperature distribution. These led to LPT blade cracks. After the engines were refitted with the original SAC chambers the Green Economically friendly logo on the engine cowling left on of course.:)

[@ChrisBrady737]

Some great additional information, thank you again. As pilots we certainly noticed the vibration from the DAC engines at certain N1's during the nozzle transitions.

[@nicolasortega9168]

Thank you so much for providing all your knowledge free to watch. I also bought your book but all these videos are a godsend

[@ChrisBrady737]

You are very welcome. Thanks for buying the book, I hope you found it useful.

[@flapthrottle4394]

Thank you very much 🙏🙏 ....another great video. we need more such precise and informative/fact full videos.... In fact ...without an advanced “aviation” knowledge difficult to understand but for ATPL-students or someone intending doing his 737 type rating... indispensable

[@ChrisBrady737]

Thank you very much for your kind words. More videos to come. Please share the links amongst your friends and colleagues.

[@ccacrislan]

Outstanding video, great refresher, thanks 👍

[@ChrisBrady737]

Glad you enjoyed it

[@germangamerpros]

Very interesting and comprehensive presentation! Thank you very much for the video.

[@ChrisBrady737]

My pleasure, thanks for watching.

[@luanabuga]

Thank you for this comprehensive video!

[@ChrisBrady737]

You're very welcome. Please tell your colleagues about the videos.

[@OsagieFrankIgbinovia]

Great content Chris. Thanks for sharing once again. 👍🏾

[@ChrisBrady737]

No problem, glad you enjoyed it.

[@stuartfriend4930]

Amazing work Chris

[@ChrisBrady737]

Glad you liked it!

[@UAL320]

41:30……Chris, my MAX training materials indicate starter cutout at 63%, and I have indeed seen that on the line.

[@ChrisBrady737]

Thanks, I forgot that difference. Well spotted!

[@UAL320]

@@ChrisBrady737 …Thanks for the content!

[@nicolaslutun6361]

Very interesting, thank you Chris

[@ChrisBrady737]

My pleasure, glad you enjoyed it

[@nanjundaiahtc4528]

Thanks for the great video.

[@ChrisBrady737]

Glad you liked it!

[@soumyadeephait70]

Thank you Captain 👍

[@ChrisBrady737]

My pleasure, glad you enjoyed it.

[@trevorbodnar5495]

Fun fact: Concorde also had a bowed rotor motering procedure. Was only done if engine had been shutdown less than 4 hours.

[@ChrisBrady737]

I knew that. Makes you wonder how many other aircraft have to do it, military aircraft maybe?

[@jasonbourne1451]

Hi Chris, All 737 pilots including me sometimes can not reach the document which contains engine failure identification. Can you make a video of it? For example, These signs will show you engine seizure, seperation, severe damage vs...

[@ChrisBrady737]

Do you mean the document "Airplane Turbofan Engine Operation and Malfunctions Basic Familiarization for Flight Crews" or some other document?

[@jasonbourne1451]

Yess exactly this document. "Airlane Turbofan Engine Operation and Malfunctions Basic Familiarization for Flight Crews"

[@Driver170]

Hi, regarding the NG start attempt. Does this mean your GRD switch can only be on for 2 minutes before placing it OFF?

[@ChrisBrady737]

That is how I understand it

[@flyingskullb737]

For MAX, Starter cutout is 63% N2.

[@akshitkaushal3014]

Oil temp is measured during supply and not during return.. correct me if I’m wrong.. (around 26 min into video, can you re-check what you said)

[@leg01]

Thanks again for these very informative presentations. The most professional aviation content on KZbin IMO. I have one question regarding extended engine motoring. I see the limit for extended motoring on the CFM567B is 15 mins for the first two motorings with further limitations for the third and subsequent motorings. In what scenario would such a long motoring be required? (I can only think of a tail pipe fire scenario... but that would not require anywhere near 15 mins of motoring..). Perhaps for maintenance procedures? Many thanks!

[@ChrisBrady737]

Thanks for your kind comments. Re 15 minutes of motoring, I am told that there is an engine control test of the system which takes several minutes.The engines control actuators and valves are powered by fuel hydraulics,so the gearbox needs to turn so instead of an engine run the starter can be used. An engineer would know more about this than me.

[@leg01]

@@ChrisBrady737 thanks very much Chris. I didn’t think it was likely to be a pilot related procedure. Cheers.

[@murraywoodington2125]

Can confirm long motoring is used by engineers for ground tests and compressor wash.

[@bzmouse]

Hi great videos, i am a big fan of your book, app and videos. Question: on a 400 I was taking out of MX and each time we went to start the L engine - we would get light off but then the EGT gauge kept flashing at us around 628. It didn't hit the hot start numbers and it didn't hung start. We went through this several times before we took off. Somehow the indication was reset by mx but I never understood the cause. Mystery. However, we didn't know to do this BITE Test on the EIS, I assume its normally a MX Function.

[@ChrisBrady737]

Hi, that is a new one on me. I would take some convincing to depart with an engine that was behaving like that. Yes, maint will perform the EIS test and several others for situations like this.

[@steffenleo5997]

Good Day Capt Brady, do the 737 NG engine CFM56-7 and 737 classic CFM56-3 have a bowed rotor monitoring system?

[@ChrisBrady737]

No, they don’t need one. Only the MAX with its LEAP engine needs bowed rotor motoring.

[@alphapilot1908]

Keep up the good work, sir. I've got a question. Why isnt there any Bowed Rotot Motoring for the N1 shaft? Isnt the N1 shaft also susceptible to bowing like the N2 shaft is? Thanks

[@ChrisBrady737]

The reason stated by CFM/Boeing only refers to the N2 shaft. Perhaps the N1 shaft is less susceptible to bowing. Maybe it doesn’t reach the same temperatures or speeds as the N2 shaft.

[@alphapilot1908]

@@ChrisBrady737 got it. Thank you for taking the time to respond

[@35Frost]

I don't remember if it was explained previously but my inner aviation enthusiast wonders what that little round vent on the translating sleeve is visible at 1:07:57

[@ChrisBrady737]

It is surprising how many people ask me that! The answer is here: www.b737.org.uk/thrustrevvent.htm

[@35Frost]

@@ChrisBrady737 Thanks a lot :)

[@СергейНосарев-ъ1з]

Hello! Great content, thank you very much. I would like to ask a question, maybe you know the answer. What N1 and N2 percents actually mean? Percent of what? And why is it possible to have more than 100%?

[@ChrisBrady737]

100% is a nominal figure assigned during the development stage. As the engine matures during development is it often possible to increase the output and therefore exceed 100%.

[@СергейНосарев-ъ1з]

Thank you 🙏

[@ravr7764]

Hi Cpt, you are doing a really great job. With reference to the material presented I'm just wondering (cause 've seen that in some other not official materials) where this 10 secs to abort start come from (40:47), in our SOP and FCOM we have 15 secs.

[@ChrisBrady737]

Hi Rav, this is the risk with me giving operational rather than technical info, as operational info can change. It always used to be 10s and in some places it still is.

[@ravr7764]

@@ChrisBrady737 All clear, thx for the great job.

[@mikkelkaslov]

Hi Chris, many thanks for making these videos, I really appreciate that. I am a LTC on the 737 and have a question I can't find the answer to, maybe you can help me. If you make a takeoff on a 26K aircraft with a 24K derate and advance thrusts levers manually, just after takeoff, will you then get max thrust for 24K or 26K? Many thanks Mikkel

[@ChrisBrady737]

In your example if you advance the thrust levers to the forward stops you will get 26K. This is for emergency use only (windshear / terrain or obstacle avoidance) and you should be extremely careful about doing this if OEI.

[@mikkelkaslov]

Thanks for your answer. Yes, we discussed this with regards to windshear vs derated takeoff. I am aware of the issue regarding Vmca.

[@nallenkunumal7552]

Pls make a video on how to check engine vibration on Max using PMD and finding balance solutions

[@ChrisBrady737]

Hi Nallen, I wish I could help you but unfortunately that is way beyond my knowledge. I am a pilot not an engineer.

[@AbdallahiKreiked]

Hello captain I've a question about engine start . “ Operation in a Sandy or Dusty Environment” when it is the case ,the SP Procedure tell to motor the engine for 2 min to help remove contaminations .then engine start lever IDLE . SO how could we coordinate that with the limitation of the starter usage (2min maximum ) . Thanks 🙏

[@ChrisBrady737]

Please ask questions here: facebook.com/groups/737tech

[@aviationmania8]

nice informative video!!! do you have it pdf ? like an engine component identification pdf?

[@ChrisBrady737]

Thank you. I dont produce a PDF but a lot of this information is in my book.

[@aviationmania8]

@@ChrisBrady737 may I know the name of the book you refer to?

[@ChrisBrady737]

It is the Boeing 737 Technical Guide, available here: www.b737.org.uk/book.htm

[@ke282]

Hi, are there any resources that would state the dimension (diameter or cross-sectional area) of the cfm56-3 and -7 inlet and exhaust? Would greatly appreciate the help as I am struggling to find it for my report. Thank you.

[@ChrisBrady737]

Not that I know of

[@张炜-h7p]

wonderful video, thank you. but i still can't understand “if both the EGT redline and the EGT start limit redline are shown, the start limit redline is the inflight start EGT limit for all engine starts”, how can i understand this sentence😂

[@ChrisBrady737]

Sorry if I confused you. The EGT limit is always the first (lower) red line. The FCOM also explains this in the Engine - Displays section.

[@mikoajkula4093]

hello captain I'm curious why 34:41 Tat temperature is so high? greetings

[@ChrisBrady737]

It is possibly a non-aspirated TAT probe.

[@dinamiena6186]

Great video as always Captain ! I have a question to make it more clear in my mind . In NG and max there is a FADEC in each engine which lets say controls all the engines parameters . Then a part of FADEC is the EEC which lets say is the brain of FADEC and control engine by fuel flow through a HMU . Correct? Thank you

[@ChrisBrady737]

The FADEC is the EEC. FADEC stands for "Full Authority Digital Engine Control" EEC is "Electronic Engine Control". They are the same thing.

[@dinamiena6186]

@@ChrisBrady737 thank you!

[@AG-un7dz]

You'll find that many times both terms are used interchangeably. Generally speaking the FADEC is the system and the EEC is the component. In this case the EEC is the computer that schedules fuel flow, VBV, VSV and turbine clearance control valve position to name a few. While the HMU is a metering valve that purely modulates according to the commanded electrical signals sent by the EEC. All of this falls under the FADEC moniker. Even the same engine manufacture will sometimes identify the electronic engine control as an EEC in one manual while they will call the came component a FADEC for another manual.

[@ChrisBrady737]

Thanks AG, much better explanation than mine!

[@balazsegressy3788]

​@@AG-un7dz just to be 100% correct about the role of the HMU : The actuators (vsv vbv etc) on the engine are fuel pressure operated. The EEC being a computer we need some device which changes the electrical signal to fuel pressure to move the actuators. This called Electro Hydraulic Sevo Valve. These valves are located in the HMU together with the servo fuel circuits. From the HMU the EHSVs are sending the fuel to the actuators. Plus the HMU contains the fuel metering valve the shutoff valve and a mechanical overspeed governor.