Private Pilot Flying Lesson, Part 7, Engine and Carb Heat. www.askcaptainscott.com

What's under the cowling of a Cessna 172. Different engine components explained by a non mechanic.
More supplemental flight training video's are available at
www.askcaptainscott.com/

[@Alienfanatic]

Using the throttle to prime the engine on start does work, but only while cranking. The action of the pistons creates suction at the throttle body so the air/fuel mixture is pulled into the cylinders. It's not the recommended method--priming is--but it does work. Moving the throttle without cranking, of course, does absolutely nothing. The info about carburetor heat is interesting, but remember that at low rpms the throttle plate is turned to reduce airflow. As a result, the opening is narrower so that if icing is likely to occur at the throttle plate there is a smaller opening and full blockage can occur more easily. While the green arc may indeed refer to performance, the arc is still a good reminder to apply heat, in my humble opinion. And the clicking is the sound of the solenoid when turning on the master switch. This allows current to flow from the battery to most of the systems other than the starter. (There's another solenoid for the Start position on the that allows current to flow to the starter.) Internally, there's an electromagnet that pulls a cylindrical switch closed to complete the circuit. It's through that switch that very high current can flow. When you activate the switch, though, you're not adding power to the solenoid--it's already connected--but rather you're just connecting it to a common ground.

[@bryansousa2199]

Would be so cool to see a collab with capt. Scott , Kelsey and capt Joe, my 3 favorite aviation channels.

[@BackTo4chan]

Right!

[@Shannonbarnesdr1]

oh hell yeah!

[@G4Disco]

I remember my Grandfather's '59 172 or early '60s 150 had a bigger panel to check oil. I remember using the fuel sump tool to open the dzus fasteners. It's been 30 years, so maybe I'm wrong.

[@rickclayburn9111]

Thank you Scott. This is something you never see. Much appreciated.

[@dungareesareforfools]

As a car nut and a plane enthusiast / wannbe pilot, that was brilliant! Thank you.

[@askcaptainscott]

Thanks man. I'd never seen a video like this before as to what's under the hood so I figured why not shoot something like this.

[@viccabrales3091]

What an amazingly interesting video. As a student pilot this was incredibly helpful! Thanks Capt!

[@askcaptainscott]

Thanks Vic. I thought I might get two views on this vid because the topic is rather dry but I was surprised people liked it....Its nice to have a clue how that stuff works isn't it.

[@akfox38]

Thanks for this, this was timely and helpful. I flew a plane I rent on a short cross country and after returning home and landing I noticed a red tube and metal housing that was hanging down from the lower engine cowling and dangling next to the nosewheel. I thought it was the cabin heat hose and connector but after seeing this I'm pretty sure it was the Carb Heat connection.

[@howieduwit2551]

A friend of mine who is a Pilot told me that I would be perfect for the world of aviation. It brought me here.

[@fizadyan3274]

Love from OZ Capt. Scott. If I was living in US, I'll be learning to fly with you. They way you explain things, bloody awesome. Good on ya Mate and God bless.

[@tony6890]

Thank you so much for your videos. You put things in a very easy way to follow...you are a very good teacher! I’m glad you took this approach to literally show how things work under the hood… this is something I always missed during my training. Well done. Thank you!

[@PaintmanJohn]

Every lil' bit helps us learn from a different perspective. Thank you sir.

[@TheTowman89]

Captain Scott you're a very good instructor I'm learning a lot on these videos..

[@jvkrause]

I think I just found my favorite channel. Thanks!

[@cisco0375]

Thanks for the visual explanation of these different systems. I'm currently working on my PPL and would love for you to make some videos on stalls as well as landings. I really enjoy your videos .. keep up the good work!!

[@Shannonbarnesdr1]

this is actually very helpful for some engine basics for me as a student pilot in training thanks man ! much appreciated

[@aquilotti1987]

Welcome back captain

[@WolfgangNigischer]

Especially as a student pilot, it is always good to idea, strolling through the aircraft hangar. I was able to watch a flight mechanics work a couple of times and helped (only holding 😉) something.

[@johnhoon7069]

Thank you Captain Scott I was very informative and answered a few questions I've had about airplanes

[@bigalbbq4597]

Great info! Thank you for taking time to show us!

[@mindlab780ab6]

Thank you captain Scott 👨🏼‍✈️ for the video.

[@Alfaspiderman84]

Great vid Capt Scott. On some planes they have a yellow and green arch on the tach. It has to with the engine/prop combination. Some props can set up a harmonic vibration at certian RPMs that are not good for the motor. Hence the yellow arc. Itermittent operation in that area only. But since your plane has fixed pitch prop you have no such limitation. Thanks for your vids!

[@askcaptainscott]

Ya I've seen that on some constant speed prop planes. I'm flying my nieces 182 next week and will see if her plane has it.

[@adamgardener8624]

I enjoyed the tour. Thanks, sir.

[@1PickJesus]

Thanks, Scott. I'll pass this on to my students. The Prime actually ports into the intake manifold upstream of the intake valve.

[@askcaptainscott]

Thanks man. I didn't know where it actually shot into. Good info.

[@andylee-fl]

Awesome Capt. Scott! Thanks!

[@67polara]

Excellent logic on the inneffectiveness of 'pumping the throttle' prior to start. Possibly it can work 'while' the cranking is taking place and there's some velocity through the carb but on a few vids I've watches of them starting a beaver they did the throttle cycling PRIOR to cranking. That squirt of fuel probably just runs out on the water.

[@TGDylan96]

Very informative. Great video again!

[@johndoe-gt1wk]

Captain Scott is the best... Thanks

[@rionbain2922]

Great video Capt

[@pattieduffy4992]

Amazing and Very informative video. Thank you !

[@billnelson3732]

Excellent video, thanks!

[@michaelyoungTheAV8TOR]

Great video! Please do more of these!

[@skylife0072]

Very informative. Thank you captain Scott

[@memeish3831]

Great video Scott!!

[@donnieallen5927]

very informative. You hear the lingo, but still dont know 100% what it means. Thanks for explaining it all the way through!

[@finnagler107]

The green arc is the RPM range you must fly in on St. Patricks day.

[@askcaptainscott]

My two Irish Setters would agree.....

[@Captain_SQ]

Welcome back!

[@thebigbabinski5255]

Great video thanks so much for sharing!

[@MrTONYTONYM]

I miss flying those good old carburated Cessnas. Yeah they are loud and they are slow, but deadnuts stable and reliable. Still remember the good old times my CFI used to yell at me everytime i forget carb heat on downwind

[@askcaptainscott]

Your not the only one who got yelled at. I forgot that thing all the time when I was learning.

[@jeffkelley4055]

Super interesting and great idea for a video

[@jimpease280]

It's carbon monoxide that the killer! Keep up the good work!

[@newgenmusic3582]

Thank you so much sir You are doing a great job 🙏

[@ryancourt8065]

Before reducing power for landing, the carb heat knob is first to get pulled out. After adding power for goaround its the last to go in so just remember: "FIRST-OUT, LAST-IN"

[@saipansmall]

Awesome video.

[@tscottme]

I don't see how anyone can preflight without, at least, removing the top cowling off of the Cessnas. As a pilot turned A&P mechanic I never heard anyone claim the green arc on the tach had anything to do with carb icing. I took care of 2 C-172s both almost ran 100 hours in a month at a flight school. My first "executive decision" was to remove the wheel pants. They provide almost no benefit in a flight training environment, other than giving students a chance to hide the flat spots they generate when learning short field landings. The C-150/152 & C-172 are susceptible to water-ligged air filters if flying in heavy rain because their air filters are facing forward and just below the prop. Similar Pipers are not as susceptible. At the first sign on reduced performance in rain activate carb heat, also called indirect induction. Doing so bypasses the clogged air filter and can keep engine operating with just the slight power loss due to carb heat rather than potential engine stoppage. This is very important if your aircraft is using a paper air filter. I think paper air filters may be prohibited by Service Bulletin or Airworthiness Directive. The C-150/152, and to a lesser extent the C-172 really benefit from very lean operation during ground operation. The 150/152 engine spark plugs really load up with lead deposits during rich ground operations. I always did ground ops as lean as the engine could stand. You are developing vety little power (inherently cool). If you forget to enrich the carb for takeoff the engine will choke when you apply full power before you pick up any speed.

[@Joyvelfilmmaker]

Thank you! This will help me with my next 3D animation about the Cessna 172 on my other channel Joyplanes.

[@askcaptainscott]

I joined your channel. Great videos. I'd like to talk to you about using one of your videos about engine types and combustion systems. Did you do the 3D motion graphics on that....I'm a crew guy just getting back into it.

[@JoseMedina-gf4cu]

Awesome content

[@johnfitzpatrick2469]

Hello, from Sydney, Australia * Thank you for explaining the priming fuction. Readying the cylinder for combustion is accurate. Filling the carburettor bowl is not getting the gas to the cylinder to receive the plug spark generated by the magneto. * I assume the design of having the carburettor under the engine is: 1. Close to exhaust system for heat (de-ice). 2. Enjoy the new oil in the engine. (next change would you drain and open the filter, to inspect between the fins). Just to see if any particle or ferrous metal is evident? Such as: cylinder wall or piston head burring. 🌏🇭🇲👨‍🍳

[@askcaptainscott]

Ya we opened the filter to check it. No metal, that's a plus. I'm putting a new engine on it pretty soon as this ones hit TBO plus Im going from a tired 160HP to a shiny brand new 180HP.

[@flywithdanny8150]

I think the green arc (RPM gauge) is reminding to use carb heat when below, to prevent shock cooling (basically, slow down the cooling). When you throttle down below green arc, the engine cools down rapidly while much less heat is being generated. Cooling too fast can result possible stress on metal parts.

[@agentorange153]

That's how Chkalov bought the farm, right?

[@spencerhousley8856]

Very helpful, thank you!

[@gerdawhite6012]

Thanks, Capt. Scott, very well done. I always thought carburetor heat was electric. I would never have guessed it was a passive radiant header system; seems inefficient. Appreciate the knowledge.

[@askcaptainscott]

Hey Gerda, I had no clue myself when I was learning how to fly. It wasn't until I bought the plane and started asking my mx guy questions that the light went on in my head....

[@gerdawhite6012]

@@askcaptainscott - I love it when that happens -- plus you can see whether your shoes need a buff on not...

[@askcaptainscott]

@@gerdawhite6012 lol

[@muhammadsteinberg]

Having experienced carb icing in Cessna's I can assure you it works very well and quickly.

[@agentorange153]

A passive radiant heater system is actually MORE efficient than electric heating, because it uses waste heat!

[@MartinSage]

My old VW Bug had the same heating system. It didn’t really work that great on Snowy/Freezing days. We used to joke that by the time the engine was warm enough to blow heat you had arrived at your destination. I don’t know if these older planes have electric blowers but the VW’s heat was blown by the engine rpm so if you were loping along in town the heat hardly blew out the vents.

[@askcaptainscott]

Ya the cabin heat in the 172 is similar. It's rather worthless and when the heat pours out, it comes out of the sidewall by your foot so your foot gets way to hot.....

[@okcpicker]

Good overview of what is under the hood. I took instruction in a Champion Citabria in the mid sixties, and although my instructor taught great stick & rudder skills, he never went over the powerplant details. The Champ had large sections of the cowling that opened up easily on both sides of the engine, but I never really learned about anything except where to check the oil and where to drain fuel to test. Thanks Captain Scott. Wish I had gotten certified back when it was a lot cheaper to fly GA.

[@askcaptainscott]

Hey Mark, I was never shown or had any of it explained either. Funny how that doesn't seem to be to important during flight training does it.

[@luissol3964]

Thanks for the video

[@michaelpardovich300]

Thank you, Sir!

[@budowens6478]

Good job, thanks

[@tymcbride3477]

Thanks ! You are great

[@crazytactics3603]

Very cool. Thanks

[@gibranali2368]

Capt. Scott can you please recommend an instructor near the San Jose (CA) area?

[@kamvacewu4579]

😂😂😂Thank you captain Scott. Do say "hi" the next time you fly around South Africa😂

[@askcaptainscott]

Man I used to fly there all the time on the 747 Classic.... Ill say hey next time I'm down that way.

[@beieber4life]

Captain Scott #1

[@maheralazzawi7814]

very good

[@theturtle5069]

What exactly type of Cessna is it?

[@gregorywilson7766]

If you don't mind me asking where are you located because I'm trying to look for someone to teach me how to fly an airplane and I would just like to know where are you located cuz I'm in California I'm in the Los Angeles area okay and I don't know where you are or anything like that but I've been looking at all your videos and stuff and I like for what it is you know that you do even the one with the blind kid that wanted to be a pilot and stuff I was interested in that as well because you took the time out and did what you had to do to make it easier not only for him but for you as well too

[@askcaptainscott]

Hey man, I'm up here in Seattle but don't actually flight instruct. I just like shooting flight training video.

[@danielthornley248]

why is it that the POH wants you to use carb heat outside of the green arc? I know a lot of guys don't do it but thats always what i was taught

[@askcaptainscott]

Hey Daniel, What model and year of plane are you referring to. My POH for a 1979 172N only says to use it prior to large power reductions. My guess there is that if there is ice in the carburetor any further reduction of power would cause less airflow through the carb causing complete airflow blockage due to ice buildup.....I'm sure some youtuber has done a video about that... I guess Ill search and see.

[@HolahkuTaigiTWFormosanDiplomat]

WE GOT TO FLY

[@mylayovers7233]

Throttle controls air by moving butterfly

[@santoorandzarb]

Thank you very much for all your nice informative videos. I was wondering if you have any flight school and taking new students for flights. I live in Bellevue and would love to get my private pilot certification. I’m almost 64 years old and have about 30 hours of flights so far.

[@askcaptainscott]

Unfortunately I don't instruct at all. I just shoot flying videos for fun. Where did you get the 30 hours of flight time?

[@markwagner6890]

@@askcaptainscott at rainier.

[@askcaptainscott]

@@markwagner6890 Ya Rainier is a great school. There down in Renton. Give them a call.

[@joesteffe6155]

is it not better to have Fuel injection ? Like on cars Carbator are a think in the pass.

[@agentorange153]

This is an old Cessna, it was built before fuel injection was a thing!

[@muhammadsteinberg]

Is that your 172? What year is it? Who did interior? Sorry for questions. I just updated stack (1978 172N) and now looking to update interior.

[@askcaptainscott]

Ya, its my plane. I bought it with that interior installed. Its a 1979 N model. I'm guessing it was a company in Southern California that did the interior.

[@muhammadsteinberg]

@@askcaptainscott Thanks!

[@Davi3038849844]

@@askcaptainscott at 109 kias, can you set flaps 10?

[@Uncleluckybuck]

Then you for the great info, however your carb- heat info was rather grey in explanation! All the same, you’re my greatest!

[@askcaptainscott]

Hey Brett, are you referring as in when to use it. This was more a systems explanation rather than a flight training when to use it sort of video. I have the flight training vids on the website. Glad you liked it though.

[@Uncleluckybuck]

@@askcaptainscott thank you for your response, what I wanted to know is when you push the carb icing lever ( you showed a square metal shroud around a pipe) what I want to know is when you push the carb icing lever, what are the moving parts, what happens to that metal shroud, does it move like with the cabin head butterfly?? Does it open a channel to the carb Venturi?? I will go and study further... however with your blog I would like to have seen how it works! Lol... just saying.. love your show and will always follow! Cheers

[@mohshehri]

Captain are you still flying for airlines ?

[@askcaptainscott]

Ya, I'm flying the 777 these days.

[@mohshehri]

@@askcaptainscott nice 👍

[@simolous99]

you retired from Airline role?

[@askcaptainscott]

No I'm still flying the 777

[@kakandaville]

Super cool

[@susanburke7995]

Thanks again for another informative video! You are very well spoken and handsome too! Do you have a girlfriend?

[@caseykelso1]

alright ??? Alright nothing ... where the hell has Hannah been?

[@askcaptainscott]

Where shooting another video together soon. She's flying jets now...

[@caseykelso1]

@@askcaptainscott lol , very cool. Yah did good a good job with her ! Interesting stuff about the differences between the fuel primer and carb. Lesson thanks for sharing !