King Air Propeller Demonstration
HTML-код
- Опубликовано: 10 фев 2020
- With the cowls off, this video demonstrates how the prop levers and linkages work to command the governors to increase, decrease, or maintain propeller RPM as required by the pilot.
Edit: I’ve added the following text to answer some common questions in the comments.
-------
What prop settings do you set during different stages of flight.
In essence, regarding prop lever settings, the only pilot action during a “normal” flight in this type of aircraft is as follows:
-Props full forward (fine pitch) for taxi and Take Off. See Note 1 below.
-Adjust the props to “Maximum Continuous RPM, or Climb RPM shortly after take off. See Note 2 below.
-Reduce Prop RPM for the cruise. See Note 3 Below
-During the approach phase adjust your props to
full forward for the landing (reverse thrust) or for the anticipated “go around”. See Note 4 Below.
That’s it. The rest of the time, the governor works to achieve the RPM that the pilot has “asked for”/selected. So when there is excess power, it simply reduces the pitch of the blades to take a bigger “bite” of the air.
Notes.
Note 1: The props won’t achieve the High RPM you require, until you apply sufficient power using the power (thrust) levers to turn them fast enough. Once you have enough (and excessive) power, the governor will continuously adjust the propeller pitch to maintain the RPM you requested.
Note 2: In the C90GTX, the difference between Maximum RPM (time limited) and Maximum Continuous RPM is very small. Just a fine tickle back of the prop levers. If the props are rigged correctly, this is a change of 1,926 RPM to 1,900 RPM. In other King Air models, the difference between Max RPM and Max Continuous is more of an adjustment. (300-400 RPM in the in the models I’ve flown)
Note 3: Refer to the Cruise Tables in your Pilot Operating Handbook. In this particular model, you can leave the props at 1,900. We do however tend to adjust them to 1,800 for longer cruises, because it changes the “tone” of the props to a more comfortable one for passenger comfort.
Note 4: Pilot technique differs here, based on the types of props you have fitted, runway available and passenger comfort. In the C90GTX, I always adjust the Props to full forward in the final approach phases of a flight. That way, the “Reverse Thrust” is ready on the ground and I simply have to put the power levers in reverse. Same with a go-around... it leaves me less things to do.
In the B200 or other models of the 90 that I’ve flown, you could be adjusting the props from 1,600 to 2,200 RPM ready for the reverse or go around. This can have quite a noise increase for passengers. So, many pilot choose to leave the props where they are until after touchdown, when they will then whack prop levers full forward before applying reverse thrust. This of course, is runway length and other conditions permitting.
---------
Another common question is “why do you manually close the gen ties before start”.
Lazy but most obvious answer: Because the C90GTX POH says so!
Real explanation: the C90 GTX has a “triple fed” electric bus system. The flashing beacon light outside the aircraft, operates off the Left Bus.
So until the left generator bus is online... the Beacon light won’t be on and flashing outside, regardless of the Beacon Light switch position. So you manually close the gen ties before start for that reason. 
Наука
The King Air is just a gorgeous turboprop inside and out. But, really love the cockpit.
It's also a ferocious sounding plane.
That prop tone you hear at 2:10 is often the loudest sound at the airport if it isn't a military base.
I call King Airs the Dodge Hellcats of General Aviation. Because they sound mean as can be, they sound powerful, and they are a joy to listen to. (Even a bit humbling when you're right up next to one while its running)
Even if you need hearing protection within 700 feet of them 😅
As someone that’s worked on these things & hates them with a burning passion I just wanna say that I appreciate people like you who love them. They do look good though. 😂
Yeah, it’s gorgeous, but the inboard tanks between the engines and fuselage are a pain in the a$$ to get to and fuel!!!
@@goofygolfer56. Not ‘signal point?’
@@Posttrip Nope. One, two or three tanks per wing with the mains being between the engines and fuselage
Either thats a brand new aircraft, or someone has been taking very very good care of the control panels. Not a scratch on them, they all look brand spanking new
Thank you! Aircraft about 7 years old and just over 1,000 hours!
@@Mode_Sierra it's very obvious you give this craft the attention/care it deserves
@@slashz0r Credit goes to the engineer/mechanic. I look after it in the sky.
Very interesting, thanks!
Brilliant video, simple to understand, amazing to see the feathering mechanics at work and whilst for many this might seem banal, I found it fascinating.. Well done lad for a super piece of footage and delivery.
I agree! And I love Beaker!! Greetings from Austria
You’re very welcome!
Good illustration of how many systems and controls come into play just to start the engines. Thank you!
I was watching and just thinking about how much I love the sound of turbines when you said it for me!
I don't fly so this means nothing to me but it came up in my feed so YT felt I needed to see this. Was not disappointed. My inner geek has been satisfied.
Hahaha. Glad I could help and find mutual geekinessz
I love this video! What a concise explanation of how the prop control works!
This is one of the best videos that explains and shows how the props change pitch and I too love that turbine sound. The KingAir is a beautiful aircraft.
Thanks for taking the time to show this Johan and explain what the mechanisms are doing too.
Very nice and very nerdy. Thanks for uploading and catering for those of us who like to see what goes on under the cowls, covers and access panels.
Thanks, believe it or not I've always wondered what the change in engine noise was on start-up. Now I know it's the revs changing as the governor takes over.
You are right, not something you get to see very often. I like that you went through the start up. Good video. Thanks for sharing.
The Blue Max,great film.
@@eugeneoreilly9356 nice you are the only one to make that connection. My grandfather was a Lt. Col. In the A Force and that was his call sign.
0:55 I love that sound when a king air starts! I've gotten to work on some king airs in the hangar I work at, while they're a little difficult as far as their engineering goes, they are a joy to look at, and a joy to be around. King Air is easily one of the best planes ever built.
Great demonstration!
Used to love cranking up the APU on the C-141B. Sweet music to the ears.
This was great to see behind the curtain a bit. Thank you 👍
King Airs are so sweet. Thanks for the demo, it's fantastic.
I love the start sound ❤
the PT6 is a nice engine to begin with
Very Nice video! Completely clear, direct and didatic. Great!
Hello from São Luís Maranhão Brazil!
Reading about this in theory makes me scratch my head wondering what the heck are they talking about. Thanks to your video I can finally visualize it properly.
Really interesting video. Thanks for taking us thru each step and explaining the reasoning for each.
Although I knew almost nothing about aircraft, this vid is very interesting for me (and others alike)... Thanks for the rare demo. Be safe 🌹
Thanks for that demonstration. Its good to see it in real life. Keep'em coming, love the King Airs
Thank you for this video!
What an awesome video,thanks!
Great video .. never saw propeller pitch change function in action before .. good one
fascinating demonstration! your camera even enables to see the propeller pitch movements!
Very interesting demonstration, Thanks
Nice simple demo and explainations, thank you!
No problem... sometimes simpler is better hey :)
Awesome video!! Thanks for this!
A very good, educational video.
Lovely demo!
Thanks you answered several questions I had
Great demonstration! Thanks!
I’ll do some more some time
absolutely love this
Very cool. Thanks for sharing.
Beautiful aircraft
I remember on the 99's every winter rigging the reverse torque and every spring rigging them back. This was in northern Ontario where winter daytime temperatures could be below -30c.
I just know you have interesting stories as soon as you mention 99’s and Ontario Winters.
@@Mode_Sierra I worked for Bearskin from 86 to 88. Seen plenty of 99's operating in some harsh conditions.
Interesting! I used to fly my multiengine schoolflights at c90. Nice plane and plenty of power. You have even glass cocpit! We had steam gauges all over 😄
What a treat thank you!
I worked on 350’s and next will be 1900’s. In my opinion, beautiful aircraft.
Makes me wish that I could have gone to pilot school. That was beautiful
Do it!
I don't know what company would want to hire a pilot as old as I am. At least from the research I've done
How old are you sir?
@@wowwowwiiwowiwwiwiwiwiwiwi8294 38
You can always fly for a drug cartel in the middle of a jungle. :D
Marvelous 😍
Thanks captain for the excellent demonstration 👌
You got it 👍🏻
Great video!
Thanks For this vid !
That was incredible. Very few vids that have an actual person with actual knowledge. Would love to see the inside mechanical part of pitch
Thank you so much!
This is super interesting!
Beautiful.
perfect, thanks for this lesson :-)
Great video instruction!
This guy is a legend. He says Governor like a proper champ, and he sets the prop rpms to 420 in the video and doesn't even make a joke about it, but pauses a bit when saying it and hurries over it.
That’s such a smart observation! Love it.
incredible video thx
That was fascinating 😀
Amazing!
Wow...that is awesome ...
Fascinating! It is interesting how those boost pumps would run, even before the battery master switch was switched on.
Yes, they are on the “hot bus” and one of the C90 “gotcha’s” to look out for. Could drain the battery regardless of battery switch position.
This is sooooo cooooool!
I saw flames, im happy
Fine: pushes air, lets you fly
Coarse: almost no air resistance, lets you glide
The way I used to remember it is Coarse sounds like Cut, props turn into little knives in the air.
Fine: pushes little air per revolution, results in higher RPM and less torque, keeping power reserves for go-around etc.
Coarse: pushes more air per revolution, lower RPM, higher torque. Too much torque will damage the engine.
Feather: pushes little to no air, reduces drag and allows for better glide performance in case of engine failure
@@matthiaspatzelt3085 thanks, sure its nothing for those who knows but means a lot for those who know nothing like me... 😅👍
@@matthiaspatzelt3085 wait, i thought coarse is feather in props ?!
because the angle of blades in feathering and in coarse results in little to no RPM
Nice one Johan
Love it!
Fascinating
good job
Nice video👍
That was very informative and concise, now I'm sure I can fly it! I'm interested in the mechanical linkage that alters the pitch of the propellers.
Hi, if you research “propeller governors” you’ll see how the governor works to maintain propeller RPM using engine oil.
Cool vid 😎👌👍
loved it
Wow! Thanks
Thanks! Cool video.....
Nice thank you
Cool. Thanks
Best video I've seen to date!
True praise! I got into helicopters too in the last few years! From your profile pic, you could teach me a thing or two!
@@Mode_Sierra I'm a true fan! loved helis since age 3. This is the first video I've found that answers all my questions in full, i'll be sure to check out your others ;)
@@Whirlynerds I’ve been reluctant to post more, but the response has been encouraging.
Very neat
God that is such a beautiful airplane.
Agreed, King Air is easily one of the most handsome twin prop planes ever built.
Fantástica tecnologia!
Sweet music
Gracias🇲🇽
Osm vdo sir i like it.. Make more vdo like this.
Props to you
gaggety
Interesting!
Cool video, thanks!
Great video! Which airport is this at?
Wouldn't it be fascinating to be able to see through the whole of the engine as if it were glass and be able to observe all of the internal workings. CGI animations can provide this but they're not the "real deal", maybe in the future a material will be designed that would allow this.
Does the red morse cable on the port engine shown.. have too much kink behind the casing mount.. causing a cable core fray to failure point.. ???????? it might be interesting to cut the ends off a used cable and extract the cable core to check for hard spots from excessive flexing. then unwind the core strand by strand. in that area..
Oooohhh, soooo many shiny buttons!! Must... Press... Them... All.......
Oh, and nice plane and start-up sound too i suppose! Haha!
Boa Noite meu amigo Donizete Bragança Paulista SP. Brasil
Quick question, do ones require somekind of key or card to start an aircraft (ie like starting a car engine) before all those starting seq? 🙏
Thank you for showing the prop mechanism, never actually saw it in action during eight years of aviation! Gotta love pilots thinking of the community while doing those kind of tests :-)
Got a question for you: Why do the boost pumps need to be on during shutdown or a least until N1 being below 10 percent? The condition levers are already in the cutoff position, why worry about boost pumps and N1?
You are welcome! Glad you liked it. Someone else asked the same question, so I’ve copied the answer. Let me know if it explains it ok.
The purpose of the electric boost bumps is to prevent cavitation of the engine driven fuel pumps. Cavitation (destructive) happens when there is back pressure in the fuel flow and “bubbles” that vaporise form in the fuel pump. Cavitation can destroy your engine driven fuel pump over time. And no engine driven fuel pump means “bye bye engine”. The electric boost pump operates at a much lower pressure than the engine driven fuel pump and can’t support the required fuel pressure for the engine. It only serves to protect the engine driven pumps from cavitation damage. Above 10% The electric boost pumps still do their “job” of preventing cavitation. Once below 10% the risk of cavitation ceases and the boost pumps can be turned off. Hope that explains it ok.
i allways know the sound these props make when takeing off i live 10 miles from alb int i can hear them takeing off
Very interesting indeed ! Thanks for this demonstration. I am not used to turboprops, flying only small piston engines. What about the fuel consumption during feathering ? Does it increase because of the higher resistance of the prop ?
It’s neglible. Remember that the engine is never working any harder throughout the process. The “Power Levers” are never touched during the demonstration… it’s idle power throughout.
That was really interesting to watch without engine cover.
One question, which may appear really minimal, but when you toggle some switches you use a thumb and forefinger movement as if "pulling" the switch. Is this a mechanism in the switch requiring to pull it out, or is just best practice so you know you've completed it?
That’s a good observation. Yes, your assumption is correct. Some switches on the panel are of the type that requires you to pull the switch before moving it. This is to avoid unintentional or accidental switching.
I agree with Johan, that was a really good observation. I tried to find a diagram of one, but couldn't. Essentially some of the King Air switches have a tooth that you have to pull the spring-loaded sleeve on the switch back over the tooth to shut it off. That is so they aren't inadvertently turned off in flight. If I find a diagram I'll come back and post it.
@@Mode_Sierra I noticed that too. I thought with that panel down by your left hand side you could wreak havoc with just the brush of an arm.
Now I know why you don’t. Thanks very much 👍🏻👍🏻
Mooi
Way fancier than the B200 I maintain. It's missing all the steam gages and the overhead switch panel!
You can either buy it part by or buy plane and a business jet have 2 different motor for flight
Great video. Why do you wait until N1 is below 10% to shut off the boost pumps?
Hi there, the purpose of the electric boost bumps is to prevent cavitation of the engine driven fuel pumps. Cavitation (destructive) happens when there is back pressure in the fuel flow and “bubbles” that vaporise form in the fuel pump. Cavitation can destroy your engine driven fuel pump over time. And no engine driven fuel pump means “bye bye engine”. The electric boost pump operates at a much lower pressure than the engine driven fuel pump and can’t support the required fuel pressure for the engine. It only serves to protect the engine driven pumps from cavitation damage. Above 10% The electric boost pumps still do their “job” of preventing cavitation. Once below 10% the risk of cavitation ceases and the boost pumps can be turned off. Hope that explains it ok.
@@DylanClements98 Always learning! Are you related to Tom Clements?
Nevertheless a good explanation of quite difficult terms in gas turbine engines I don't understand.
I found it interesting that as you varied the prop pitch the RPM changed. I'm familiar with the turboprop engines used on the C-130 Hercules. On those engines the RPM's are tightly governed to a very narrow speed range of about + or - 1.5%. When the pilot increases the prop pitch the torque and fuel flow increase drastically but the RPM's stay constant. I thought all turboprop engines worked like that.
The C130 uses a fixed turbine. All the engine and prop are geared and run together. This video shows a PT6, its a free turbine. The compressor is mechanically independant of the power, and its driven by exhaust gases from the compressor. Ive seen people hold the propeller still while running the engine to check for leaks.