Cessna 180 power setting for take-off

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tazin river
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Cessna 180 power setting for take-off

Post by tazin river »

The floatplane should be back in the water soon....

...just going over various power settings for take-off...

1) full throttle and 2600 rpm to 500 feet on take-off
2) reduce power to 23 inch and top of the green arc on the RPM
3) remove flaps slowly...
4) adjust for normal cruise climb settings.

Am I right?

Cheers
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CamAero
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Re: Cessna 180 power setting for take-off

Post by CamAero »

Yup ~ that's about what I do.

I don't worry too much about 500' though. Depends what sort of terrain you've got in front of you or if it's gusty.

With no obstacles and favourable wind & load, I pull it back to 23" & 2300 - 2400 for cruise/climb as soon as I know she's off the water and sure she's not going to settle.

Otherwise, for a more assertive climb, if so required, 24" and let her scream until you're not puckered any more.

Cowl gills full open for the climb & no leaning until you're pretty much in cruise is my rule.

Good discussion; I've got to get my head back around this too before we plunk her in for the year..

C.A.
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Hornblower
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Re: Cessna 180 power setting for take-off

Post by Hornblower »

um ... full power and 2 notches to 500 ft ... no.

All in to get off the water, level to get 80 mph clear of water, once you have 80 then climb power (25 in and 2500 rpm or thereabouts) if obstacles cleared, and climb initially at 80 - 90 if wind not too gusty then carefully or gradually reduce flaps and climb at 80 - 90 (hot wx gusty winds 100)
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sheephunter
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Re: Cessna 180 power setting for take-off

Post by sheephunter »

I'm with hornblower's procedure and I don't get too excited about the flaps until I am sure I have positive climb and I am clear of what is in front of me especially with a heavy load and then ease off the flaps and trim accordingly to keep that nose up/level. I also start to lean well before I am hitting cruise altitude and keeping an eye on the gauges as well outside.
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Lost Lake
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Re: Cessna 180 power setting for take-off

Post by Lost Lake »

Why do you want to lean well before cruise. You are running high rpm's and temps. The fuel that is not burned on climb is used to cool the engine. Leaning will only reduce the engine life. Good way to blow jugs. IMHO
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sheephunter
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Re: Cessna 180 power setting for take-off

Post by sheephunter »

I've never found when climbing out at 90 that I needed to burn 27gph to keep the cylinder temps in the green. I don't upright crank it down to 10.5 gph but slowly lean and watch, listen and feel. Might be my machine or maybe I'm completely wrong, so I'm kinda waiting for more opinions/advice. I know what you're saying about using the fuel to cool, but how much is truly necessary?
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Lost Lake
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Re: Cessna 180 power setting for take-off

Post by Lost Lake »

What ever the POH says. .7 litres/min x $1.60 per liter = $1.17 per minute difference between take off power vs. leaned cruise. At 300' per minute? (less or more?) = an additional $5 per take off. Better lean in cruise woulod probably compensate for this.

Like Master card says,to keep the engine cool an extra $5 per take off , Extended engine life $20 per hour, Knowing your engine is in good shape...priceless!
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sheephunter
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Re: Cessna 180 power setting for take-off

Post by sheephunter »

Your absolutely right, the fuel is the cheapest part of flying. Sure wish I could find where you were getting it for $1.60/ltr?
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Big Pistons Forever
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Re: Cessna 180 power setting for take-off

Post by Big Pistons Forever »

When I had a 180 on floats I left the throttle full in but rolled the prop back to 2500 RPM as soon as I broke free of the water and had a positive rate of climb. When I was clear of all obstacles and ready to cruise climb it was 25 in and 2400 RPM and 90 to 100 MPH depending on weight and temp.
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CamAero
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Re: Cessna 180 power setting for take-off

Post by CamAero »

Big Pistons Forever wrote:When I had a 180 on floats I left the throttle full in but rolled the prop back to 2500 RPM as soon as I broke free of the water and had a positive rate of climb. When I was clear of all obstacles and ready to cruise climb it was 25 in and 2400 RPM and 90 to 100 MPH depending on weight and temp.
Over-Square~?
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tazin river
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Re: Cessna 180 power setting for take-off

Post by tazin river »

Thanks guys

Some reduce power first then rpm, others rpm first like big piston foreever said...is that ok to do so (rpm first that is)?

Really yelpful folks

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Lost Lake
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Re: Cessna 180 power setting for take-off

Post by Lost Lake »

Take offs and landings... Always power first, props second. Otherwise you will be overloading the engine. It's like reving the engine in neutral, When you drive a standard, you reduce engine speed before shifting. Imagine keeping the revs up on your car and dropping from 4th to second gear.
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Big Pistons Forever
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Re: Cessna 180 power setting for take-off

Post by Big Pistons Forever »

CamAero wrote:
Big Pistons Forever wrote:When I had a 180 on floats I left the throttle full in but rolled the prop back to 2500 RPM as soon as I broke free of the water and had a positive rate of climb. When I was clear of all obstacles and ready to cruise climb it was 25 in and 2400 RPM and 90 to 100 MPH depending on weight and temp.
Over-Square~?
Yup in fact if you go to the Contintal engine operating manual you can see you can go all the way to 29 inches at or above 2400 RPM ( O 470 R )
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iflyforpie
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Re: Cessna 180 power setting for take-off

Post by iflyforpie »

Over square is a myth. Any Beaver driver should know that. Can you imagine flying (or trying to fly) a Beaver at 18 square?

The only source for proper power settings is the POH/AFM or the Engine Operating Handbook. Going through the power settings, you will find many cases where it is perfectly alright to use over square power settings.

Square is just a rule of thumb to make it simple on small, normally aspirated engines where the maximum and minimum manifold pressure correspond with the first two numbers of the maximum and minimum RPMs. The engine--being a constant displacement pump--should be happy with the most amount of air at the maximum RPM and the least amount of air at minimum RPM... straight line variation between the two.

But your engine isn't going to blow up if you bring back the RPM first. It's only bad if it is lugging the engine, which means it doesn't respond to more power, it just gets louder and/or detonates. All of the NA Lyc 540s I ever flew, you kept the throttle firewalled until you set cruise, you just brought back the prop. You can save a ton of fuel and noise by going over square. Excessive RPM wears out engines too.

Same with mixture. There is no harm in bringing it back a bit... fuel injected engines are operated like this in climb all of the time. Just keep your EGTs a bit lower, and keep an eye on your CHTs. Leaning for best power is still a rich mixture because the fuel cooling makes the charge denser. Continental also says on most 470s that you can go right to peak EGT below 65% BHP..
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Rowdy
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Re: Cessna 180 power setting for take-off

Post by Rowdy »

iflyforpie.. I was literally typing up something similar.. thanks for saving me the hassle.

You will see more wear at higher rpm than you will at higher MP. UNLESS you are detonating.. which shouldn't be happening with the correct grade of fuel on a naturally aspirated engine thats in proper tune.

Save the world from your noise complaints, maintain good engine health and bring the rpm back after breaking water!!!
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Cat Driver
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Re: Cessna 180 power setting for take-off

Post by Cat Driver »

There are a lot of piston engines in airplanes where it is not advisable to reduce R.P.M. before reducing manifold pressure ( Throttle ) during full power operations such as just after take off.

Maybe it would be wise to read the POH and the part that explains engine handling?

Rote learning and rote actions with regard to power settings can lead to dumb decisions sometimes.
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Rowdy
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Re: Cessna 180 power setting for take-off

Post by Rowdy »

Cat Driver wrote:There are a lot of piston engines in airplanes where it is not advisable to reduce R.P.M. before reducing manifold pressure ( Throttle ) during full power operations such as just after take off.

Maybe it would be wise to read the POH and the part that explains engine handling?

Rote learning and rote actions with regard to power settings can lead to dumb decisions sometimes.
Of course! Those being engines that are force fed.. such as turbo or supercharged applications, not to mention the more complex geared engines which would not tolerate the torque of high MP and low RPM styled power settings. However, my remarks were directed at the naturally aspirated flat six found in the Cessna 180 as mentioned.

There is also a difference between MAX and FULL power too ;)
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Cat Driver
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Re: Cessna 180 power setting for take-off

Post by Cat Driver »

My comment was not directed at you Rowdy, I was making a generic observation. :mrgreen:

There is also a difference between MAX and FULL power too ;)
Yes, it is known as M.E.T.O. :mrgreen:
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howard40
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Re: Cessna 180 power setting for take-off

Post by howard40 »

Some of these direct drive flat engines with carbs, and no turbos, prefer to have rpm reduced before manifold pressure due to the "power enriching " that is built into the carb. At high throttle openings it dumps extra fuel in . Reducing rpm a 100 or 200 but leaving the throttle wide open actually is kinder than reducing throttle position and leaving rpm high (this causes leaning to occur ,that you did not directly ask for , as the power enrichment feature closes up and "leans" the charge). I also agree that the manual is your source.....
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tazin river
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Re: Cessna 180 power setting for take-off

Post by tazin river »

Some Cessna 180 drivers cruise at 22 square....is this a bad habit?
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