Cessna 152 power

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jays_86
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Cessna 152 power

Post by jays_86 »

I have a 152 . When it is full fuel and 2 passengers, it's takes almost full power to keep it in cruise. Is this normal or is there a problem here?
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ahramin
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Re: Cessna 152 power

Post by ahramin »

If it takes almost full power to stay in cruise, how do you get to cruise? Slew button perhaps?

How about starting with a simple weight and balance. Using actual weights for everyone and everything in the plane, what is your takeoff weight?
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CpnCrunch
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Re: Cessna 152 power

Post by CpnCrunch »

Also, what do you mean 'almost full power'? Cruise is defined as a certain power setting. Are you saying you have to cruise at higher than 75% (or whatever) power?
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ahramin
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Re: Cessna 152 power

Post by ahramin »

I'm guessing full throttle, not full power Crunch. And probably with mixture full rich as well.
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jays_86
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Re: Cessna 152 power

Post by jays_86 »

yes that is correct
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Big Pistons Forever
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Re: Cessna 152 power

Post by Big Pistons Forever »

The first thing to check is if it makes full static RPM. If it does not you need to find out why before further flight.

I once saw an airplane with the same complaint. It turned out there was leaking plumbing to the ASI. At takeoff and landing speeds the airspeed indicator was OK but at higher speeds it significantly under read.
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fish4life
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Re: Cessna 152 power

Post by fish4life »

A lot of 152's are going to be at or over gross weight with 2 adults and full fuel. Also with in the height of summer your density altitude is a lot higher than you may even think it is and your probably running far too rich a mixture.
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jays_86
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Re: Cessna 152 power

Post by jays_86 »

could there be any problems with the engine?
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photofly
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Re: Cessna 152 power

Post by photofly »

There could; what rate of climb do you get after takeoff at maximum weight?

And when you say "to keep it in cruise" - what airspeed are you expecting to see for "cruise", that needs nearly full throttle?
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ahramin
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Re: Cessna 152 power

Post by ahramin »

Sounds more like a problem with the pilot.
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CpnCrunch
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Re: Cessna 152 power

Post by CpnCrunch »

Have a look in your POH and see what rpm it says to use for 75% power (or whatever maximum recommended cruise power is). Assuming you're at a few thousand feet you should definitely be able to bring the throttle back a fair bit to achieve that rpm. If not, either your engine is knackered or you're way over gross (or possibly your rpm gauge is reading low).
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Shiny Side Up
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Re: Cessna 152 power

Post by Shiny Side Up »

ahramin wrote:Sounds more like a problem with the pilot.
That would be my guess.

What altitude are you cruising at? How do you lean the mixture? What's the weight of your fuel and people? Check the easy answers first before taking the engine apart.

Guy I've know for 15 years, told me he leaned the mixture on his airplane for the first time ever. He was apparently amazed at how much better fuel consumption it got. Said he thought about it when someone forwarded him an email about leaning....

15+ years of full rich, everywhere...
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CpnCrunch
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Re: Cessna 152 power

Post by CpnCrunch »

Shiny Side Up wrote:
ahramin wrote:Sounds more like a problem with the pilot.
That would be my guess.
Or the instructor :)
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Chris M
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Re: Cessna 152 power

Post by Chris M »

jays_86 wrote:could there be any problems with the engine?
See above:
Big Pistons Forever wrote:The first thing to check is if it makes full static RPM. If it does not you need to find out why before further flight.
An engine's ability to make rated power is part of it's airworthiness. Perform a full power static run up either on your own or with maintenance and see if the engine is making it's rated power. If not, you're grounded.
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PilotDAR
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Re: Cessna 152 power

Post by PilotDAR »

Just for reference, the Type Certificate Data Sheet says this:

"Static rpm at full throttle (carburetor heat off and mixture
leaned to maximum r.p.m.) is 2280 to 2380 r.p.m. For
allowable variations in static r.p.m. at non-standard
temperatures, refer to the Service Manual."

Make sure your tachometer is accurate, and do the test (not over gravel or loose ground, for the sake of your prop). It is possible for any engine to get "tired" (generally low compression), and this will turn it up most easily, and with certainty.

There are a few rigging adjustments, which could be out, and combining to increase drag. Has anyone installed a trim tab on a aileron? The need for one is a bad sign for your rigging.

Other than that, do your weight and balance. Aft C of G will fly a smidge faster. Climb rates and speeds you see will be with wheel pants installed. It could be a combination of many things, each having a small effect.
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skymarc
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Re: Cessna 152 power

Post by skymarc »

Normal, its a C152. :lol:

Why full fuel and 2 passengers?
There is only 2 seats and you should not ride 3 in a 2 seater?

:rolleyes:
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slam525i
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Re: Cessna 152 power

Post by slam525i »

skymarc wrote:There is only 2 seats and you should not ride 3 in a 2 seater?
It's possible that he has the incredibly rare rear bench child seat. (Max 120 pounds seat hardware + child I think... it's been a while)

Unlikely, but possible. :lol:
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PilotDAR
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Re: Cessna 152 power

Post by PilotDAR »

I used to carry my wife, and two kids in the back of my 150 regularly, when they were small. Full fuel was not always possible, but with three people aboard, there'll be little interest in a many hours long flight anyway! It's wise to do the W&B, to make sure you have it right.

After the kids grew up, it became my wife, two bikes, a tiny amount of baggage, and full fuel, then we were at gross. I took less than fuel fuel, and life jackets to fly across to the Bahamas once, and we biked around for a few days. You can't throw whatever you want into a 150/152, but carefully loaded, they are capable aircraft.

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