Whats up lately with Cessna 152s

[gfvalvo]

Horsepower sells aircraft, but it's torque that makes it go.

At the risk of restarting and old feud, Thrust makes an airplane go. You get Thrust by coupling engine Power to the air via a propeller. Props can only do this efficiently over a relatively small range of low RPM’s. Power is proportional to the product of Thrust and RPM. Low RPM and high Power means you need high Torque.

 

[spudskier]

seriously, if you want a small aircraft, don't care about going much faster than a 152 or 172... go with an Aviat Husky http://www.aviataircraft.com/aircraft/husky.htm

Or I hear thay're starting to make new Super Cubs! The essence of flying, either one will get in and out of anywhere, and the Husky has a beefy engine (O-360 180hp constant speed) 830lbs useful load, 120kt cruise, 7.7gph and a 50(usable)gallon tank

 

[Jeff0500]

Jeff,

The Cessna 152 hasn't seen any innovations in the last ten years largely because production ceased...the aircraft aren't being built, and there was never anything wrong with the aircraft to begin with.

I wasnt taking myself seriously last nite. Thanks for taking the time to reply thgough!

 

[avbug]

At the risk of restarting and old feud, Thrust makes an airplane go. You get Thrust by coupling engine Power to the air via a propeller. Props can only do this efficiently over a relatively small range of low RPM’s. Power is proportional to the product of Thrust and RPM. Low RPM and high Power means you need high Torque.

You missed the point. Double the size of the engine turning that fixed pitch propeller at a given RPM, and the thrust produced by that prop doesn't increase, nor does the airplane go faster. Horsepower impresses the layman. Torque imparted to the propeller is a bigger concern, but nobody is impressed with torque. Hence, the salesman speaks in terms of horsepower. The customer believes that increasing horsepower makes a faster airplane, and is better.

The saying "horsepower sells airplanes, but torque makes them go," is a very old one.

A bigger engine with more horsepower has the potential to apply more torque to the prop, but in level flight when one is using a fixed pitch propeller at a given RPM, this is entirely meaningless. Excess power means more climb, but no more speed.

 

[Yankee Boy]

Time to look at the new generation of airplanes! Go to www.tecnamaircraft.com and look at light sport. The value of the Tecnam is that it can be flown without a medical, modern rotax engine with electronic ignition systems, and can be IFR certified! Why look at 50 year old technology when you can fly faster, and cheaper using auto fuel.

 

[Avenger29]

Let us not forget that most of the 150/152s have been bouncing off of runways for decades with inexperienced student pilots at the controls. The 152 is a trainer, and not good for much more. It is not viable to upgrade it. Spend the money on something else.

 

[Jeff0500]

Thanks everyone! Im going to find back issues of AOPA and Flying, for the last 8 years and become a more informed pilot.

 

[NW_Pilot]

What about a field approval for an electronic Constant Speed Prop? I think that would benefit the 150 the most.

 

[erj-145mech]

What about a field approval for an electronic Constant Speed Prop? I think that would benefit the 150 the most.

First, you're going to have to design and build one, it doesn't exist yet. It would have to be FAA Approved in order to field approve the installation anyway. Whats going to happen when you throw that much extra weight up front? A 150 doesn't have much in the way of un-used pounds hanging around.

 

[NW_Pilot]

First, you're going to have to design and build one, it doesn't exist yet. It would have to be FAA Approved in order to field approve the installation anyway. Whats going to happen when you throw that much extra weight up front? A 150 doesn't have much in the way of un-used pounds hanging around.

You may want to look here close enough http://mt-propeller.com/en/electrvp.htm

http://mt-propeller.com/pdf/datsheet/mtv-1.pdf
&
http://mt-propeller.com/pdf/datsheet/mtv-7.pdf

Non TSO & faa approved items can be installed under field approval from the faa yea its hard to get but as in all thing aviation if you know the right people? If I had $10k to blow on my 150 I would say why the hell not? Wouldn’t one look cool with a 3 blade composite variable pitch prop?

 

[gfvalvo]

You missed the point.

Sorry.

Double the size of the engine turning that fixed pitch propeller at a given RPM, and the thrust produced by that prop doesn't increase, nor does the airplane go faster.

Yup. With a fixed pitch at a given RPM you'll require the same torque (and thus same power) to turn the prop. That engine may be able to produce 200HP, but with the same prop at 2350 RPM it's only making 100 HP. It's just working at 50% of rated power instead of 95%.

Horsepower impresses the layman. Torque imparted to the propeller is a bigger concern, but nobody is impressed with torque. Hence, the salesman speaks in terms of horsepower. The customer believes that increasing horsepower makes a faster airplane, and is better.

The saying "horsepower sells airplanes, but torque makes them go," is a very old one.

A bigger engine with more horsepower has the potential to apply more torque to the prop, but in level flight when one is using a fixed pitch propeller at a given RPM, this is entirely meaningless. Excess power means more climb, but no more speed.

To expand on you point ... Even if more HP translated directly to more speed, physics says it takes A LOT more power to make an airplane go A LITTTLE bit faster!

 

[erj-145mech]

Non TSO & faa approved items can be installed under field approval from the faa yea its hard to get but as in all thing aviation if you know the right people? If I had $10k to blow on my 150 I would say why the hell not? Wouldn’t one look cool with a 3 blade composite variable pitch prop?

Thats the theory, this is real world. I deal with the Federales on a weekly basis, and unless you have cold hard engineering data, they will not even give the impression of going out on a limb. Ten grand is not a drop in the bucket as far as the costs would go on this venture.

But, don't listen to any professionals that have voiced an expert opinion, you just grab your check book and go to town. I'm going to wait to read about your venture in the trade journals. When you get it accomplished, I'll be the first to congratulate you.