thrust required to move cessna 172 from rest...

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dtvonly

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dtvonly
Just curious. Imagine...I am sitting in a cessna 172 at rest on asphalt. How much (minimum) thrust power is required for the plane to start moving?
I know that thrust force is 90 degrees to weight force (say 2500 pound gross weight). Furthermore, thrust force must overcome static friction force.
From google, the maximum thrust for cessna 172 is around 230kg (230x2.2=506 pounds). Does this means that the "static friction" force of the cessna at rest is less than 230kg (506 pounds)?

I don't need all the physics equation. If possible, just quick simple numerical answer. Thank you.
 
dtvonly said:
Does this means that the "static friction" force of the cessna at rest is less than 230kg (506 pounds)?
Click to expand...

I think the answer to this is quite obvious, as most pilots are not world-class powerlifters and yet often move 172's around with a tow bar.
 
Depends on the tire pressure.
Moving a 172 by hand with half flat tires - good luck.
The rolling resistance of the tires is the big factor in how much poop you need.
 
dtvonly said:
From google, the maximum thrust for cessna 172 is around 230kg (230x2.2=506 pounds). Does this means that the "static friction" force of the cessna at rest is less than 230kg (506 pounds)?
Click to expand...
A 172 can move under it's own power, so the force required to move one must be less than the total thrust available.
 
If you want an easy WAG answer, then grab a fish scale, hook it to your tow bar, and then see how much you pull before it moves. This is applied science.


If you want an accurate answer, then your input data is seriously lacking.
Surface type? Friction coefficient?
Tire size? Tire inflation? = footprint?
Weight of aircraft? (Type is irrelevant)
Friction coefficient of wheel bearings?
This is physics.


I’m an applied science type of guy.

In my applied science, I know that if I hook a tow bar to a 172 or a Cherokee 140 and lean back with my fat a$$ 225 pounds, the airplane moves…so less than 225 lbs. of force (lbf).
 
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dtvonly said:
... From google, the maximum thrust for cessna 172 is around 230kg (230x2.2=506 pounds). Does this means that the "static friction" force of the cessna at rest is less than 230kg (506 pounds)?
Click to expand...
Yes. The 506 lbs. figure for max static thrust sounds in the right ballpark. But it will depend on the engine horsepower and prop size & pitch.

It's quoted as static thrust because power is thrust * speed, so static thrust is the highest -- theoretically. Yet not actually due to fixed pitch prop, varying RPM, and prop efficiency.

I push mine around all the time, and guess it's about 50 lbs. or force, more or less depending on conditions.
 
A lot of non-aviation people honestly seem surprised to watch you move an airplane around single handed. Most of us would not attempt to move a car by hand in the same fashion.
 
My airplane sitting on the ramp weighs about 1500-1600 lbs, about half what a typical small-medium car weighs. It's much easier to push around than my car.

That said, if I'm only moving my car a short distance, like out of the garage onto the driveway, I push it without starting the engine. One of the advantages of stick shift.
 
MRC01 said:
That said, if I'm only moving my car a short distance, like out of the garage onto the driveway, I push it without starting the engine. One of the advantages of stick shift.
Click to expand...
I do the same, but it doesn't have to be a stick. Neutral on an automatic works just fine.
 
Some modern automatics (like my wife's Subaru) won't shift out of park unless the engine is running.
 
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