Is common air plane flight OU?

[schuler]

  Hello

I think this is the right place to post the question: is the flight of an air plane over unity? Let me explain: the power generated by most engines is not sufficient to lift an air plane. How can an air plane fly?

Follows an interesting link: http://www.allstar.fiu.edu/aero/airflylvl3.htm

If we estimate that the average vertical component of the downwash of a Cessna 172 traveling at 110 knots to be about 9 knots, then to generate the needed 2,300 lbs of lift the wing pumps a whopping 2.5 ton/sec of air! In fact, as will be discussed later, this estimate may be as much as a factor of two too low. The amount of air pumped down for a Boeing 747 to create lift for its roughly 800,000 pounds takeoff weight is incredible indeed.

This interesting thing is: a Cessna engine doesn't generate 2,300 libs of force. This is not just a force multiplier because 2.5 ton/sec of air is pumped per second. It seems to be energy multiplier (over unity).

Please share your point of view.

Have fun.

[schuler]

Hi Gianna,

If we estimate that the average vertical component of the downwash of a Cessna 172 traveling at 110 knots to be about 9 knots, then to generate the needed 2,300 lbs of lift the wing pumps a whopping 2.5 ton/sec of air!

Please explain from where the energy to pump 2.5 ton/sec is coming from. Some technical specs can be found here: http://en.wikipedia.org/wiki/Cessna_172 .

In your reply, I would recommend avoiding statements such as "I have faith that wings can do the magic". Please concentrate the reply in terms of energy. It is known fact 210hp can't lift 2,300 libs.

Have fun 

[schuler]

Follows interesting links:
http://www.grc.nasa.gov/WWW/k-12/airplane/thrust1.html

http://www.av8n.com/how/htm/4forces.html

   
• Lift is the component of aerodynamic force perpendicular to the relative wind.
• Drag is the component of aerodynamic force parallel to the relative wind.
• Weight is the force directed downward from the center of mass of the airplane towards the center of the earth. It is proportional to the mass of the airplane times the strength of the gravitational field.
• Thrust is the force produced by the engine. It is directed forward along the axis of the engine.

In most civilian airplanes (if not all), thrust is smaller than weight.

Follows interesting link about
Thrust-to-weight ratiohttp://en.wikipedia.org/wiki/Thrust-to-weight_ratio
Have Fun  [/li]
[/list]

[tagor]

It is known fact 210hp can't lift 2,300 libs.

Have fun 

LOL
you are very funy

in french
des objets plus lourd que l'air ne peuvent pas voler

[L4ZEP]

L4ZEP:
Common air flight isn't OU, because the energy is after the landing of the airplane exhausted and gone as a warm packet of air.