Forces of Flight

Making Flight Possible

What FOUR Forces are acting on Aircraft?

What is the role of Newton’s 2nd Law of Motion (f=ma)?

Aircraft and Equilibrium

Four Forces in Flight

Lift - verse - Weight Lift is the Key to flight. If you can overcome weight

you can FLY. To do this, wings are made with a CURVED upper

surface and a FLAT lower surface.

Air now flows faster over the Top and the Bottom This creates a difference in pressure (Top-More &

Bottom–Less) thus Lift is created (Net Force-UP)

What is Weight ?

The effect of the force of GRAVITY on an object pulling it towards the center of the Earth. Aircraft have a center point of this pull called the “Center of Gravity”. In flight, it rotates around this point. Aircraft’s weight can be great. It is the combination of all the mass (parts, fuel, payload) distributed throughout the airplane.

Thrust – verse - DragTo create LIFT force air has to flow over the wing. To get air moving over the wing, one needs to create – THRUSTThrust is the FORCE that is generated (airplane’s engine)Thrust is aligned with the direction of flight and opposite the direction of the airflow over the wing.

NO THRUST – NO FORCE - NO LIFT

What is Drag?

Air resists the movement of the aircraft.As the aircraft flies through the air, it causes air molecules to separate in front of it's path. This occurs along the wing and bodyDrag will slow the forward motion of the aircraft thus requiring more thrust.

Newton & Flight (F=MA)This is what makes Airplanes

Fly This equation tells us that an aircraft subject

to an external force will accelerate (velocity) and that acceleration (velocity) is related to the mass.

The heavier the aircraft the more the velocity to fly. The change is velocity generated the Force to fly … creates lift

What’s Equilibrium & Flight?

Two types of StabilityStatic: No Movement & Dynamic:

MovementFlight Equilibrium

Equilibrium Flight: Lift = Weight and Thrust = Drag

NET Force Equals ZEROAircraft continues to either sit on the

ground or fly (Newton’s 1st Law) Change in NET Force and you …..

Put it all Together

The Wright Brother’s got it WRIGHT (right)

Mr. Heck Flying the Wright B Aircraft Video

References• http://www1.nasa.gov/audience/foreducators/k-4/features/F_Four_Forces_of_

Flight.html

• http://www.bing.com/videos/search?q=NASA+Forces+of+Flight&FORM=VDRE&qpvt=NASA+Forces+of+Flight#

• http://www.grc.nasa.gov/WWW/K-12/airplane/forces.html

• http://www.ueet.nasa.gov/StudentSite/dynamicsofflight.html

• http://www.grc.nasa.gov/WWW/K-12/airplane/short.html

• http://quest.nasa.gov/aero/planetary/atmospheric/forces.html