Materials:
Directions:
***Based on what you have observed, make the plane that you think will fly the
longest.***
*** Challenge: Create an airplane that will fly in a curved path****
Questions:
Why does my paper airplane not look like a real airplane?
Most full size planes have wings, a tail, and a fuselage (body) that holds the pilot and
passengers. Most paper airplanes have just a wing and fold of paper on the bottom that you hold
when you throw the plane. The main reason why paper airplanes look different than real planes
is to allow the paper airplane constructor to make a plane as easily and quickly as possible.
The simplest airplane is the flying wing, and that's what most paper airplanes are. Also, many
features of a real airplane permit functions that a paper airplane simply doesn’t need. For
example, the flaps, which are the control surfaces on the edge of the wing, allow the plane to
take off and land slower. With a paper airplane, these functions are obviously not needed!
How does plane weight affect flight?
The simple answer is weight forward is good. In every object there is a center of gravity – a
neutral point where all of the mass is balanced. If an airplane has a center of gravity ahead
of the neutral point, then this plane is stable. If this center of gravity is behind the neutral
point then it becomes unstable causing nose-dives and spins.
What really is stability?
Stability means that the plane, if disturbed, will return to its original state. A stable
airplane tends to oscillate up and down a few times, but converge on a steady flight. Many
typical paper airplane designs are stable, but just barely. A plane that is unstable will
either pitch up into a stall, or nose-dive, but won’t settle out anywhere in-between.
As a plane becomes more and more stable, it wants to fly faster and faster. To counter this
tendency, up elevator must be used to produce a good trim airspeed. This is why many of the
classic paper airplane designs are nearly neutrally stable. Few people realize good pitch
stability requires a heavy nose and some up elevator. The classic designs rely on the small
inherent "up elevator" effect (positive zero lift pitching moment) resulting from the swept
wing, and possibly the airfoil shape. Thus many classic paper airplanes can be flown with no
elevator adjustment. Sometimes they fly well, many times they don't, and they always have poor
stability.
What is the importance of winglets?
The Fuselage acts like the vertical stabilizer of real airplanes. Sometimes bending the wingtips
up on paper airplanes also helps to add directional stability. The combination of the fuselage
and wingtips on paper airplanes allows them to have positive directional stability. This
stability is provided in real airplanes by a vertical tail.
Does material matter?
Paper airplanes usually have short "stubby" wings, called "low aspect ratio" wings. The distance
from wing tip to wing tip is called wing span, and the distance from the front to the back of
the wing is called the chord. The ratio of wing span to average chord is called "aspect ratio",
and is an important characteristic of wings. Paper is a lousy building material. There is a
reason why real airplanes are not made of paper. Although high aspect ratio wings reduce drag,
they also require better building materials. The low strength of paper does not allow the use
of high aspect ratio wings. With a thicker material or paper, it is easier to make planes with
high aspect ratio wings.
For more information on airplanes, real and paper, check out: