Section C Chapter 3: Aerodynamics Of Maneuvering Flight continued

Section C goes on to explain the forces that act when turning a plane. Before a plane can turn it must over come inertia. The necessary force is caused by using the ailerons. The horizontal component of lift causes the airplane to turn. The center seeking force that causes the airplane to turn is called centripetal force. Centripetal force works against inertia, this is called centrifugal force. Centrifugal force isn't really a force. Its really inertia wanting to go straight again. Another force is when you roll into a turn one wing has more lift than the other and the inside wing has more drag, this can cause an adverse yaw which has to be corrected by using the rudder. When you enter a turn the plane feels like it wants to keep rolling, pilots have to be careful not to over bank or over correct. Airplane performance is judged on rate of turn and radius of turn. Rate of turn is the amount of time it takes for the plane to turn a certain amount of degrees. The amount of horizontal distance a airplane uses to complete a turn is the radius of turn.

Load factor is the ratio of the load supported by the airplanes wings to the wait of the plane. In turning a airplane you have to know your load factor or you can loose altitude. Load factor is also important because if not correctly maintained it can cause stalls. The limit load factor is the amount of stress an airplane can stand before structural damage starts. Most small planes weighing 12,500 are certified either normal, utility, or acrobatic depending on their limit load factor, you wouldn't want to do tricks in a normal airplane because it could break up. To know what your planes load limit factor is you refer to V/g diagram, staying below the limit load factor will prevent stalls and damages to the plane.

New Dawn for electric rockets

Author: Choureiri, Edgar Y.
Source: Scientific American; February 2009

I wonder if I'll ever fly an electric propelled plane? right now electric plasma engines are only fueling space probes but, I predict, this technology will soon fuel all aircraft.

Burning chemical fuel is how rockets generate thrust. electric rockets generate thrust by applying electric our electromagnetic fields to charge particles, also called plasmas, to move them. This next point is why rockets, not airplanes are using electricity... electric rockets offer much lower thrust power than fueled rockets. Slowly they reach greater speeds, their officiant use of propellant makes them best for deep space missions.

Whether you use chemical or electric propulsion systems depends on the type of mission. Chemical rockets make lots of thrust so they get to high speeds fast but they burn a lot of fuel. Chemical rockets are good for short range trips. Electric rockets use plasma that doesn't generate much thrust, but its so efficient it can operate for a long time. As space is frictionless a small force is all that is needed. plasma rockets are best for deep space missions.

Electric rockets have been in the works since 1903 since Konstantin Tsiolkovsky when he invented the "rocket equation" which said how much fuel is needed for deep space missions. In 1999 NASA's Jet Propulsion Lab showed the first use of a ION or electric engine. I hope i get far enough down the path of being a pilot to see this technology being used.

Figuring glide ratio

Section C Chapter 3: Aerodynamics Of Maneuvering Flight

This section talks about how design effects how a plane can maneuver. When a plane goes up its called lift, pushing down on lift is weight. How fast a plane goes forward depends on its thrust, it's help back by its drag. When a plane climbs it has a tendency to turn left and a pilot has to correct for this. The propellers clockwise action causes a torque reaction which makes the airplane want to go counter clockwise. Pilots have to learn how to correct for this. Another correction pilots must make is for asymmetrical thrust which happens when an airplane is flown at a high angle. At a high angle, the ascending propeller blade grabs more air making the plane want to yaw to the left. As the propeller rotates it makes a backward flow of air called a slipstream. The slipstream also causes the plane to yaw. Some air crafts have design features that counter act the left turning tendencies and make the airplane easier to control, placement of the rudder and the engine are two of these.

How well a plane flies is measured in several ways. The lift-to-drag ratio measure how well your plane glides. Glide speed is the best speed for a plane to go to get maximum glide. Its always best to go at your best glide speed. If your engine breaks down you have a better chance to glide to a land. During a decent the path your airplane takes to the ground is called the glide angle. Many factors affect the glide; how much your plane weighs, how its configured - like are your wheels down, and wind resistance.

Section B chapter 3 Stability

Stability is when a airplane in flight can return to being steady after it has been disturbed. If a airplane has been disturbed it tends to go back to its original position. This is called positive static stability; when it doesn't go back but keeps jumping around its called positive dynamic stability. Maneuverability is how well the plane handles and withstands stress. Controllability is how good a airplane responds to your control input.

There are three axes of flights. This is how a plane will rotate. The common reference point is called the center of gravity evn though it is imaginary. Longitudinal axes is when you begin a turn and you roll around the longitudinal axis. You will continue on the longitudinal as long as the ailerons are engaged. Lateral axis is when a plane pitches and leans side to side. Vertical axis is yawing which is the rear of the plane swings lift to right.

The longitudinal stability of an airplane means how much pitching motion a plane has. Longitudinally unstable planes are dangerous to fly. When a plane is designed they have to think about balance. The pressure of the wings in relationship to the center of gravity is important. The pressure of the wings has to be forward to the center of gravity. The center of gravity is decided by how the weight of the airplane is distributed. If the CG is too forward the plane becomes nose heavy. When baggage is loaded into a airplane it has to be spread around to maintain the center of gravity.

When a Plane is properly loaded the CG is in front of the center of pressure and the airplane is a little nose heavy. The nose heaviness is off set by the horizontal stabilizer, which provides a downward force.

Lateral stability is keeping the plane from rolling. A design called dihedral is the upward angle of the airplanes wings, it's only a few degrees. Another design feature is called sweepback, where the wing is positioned at an angle instead of straight 90 degrees.

Why is stability important? One reason is so we don't have stalls. Stalls will be something we practice during our flying practice. Pilots learn when a stall is coming and how to correct it. Poor stability also leads to spins like a cork screw. pin recovery will also be something I learn in the air.

Quotes

"The knack of flying is learning how to throw yourself at the ground and miss. " by Doug Adams, Hitchhikers Guide to the Galaxy


You haven't seen a tree until you've seen its shadow from the sky. ~Amelia Earhart

The engine is the heart of an airplane, but the pilot is its soul. ~Walter Raleigh

In the space age, man will be able to go around the world in two hours - one hour for flying and one hour to get to the airport. ~Neil McElroy

The Wright Brothers created the single greatest cultural force since the invention of writing. The airplane became the first World Wide Web, bringing people, languages, ideas, and values together. ~Bill Gates

When you think about flying, it's nuts really. Here you are at about 40,000 feet, screaming along at 700 miles an hour and you're sitting there drinking Diet Pepsi and eating peanuts. It just doesn't make any sense. ~David Letterman

I think it is a pity to lose the romantic side of flying and simply to accept it as a common means of transport.... ~Amy Johnson

Aerodynamically the bumblebee shouldn't be able to fly, but the bumblebee doesn't know that so it goes on flying anyway. ~Mary Kay Ash

Watching Top Gun

The movie is about these two fighter pilots who have been in the same fighter jet their whole career and have a big history together. they get into a military program called Top Gun which is the highest level of flight training for fighter pilots. During this time they pass many hard test and have to be able to be better than everyone El's but near the end of the movie Tom Cruise's (Maverick) co-pilot is killed in a freak accident when they have to abort the plane because it was going to crash. Then they all graduate from Top Gun and do their first real mission after their training. The mission is a success after winning a "dog fight" 3 against 6 or 8 enemy planes. in the end I learned that this is a very rewarding career but you can suffer major losses in it, including losing your own life. But to me that's just part of life is to take risk and live with the consequences.