PHYSICS OF FLIGHT - UNIT 1

What is International System of Units? What are the U.S.’s?

The S.I. is the modern metric system. The U.S. uses imperial units.

Atmospheric Pressure

Standard atmosphere (atm)

What is the atmospheric pressure at sea level?

1 atm

Bernoulli’s Equation =

Static + Dynamic = Total Pressure

What kind of fluid does Bernoulli’s Equation only work for?

Incompressible fluids

Static Pressure

The amount of resistance to air flow in a system

Dynamic Pressure

The kenetic energy of moving fluid per unit volume

What do compressible fluids do?

change density significantly under pressure

What do incompressible fluids do?

maintains a near constant density

When is air compressible?

compressbility is significant when Mach = 0.3 (100m/s)

How many basic flight instruments are in a plane?

6

What does Pitot-Static mean?

Instruments that are Pitot-Static are pressure sensitive sensors.

What does Gyroscopic mean?

A gyroscope is a device used for measuring/maintaining angular velocity. Instruments that use a gyroscope to ooperate are gyroscopic.

Airspeed Indicator (Pitot-Static)

Aircraft’s reactive speed to surronding air

Additude Indicator (Gyroscopic)

shows aircraft’s relation to horizon

Altimeter (Pitot-Static)

shows aircraft’s altitude above sea-level

Turn and slip coordinator (Gyroscopic)

indicates rotation about the longituinal axis

Heading Indicator (Gyroscopic)

displays the aircraft’s heading in compass points

Vertical Speed Indicator (Pitot-Static)

aka variometer, measures the rate of climb or descent (m/s, ft/m, knots)

Absolute Altitude

Vertical distance above ground (AGL: “Drop a tape measure”)

True Altitude

Vertical distance above average sea level

Pressure Altitudes

The height of an aircraft above U.S. standard (datum) plane (18,000ft)

Density Altitude

Air density expressed as a height above sea level (non-standard conditions)

Flight Level

NOT height above the ground, but the aircraft’s vertical position based on constant atmospheric pressure

What is a nautical mile equivalent to in miles?

1.151 mi

(CAS) Calibrated Air Speed

Airspeed corrected for errors

(TAS) True Air Speed

CAS corrected for environment (altitude, non-standard temps)

(GS) Ground Speed

Actual Speed over ground (Adjusted for wind!)

What is a scalar?

A magnitude without a direction associated with it (time, energy, speed, temp.)

What is a Vector? (oh yeah!)

a magnitude with a direction (velocity, accel., weight)

G-Force (misnomer!)

Acceleration over gravity

Why is G-Force a misnomer?

It measures accelration, not an actual physical force; it’s not even caused by gravity

The Fathers of Aviation

Sir George Cayley, Otto Lillenthal, Wright Brothers

Who was Sir George Cayley?

1st aeronautical engineer, developed the modern airplane, 4 principles of flight, developed gliders

What are Sir George Cayley’s 4 principles of flight?

Thrust, Lift, Drag, Weight

Which two principles are aerodynamic forces?

Lift, Drag

Who was Otto Lilienthal?

First person to successfully replicate/complete glider tests (heavier-than-air flight)

Who were the Wright Brothers?

The first people to ever conduct the first controlled, sustained, powered heavier-than- air flight

What were their key reasons for success?

They built wind tunnels for airfoils, used force balance to measure lift, stability, internal combustion engines made power!