Early Airline History and Airmail Service

The path an aircraft travels over the ground.

Specialized maps used by pilots for aerial navigation.

Aeronautical charts used for Visual Flight Rules (VFR) navigation, covering smaller areas in detail.

Aeronautical charts used for Instrument Flight Rules (IFR) navigation, covering larger areas with less detail.

Information displayed on sectional charts, including cities, highways, railroads, airports, terrain features, and distinctive objects.

Navigation aids, federal airways, and air traffic control facilities depicted on sectional charts.

Scale of sectional charts, representing 8 statute miles per inch.

Scale of World Aeronautical Charts (WACs), representing 16 statute miles per inch.

A method of navigation where pilots use forecasted wind conditions and trigonometry to calculate the heading needed to counteract crosswinds.

A visual reference used in flight planning that shows the direct line from the departure airport to the destination.

The angle between the aircraft's heading and the true course, necessary to compensate for crosswinds.

An instrument that indicates the aircraft's magnetic heading. It doesn't point to true north, but magnetic north.

The process of using dead reckoning and pilotage to plan a flight. It involves determining the true course, accounting for wind, and calculating the aircraft's heading.

Using visual landmarks and navigation tools to determine an aircraft's position.

The difference between true north and magnetic north, which affects compass readings.

The chosen height at which an aircraft will fly. This is important as wind conditions change with altitude.

The first scheduled airline service in the US, launched in 1914 between St. Petersburg and Tampa, Florida, which lasted for three months.

After World War I, the US government sold surplus military aircraft to private individuals, triggering the aviation industry's growth.

The availability of inexpensive surplus aircraft initially fueled the growth of airlines after WWI, but their high operating costs and maintenance led to high passenger ticket prices.

Established in 1918, the US Post Office Department initiated the nation's first official airmail service using U.S. Army aircraft.

The US Post Office Department's airmail service quickly became profitable, leading to expanded routes and the use of dedicated aircraft and pilots by 1918.

In an effort to stabilize the struggling airline industry, the US Post Office Department contracted airmail routes to existing airlines, enabling them to offer passenger flights and reduce ticket prices.

The airmail contracts awarded to airlines provided a financial lifeline, allowing them to reduce passenger fares and attract more customers.

The availability of inexpensive surplus aircraft and the introduction of airmail services played crucial roles in the development of the aviation industry in the United States.

The US Post Office provided a crucial role in jumpstarting the commercial aviation industry in the early 20th century.

A mechanical failure of the heading indicator that prevents it from accurately displaying the aircraft's heading, even when properly set.

A gradual drift in the heading indicator's reading, caused by friction and gyroscopic forces. It needs regular adjustment to ensure accuracy.

En route checkpoints used in VFR navigation to verify the aircraft's position and ensure it's on course.

The magnetic compass will not show the correct heading during acceleration or turning, leading to inaccuracies in the indicated direction.

A gyroscopic instrument used to display the aircraft's magnetic heading, unaffected by acceleration or turning, unlike the magnetic compass.

The heading indicator is susceptible to internal friction, causing its indicated heading to drift slowly over time.

The pilot needs to periodically adjust the heading indicator to account for its inherent drift, ensuring an accurate display of the aircraft's magnetic heading.

Objects that contain metal or are magnetized, such as flashlights or tools, can interfere with the magnetic compass, causing inaccuracies in the indicated heading.

The magnetic compass provides the most accurate reading when the aircraft is in a stable, non-accelerated flight condition.

A gyroscopic instrument's main function is to maintain a stable and accurate heading despite external forces like turning or acceleration.

The heading indicator is not affected by magnetic fields, unlike a magnetic compass, which is impacted by nearby magnets or metal objects.

Orange-colored cone used to make airport landing lights visible during daylight hours.

Rotating beacon lights used to guide pilots along airways at night, installed at regular intervals along the airway.

The rotating beacons on airways had a colored lens that identified each beacon and enabled pilots to determine their position along the airway.

Airports have a rotating beacon with a clear lens and a green lens to help pilots identify their location.

The rotating beacons were equipped with 1,000-watt electric lamps that produced a bright white light of 1,000,000 candlepower, which could be seen from a distance of over 40 miles.

The rotating beacons helped pilots navigate along the airway by flying from one beacon to the next.

Rotating beacon lights with clear and green lenses are still used at civilian airports today.

Different color combinations are used to differentiate between different types of airports.