Lecture 15 - Parts of Airplane

Summary

The lecture introduces the main components of an airplane, distinguishes the airframe from the aircraft as a whole, and explains the major parts of a conventional airframe.

Primary Components of an Airplane

The instructor groups an airplane’s components into five broad categories:

• Airframe: The airplane’s structural assembly, including its main body, lifting surfaces, tail, and landing gear. The airframe supports or houses other components, but it is only one part of the airplane—not a synonym for the entire aircraft.
• Engine: The propulsion component that produces thrust to overcome drag. Engines may be mounted on the wings or, in some designs, toward the rear of the aircraft.
• Avionics: The aircraft’s electronics. Avionics collect information from sensors, help control and stabilize the airplane, guide it along its intended trajectory, and may record sensor data.
• Payload: What the aircraft is built to carry, such as passengers, goods, surveillance equipment, cameras, or—on military aircraft—weaponry.
• Additional support systems: Systems and equipment that help the aircraft operate or serve its occupants. Examples include actuators, hydraulics, cabin pressurization, air conditioning, seats, and screens.

These categories work together and are all important. An aircraft’s appearance can also reflect its purpose: military aircraft may use subdued colors to be less conspicuous, while transport aircraft may use bright colors and logos.

Cabin Pressurization

As altitude increases, air pressure and density decrease. This reduces the oxygen available and can cause discomfort. The lecture says cabin pressurization is required above 10,000 feet, citing the FAA and other regulators.

Rather than maintaining sea-level pressure—which would create a larger pressure difference between the cabin and the outside air—the cabin is typically kept at a pressure comparable to an altitude of about 6,000–8,000 feet. This balances passenger comfort with the structural demands created by the pressure differential.

Major Parts of the Airframe

• Wings: The primary lifting surfaces, which generate lift to balance the airplane’s weight.
  • The root is the part of the wing attached to the fuselage; the tip is its outer end.
  • Span is the distance from one wingtip to the other.
  • The lecture also refers to the wing’s chord and airfoil-shaped cross-section.
  • Some wings contain fuel, a configuration called a wet wing. Fuel may also be carried in the fuselage.
• Fuselage: The central body that connects the airplane’s major structures. It can carry passengers or other payloads, avionics, and sometimes fuel. The front of the fuselage is the nose. The pilot and co-pilot sit near this end so they can see ahead.
• Horizontal tail and vertical tail: Surfaces at the rear of the airplane that help stabilize it. Smaller portions also help control its motion. Together, the tails are called the empennage.
• Landing gear: The wheels or other landing equipment used during takeoff and landing. It is generally retracted during level flight.

The instructor describes the wing, horizontal tail, and vertical tail as lifting surfaces, while noting that the tails also contribute to stability and control.

Design Implications

The airframe components students will need to design later in the program are the wings, fuselage, horizontal tail, vertical tail, and landing gear. The lecture connects this work to later subjects:

• Aerodynamics covers aerodynamic shapes and performance.
• Aircraft structures covers structural design, material selection, and analysis to ensure components can withstand loads.

The instructor notes that fuselage design may be simpler for some unmanned aircraft, particularly when cabin pressurization is not needed.

Speakers and Sources

The speaker is an unnamed instructor or lecturer. The FAA and other regulators are mentioned in connection with the stated cabin-pressurization requirement. No other speakers are identified.