Aircraft Structures 1 - Introduction to Design

These flashcards cover the fundamental concepts of aircraft structural design, including classification methods, certification categories, structural stresses, major components, stability axes, and standard maintenance chapters.

Aircraft

A vehicle capable of flight by obtaining support from the air, operating within the atmosphere.

Aerostat

The technical classification for lighter-than-air aircraft, such as hot air balloons and airships, which are kept aloft by gases lighter than air.

Aerodyne

The technical classification for heavier-than-air aircraft that rely on aerodynamic lift and powered lift to remain airborne.

Aircraft Category (Certification)

A broad designation grouping aircraft by their key characteristics, intended use, and operating limitations.

Aircraft Class (Certification)

A grouping within a category of aircraft that share similar operating, propulsion, in-flight handling, or landing characteristics.

Powered Lift

An airmen certification category for aircraft capable of vertical takeoff and landing that uses engine thrust or non-rotating airfoils for horizontal flight.

Standard Airworthiness: Acrobatic

A category for aircraft with minimal flight maneuvering restrictions, limited to nine seats and a maximum weight of $12,500\,pounds$.

Standard Airworthiness: Commuter

Multi-engine, propeller-driven aircraft that can seat up to 19 passengers with a maximum weight below $19,000\,pounds$.

Standard Airworthiness: Transport

Aircraft categorized by engine type; jet engines require over 10 seats or weights over $12,500\,pounds$, while piston engines allow up to 19 people over $19,000\,pounds$.

Provisional Category

A temporary aircraft certification valid for 24 months (Class I) or 12 months (Class II).

Aircraft Approach Category

A classification determined by the Maximum Takeoff Weight (MTOW) that dictates the required approach speed $V_{REF}$ during landing.

Category A Approach Speed

An approach category for aircraft with an indicated airspeed of less than $91\,knots$.

Category E Approach Speed

An approach category for aircraft with an indicated airspeed of $166\,knots$ or more, but less than $211\,knots$.

Tension

A tensile stress that stretches and elongates material due to outward pulling forces acting in opposite directions.

Compression

A stress that squeezes, crushes, or shortens material due to inward pushing forces acting in opposite directions.

Torsion

A twisting stress caused by torque when a structural member is turned around its longitudinal axis.

Shear

A stress caused by forces acting parallel to the surface, resulting in internal layers sliding past one another.

Bending

An internal stress developing when an external load creates a moment, causing tension on one side and compression on the other.

Truss Type Fuselage

A rigid framework of beams, struts, and bars, typically covered in fabric, designed to resist deformation.

Monocoque

A 'single shell' construction that uses bulkheads and frames for shape but relies primarily on the skin to carry loads.

Semi-monocoque

A modification of monocoque construction where the skin is reinforced by longitudinal members like stringers and longerons.

Longeron

The principal longitudinal member in a semi-monocoque fuselage that helps the skin support primary bending loads.

Spar

The principal spanwise structural member of a wing that carries aerodynamic loads from the ribs to the fuselage.

Rib

A chordwise member shaped like an airfoil that provides form to the wing and transfers loads from the skin to the spar.

Full Cantilever Wing

A wing design that is supported internally and requires no external bracing like wires or struts.

Longitudinal Axis

The axis running from the nose to the tail of the aircraft; rotation around this axis is known as roll and is controlled by ailerons.

Lateral Axis

The axis running wingtip to wingtip; rotation around this axis is known as pitch and is controlled by elevators.

Vertical Axis

The axis passing through the center of gravity; rotation around this axis is known as yaw and is controlled by the rudder.

Ruddervator

A control surface found on V-tail aircraft that combines the functions of the rudder and the elevator.

Trim Tab

A secondary control surface that moves opposite to the primary surface to statically balance the aircraft for 'hands-off' flight.

Empennage

The tail assembly of the aircraft, which includes fixed stabilizers and movable control surfaces for stability.

Ground Loop

A terminology for the sudden, uncontrolled rotation of a taildragger aircraft on the ground during takeoff or landing.

Firewall

A fireproof partition, usually made of stainless steel, between the engine and the cockpit to protect occupants.

Nacelle

An aerodynamic housing that holds an aircraft engine away from the fuselage.

Cowling

The specific removable or opening skin panel of a nacelle that allows manual access to the engine.

ATA Chapter 32

The standard IATA chapter designation for the Landing Gear system.

Major Zone 100

The aircraft zoning identification for the lower half of the fuselage.

Major Zone 400

The aircraft zoning identification for Powerplants, including struts and pylons.