Aviation - Wikiparency

# Aviation **Aviation** is the design, production, operation and use of [[Aircraft|aircraft]] — machines that achieve [[Flight|flight]] through the [[Buoyancy|buoyancy]] of an [[Aerostat|aerostat]] or the aerodynamic lift of a [[Fixed-wing_aircraft|fixed]] or rotary wing such as the [[Helicopter|helicopter]]. It runs from the lighter-than-air [[Balloon_(aeronautics)|balloon]] and [[Airship|airship]] to heavier-than-air flight pioneered by [[George_Cayley|George Cayley]], [[Otto_Lilienthal|Otto Lilienthal]] and the [[Wright_brothers|Wright brothers]], transformed by the [[Jet_engine|jet engine]] into the modern [[Airliner|airliner]], and it divides into [[General_aviation|general]], [[Commercial_aviation|commercial]] and [[Military_aircraft|military]] aviation coordinated through [[Air_traffic_control|air traffic control]]. This page is the Aviation hub of Wikitube: the pair's skeleton, section by section, with one microsim per section that puts the governing equation under the reader's hand. A [[Glider_(aircraft)|glider]] on a polar shows why lift-to-drag is the whole story of unpowered flight; an [[Airfoil|airfoil]] shows where the lift comes from; the [[Turbofan|turbofan]] shows why moving more air more slowly is cheaper; the [[Range_(aeronautics)|Breguet equation]] draws the payload–range diagram of an airliner; and the [[Aviation_accidents_and_incidents|Swiss-cheese model]] turns air safety into arithmetic. Each section names its main article, what to move in the sim, and which other sections it connects to. The sister hub [[Avionics]] carries the electronics that fly the same aircraft; six sections (weight and balance, wind shear, terrain awareness, air traffic control, surveillance and fly-by-wire) are shared between the two pages and built once. ## Links (Wikipedia order)  `Abbas_ibn_Firnas` · `ACAC_consortium` · `Ader_Avion_III` · `Ader_Éole` · `Aerial_photography` · `Aerial_reconnaissance` · `Aero_Engine_Corporation_of_China` · `Aeronautics` · `Aerosol` · `Aerostat` · `Air_charter` · `Air_traffic_control` · `Air_traffic_controller` · `Air_traffic_management` · `Airbus` · `Aircraft` · `Aircraft_flight_dynamics` · `Airliner` · `Airplane` · `Airship` · `Alberto_Santos-Dumont` · `Antonov` · `Archytas` · `Aviation_biofuel` · `Aviation_gasoline` · `Avionics` · `Balloon_(aeronautics)` · `Bartholomeu_Lourenço_de_Gusmão` · `Beechcraft` · `Berlin` · `Boeing` · `Boeing_707` · `Bombardier_Aerospace` · `Bomber` · `Brazil` · `Buoyancy` · `C-130_Hercules` · `C-17_Globemaster_III` · `Canada` · `Canada–United_States_relations` · `Carbon_dioxide` · `Cargo_aircraft` · `Cessna` · `Charles_Furnas` · `Charles_Kingsford_Smith` · `Charles_Lindbergh` · `China` · `Cirrus_cloud` · `Climate_change_mitigation` · `Climate_crisis` · `Cloud_computing` · `Clément_Ader` · `Comac` · `Comac_ARJ21` · `Combustion` · `Commercial_aviation` · `Communication` · `Communications_satellite` · `Composite_material` · `Concorde` · `Contrail` · `Convention_on_International_Civil_Aviation` · `Cybersecurity` · `David_Schwarz_(aviation_inventor)` · `De_Havilland_Comet` · `Douglas_DC-3` · `Eilmer_of_Malmesbury` · `Electric_battery` · `Electricity` · `Embraer` · `Environmental_impact_of_aviation` · `Ethanol` · `Extended_reality` · `Facial_recognition_system` · `Father_of_aviation` · `Fighter_aircraft` · `Fixed-wing_aircraft` · `Flag_carrier` · `Flight` · `Flight_length` · `Flight_training` · `Fort_Myer` · `France` · `Free_content` · `Fuel_economy_in_aircraft` · `Gabriel_de_La_Landelle` · `Gas_turbine` · `Gasoline` · `General_aviation` · `General_Electric` · `George_Cayley` · `Giffard_dirigible` · `Glider_(aircraft)` · `Glider_(sailplane)` · `Global_Positioning_System` · `Greenhouse_gas` · `Ground_attack` · `Hang_gliding` · `Hans_von_Ohain` · `Head-up_display` · `Heavier_than_air` · `Helicopter` · `Henri_Giffard` · `Homebuilt_aircraft` · `Honeywell_International` · `Hot_air_balloon` · `Hybrid_electric_aircraft` · `Hydrogen-powered_aircraft` · `Icarus` · `Ilyushin` · `Index_of_aviation_articles` · `Instrument_flight_rules` · `International_Air_Transport_Association` · `International_Civil_Aviation_Organization` · `Jamshid` · `Japan` · `Jean-Pierre_Blanchard` · `Jet_airliner` · `Jet_engine` · `Joint_Base_Myer–Henderson_Hall` · `Kay_Kāvus` · `KLM` · `LED` · `Light_aircraft` · `Lilienthal_Normalsegelapparat` · `Long_haul` · `Low-cost_carrier` · `LZ_127_Graf_Zeppelin` · `LZ_129_Hindenburg` · `McKinsey_&_Company` · `Mil_Mi-26` · `Military_aircraft` · `Military_transport_aircraft` · `Missile` · `Mitsubishi_Electric` · `Montgolfier_brothers` · `MQ-1C_Gray_Eagle` · `MQ-9` · `Neologism` · `Nitrogen_oxide` · `Noise_pollution` · `North_America` · `Open_skies` · `Orville_Wright` · `Otto_Lilienthal` · `Ozone` · `Pan_Am` · `Parachuting` · `Paragliding` · `Patent` · `Patent_application` · `Piper_Aircraft` · `Power-to-weight_ratio` · `Powered_hang_glider` · `Private_aviation` · `Propulsion` · `R38-class_airship` · `Radar` · `Regional_airliner` · `Rigid_airship` · [[Robotics]] · `Rocket` · `Rolls-Royce_Holdings` · `RQ-4` · `RTX_Corporation` · `Russia` · `Ryanair` · `Safran` · `Scheduled_air_transport` · `Security` · `September_11_attacks` · `Severe_acute_respiratory_syndrome` · `Shah` · `Solar_energy` · `Sonic_boom` · `Soot` · `South_Korea` · `Southwest_Airlines` · `Spaceflight` · `SpaceShipOne` · `Speech_recognition` · `Strategic_bombing` · `Sukhoi` · `Supersonic_transport` · `Surveillance_aircraft` · `Sustainable_aviation_fuels` · `Synthetic_vision` · `Tactical_bombing` · `Tarentum` · `Tenerife_airport_disaster` · `Tetraethyllead` · `Thomas_Selfridge` · `Three-axis` · `Timeline_of_aviation` · `Traffic_reporting` · `Transatlantic_flight_of_Alcock_and_Brown` · [[Transistor]] · `Transport_in_the_European_Union` · `Tropopause` · `Tupolev` · `Turbojet` · `Ukraine` · `Ultralight_aviation` · `United_Aircraft_Corporation` · `United_States` · `Unmanned_aerial_vehicle` · `User_interface` · `Visual_flight_rules` · `WestJet` · `Wired_glove` · `World_Intellectual_Property_Organization` · `World_War_I` · `World_War_II` · `Wright_brothers` · `Wright_Flyer` · `Wright_Model_A` · `Yakovlev` · `Zeppelin` ## Etymology The word *aviation* was coined in French in 1863 from the Latin *avis*, "bird"; *aeronautics*, the older term, names the science of travel through the air and remains the name of the discipline ([[Aeronautics]]). In Wikitube's usage aviation is the activity and aeronautics the science behind it; the sections below follow the activity but stop at each point to show the science. ## History ### Early beginnings *Main article: [[Glider_(aircraft)]] · See also: [[George_Cayley]], [[Otto_Lilienthal]]* Heavier-than-air flight began with gliders, and the glider's whole performance is one curve: the polar of sink rate against airspeed. The tangent from the origin to the polar is the best glide, and its slope is the lift-to-drag ratio; George Cayley's 1804 model and 1853 full-size glider, Otto Lilienthal's two thousand flights of 1891–96 and a modern 15-metre sailplane sit on the same diagram at glide ratios of about 5, 6 and 45.[^marchman66][^ruijgrok212] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Glider_(aircraft).html" data-title="Glider (aircraft)"></div> *Try:* pick the Cayley preset and release from 1000 m, then the modern sailplane: the polar flattens, the tangent point moves out and the landing spot moves from 5 km to 45 km. Connects to: [[#The finite wing]] · [[#General aviation]] ### Lighter than air *Main article: [[Balloon_(aeronautics)]] · See also: [[Airship]], [[Hot_air_balloon]], [[Lifting_gas]]* A balloon lifts the weight of the air it displaces minus the weight of its own gas, so its lift per cubic metre — about 1.14 kg for hydrogen, 1.06 kg for helium and 0.28 kg for air heated to 100 °C at sea level — falls with altitude as the atmosphere thins, and the balloon stops where that lift equals the load it carries.[^marchman25] The Montgolfier brothers' hot-air balloon and Jacques Charles's hydrogen balloon both flew in 1783; the airship added an engine and a hull to the same buoyancy. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Balloon_(aeronautics).html" data-title="Balloon (aeronautics)"></div> *Try:* switch the gas from helium to hydrogen and watch the ceiling rise; switch to hot air and lower the burner until the basket touches the ground. Connects to: [[#Early beginnings]] · [[Avionics#Air data]] ### Heavier than air Lilienthal showed that a curved wing could carry a man; the Wright brothers added control in three axes, a wind tunnel of their own and a light engine, and flew at Kitty Hawk on December 17, 1903.[^nasm] The subsections below take the physics of the aeroplane in the order it had to be solved: where lift comes from, how it is controlled, what a finite wing costs, and then the engines and the speeds that followed. #### Lift and the airfoil *Main article: [[Airfoil]] · See also: [[Lift_(force)]], [[Angle_of_attack]], [[Kutta–Joukowski_theorem]]* A wing section makes lift by lowering the pressure over its upper surface more than it raises it below; the suction peak sits near the nose, the flow leaves the trailing edge smoothly (the Kutta condition), and the lift coefficient rises at 2π per radian of angle of attack until the flow separates.[^marchman55] The section sim draws the pressure distribution of a NACA four-digit airfoil from a panel-method family baked offline, with the thin-airfoil line as the comparison. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Airfoil.html" data-title="Airfoil"></div> *Try:* pitch the NACA 2412 from −4° to 12° and watch the suction peak grow and *cl* climb; switch to the symmetric 0012 and see the zero-lift angle move to zero. Connects to: [[#Control in three axes]] · [[#The finite wing]] · [[#Air safety]] #### Control in three axes *Main article: [[Wing_warping]] · See also: [[Aileron]], [[Adverse_yaw]], [[Flight_control_surfaces]], [[Aircraft_principal_axes]]* The Wrights rolled their gliders by twisting the wing; the aileron does the same job with a hinge. Either way the wing that makes more lift also makes more induced drag, so the nose swings away from the turn — adverse yaw — and the 1902 glider's movable rudder was the cure.[^ruijgrok70] The sim computes the rolling moment by strip theory and the yaw from the differential drag, and lets the rudder cancel it. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Wing_warping.html" data-title="Wing warping"></div> *Try:* warp to 10° with the rudder off and watch the nose swing left; switch the device to an aileron and the rudder on. Connects to: [[#Lift and the airfoil]] · [[#Fly-by-wire]] · [[Avionics#Aircraft flight-control system]] #### The finite wing *Main article: [[Lift-induced_drag]] · See also: [[Aspect_ratio_(aeronautics)]], [[Wingtip_device]], [[Lifting-line_theory]], [[Lift-to-drag_ratio]]* A wing of finite span must shed vortices to make lift, and the vortices are the bill: the induced drag coefficient is *CL²/(π·AR·e)*, so the drag polar is a parabola and the best lift-to-drag ratio is 1/(2√(K·CD0)) at the point where induced drag equals the parasite drag.[^marchman231] Aspect ratio narrows the penalty, which is why a sailplane's wing is long and thin. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Lift-induced_drag.html" data-title="Lift-induced drag"></div> *Try:* raise the aspect ratio from 8 to 30 and watch the polar narrow and (L/D)max climb from 16 to 28. Connects to: [[#Lift and the airfoil]] · [[#The turbofan]] · [[#Air transport]] #### The jet age *Main article: [[Turbojet]] · See also: [[Jet_engine]], [[Gas-turbine_engine]], [[Hans_von_Ohain]]* Frank Whittle in England and Hans von Ohain in Germany built the first turbojets independently in the late 1930s, and the Heinkel He 178 flew on von Ohain's engine in August 1939.[^nasm] The turbojet is the Brayton cycle on one shaft: intake, compressor, combustor, turbine, nozzle. The existing Wikitube sim plays the cycle. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Turbojet.html" data-title="Turbojet"></div> *Try:* follow the air through the five stations — intake, compressor, combustor, turbine, nozzle — and watch the pressure and temperature at each. Connects to: [[#The turbofan]] · [[Avionics#Engine control]] #### The turbofan *Main article: [[Turbofan]] · See also: [[Bypass_ratio]], [[Propulsive_efficiency]]* A jet is efficient when its exhaust leaves only a little faster than the aircraft flies: the propulsive efficiency is 2/(1 + Vj/V0). The turbofan spends the core's power on a large, slow bypass stream, so for the same thrust at Mach 0.8 a bypass ratio of 10 wastes far less kinetic energy in the wake than a turbojet — and, by Lighthill's law, makes far less noise.[^ruijgrok176] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Turbofan.html" data-title="Turbofan"></div> *Try:* slide the bypass ratio from 0 to 12 at 250 m/s and watch the propulsive efficiency climb from 0.36 to 0.75 while the fan grows. Connects to: [[#The jet age]] · [[#Noise]] · [[#Unmanned aircraft]] #### Rotorcraft *Main article: [[Helicopter]] · See also: [[Dissymmetry_of_lift]], [[Autorotation]]* A rotor in forward flight meets faster air on its advancing side than on its retreating side; without cyclic feathering the lift would be unequal and the helicopter would roll. Igor Sikorsky's VS-300 of 1939 settled the single-main-rotor layout with a tail rotor for anti-torque.[^nasm] The existing Wikitube sim shows the dissymmetry of lift. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Helicopter.html" data-title="Helicopter"></div> *Try:* speed the helicopter up and watch the lift of the advancing and retreating blades diverge. Connects to: [[#Unmanned aircraft]] #### Faster than sound *Main article: [[Sonic_boom]] · See also: [[Mach_number]], [[Sound_barrier]], [[Supersonic_transport]], [[Concorde]], [[Compressible_flow]]* Above Mach 1 the pressure disturbances an aircraft makes cannot run ahead of it and pile into shock waves that sweep a carpet of sound along the ground. Chuck Yeager's Bell X-1 crossed the "barrier" on October 14, 1947; Concorde carried passengers at Mach 2 from 1976 to 2003 and the boom kept it off overland routes.[^nasm] The existing Wikitube sim draws the boom carpet. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Sonic_boom.html" data-title="Sonic boom"></div> *Try:* take the aircraft through Mach 1 and watch the shock cone and its carpet form on the ground. Connects to: [[#The turbofan]] · [[#The flight envelope]] ## Operations of aircraft ### Civil aviation #### Air transport *Main article: [[Range_(aeronautics)]] · See also: [[Airliner]], [[Payload_fraction]], [[Jet_airliner]]* The Breguet range equation, *R = (V/c)(L/D) ln(W0/W1)*, is the economics of the airliner in one line: speed over fuel consumption, aerodynamic efficiency, and the logarithm of how much of the take-off weight is fuel.[^marchman172] Drawn against payload it gives the payload–range diagram with its three corners — maximum payload, maximum fuel, and the empty ferry — and a ceiling set by the maximum take-off weight. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Range_(aeronautics).html" data-title="Range (aeronautics)"></div> *Try:* trade payload for fuel along the MTOW wall and read the range; raise L/D to 22 and the ferry corner leaves the chart. Connects to: [[#General aviation]] · [[#Environmental impact]] · [[#Innovation and development]] · [[Avionics#Aircraft management systems]] #### General aviation *Main article: [[Rate_of_climb]] · See also: [[Density_altitude]], [[Aircraft_flight_mechanics]]* The light single is where most pilots learn the performance diagram: power required (drag times speed) against power available (propeller efficiency times engine power, falling with the density ratio), the excess between them being the weight times the rate of climb.[^ruijgrok212] On a hot day at a high field the density altitude climbs and the excess shrinks — 3000 m on an ISA+30 day is worth about 4000 m of performance, and the climb halves.[^faaweather100] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Rate_of_climb.html" data-title="Rate of climb"></div> *Try:* climb to 3000 m and add 30 °C to the day; watch the blue power-available line sink into the gold curve. Connects to: [[#Air transport]] · [[#Takeoff and landing]] · [[#Energy and maneuver]] · [[Avionics#Air data]] #### Weight and balance *Main article: [[Center_of_gravity_of_an_aircraft]] · See also: [[Aircraft_fuel_system]]* Every loading is a sum of moments: the centre of gravity is the total moment over the total weight, quoted as a percentage of the mean aerodynamic chord, and it must sit inside an envelope whose forward limit rises with weight and whose aft limit is set by the neutral point.[^amt239] Fuel burn walks the CG in flight; an airliner's trim tank walks it back on purpose, which is the shared section of the [[Avionics]] hub. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Center_of_gravity_of_an_aircraft.html" data-title="Center of gravity of an aircraft"></div> *Try:* load 200 kg in front and nothing behind, then the reverse; burn the fuel to 100 % with heavy rear seats and watch the landing point cross the aft limit. Connects to: [[#General aviation]] · [[Avionics#Fuel Systems]] · [[Avionics#Inertial navigation]] #### Takeoff and landing *Main article: [[Takeoff]] · See also: [[Landing]]* The ground run integrates *dV/dt = A − B·V²* from rest to a lift-off speed of about 1.1 times the stall speed; the run grows with wing loading and density altitude and shrinks with thrust-to-weight and CLmax, and the same arithmetic run backwards with the brakes on gives the landing roll.[^marchman189] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Takeoff.html" data-title="Takeoff"></div> *Try:* drop thrust-to-weight to 0.15 at 3000 m density altitude and watch the run pass the end of the runway; tick the brakes for the landing roll. Connects to: [[#General aviation]] · [[#Air safety]] · [[#Wind shear]] ### Military aviation #### Types of military aviation Military aviation divides by mission — fighters, bombers, transports, reconnaissance and surveillance, maritime patrol, rotary-wing — and by the sensors and data links each carries, which are the [[Avionics#Mission or tactical avionics|tactical avionics]] of the sister hub. The physics that separates a fighter from an airliner is the subject of the next section. #### Energy and maneuver *Main article: [[Aircraft_specific_energy]] · See also: [[Energy–maneuverability_theory]], [[Fighter_aircraft]]* A fighter's state is its energy height, *Es = h + V²/2g*, and its power to change it is the specific excess power *Ps = (T − D)·V/W*.[^afh87] Drawn on the altitude–speed plane the *Ps* = 0 contour is the aircraft's dome; the turn-rate "doghouse" shows the corner speed where the stall limit meets the structural limit.[^ruijgrok272] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Aircraft_specific_energy.html" data-title="Aircraft specific energy"></div> *Try:* raise thrust-to-weight to 1.2 and watch the dome fill red; find the corner speed on the doghouse. Connects to: [[#General aviation]] · [[#The flight envelope]] ### Air safety *Main article: [[Stall_(fluid_dynamics)]] · See also: [[High-lift_device]]* An aircraft stalls when the lift coefficient the flight demands — 2nW/(ρV²S) — exceeds the most its wing can give. The stall speed therefore scales with the square root of weight and of load factor: a 60° bank doubles the load and raises the stall speed by 41 %. Flaps raise CLmax for take-off and landing.[^marchman55] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Stall_(fluid_dynamics).html" data-title="Stall (fluid dynamics)"></div> *Try:* bank to 60° at 50 m/s and watch the section stall; select the landing flap and watch the demand drop under the new line. Connects to: [[#Lift and the airfoil]] · [[#Takeoff and landing]] · [[#The flight envelope]] #### The flight envelope *Main article: [[Flight_envelope]] · See also: [[Load_factor_(aeronautics)]]* The V–n diagram bounds the loads an airframe may carry: a stall parabola up to the manoeuvring speed *V_A*, a structural ceiling out to *V_NE*, and gust lines fanning from *n* = 1. Below *V_A* the wing stalls before the structure breaks; above it the order reverses.[^ruijgrok205] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Flight_envelope.html" data-title="Flight envelope"></div> *Try:* raise the limit load factor from 3.8 to 6 and watch the corner move; add a 15 m/s gust at cruise speed. Connects to: [[#Energy and maneuver]] · [[#Air safety]] · [[#Fly-by-wire]] #### Wind shear *Main article: [[Wind_shear]] · See also: [[Airborne_wind_shear_detection_and_alert_system]], [[Downburst]]* A microburst gives an approaching aircraft a headwind, then a downdraft, then a tailwind, and the airspeed that rose on the way in falls away on the way out.[^faaweather116] The point-mass equations with the shear terms show how much energy height is lost and why the escape — thrust up, pitch to 15° — must be flown at once; the same sim is the shared section of the [[Avionics]] hub, where the alert system that computes the F-factor is the subject.[^ruijgrok199] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Wind_shear.html" data-title="Wind shear"></div> *Try:* set the pilot to "hold airspeed" and watch the ground contact at 71 s; set "escape" and watch the climb-out. Connects to: [[#Takeoff and landing]] · [[#Aviation MRO]] · [[Avionics#Weather systems]] ### Aviation MRO *Main article: [[Aircraft_maintenance]] · See also: [[Paris'_law]], [[Damage_tolerance]], [[Crack_growth_equation]], [[Fatigue_(material)]]* Maintenance, repair and overhaul rests on damage tolerance: a crack grows a little on every flight cycle by the Paris law *da/dN = C·ΔK^m*, it is critical when the stress intensity reaches the fracture toughness, and the inspection interval is a fraction of the flights between the smallest crack an inspection can find and the largest the structure can carry.[^amt239][^paris] The Comet losses of 1954 and Aloha Airlines flight 243 in 1988 are the lessons behind the rule.[^ntsb243] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Aircraft_maintenance.html" data-title="Aircraft maintenance"></div> *Try:* raise the stress range from 100 to 160 MPa and watch the interval fall from eleven years to a few hundred flights. Connects to: [[#The flight envelope]] · [[#Aviation accidents and incidents]] ## Aviation accidents and incidents *Main article: [[Aviation_accidents_and_incidents]] · See also: [[Swiss_cheese_model]], [[Controlled_flight_into_terrain]], [[Tenerife_airport_disaster]]* James Reason's Swiss-cheese model says an accident needs a hole in every barrier at once; if the holes are independent the probability multiplies down — five barriers with 10 % holes give one in a hundred thousand — and if they share a cause it does not.[^reason] Investigation exists to find the shared cause. Tenerife, 1977, is the textbook case of aligned holes; controlled flight into terrain is the case the terrain-awareness system of the [[Avionics]] hub was built to close. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Aviation_accidents_and_incidents.html" data-title="Aviation accidents and incidents"></div> *Try:* set the common-cause fraction to 1 and watch every hole line up; roll the dice. Connects to: [[#Wind shear]] · [[#Air traffic control]] · [[Avionics#Terrain awareness]] ## Air traffic control *Main article: [[Air_traffic_control]]* Controlled airspace keeps aircraft apart with separation cylinders — laterally by miles, vertically by 1000 ft under reduced vertical separation minima — and a controller who sees every aircraft's position and altitude. The existing Wikitube sim draws the cylinders; how the controller sees the aircraft is the next section, shared with the [[Avionics]] hub. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Air_traffic_control.html" data-title="Air traffic control"></div> *Try:* bring two aircraft together and watch their separation cylinders meet. Connects to: [[#Surveillance: transponders and ADS-B]] · [[Avionics#Communications]] · [[Avionics#Collision-avoidance systems]] #### Surveillance: transponders and ADS-B *Main article: [[Automatic_Dependent_Surveillance–Broadcast]] · See also: [[Secondary_surveillance_radar]], [[Transponder_(aeronautics)]], [[Air_traffic_control_radar_beacon_system]]* Secondary radar interrogates a transponder once per antenna sweep and paints a plot that goes stale until the next pass; ADS-B has the aircraft broadcast its own satellite position every second. Both are bounded by the radio horizon, 1.23(√h1 + √h2) nautical miles for heights in feet, which is why a ground station at 100 ft hears an airliner at 35 000 ft from 240 nmi and a light aircraft at 500 ft from 40.[^ellingson96] The FAA required ADS-B Out in most controlled airspace from January 1, 2020.[^faaadsb] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Automatic_Dependent_Surveillance–Broadcast.html" data-title="Automatic Dependent Surveillance–Broadcast"></div> *Try:* switch the mode from SSR to ADS-B and watch the stale-distance sawtooth collapse; drop the altitude to 500 ft and watch the horizon ring shrink. Connects to: [[#Air traffic control]] · [[Avionics#Surveillance: transponders and ADS-B]] · [[Avionics#Radar]] ## Environmental impact *Main article: [[Environmental_impact_of_aviation]] · See also: [[Fuel_economy_in_aircraft]], [[Aviation_biofuel]]* A kilogram of jet fuel burns to 3.16 kg of CO2, so the climate cost of a flight is its fuel burn per seat: highest on short stages, where the climb is a large share of the fuel, lowest around 3000 km, and creeping up again on the longest stages where fuel is carried to carry fuel.[^marchman172] Non-CO2 effects — contrails and nitrogen oxides — add to the CO2 warming by a factor the assessment of Lee and colleagues puts at roughly 1.7 on a hundred-year basis.[^lee2021] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Environmental_impact_of_aviation.html" data-title="Environmental impact of aviation"></div> *Try:* shorten the stage to 300 km and watch the climb's share of the fuel reach nearly half; raise the load factor to 100 %. Connects to: [[#Air transport]] · [[#Contrails]] · [[#Noise]] · [[#Innovation and development]] #### Contrails *Main article: [[Contrail]] · See also: [[Cirrus_cloud]]* An engine's exhaust is hot and wet; mixed into cold, thin air it can cross the saturation curve and freeze into a line of cirrus. The Schmidt–Appleman criterion says when, and the existing Wikitube sim draws the mixing line against the saturation curve. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Contrail.html" data-title="Contrail"></div> *Try:* cool the ambient air until the exhaust's mixing line crosses the saturation curve and the trail forms. Connects to: [[#Environmental impact]] · [[#The turbofan]] #### Noise *Main article: [[Aircraft_noise_pollution]] · See also: [[Jet_noise]], [[Lighthill's_eighth_power_law]]* Lighthill showed in 1952 that the acoustic power of a turbulent jet scales with the eighth power of its speed: halve the jet speed and the noise falls by 24 dB.[^lighthill] The high-bypass turbofan is quiet for the same reason it is efficient, and noise certification under 14 CFR Part 36 has ratcheted the limits down through successive stages.[^part36] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Aircraft_noise_pollution.html" data-title="Aircraft noise pollution"></div> *Try:* raise the bypass ratio from 0 to 12 at 300 m/s and watch the sound power fall by nearly 40 dB. Connects to: [[#The turbofan]] · [[#Environmental impact]] ## Innovation and development *Main article: [[Electric_aircraft]] · See also: [[Hydrogen-powered_aircraft]]* The battery never gets lighter, so an electric aircraft's range is *E·η·(L/D)·f/g* with no logarithm in it: at 250 Wh/kg a cell holds a fiftieth of kerosene's energy per kilogram, and even 500 Wh/kg with half the take-off mass in batteries gives under 2000 km.[^viswanathan] Hydrogen carries three times kerosene's energy per kilogram but needs a tank that weighs more than the fuel. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Electric_aircraft.html" data-title="Electric aircraft"></div> *Try:* slide the store fraction to 0.5 at 500 Wh/kg and read the range; switch the store to liquid hydrogen. Connects to: [[#Air transport]] · [[#Environmental impact]] · [[#Unmanned aircraft]] #### Unmanned aircraft *Main article: [[Unmanned_aerial_vehicle]] · See also: [[Momentum_theory]], [[Propeller_(aeronautics)]]* A multirotor hovers on momentum theory: the induced velocity is √(T/2ρA), the ideal power is thrust times that velocity, and the real power is the ideal over a figure of merit near 0.7. Endurance falls with the square root of disk loading, which is why the aircraft that stay up longest have big, slow rotors.[^ruijgrok176] <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/flight/Unmanned_aerial_vehicle.html" data-title="Unmanned aerial vehicle"></div> *Try:* shrink the rotors and watch the hover power climb and the endurance fall. Connects to: [[#The turbofan]] · [[#Innovation and development]] · [[Avionics#Satellite navigation]] #### Fly-by-wire *Main article: [[Fly-by-wire]] · See also: [[Relaxed_stability]]* When the pilot's inceptor commands a computer instead of a cable, the aircraft can be built unstable for agility and flown stable by the control law, and the envelope of the [[#The flight envelope|V–n diagram]] can be enforced rather than placarded. The Airbus A320 of 1988 was the first airliner with digital fly-by-wire controls. The existing Wikitube sim is shared with the [[Avionics]] hub, where the control laws are the subject. <div class="wt-sim" data-src="https://wikitube-3d-microsims.netlify.app/Fly-by-wire.html" data-title="Fly-by-wire"></div> *Try:* disturb the aircraft and watch the control law bring it back where the bare airframe would diverge. Connects to: [[#Control in three axes]] · [[#The flight envelope]] · [[Avionics#Aircraft flight-control system]] · [[Avionics#Autopilot]] ## See also [[Aeronautics]] · [[Aircraft]] · [[Airline]] · [[Airport]] · [[Aerospace_engineering]] · [[Avionics]] · [[Flight]] · [[Glossary_of_aerospace_engineering]] ## Notes [^marchman25]: Marchman, *Aerodynamics and Aircraft Performance*, pp. 25–29 (the standard atmosphere). [^marchman55]: Marchman, pp. 55–62 (lift coefficient, angle of attack, camber, stall). [^marchman66]: Marchman, pp. 66–69 (the drag polar and the glide). [^marchman172]: Marchman, pp. 172–188 (range and endurance; the Breguet equation). [^marchman189]: Marchman, pp. 189–208 (take-off and landing performance). [^marchman231]: Marchman, p. 231 ((L/D)max and the induced-drag factor). [^ruijgrok70]: Ruijgrok, Voskuijl and Varriale, *Elements of Airplane Performance*, pp. 70–85 (moments and control). [^ruijgrok176]: Ruijgrok et al., pp. 176–185 (propulsive efficiency; momentum theory). [^ruijgrok199]: Ruijgrok et al., pp. 199–201 and 392–395 (flight in wind shear). [^ruijgrok205]: Ruijgrok et al., pp. 205–209 (the manoeuvre and gust envelopes). [^ruijgrok212]: Ruijgrok et al., pp. 212–237 (climb, glide and the performance diagram). [^ruijgrok272]: Ruijgrok et al., pp. 272–291 (turning flight and energy methods). [^afh87]: FAA, *Airplane Flying Handbook* FAA-H-8083-3C, pp. 87–105 (energy management). [^faaweather100]: FAA, *Aviation Weather Handbook* FAA-H-8083-28B, pp. 100–109 (density altitude). [^faaweather116]: FAA, *Aviation Weather Handbook*, pp. 116–133 (wind shear and microbursts). [^amt239]: FAA, *Aviation Maintenance Technician Handbook — General* FAA-H-8083-30B, pp. 239–241 (weight and balance) and the damage-tolerance material of the airframe volume. [^ellingson96]: Ellingson, *Radio Systems Engineering*, pp. 96–107 (thermal noise, sensitivity and the radio horizon). [^paris]: Paris and Erdogan, "A critical analysis of crack propagation laws", *Journal of Basic Engineering* 85 (1963), pp. 528–534. [^lighthill]: Lighthill, "On sound generated aerodynamically. I. General theory", *Proc. R. Soc. A* 211 (1952), doi:10.1098/rspa.1952.0060. [^lee2021]: Lee et al., "The contribution of global aviation to anthropogenic climate forcing for 2000 to 2018", *Atmospheric Environment* 244 (2021), doi:10.1016/j.atmosenv.2020.117834. [^viswanathan]: Viswanathan et al., "The challenges and opportunities of battery-powered flight", *Nature* 601 (2022), doi:10.1038/s41586-021-04139-1. [^reason]: Reason, *Human Error* (Cambridge University Press, 1990), the barrier model. [^ntsb243]: NTSB, *Aircraft Accident Report* NTSB/AAR-89/03, Aloha Airlines flight 243 (1989). [^nasm]: Smithsonian National Air and Space Museum, collection records for the 1903 Wright Flyer, the Heinkel He 178 programme, the Sikorsky VS-300 and the Bell X-1. [^faaadsb]: FAA, 14 CFR 91.225 and 91.227 (ADS-B Out equipment and performance requirements). [^part36]: FAA, 14 CFR Part 36 (noise standards: aircraft type and airworthiness certification). ## Bibliography - Marchman, J. F., *Aerodynamics and Aircraft Performance*, 3rd ed. (2004) — Portal Book 005. - FAA, *Airplane Flying Handbook*, FAA-H-8083-3C (2021) — Portal Book 006. - FAA, *Aviation Weather Handbook*, FAA-H-8083-28B (2026) — Portal Book 007. - Ruijgrok, G. J. J., Voskuijl, M. and Varriale, C., *Elements of Airplane Performance* (2025) — Portal Book 008. - FAA, *Aviation Maintenance Technician Handbook — General*, FAA-H-8083-30B (2023) — Portal Book 081. - Ellingson, S. W., *Radio Systems Engineering* (2023) — Portal Book 011. - Lighthill, M. J. (1952); Paris, P. and Erdogan, F. (1963); Lee, D. S. et al. (2021); Viswanathan, V. et al. (2022) — as cited in the notes. ## External links - [Wikitube microsim set for this hub](https://wikitube-3d-microsims.netlify.app/flight/manifest.json) — every sim on this page and its sources, one JSON row each. - [FAA handbooks and manuals](https://www.faa.gov/regulations_policies/handbooks_manuals) — the Portal Books 006, 007 and 081. ## Microsims The sims on this page are the Aviation half of the *flight* set built by the Wikitube microsim framework (`MICROSIM_GUIDE/specs/`, pack `PORTAL_Aviation_Avionics`), one per section: [[Glider_(aircraft)]], [[Balloon_(aeronautics)]], [[Airfoil]], [[Wing_warping]], [[Lift-induced_drag]], [[Turbofan]], [[Range_(aeronautics)]], [[Rate_of_climb]], [[Center_of_gravity_of_an_aircraft]], [[Takeoff]], [[Aircraft_specific_energy]], [[Stall_(fluid_dynamics)]], [[Flight_envelope]], [[Wind_shear]], [[Aircraft_maintenance]], [[Aviation_accidents_and_incidents]], [[Automatic_Dependent_Surveillance–Broadcast]], [[Environmental_impact_of_aviation]], [[Aircraft_noise_pollution]], [[Electric_aircraft]] and [[Unmanned_aerial_vehicle]], with the existing [[Turbojet]], [[Helicopter]], [[Sonic_boom]], [[Air_traffic_control]], [[Contrail]] and [[Fly-by-wire]] sims reused in their sections. Each article carries its own sim and the See-also variants built beside it; every number a sim shows comes from `libs/wt-flight.js` with the book and page in the sim's sources, and anything a fit stands in for says ILLUSTRATIVE on screen. ## Minnesota Minnesota's aviation runs from Charles Lindbergh, raised in Little Falls, through the Minneapolis–Saint Paul airport that is the state's gateway, to the general-aviation industry of Duluth, where Cirrus Aircraft builds the SR-series singles with a whole-airframe parachute, and the avionics heritage of Honeywell's Minneapolis plants that carries into the sister hub. The Minnesota Air National Guard's 133rd Airlift Wing at Minneapolis–Saint Paul flies the C-130.[^mn] [^mn]: Charles A. Lindbergh House and Museum (Minnesota Historical Society); Cirrus Aircraft, Duluth; Metropolitan Airports Commission; Minnesota National Guard, 133rd Airlift Wing — institutional sources to be linked in the article pass. ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Aviation) : [Wikitube](https://en.wikitube.io/wiki/Aviation) ## Previous hub tags Room: [[PORTAL_Aviation]]. Legacy hubs: none (new hub seeded 2026-08-05). --- *Text adapted from [Wikipedia](https://en.wikipedia.org/wiki/Aviation), licensed [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/). Seed stub minted 2026-08-05 alongside PORTAL_Aviation.*  ## Microsim-first spine · expanded 2026-08-05 ### Movement I — three.js (queued) Troy is hand-building the three.js stations for this spine next; the concept pages below are publish-ready now and will take the players as they land. Candidate first stations: [[Aircraft]] (lift categories), [[Jet_engine]] (Brayton-cycle propulsion), [[Helicopter]] (rotor lift/anti-torque). ### Movement II — concept spine (publish-ready, text transferred/sourced 2026-08-05) | Station | Article | Note | |---|---|---| | 1 | [[Aircraft]] | The three lift families: fixed-wing, rotorcraft, lighter-than-air. Shared with [[PORTAL_Avionics]]. | | 2 | [[Jet_engine]] | Brayton-cycle thrust: intake → compressor → combustor → turbine → nozzle. | | 3 | [[Helicopter]] | Cyclic/collective control, main-rotor lift, tail-rotor anti-torque. Shared with [[PORTAL_Avionics]]. | | 4 | [[Air_traffic_control]] | Radar-and-radio separation of aircraft in controlled airspace. Shared with [[PORTAL_Avionics]]. | ## Sibling spine [[Avionics]] is the electronic-systems twin of this hub — same aircraft, the instruments and computers that fly them. Shared stations across both spines: [[Aircraft]], [[Helicopter]], [[Air_traffic_control]], [[Radar]]-adjacent surveillance. Portal doors: [[PORTAL_Avionics]] · [[PORTAL_Aviation]]. *Spine expanded 2026-08-05 · concept articles transferred/Wikipedia-sourced, three.js queued · append-only, 0 deletions.*