visual ground position indicator

indicator n abbreviated visual indicator system (глиссады) acceleration indicator airborne moving target indicator airborne proximity warning indicator aircraft position indicator aircraft surface movement indicator air-flow indicator air-mileage indicator air position indicator airspeed indicator air-speed indicator calibration altimeter setting indicator altitude indicator altitude-limit indicator altitude-rate indicator angle-of-attack indicator approach angle indicator approach slope indicator attitude director indicator attitude indicator ball-bank indicator ball-slip indicator bank-and-pitch indicator bank-and-turn indicator bank indicator bank indicator ball bearing-heading indicator bearing indicator boost pressure indicator busting disc indicator cabin altitude indicator cabin overpressure indicator cabin pressure indicator calibrated airspeed indicator calibrate the indicator climb-and-descent rate indicator collective pitch indicator combination airspeed indicator compass repeater indicator consumption indicator control position indicator course-bearing indicator course deviation indicator course direction indicator course-drift indicator course-heading indicator course indicator cross-pointer indicator dead-reckoning indicator deviation indicator dial indicator dial test indicator differential pressure indicator digital indicator directional gyro indicator direction indicator discharge indicator disregard indicator display disregard the indicator distance flown indicator distance indicator distance-to-go indicator drift angle indicator drift-speed indicator elapsed time indicator engine tachometer indicator engine vibration indicator exhaust gas temperature indicator flap position indicator flight director course indicator flight director indicator flight indicator flowmeter indicator fuel flow indicator fuel mixture indicator fuel pressure indicator fuel quantity indicator fuel quantity indicator selector switch fuel remaining indicator glide-path indicator ground position indicator ground speed indicator ground wind indicator heading indicator height indicator horizontal situation indicator ice-warning indicator icing indicator icing rate indicator landing direction indicator landing direction indicator lights landing gear position indicator lever position indicator location indicator low quantity indicator Mach number indicator magnetic compass indicator mechanical position indicator message type indicator M-number indicator mode indicator moving target indicator neglect the indicator off-course indicator off-track indicator oil temperature indicator omnibearing indicator originator indicator outside air temperature indicator overheat indicator oxygen flow indicator pictorial deviation indicator pictorial navigation indicator pitch angle indicator plan position indicator position indicator power indicator power-lost indicator precision approach path indicator priority message indicator proximity warning indicator radar indicator radar target indicator radio magnetic indicator range indicator rate-of-climb indicator rate-of-roll indicator rate-of-turn indicator rate-of-yaw indicator regard indicator display remote-reading indicator rising runway indicator routing indicator runway alignment indicator runway alignment indicator lights shock strut compression indicator sideslip indicator silica-gel indicator slave indicator slip indicator slip indicator ball slope indicator system stabilizer position indicator stopping position indicator storm indicator surface position indicator tachometer indicator tank level indicator target lock-on indicator terrain clearance indicator throttle position indicator thrust-reverse indicator time-to-go indicator top-center indicator total fuel indicator touchdown indicator transmission test indicator trim indicator trim tab indicator true-range indicator turn-and-bank indicator turn-and-slip indicator turn indicator two-pointer indicator unsafe indicator up indicator vertical-situation indicator vertical speed indicator visual approach indicator visual approach slope indicator system visual downlock indicator visual indicator wear indicator wear indicator rod weather radar indicator wind direction indicator wind speed indicator

- acceleration indicator - airborne moving target indicator - airborne proximity warning indicator - aircraft icing indicator - aircraft position indicator - aircraft surface movement indicator - airfield surface movement indicator - air-flow indicator - air-mileage indicator - air-position indicator - airspeed indicator - altimeter setting indicator - altitude indicator - altitude-limit indicator - altitude-rate indicator - angle-of-attack indicator - approach angle indicator - approach slope indicator - attack angle indicator - attitude director indicator - attitude indicator - ball-bank indicator - ball-slip indicator - bank indicator - bank-and-pitch indicator - bank-and-turn indicator - baro data indicator - bearing indicator - bearing/heading indicator - boost pressure indicator - bursting disc indicator - cabin altitude indicator - cabin overpressure indicator - cabin pressure indicator - calibrated airspeed indicator - circular scan indicator - climb-and-descent rate indicator - climb-and-dive indicator - collective pitch indicator - combination airspeed indicator - compass repeater indicator - consumption indicator - control position indicator - course indicator - course-and-bearing indicator - course deviation indicator - course direction indicator - course/drift indicator - course/heading indicator - cross-pointer indicator - dead-reckoning indicator - deviation indicator - dial indicator - dial test indicator - differential pressure indicator - digital indicator - digital pressure indicator - direction indicator - directional gyro indicator - direct-reading indicator - discharge indicator - distance indicator - distance flown indicator - distance-to-go indicator - diversion addressee indicator - diversion indicator - Doppler distance-gone indicator - Doppler hover indicator - drift indicator - drift angle indicator - drift/speed indicator - elapsed time indicator - engine tachometer indicator - engine vibration indicator - exhaust gas temperature indicator - failure indicator - failure warning indicator - flap position indicator - flight indicator - flight director indicator - flight director course indicator - flowmeter indicator - fuel indicator - fuel flow indicator - fuel mixture indicator - fuel pressure indicator - fuel quantity indicator - fuel remaining indicator - glide-path indicator - ground-position indicator - ground speed indicator - ground wind indicator - heading indicator - height indicator - height-position indicator - height-range indicator - horizontal situation indicator - ice-warning indicator - icing indicator - icing rate indicator - illuminated indicator - landing direction indicator - landing gear position indicator - lever position indicator - local indicator - location indicator - low quantity indicator - Mach number indicator - magnetic compass indicator - measuring indicator - mechanical position indicator - message type indicator - M-number indicator - mode indicator - moving target indicator - off-course indicator - off-track indicator - oil-pressure indicator - oil temperature indicator - omnibearing indicator - originator indicator - outside air temperature indicator - overheat indicator - overload indicator - oxygen flow indicator - P-indicator - pictorial deviation indicator - pictorial navigation indicator - pitch angle indicator - plan position indicator - pointer indicator - position indicator - power indicator - power-lost indicator - precision approach path indicator - pressure indicator - priority message indicator - proximity warning indicator - radar indicator - radar target indicator - radiation indicator - radio magnetic indicator - range indicator - range-height indicator - rate of climb and descent indicator - rate-of-climb indicator - rate-of-roll indicator - rate-of-turn indicator - rate-of-yaw indicator - remote-reading indicator - rising runway indicator - routing indicator - runway alignment indicator - scoring indicator - shock strut compression indicator - sideslip indicator - silica-gel indicator - slave indicator - slip indicator - space target Doppler indicator - stabilizer position indicator - stopping position indicator - storm indicator - surface position indicator - tachometer indicator - tank level indicator - target lock-on indicator - terrain clearance indicator - throttle position indicator - thrust-reverse indicator - time-to-go indicator - top-center indicator - total fuel indicator - touchdown indicator - transmission test indicator - trim indicator - trim tab indicator - true-range indicator - turn indicator - turn-and-bank indicator - turn-and-slip indicator - two-pointer indicator - unsafe indicator - up indicator - vertical-situation indicator - vertical speed indicator - visual indicator - visual approach slope indicator - visual downlock indicator - wear indicator - weather radar indicator - wind direction indicator - wind speed indicator - yaw indicator

- airspeed indicator
- alphabet indicator
- alphameric indicator
- alphanumeric indicator
- antenna position indicator
- attitude indicator
- automatic direction indicator
- azel indicator
- azimuth-elevation indicator
- azimuth-stabilized plan-position indicator
- B-indicator
- bearing indicator - C-indicator
- call indicator
- capacitance level indicator
- cathode-ray indicator
- cathode-ray tube indicator
- cathode-ray tuning indicator
- ceiling-height indicator
- character indicator
- chargeable time indicator
- clearing indicator
- coherent moving-target indicator
- colorama tuning indicator
- column indicator - continuous-reading indicator
- course-line indicator
- course-line deviation indicator
- crossed-pointer indicator
- CRT indicator
- D-indicator
- delayed plan-position indicator
- density indicator
- depression-deviation indicator
- depth-deviation indicator
- dew-point indicator
- digital indicator
- direct indicator
- direction indicator
- direction finder bearing indicator
- direct-reading indicator
- drive activity indicator
- drop indicator
- E-indicator
- echo-Doppler indicator
- electroluminescent indicator - elevation-position indicator - failure indicator
- fault indicator
- flight indicator
- flight-path deviation indicator
- frequency indicator
- G-indicator
- gamma-ray level indicator
- glow-discharge indicator
- ground indicator
- ground-position indicator
- H-indicator
- height-position indicator - in-lock indicator
- J-indicator
- K-indicator
- key status indicator
- L-indicator
- landing-direction indicator
- level indicator
- local indicator
- loran indicator
- luminescent indicator
- M-indicator
- message indicator
- mnemonic indicator
- mode indicator
- moving-target indicator
- multiple LED tuning indicator
- N-indicator
- needle indicator
- neon indicator
- neutralizing indicator
- noncoherent moving-target indicator
- null indicator
- null-frequency indicator
- numeric indicator
- off-center plan-position indicator - optical groove locating indicator
- output indicator
- overload indicator
- overrange indicator
- P-indicator
- panoramic indicator
- plan-position indicator - radar indicator
- radar-coverage indicator
- radiation indicator
- radio magnetic indicator
- range indicator - remote indicator
- resonance indicator
- resonant-circuit-type frequency indicator
- RF indicator
- ring indicator
- RMI indicator
- shadow tuning indicator
- sign indicator
- solid-state frequency indicator
- standing-wave indicator
- status indicator
- supervisory indicator
- tape-position indicator
- terrain-clearance indicator
- to-from indicator
- tuning indicator
- visual approach slope indicator
- visual Doppler indicator - volume indicator
- volume-unit indicator
- VU indicator
- wind indicator
- zone-beat indicator
- zone-position indicator

- airborne moving-target indicator
- air-position indicator
- airspeed indicator
- alpha meric indicator
- alpha numeric indicator
- alphabet indicator
- antenna position indicator
- attitude indicator
- automatic direction indicator
- azel indicator
- azimuth-elevation indicator
- azimuth-stabilized plan-position indicator
- bearing deviation indicator
- bearing indicator
- B-indicator
- blown-fuse indicator
- call indicator
- capacitance level indicator
- cathode-ray indicator
- cathode-ray tube indicator
- cathode-ray tuning indicator
- ceiling-height indicator
- character indicator
- chargeable time indicator
- C-indicator
- clearing indicator
- coherent moving-target indicator
- colorama tuning indicator
- column indicator
- communication zone indicator
- continuous indicator
- continuous-reading indicator
- course-line deviation indicator
- course-line indicator
- crossed-pointer indicator
- CRT indicator
- delayed plan-position indicator
- density indicator
- depression-deviation indicator
- depth-deviation indicator
- dew-point indicator
- digital indicator
- D-indicator
- direct indicator
- direction finder bearing indicator
- direction indicator
- direct-reading indicator
- drive activity indicator
- drop indicator
- echo-Doppler indicator
- E-indicator
- electroluminescent indicator
- electronic position indicator
- elevation-deviation indicator
- elevation-position indicator
- expanded plan-position indicator
- failure indicator
- fault indicator
- F-indicator
- flight indicator
- flight-path deviation indicator
- frequency indicator
- gamma-ray level indicator
- G-indicator
- glow-discharge indicator
- ground indicator
- ground-position indicator
- height-position indicator
- height-range indicator
- H-indicator
- I-indicator
- in-lock indicator
- J-indicator
- key status indicator
- K-indicator
- landing-direction indicator
- level indicator
- L-indicator
- local indicator
- loran indicator
- luminescent indicator
- message indicator
- M-indicator
- mnemonic indicator
- mode indicator
- moving-target indicator
- multiple LED tuning indicator
- needle indicator
- neon indicator
- neutralizing indicator
- N-indicator
- noncoherent moving-target indicator
- null indicator
- null-frequency indicator
- numeric indicator
- off-center plan-position indicator
- omnibearing indicator
- open-center plan-position indicator
- optical groove locating indicator
- output indicator
- overload indicator
- overrange indicator
- panoramic indicator
- P-indicator
- plan-position indicator
- position indicator
- power-level indicator
- precision plan-position indicator
- proximity warning indicator
- radar indicator
- radar-coverage indicator
- radiation indicator
- radio magnetic indicator
- range indicator
- range-height indicator
- recording level indicator
- remote indicator
- resonance indicator
- resonant-circuit-type frequency indicator
- RF indicator
- ring indicator
- RMI indicator
- shadow tuning indicator
- sign indicator
- solid-state frequency indicator
- standing-wave indicator
- status indicator
- supervisory indicator
- tape-position indicator
- terrain-clearance indicator
- to-from indicator
- tuning indicator
- visual approach slope indicator
- visual Doppler indicator
- visual glide path indicator
- visual-tuning indicator
- volume indicator
- volume-unit indicator
- VU indicator
- wind indicator
- zone-beat indicator
- zone-position indicator

grounding v above ground level aerodrome ground profile aerodrome ground signal aerodrome ground visibility Aerodromes, Air Routes and Ground Aids Section (ИКАО) aeronautical ground light aeronautical ground mark at the ground level come clear of the ground engine ground test time en-route ground mark ground aids ground air starting unit ground attenuation ground based aids ground beacon Ground Branch ground check ground circuit ground conditions ground contact ground control ground controlled approach ground control system (полетом) ground crew ground cue ground cushion ground effect ground effect takeoff ground equipment ground guidance system ground handling ground handling charge ground handling facilities ground handling operation ground hold ground idle grounding cable grounding link ground interrogation address ground inversion ground level ground load ground locking pin ground loop ground mapping range ground marking ground movement controller ground operating time ground operation ground personnel ground position fix ground position indicator ground power unit ground pressurization connection ground proximity ground proximity warning ground proximity warning system ground reaction ground reference ground reference navigation ground reflection coefficient ground reflection effect ground run ground run monitor ground runup ground run-up noise abatement ground service equipment ground servicing ground shift system ground speed (скорость воздушного судна относительно земли) ground speed indicator ground speed vector ground spoiler (используемый на земле для гашения подъемной силы) ground starting unit ground station (обеспечения полетов) ground storage battery ground surveillance radar ground taxi from landing operation ground taxi operation ground testing connection ground tests ground time ground tow ground tracking ground training ground training procedure ground transmission ground turn-around time ground velocity ground weather radar ground wind indicator hovering in the ground effect in ground effect instrument ground time maintenance ground time out of ground effect radar ground mapping 2. радиолокационный обзор земной поверхности rotorcraft ground resonance static ground angle visual ground aids visual ground fixing visual ground signal

approach n abbreviated visual approach advisory approach aerodrome approach aerodrome approach aids aerodrome approach area aerodrome approach chart aerodrome approach control system aerodrome approach lights aerodrome approach road aeronautical approach chart aids to approach angle of approach angle of approach light approach angle correction approach angle indicator approach area approach area hazard approach azimuth approach azimuth antenna approach azimuth guidance approach beacon approach beam approach ceiling approach chart approach clearance approach computer approach control approach controller approach control point approach control radar approach control service approach control tower approach control unit approach course approach elevation antenna approach end approach facilities approach final approach fix approach flight reference point approach flight track distance approach flow approach funnel approach glide approach glide slope approach guidance nose-in to stand system approach heading approach height approach idle approach information approaching aircraft approach landing approach leg approach light beacon approach lighting approach lighting system (к ВПП) approach lights approach lights collision approach mass correction approach measurement distance approach navigation approach noise angle approach noise level approach noise measurement approach noise path approach noise reference point approach operation approach path approach pattern approach phase approach procedure approach profile approach radar system approach rate of descent approach sector approach segment approach sequence approach setting approach slope guidance approach slope indicator approach speed approach system approach technique approach terrain approach test procedure approach the beam approach threshold lights approach time approach to land procedures approach with flaps down approach zone automatic approach automatic approach system azimuth approach path back course approach beam approach beam approach beacon system blind approach center line approach circling approach circling approach area clearance for straight-in approach complete approach contact approach continuous descent approach coupled approach crossbar approach lighting system (к ВПП) crosswind approach curved approach decelerating approach direction of approach discontinue approach discontinued approach discontinued approach climb enter the final approach track execute approach expected approach time final approach final approach altitude final approach fix final approach operation final approach path final approach track flap approach position flat approach front course approach gliding approach ground controlled approach ground-controlled approach procedure head-on approach helicopter approach height initial approach initial approach altitude initial approach fix initial approach segment inner approach lighting instrument approach chart instrument approach course instrument approach landing instrument approach procedure instrument landing approach intermediate approach intermediate approach fix intermediate approach operation land approach landing approach speed left-hand approach localizer approach localizer approach track long approach low-visibility approach measured approach profile miss approach missed approach missed approach azimuth missed approach operation missed approach procedure missed approach procedure track no-aids used approach no-flap approach speed no-flap - no-slat approach speed noise certification approach path nominal approach path nonprecision approach nonprecision approach procedure nonprecision approach runway nonstraight-in approach normal approach no-slat approach speed offset approach one-eighty approach practice low approach precision approach precision approach lighting system precision approach path precision approach path indicator precision approach procedure precision approach radar precision approach radar system precision approach runway precision approach terrain chart procedure approach track radar approach radar approach beacon radar approach control radio approach aids rectangular approach traffic pattern rectangular traffic pattern approach reference approach angle reference approach height right-hand approach runway approach surveillance radar segmented approach segmented approach path selected approach altitude selected approach slope serve approach short approach simple approach simple approach lighting system (к ВПП) standard approach standard approach system standard beam approach system steadiness of approach steady approach steep approach step-down approach straight-in approach straight-in approach path straight-in ILS-type approach surveillance radar approach symmetric thrust approach teardrop approach timed approach upwind approach visual aids to approach visual approach visual approach indicator visual approach slope indicator system visual approach streamline

- acceleration warning system - accessory power system - active beacon collision avoidance system - aerodynamic roll system - airborne collision avoidance system - airborne early warning system - airborne lightweight optical tracking system - airborne prospecting system - airborne television system - airborne warning and control system - aircraft electrical system - aircraft integrated data system - aircraft intercommunication system - aircraft system - airdrop system - air-ground data link system - airlocking system - air transport system - airway system - alarm signal system - alarm system - alarm warning system - altitude alerting system - anti-icing system - antiskid system - approach lighting system - area forecast system - associated aircraft system - automated data interchange system - automatic direction finder system - automatic flight control system - autonomous life support system - autopilot system - aviation safety reporting system - avionics system - backpack life support system - balloon-tracking system - canard foil system - co-axial rotor system - collision avoidance system - communication system - computerized system - conical coordinate system - control system - countermeasures system - digital avionic systems - dimmer system - docking guidance system - dual-channel system - dual flight control system - early warning system - economical space transportation system - electric flight control signalling system - electronic attack system - electronic support system - elevator control system - enhanced ground proximity warning system - enroute navigation systems - Entry Sensor System - exhaust system - exit sensor system - explosives detection system - extraterrestrial transportation system - facility performance category I instrument landing system - facility performance category II instrument landing system - facility performance category III instrument landing system - fail safe system - fail tolerant system - FBW system - flight control system - flight management system - FLIR system - fly-by-wire system - forward-looking infra-red system - fuel system - general purpose system - global positioning system - ground proximity warning system - guidance system - high lift control system - inertial navigation system - infrared search and tracking system - instrument landing system - integrated electronic warfare system - inorbit-on-demand space transportation system - jet engine starter system - landing navigation system - landing system - LEO-to-GEO transportation system - long-range position finding system - lubricating system - lubrication system - microwave landing system - multifunctional system - narrow gauge lighting system - navigation system - offensive fire-control system - oil system - orbital coordinate system - orbital transportation system - orbiting multibody system - oxygen system - pilot-controller system - planar coordinate system - point-defence weapon systems - position indicating system - power-operated control system - power-supply system - power system - precision approach category I lighting system - precision approach category II lighting system - precombustion chamber fuel system - pressure air system - pressure fueling system - pressure system - primary system - propeller deicing system - propulsion system - Q-feci system - Q-feel system - queueing system - radar airborne weather system - radar guidance system - radar identification system - radiation alarm system - radio command system - radio guidance system - radio navigation system - rapid response space transportation system TKJI - reporting system - safety management system - satellite communications system - satellite navigation system - satellite system - scanning beam system - SELCAL system - selective calling system - simple approach lighting system - solar system - space-based observing system - space-based transportation system - space environmental quality control system - space laser power system - space nuclear power system - space observing system - space transportation system - SPADE system - take-off monitoring system - thermal protection system - trainable system - training system - two-frequency glide path system - two-frequency localizer system - visual approach slope indicator system - visual docking guidance system - wing antiicing system - wing flap control system - wing slat system - wing spoiler system - world area forecast system

landing n land v accuracy landing achieve a smooth landing aerodrome of intended landing aft landing gear aircraft landing aircraft landing measurement system allowable landing weight all-weather landing capability amphibious landing gear angle of landing approach landing arresting landing gear asymmetric thrust landing autoflare landing automatic landing automatic landing system autorotation landing auxiliary landing field bad weather landing balked landing balked landing path be forced landing belly landing below the landing minima bicycle landing gear blind landing blind landing system body landing gear bogie-type landing gear bounced landing bumpy landing cantilever landing gear carry out a landing castor landing gear clear landing collapsed landing gear commence the landing procedure commit landing compulsory landing contact landing conventional takeoff and landing aircraft correct landing crash landing crash landing strip cross-wind landing day landing dead-engine landing dead-stick landing deck landing design landing mass design landing weight direction for landing distress landing downwind landing dummy landing gear electronic landing aids system emergency landing emergency landing gear emergency landing gear extension emergency landing provisions engine-out landing evacuation in crash landing extend the landing gear fail to extend landing gear fail to retract landing gear fear-up landing fee per landing fixed landing gear flap landing position flapless landing flaps landing setting float-type landing gear forced landing forward retracting landing gear four-wheel bogie landing gear free-fall landing gear from landing operations from landing taxiing full-circle landing full-stop landing gear-down landing glide landing glide-path landing system grass landing area ground-controlled landing ground taxi from landing operation hard landing helicopter-type landing hull equipped landing gear improper landing flareout inadvertently retracted landing gear instrument approach landing instrument landing instrument landing approach instrument landing system intended landing intermediate landing inward retracting landing gear kill the landing speed land after procedure land downwind landing accident landing aerodrome landing after last light landing aids landing approach speed landing area facilities landing beacon landing beam landing beside fix landing capability landing capacity landing characteristics landing charge landing chart landing clearance landing clearance confirmation landing conditions landing configuration landing control landing direction-finding station landing direction indicator landing direction indicator lights landing direction lights landing distance landing distance available landing distance with reverse thrust landing field landing flap landing flare landing flare path landing floodlight landing forecast landing gear landing gear bogie landing gear cycle landing gear door landing gear door latch landing gear drop tests landing gear extention time landing gear fairing landing gear fulcrum landing gear indication system landing gear is down and locked landing gear locking pin landing gear malfunction landing gear operating speed landing gear pilot landing gear pilot pin landing gear position indicator landing gear shock strut landing gear spat (не убирающегося в полете) landing gear tread landing gear well landing gear well dome landing gear wheel landing guidance system landing heading landing headlight landing instruction landing lights landing load landing mass landing minima landing noise landing off the aerodrome landing operation landing pattern landing performance landing procedure landing request landing roll landing roll operation landing run landing runway landing sequence landing sign landing site (для вертолетов) landing speed landing strip (с грунтовым покрытием) landing sudden windshift landing system landing technique landing tee landing transition segment landing turn landing water run landing weight landing windshear land into the wind land into wind land on water land the aircraft land vertically lateral drift landing level landing levered landing gear lock the landing gear lock the landing gear down lock the landing gear up lower the landing gear low visibility landing main landing gear main landing gear beam maximum permitted landing weight minimum landing speed night landing nonretractable landing gear nose landing gear nose landing gear door off-field landing overshooting landing overweight landing pancake landing partial flap landing pontoon equipped landing gear power-off autorotative landing power-on landing precision landing prematurely retracted landing gear prepared landing area prepare for landing priority landing prohibition of landing quadricycle landing gear radar landing minima radio-beacon landing system raise the landing gear rearward retracting landing gear rebound landing reduced takeoff and landing aircraft release the landing gear release the landing gear lock retractable landing gear retract the landing gear reverse-thrust landing rough landing run from landing running landing run out the landing gear safe landing semilevered landing gear short landing short takeoff and landing aircraft single-skid landing gear skid-equipped landing gear ski-equipped landing gear smooth landing speed in landing configuration (конфигурации воздушного судна) spot landing stall landing steerable landing gear straight-in landing supplementary landing gear tail-down landing tailwheel landing gear take-off and landing characteristics talk-down landing test landing three-point landing touch-and-go landing trend-type landing tricycle landing gear two-point landing unlatch the landing gear unobstructed landing area upwind landing vertical landing vertical takeoff and landing aircraft visual landing visually judged landing water landing wheel landing gear wheels-down landing wheels-up landing whilst landing wide-track landing gear wind-assisted landing gear wind landing gear zero-zero landing