I-Lockheed F-117A Nighthawk
I-F-117A iwuphawu lokuphakama kobuchwepheshe baseMelika phakathi neMpi Yomshoshaphansi.
I-F-117A Nighthawk yakhiwa ngu-Lockheed ukuphendula isidingo se-United States Air Force (USAF) senkundla ekwazi ukunyonyoba ezinhlelweni zokuvikela komoya zesitha. Kwadalwa indiza eyingqayizivele, okwathi, ngenxa yesimo sayo esingajwayelekile kanye nempumelelo yokulwa eyinganekwane, yangena emlandweni wokundiza kwezempi unomphela. I-F-117A ibonakale iyindiza yokuqala ephansi kakhulu (VLO), evame ukubizwa ngokuthi "i-stealth".
Okwenzeka ngeMpi Yom Kippur (impi phakathi kuka-Israyeli nomfelandawonye wama-Arab ngo-1973) kwabonisa ukuthi izindiza zase ziqala ukulahlekelwa ukuncintisana kwazo "kwaphakade" nezinhlelo zokuvikela emoyeni. Amasistimu we-electronic jamming kanye nendlela yokuvikela iziteshi ze-radar "ngokwembula" ama-dipoles kagesi kagesi abe nemikhawulo yawo futhi awazange anikeze ikhava eyanele yendiza. I-Defence Advanced Research Projects Agency (DARPA) isiqalile ukubheka ukuthi kungenzeka yini "ukudlula". Umqondo omusha wawuhilela ukuthuthukiswa kobuchwepheshe ukuze kuncishiswe i-radar reflection surface esebenzayo (i-Radar Cross Section - RCS) yendiza ibe sezingeni elivimbela ukutholwa kwayo ngempumelelo yiziteshi ze-radar.
Ukwakhiwa kwe-#82 kwesitshalo se-Lockheed eBurbank, eCalifornia. Indiza imbozwe nge-microwave emunca i-microwave kanye nopende ompunga okhanyayo.
Ngo-1974, i-DARPA yethula uhlelo olungakahleleki olwaziwa ngokuthi yi-Project Harvey. Igama layo lalingelona iphutha - lalibhekisela efilimini yango-1950 iHarvey, umlingisi oyinhloko okwakungunogwaja ongabonakali ocishe ube ngamamitha amabili ubude. Ngokweminye imibiko, lo msebenzi wawungenalo igama elisemthethweni ngaphambi kokuqala kwesiteji esithi "Have Blue". Olunye lwezinhlelo zePentagon ngaleso sikhathi lwalubizwa ngokuthi iHarvey, kodwa kwakungamaqhinga. Kungenzeka ukuthi ukusabalala kwegama elithi "Project Harvey" kwakuhlotshaniswa nemisebenzi yokusabalalisa ulwazi mayelana nemisebenzi yangaleso sikhathi. Njengengxenye yohlelo lwe-DARPA, icele izixazululo zobuchwepheshe ukusiza ukwehlisa i-RCS yendiza engaba khona yokulwa. Izinkampani ezilandelayo zimenywe ukuba zibambe iqhaza ohlelweni: Northrop, McDonnell Douglas, General Dynamics, Fairchild kanye noGrumman. Ababambiqhaza bohlelo kwadingeka banqume ukuthi banazo yini izinsiza namathuluzi okwakha indiza ye-RCS okungenzeka ibe nephansi kakhulu.
U-Lockheed wayengekho ohlwini lwe-DARPA ngenxa yokuthi inkampani yayingazange yenze indiza yokulwa eminyakeni eyi-10 futhi kwanqunywa ukuthi ingase ingabi nalo ulwazi. U-Fairchild no-Grumman baphumile embukisweni. I-General Dynamics ngokuyisisekelo inikelelwe ukwakha izindlela ezintsha zokumelana ne-elekthronikhi, okuthi, nokho, yehlule kulokho obekulindelwe yi-DARPA. UMcDonnell Douglas kanye no-Northrop kuphela abethule imiqondo ehlobene nokunciphisa indawo esebenza kahle yokubonisa i-radar futhi babonisa amandla okuthuthukiswa kanye ne-prototyping. Ekupheleni kuka-1974, zombili izinkampani zithole i-PLN 100 ngayinye. Izinkontileka ze-USD zokuqhubeka nomsebenzi. Kulesi sigaba, i-Air Force ijoyine uhlelo. Umkhiqizi we-radar, i-Hughes Aircraft Company, naye ubambe iqhaza ekuhloleni ukusebenza kwezixazululo ngazinye.
Maphakathi no-1975, uMcDonnell Douglas wethula izibalo ezibonisa ukuthi ingxenye ye-radar yendiza kufanele ibe phansi kangakanani ukuze iyenze "ingabonakali" kuma-radar angaleso sikhathi. Lezi zibalo zithathwe yi-DARPA kanye ne-USAF njengesisekelo sokuhlola amaphrojekthi wesikhathi esizayo.
I-Lockheed iyadlala
Ngaleso sikhathi, ubuholi buka-Lockheed baqaphela imisebenzi ye-DARPA. U-Ben Rich, okwathi kusukela ngoJanuwari 1975 wayeyinhloko yophiko lokuklama oluthuthukisiwe olubizwa ngokuthi i-Skunk Works, wanquma ukuba nengxenye ohlelweni. Usekelwe owayeyinhloko ye-Skunks Works u-Clarence L. "Kelly" Johnson, owaqhubeka nokusebenza njengonjiniyela omkhulu wophiko. UJohnson ucele imvume ekhethekile ku-Central Intelligence Agency (CIA) ukuze adalule imiphumela yocwaningo ehlobene nezilinganiso ze-radar cross section yendiza yezobunhloli i-Lockheed A-12 kanye ne-SR-71 kanye ne-D-21 reconnaissance. Lezi zinto zinikezwe i-DARPA njengobufakazi besipiliyoni senkampani nge-RCS. I-DARPA ivumile ukufaka u-Lockheed ohlelweni, kodwa okwamanje ayikwazanga ukungena naye esivumelwaneni sezezimali. Inkampani ingene ohlelweni ngokutshala izimali zayo. Lokhu kwakuwuhlobo oluthile lwesithiyo ku-Lockheed, ngoba, engaboshiwe yinkontileka, akazange alahle amalungelo kunoma yiziphi izixazululo zakhe zobuchwepheshe.
Onjiniyela be-Lockheed bebelokhu bexoxa ngomqondo ojwayelekile wokunciphisa indawo ekhombisa ukusebenza kahle kwe-radar isikhathi eside. Unjiniyela uDenis Overholser kanye nesazi sezibalo uBill Schroeder bafinyelela esiphethweni sokuthi ukubonakaliswa okusebenzayo kwamagagasi e-radar kungafinyelelwa ngokusebenzisa izindawo eziningi ezincane eziyisicaba ngangokunokwenzeka ngama-engeli ahlukene. Babeqondisa ama-microwave abonisiwe ukuze angakwazi ukubuyela emthonjeni, okungukuthi, ku-radar. U-Schroeder udale isibalo sezibalo ukuze abale izinga lokubonakala kwemisebe ukusuka endaweni eyisicaba engunxantathu. Ngokusekelwe kulokhu okutholakele, umqondisi wocwaningo we-Lockheed, u-Dick Scherrer, wakha isimo sokuqala sendiza, enephiko elikhulu, eligobile kanye ne-fuselage yezindiza eziningi.
