▁Research ▁Company ▁( A viation ), ▁call ▁sign ▁" C ra zy ▁Cat ", ▁based ▁at ▁Cam ▁Ran h ▁Air ▁Base ▁in ▁South ▁Vietnam , ▁as ▁an ▁electronic ▁" fer ret " ▁aircraft ▁intercept ing ▁low - power ed ▁tact ical ▁voice ▁and ▁mor se ▁code ▁radio ▁signals . ▁The ▁US ▁Army ▁operated ▁the ▁P - 2 ▁from ▁ 1 9 6 7 ▁until ▁ 1 9 7 2 , ▁flying ▁ 4 2 , 5 0 0 ▁hours ▁with ▁no ▁acc idents . ▁Observ ation ▁Squadron ▁ 6 7 ▁( VO - 6 7 ), ▁call ▁sign ▁" L ind y ", ▁was ▁the ▁only ▁P - 2 ▁Ne pt une ▁aircraft ▁squad ron ▁to ▁ever ▁receive ▁the ▁President ial ▁Unit ▁C itation , ▁flying ▁Ig lo o ▁White ▁miss ions ▁sow ing ▁se ism ic ▁and ▁ac oust ic ▁sens ors ▁over ▁the ▁Ho ▁Chi ▁Min h ▁Tra il . ▁V O - 6 7 ▁lost ▁three ▁OP - 2 E ▁aircraft ▁and ▁ 2 0 ▁air cre w ▁to ▁ground ▁fire ▁during ▁its ▁secret ▁miss ions ▁into ▁La os ▁and ▁Vietnam ▁in ▁ 1 9 6 7 – 6 8 . ▁The ▁Republic ▁of ▁China ▁Air ▁Force ▁( RO C AF ) ▁secret ▁ 3 4 th ▁Black ▁Bat ▁Squadron ' s ▁R B - 6 9 A / P 2 V - 7 U ▁EL INT / SI G INT ▁aircraft ▁fle w ▁a ▁low ▁level ▁electronic ▁reconna issance ▁from ▁Da ▁N ang ▁Air ▁Base , ▁flying ▁over ▁Th