▁Mc N am ara ▁sent ▁a ▁directive ▁to ▁the ▁Army ▁to ▁bro aden ▁its ▁thinking ▁about ▁air ▁operations ▁and ▁try ▁to ▁avoid ▁invent ing ▁yet - another ▁log istics ▁vehicle . ▁These ▁comments ▁led ▁to ▁the ▁formation ▁of ▁the ▁How ze ▁Board , ▁which ▁enthus iast ically ▁supported ▁the ▁use ▁of ▁hel ic op ters ▁in ▁combat . ▁The ▁increasing ▁use ▁and ▁special ization ▁of ▁hel ic op ters ▁during ▁the ▁Vietnam ▁War ▁served ▁to ▁drive ▁these ▁concepts ▁home , ▁and ▁in ▁ 1 9 6 5 ▁the ▁Army ▁began ▁the ▁Advanced ▁Aer ial ▁Fire ▁Support ▁System ▁( A AF SS ) ▁to ▁develop ▁its ▁first ▁dedicated ▁attack ▁hel ic opter . ▁ ▁In ▁ 1 9 6 6 , ▁the ▁British ▁Army ▁of ▁the ▁Rh ine ▁ran ▁a ▁series ▁of ▁tests ▁known ▁as ▁Operation ▁Hell ▁T ank ▁with ▁the ▁goal ▁of ▁testing ▁the ▁use ▁of ▁anti - t ank ▁miss iles ▁against ▁sim ulated ▁W TO ▁forces . ▁In ▁one ▁operation , ▁Hell ▁T ank ▁IV , ▁the ▁hel ic op ters ▁ran ▁up ▁a ▁ 4 5 - to - 1 ▁score ▁over ▁t anks ▁that ▁were ▁executing ▁a ▁break out . ▁The ▁tests ▁also ▁demonstrated ▁that ▁the ▁hel ic op ters ▁were ▁much ▁less ▁useful ▁against ▁t anks ▁in ▁def ensive ▁positions ▁with ▁their ▁engines ▁turned ▁off , ▁making ▁them ▁very ▁difficult ▁to ▁spot ▁from ▁the ▁air . ▁ ▁While ▁these ▁events ▁were ▁occurr ing , ▁in ▁ 1 9 6 9 ▁Richard ▁N ixon ▁form ulated ▁the ▁N ixon