Bo ats ▁off sh ore ▁of ▁the ▁Canal ▁Zone ▁under ▁direction ▁of ▁Coast ▁Def enses ▁of ▁Crist ob al , ▁from ▁ 1 ▁June ▁– ▁ 1 5 ▁November ▁ 1 9 1 8 . ▁ ▁The ▁ 7 th ▁A ero ▁Squadron ▁was ▁assigned ▁to ▁several ▁fields ▁during ▁ 1 9 1 7 ▁and ▁ 1 9 1 8 , ▁those ▁being ▁Cor oz al ▁( 1 6 ▁April ); ▁Empire ▁( May ); ▁Fort ▁Sh erman ▁( 2 9 ▁August ); ▁Crist ob al ▁( M arch ▁ 1 9 1 8 ) ▁before ▁finding ▁a ▁permanent ▁home ▁at ▁C oco ▁Walk , ▁which ▁became ▁France ▁Field ▁in ▁May ▁ 1 9 1 8 . ▁ ▁A ▁second ▁permanent ▁army ▁air field , ▁Al bro ok ▁Field , ▁opened ▁in ▁ 1 9 3 2 ▁due ▁to ▁France ▁Field ▁becoming ▁too ▁small ▁for ▁the ▁numbers ▁of ▁aircraft ▁being ▁assigned ▁to ▁the ▁Canal ▁Zone , ▁as ▁well ▁as ▁having ▁a ▁poor ▁landing ▁surface ; ▁offering ▁no ▁room ▁for ▁expansion , ▁and ▁providing ▁little ▁defense ▁for ▁the ▁Pacific ▁entrance ▁to ▁the ▁Pan ama ▁Canal . ▁A ▁third ▁air field , ▁Howard ▁Field ▁was ▁built ▁on ▁the ▁Canal ▁Bru ja ▁Point ▁Military ▁Res ervation , ▁opening ▁on ▁ 1 ▁December ▁ 1 9 3 9 . ▁By ▁ 1 9 4 0 , ▁a ▁rapid ▁increase ▁in ▁the ▁number ▁of ▁flying ▁squad rons ▁in ▁both ▁the ▁Canal ▁Zone ▁as ▁well ▁as ▁in ▁Pan ama ▁as ▁a ▁result ▁of ▁the ▁pre – World ▁War ▁II