aircraft accidentally violated
... that, only one month after the Berlin Wall was built, two West German aircraft accidentally violated East German airspace, flying to Berlin Tegel Airport on 14 September 1961?
... that, only one month after the <a href="./Berlin_Wall" id="mwFro" rel="mw:WikiLink" title="Berlin Wall">Berlin Wall</a> was built, two <a href="./West_Germany" id="mwFrs" rel="mw:WikiLink" title="West Germany">West German</a> <b id="mwFrw"><a href="./1961_F-84_Thunderstreak_incident" id="mwFr0" rel="mw:WikiLink" title="1961 F-84 Thunderstreak incident">aircraft accidentally violated</a></b> <a href="./East_Germany" id="mwFr4" rel="mw:WikiLink" title="East Germany">East German</a> airspace, flying to <a href="./Berlin_Tegel_Airport" id="mwFr8" rel="mw:WikiLink" title="Berlin Tegel Airport">Berlin Tegel Airport</a> on 14 September 1961?