▁successfully ▁carried ▁out ▁a ▁test ▁flight ▁from ▁Amsterdam ▁to ▁Düsseldorf ▁with ▁no ▁problems . ▁After wards , ▁seven ▁K LM ▁plan es ▁with ▁no ▁passengers ▁returned ▁from ▁Düsseldorf ▁to ▁Amsterdam . ▁Air ▁France ▁also ▁performed ▁a ▁test ▁flight ▁from ▁Paris ▁to ▁Toul ouse . ▁In ▁the ▁evening ▁of ▁ 1 8 ▁April ▁German ▁air space ▁was ▁partially ▁re - open ed ▁for ▁a ▁period ▁of ▁ 3 ▁hours ▁allowing ▁a ▁plane ▁of ▁str and ed ▁hol iday m akers ▁from ▁Far o , ▁Portugal ▁to ▁land ▁at ▁Han over . ▁ ▁The ▁vice ▁president ▁of ▁the ▁Dutch ▁pil ots ▁union ▁said ▁" We ▁are ▁asking ▁the ▁authorities ▁to ▁really ▁have ▁a ▁good ▁look ▁at ▁the ▁situation , ▁because ▁ 1 0 0 ▁per ▁cent ▁safety ▁does ▁not ▁exist ," ▁Mr . ▁Ver hagen ▁continued . ▁" It ' s ▁easy ▁to ▁close ▁down ▁air ▁space ▁because ▁then ▁it ' s ▁perfectly ▁safe , ▁but ▁at ▁some ▁time ▁you ▁have ▁to ▁res ume ▁fl ights ." ▁ ▁In ▁the ▁afternoon ▁of ▁ 1 9 ▁April , ▁German ▁carri ers ▁L uf th ans a ▁and ▁Air ▁Berlin ▁obtained ▁permission ▁for ▁some ▁fl ights ▁from ▁and ▁to ▁German ▁air ports ▁under ▁Visual ▁Fl ight ▁R ules . ▁L uf th ans a ▁started ▁sending ▁plan es ▁to ▁long - ha ul ▁destination ▁in ▁order ▁to ▁return ▁str and ed ▁passengers ▁later ▁that ▁day . ▁ ▁Late ▁on ▁ 1 9 ▁April ▁and ▁early ▁on ▁ 2 0 ▁April , ▁some ▁fl ights ▁were ▁permitted ▁to