▁take ▁off ▁in ▁northern ▁Europe , ▁including ▁from ▁Scotland ▁and ▁northern ▁England , ▁but ▁Manchester ▁Airport , ▁that ▁had ▁planned ▁to ▁open ▁on ▁ 2 0 ▁April , ▁remained ▁closed ▁because ▁of ▁a ▁new ▁ash ▁cloud . ▁The ▁Civil ▁A viation ▁Author ity ▁announced ▁that ▁all ▁UK ▁air ports ▁would ▁be ▁permitted ▁to ▁open ▁from ▁ 2 2 0 0 ▁on ▁ 2 0 ▁April . ▁Tw enty - six ▁British ▁Air ways ▁long - ha ul ▁fl ights ▁were ▁already ▁in ▁the ▁air ▁and ▁request ing ▁permission ▁to ▁land . ▁ ▁By ▁ 2 0 – 2 1 ▁April ▁several ▁air lines ▁confirmed ▁that ▁" air ▁service ▁will ▁be ▁res umed ▁in ▁stages " ▁and ▁started ▁publishing ▁lists ▁of ▁selected ▁fl ights ▁that ▁were ▁" most ▁likely ▁to ▁be ▁operated " ▁within ▁one ▁single ▁day . ▁" Effect ive ▁Th urs day , ▁ 2 2 ▁April , ▁L uf th ans a ▁will ▁res ume ▁normal ▁flight ▁operations ▁and ▁offer ▁you ▁the ▁usual ▁reli ability ", ▁claimed ▁the ▁air line ▁at ▁ 1 5 : 3 0 ▁on ▁ 2 1 ▁April . ▁ ▁Str and ed ▁trav ellers ▁The ▁closure ▁of ▁the ▁air space ▁left ▁five ▁million ▁trav ellers ▁str and ed ▁around ▁the ▁world , ▁of ▁which ▁up ▁to ▁a ▁million ▁were ▁British ▁according ▁to ▁AB TA . ▁Several ▁thousand ▁passengers ▁were ▁str and ed ▁in ▁Asia , ▁the ▁United ▁States , ▁and ▁Australia . ▁Dis ruption ▁was ▁greater ▁than ▁that ▁after ▁the ▁ 1 1 ▁September ▁attacks ,