7 0 s ▁▁▁▁ 1 9 7 0 : ▁Terminal ▁ 3 ▁was ▁expanded ▁with ▁the ▁addition ▁of ▁an ▁arrival s ▁building ▁in ▁ 1 9 7 0 . ▁Other ▁new ▁facilities ▁included ▁the ▁UK ' s ▁first ▁moving ▁walk ways . ▁He ath row ' s ▁two ▁main ▁east - west ▁run ways , ▁ 1 0 L / 2 8 R ▁and ▁ 1 0 R / 2 8 L ▁( l ater ▁red es ign ated ▁ 0 9 L / 2 7 R ▁and ▁ 0 9 R / 2 7 L ) ▁were ▁also ▁extended ▁to ▁their ▁current ▁lengths ▁to ▁accommod ate ▁new ▁large ▁j ets ▁such ▁as ▁the ▁Bo eing ▁ 7 4 7 . ▁The ▁other ▁run ways ▁were ▁closed ▁to ▁facil itate ▁terminal ▁expansion , ▁except ▁for ▁Run way ▁ 2 3 , ▁which ▁remained ▁available ▁for ▁cross wind ▁land ings ▁until ▁ 2 0 0 2 . ▁▁ 1 9 7 3 : ▁The ▁truth ▁about ▁the ▁secret ▁Air ▁Ministry ▁plan ▁came ▁out , ▁in ▁Harold ▁B alf our ' s ▁aut obi ography ▁( W ings ▁over ▁West min ster , ▁pub l . ▁H utch inson , ▁London , ▁ 1 9 7 3 ). ▁▁ 1 9 7 4 : ▁The ▁check - in ▁facilities ▁at ▁the ▁West ▁London ▁Air ▁Terminal ▁close . ▁▁ 1 9 7 4 : ▁He ath row ▁was ▁briefly ▁occupied ▁by ▁the ▁Army , ▁ost ens ibly ▁as ▁a ▁training ▁run ▁in ▁case ▁of ▁possible ▁I