4 ▁variant . ▁Among ▁other ▁changes ▁to ▁earlier ▁variants , ▁it ▁featured ▁G M - 1 ▁nit r ous ▁ox ide ▁' boost ' ▁for ▁its ▁Da im ler - B enz ▁DB ▁ 6 0 5 ▁engine ▁giving ▁it ▁an ▁advantage ▁to ▁contemporary ▁R AF ▁f igh ters ▁at ▁higher ▁alt itude . ▁II . ▁Gruppe ▁was ▁scheduled ▁to ▁be ▁fully ▁re equ ipped ▁with ▁the ▁B f   1 0 9   G - 4 ▁in ▁early ▁ 1 9 4 3 . ▁However , ▁Gru pp enk om mande ur ▁( group ▁commander ) ▁Haupt mann ▁Con ny ▁Meyer , ▁and ▁later ▁Gall and , ▁st alled ▁the ▁transition , ▁retain ing ▁their ▁F ock e - W ulf ▁F w ▁ 1 9 0 ▁f igh ters ▁until ▁the ▁decision ▁was ▁rev oked , ▁as ▁they ▁believed ▁the ▁F w   1 9 0 ▁to ▁be ▁superior ▁and ▁more ▁vers atile ▁to ▁the ▁B f   1 0 9 . ▁Gall and ▁claimed ▁his ▁ 2 1 st ▁and ▁last ▁aer ial ▁victory ▁of ▁ 1 9 4 2 ▁on ▁ 3 1 ▁December ▁ 1 9 4 2 . ▁On ▁New ▁Year ' s ▁E ve , ▁he ▁shot ▁down ▁a ▁Sp it fire ▁from ▁No . ▁ 3 0 6 ▁Polish ▁F ighter ▁Squadron ▁north - n orth west ▁of ▁the ▁Som me ▁Est u ary . ▁ ▁Group ▁commander ▁and ▁death ▁On ▁ 2 ▁January ▁ 1 9 4 3 , ▁Gall and ▁was ▁appointed ▁Gru