 Johnson 's first contact with enemy single @-@ engine fighters did not go as planned . Bader undertook a patrol with Dundas as his number two . Johnson followed in his section as number three with " Nip " <unk> guarding his tail as Red Four . Johnson spotted three Bf 109s a few hundred feet higher and travelling in the same direction . Johnson , forgetting to calmly report the number , type and position of the enemy , shouted , " Look out <unk> ! " ( Bader 's call sign ) . Such a call was only to be used if the pilot in question was in imminent danger of being " bounced " . The Section broke in all directions and headed to Tangmere singly . The mistake brought an embarrassing rebuke from Bader at the debriefing . 
