The Twenty Minuters is Flashheart's Royal Flying Corps Fighter squadron. When Private Baldrick asks how the squadron got the name, Lieutenant George's reads out the caption in his Book of the Air, which states that new pilots spend an average of twenty minutes in the air.[1]
When Captain Darling asks the same question during the training briefing, Flashheart states that the average flight time of twenty minutes for new pilots is actually the life expectancy. [2]