He was then sent to the Officer Candidates' School in Brazzaville, French Congo, where he graduated fifth in his class as an Aspirant (Brevet-Lieutenant).

The SAS, originally conceived as an airborne formation, had at this point been converted to a raiding force equipped with machine-gun-armed jeeps.

On his first mission, Zirnheld commanded a team of four men who raided Luftwaffe airfield Berka 3, Libya on 12 June 1942, destroying six enemy aircraft on the ground.

His later missions included the sabotage of a railway track, attacks on Axis convoys, and taking Luftwaffe prisoners.

For his actions, he was proposed for the French Médaille militaire and British Military Cross and received the Croix de Guerre ("Cross of War") with 2 palmes en vermeil (gilded silver Palm Branch pins worn on the medal's ribbon, signifying two Theater-level Mentions-in-Dispatches).

An 18-jeep force attacked the field by driving up the runway in an inverted "V" formation and strafing the parked planes.

While going through a notebook Martin recovered from Zirnheld's body, a text was found that would become La Prière du Para (The Paratrooper's Prayer).

After the war, the problem will be to discover a similar pace.Zirnheld's body was first buried in an hastily dug grave in the Libyan desert by Aspirant Martin, who left directions and landmarks to help locate its whereabouts.

After the North African campaign, Zirnheld's remains were located and interred in the British military cemetery at Mersa Matruh, Egypt.