Marcinkus participated in an early trans-European flight on 25 June 1934, and was the only Lithuanian pilot to serve in the Royal Air Force (RAF) during the Second World War.

While serving in the Lithuanian Air Force, Marcinkus was a parachute instructor, and headed the aviation sport and physical education department, and during his later years coached a junior football team.

At Stalag Luft III Marcinkus became an active member of an underground group of prisoners who organized and executed the Great Escape.

[3]: 253–254  After his father's death in 1927, Marcinkus took on the responsibility of supporting his remaining family, he also began playing football for LFLS Kaunas.

[2] The aviator Steponas Darius, with associates, had established the Lietuvos Fizinio Lavinimo Sąjunga, which soon became one of the leading football clubs in Lithuania.

[2] In 1934 Marcinkus was transferred to the air reconnaissance department, there he started improving his expertise in independent flying, mapping, photography, and weapon systems.

During the 25 days of their flight, the pilots flew three of Gustaitis' designed aircraft, the ANBO IVs, over 10,000 kilometers and visited 12 European capitals.

[1]: 320 Upon his return, Marcinkus was promoted to the rank of captain and decorated with the Order of the Lithuanian Grand Duke Gediminas Knight's Cross.

[2] Despite the fact that he was decorated with steel wings (plieno sparnai), the highest award in Lithuanian military aviation,[1]: 320  the following year proved very trying on a personal level.

[1]: 320 While the Winter War was gathering momentum, Marcinkus argued for supporting Finland, but Lithuania remained neutral during the conflict.

It is possible, however, that Marcinkus succeeded in shooting down several German military planes during his short career in the French air force.

[1]: 182  At that time, his homeland Lithuania had already lost its independence to the Soviet Union, and the Lithuanian air force was rapidly liquidated by its occupiers.

Throughout the years, Maricinkus maintained close contacts with the Lithuanian attaché in Britain in order to receive news about Lithuania and his family.

[1]: 322  Marcinkus wrote in his letter about the new challenges lying ahead: I was transferred to the night fighters – at that time the most dangerous kind of military aviation.

With this I am satisfied, but...I am lacking warmth and the comfort of my personal life in this country of "cold slob weather and so called correctness".

[1]: 182 In one of the Marcinkus's letters to the Lithuanian envoy, Bronius Kazys Balutis, he notes that he shot down his first German bomber, a Dornier Do 17 in March.

Marcinkus also wrote that he was gathering skills and knowledge in order to make a contribution towards liberating Lithuania and restoring its independence.

[1]: 183 In the RAF, Marcinkus carried out multiple tasks, including various training missions, night combat and bomber escort.

[1]: 198  The original report submitted by Marcinkus claiming one Bf 109 shot down on 21 June 1941 is held in The National Archives; he states that he fired two short bursts from his guns from 100 yards behind the German.

During the course of the battle, the British lost approximately forty planes and failed to prevent the German fleet from returning to Kiel and Wilhelmshaven.

[7] Marcinkus was sent to Stalag Luft III, a prisoner-of-war camp near Sagan that housed captured air force servicemen during the Second World War.

[1]: 82 Squadron Leader Roger Bushell selected inmates and began planning an escape, at first focused on digging a tunnel.

He was especially good at memorizing numbers, dates, and after analyzing a pile of information, he made a precise compilation of the Reich's railway schedules.

[1]: 264  The group's prospects hinged on the hope that the Germans encountered on the way would not speak or understand Lithuanian, as Marcinkus was the only member fluent in that language.

[1]: 265–268 Marcinkus and the three prisoners in his group posing as Lithuanians – Tim Walenn, Henri Picard and Gordon Brettell – managed to reach a train heading towards Danzig (now Gdansk, Poland).

[12] By the time of his death Marcinkus held the rank of flight lieutenant in the Royal Air Force Volunteer Reserve.

Its Foreign Secretary, Anthony Eden, then delivered this speech to the House of Commons: His Majesty's Government must, therefore, record their solemn protest against these cold-blooded acts of butchery.

During the 1950s articles about Marcinkus began to appear in these newspapers, including Karys, Vienas iš daugelio (1950), Paskutinis žuvusiojo lakūno atvirukas (1955), and Kapitono Marcinkaus mirtis nelaisvėje (1956).

In 2001 the British Ambassador in Vilnius gave Marcinkus' previously unclaimed war medals to a surviving relative, his nephew, Alvydas Gabėnas, during a commemorative ceremony.

[16] Gražina Sviderskytė, a CNN award-winning journalist, wrote a detailed account of Marcinkus' life in her book Uragano kapitonas ("Hurricane Captain"), which was published in 2004.