A tentative attempt was made to form an air arm in 1926, These aircraft bore Arabic inscriptions on red or possibly green panels on fuselage and rudder, that on the fuselage reading 'There is no God but Allah and Mohammed is his prophet'. It was not until 1956 that any viable military aviation unit was established. This was in effect the Imam of Yemen's private air fleet and carried his personal emblem, a red flag bearing a white sword and five white stars. During the later part of this period a roundel version was occasionaly used. Although many of these aircraft also carried civil markings, they were mostly military types supplied by eastern Europe.
For a short period, between 1958 and 1961, Yemen had a loose association with the United Arab Republic, and with the establishment of the Yemen Arab republic in 1962 a new flag of red over white over black with a single green star was adopted. This was the basis for the insignia of the Yemen Air force. The green star was dropped by 1979, and for a brief period the national flag, and therefore the fin flash, featured white crossed swords on the red area.
In 1959 the British possession of Aden split into the Aden colony and the Federation of South Arabia, the old Aden Protectorate, The federation flag was dark blue over green over blue separated by thin yellow lines, A white star and crescent was superimposed. Aircraft of the South Arabian Air Force carried the national flag, without the star and crescent, as a fin flash, A roundel in the national colours, split horizontally and including the star and crescent, was used as a wing and fuselage marking.
The British left Aden in 1967 and the country became the Yemen People's Democratic Republic, The national flag was the Yemen Arab Republic's tricolour, with a blue triangle bearing a red star, at the hoist. This was used as a fin flash until the unification of the two Yemens in 1990. The initial wing and fuselage marking was a blue triangle with a black border and a centrally placed red star. By 1980 this had been changed to a three-colour roundel with a triangular segment at the top. This insignia was abolished in favour of that of the Yemen Arab Republic, North Yemen, in 1990.Since about 1979 the aircraft marking has been a plain red, white and black roundel and fin marking. This has continued in use for the new Yemen, which unified north and south, in 1990.