1 February 1920
On 1 February 1920, the South African Air Force was established. This made it the first air force of the Commonwealth, with Lt-Col. Pierre van Ryneveld appointed Director of Air Services.  The origin of the South African Air Force can be traced back to 1912, when the Union Defence Force (UDF) was formed. This formation included the South African Aviation Corps (SAAC), which was formed as part of the Active Citizen Force (ACF). In April 1914, six pupils (with the probationary ranks of lieutenant in the ACF) were sent to England to undergo further training. Five of them eventually qualified. When World War I broke out in August 1914, these pilots were granted permission to join the newly formed Royal Flying Corps (RFC). The number of South Africans in the RFC eventually reached approximately 3,000, with 260 active-duty fatalities. These pilots took part in aerial reconnaissance and artillery spotting missions over France during the war. In 1921 the SAAF bought a site east of Roberts Height (later Voortrekkerhoogte and now Thaba Tshwane), near Pretoria. Here the first aerodrome for the SAAF was established and was named Zwartkops. The SAAF is, next to the Royal Air Force (RAF), the world's second oldest air force. The first operation of the South African Air Force was in 1922, when it helped to crush the Rand Revolt, an armed uprising by white mineworkers. The SAAF bombed targets around Johannesburg, and lost some aircraft to ground fire. Col. Sir Pierre van Ryneveld was shot down, but he survived. From 1966 to 1989, the SAAF was committed to the Border War, which was fought in northern South West Africa and surrounding states.
References

Potgieter, D.J. et al. (eds) (1970). Standard Encyclopaedia of Southern Africa, Cape Town: NASOU, v. 1|Aircraft.co.za, South African Air Force established, from AIRCRAFT, [online], Available at aircraft.co.za [Accessed: 25 January 2009]