Abstract—Seroja operation is the biggest aerial operation that has been taken by Indonesian Military. Indonesian Air Force (TNI-AU) acts as the air elements that support the Seroja Operation. The purpose of this research was to find out: 1) the background and the course of the Seroja Operation in East Timor. 2) TNI-AU involvement of Seroja Operation in East Timor 1975-1979, and 3) the effects of Seroja Operation on TNI-AU. This study employed the historical research method by Kuntowijoyo. The first stage was topic selection. The second was the collection of primary and secondary sources. The third was verification or source criticism. The fourth was interpretation. The fifth or final stage was history writing. The results of the study were as follows. 1) Seroja Operation is motivated by a civil war that happened in East Timor. This operation began on December, 7th 1975 signed Seroja Operation. Seroja Operation involved all aspects of military power. 2) TNI-AU involvement in Seroja Operation in East Timor from 1975-1979 was as the air elements of air traffic rush. This air element is intended to carry out attacks from the air either direct attack or air fire support. East Timor operations always involved TNI-AU either as an element of the air force or ground force. 3) The effects of Seroja Operation severe consequence for TNI-AU. TNI-AU started to build back its air force elements. Purchasing a variety of fighter aircraft carried out by TNI-AU strengthened the air force. The arrival of the aircraft from Western block was in addition to strengthen TNI-AU also facilitating the operations performed in East Timor. Index Terms—Seroja operation, TNI-AU, east timor. I. INTRODUCTION East Timor was once colonized by Portugal. East Timor was independent from Portuguese after the Carnation Revolution in Portugal occured. Carnation Revolution reached the peak on April 25th, 1974 and caused a huge change in Portuguese social life as well as their colonies. Decolonisation policy in East Timor caused the emerge of political parties there. They were Uniao Democratica Timorense (UDT), Associacao Popular Democratica de Timor (APODETI), and Associacao Social Democratica Timorense (ASDT). Yet, ASDT changed name to be Frent Revolucionaria de Timor Leste Independente (FRETILIN). Those parties had different thought about the future of East Timor. UDT wanted an East Timor government under Portugal protection, APODETI wanted East Timor government joining Indonesia, while FRETILIN wanted East Timor government independent. Later, UDT and FRETILIN Manuscript received August 15, 2016; revised March 1, 2017. The authors are with History Education Major, YSU, Indonesia (e-mail: Yusuf.ervanda@gmail.com, 2ozi.ahmad38@yahoo.com, zulkarnain@uny.ac.id). formed a coalition to build an independent country. Yet, it did not last long. UDT the approached Indonesia with APODETI. The difference of political ideology in East Timor caused conflict for so long. The parties who want to integrate with Indonesia asked for Indonesian governments’s help to go against the radicalism of FRETILIN party. Indonesian government assign Indonesian Military (ABRI) troops to help the parties in East Timor striving for being the part of Indonesia. The operation was called as Seroja Operation. Seroja Operation was the biggest aerial operation (Linud/Lintas Udara) that has been taken by Indonesian Military. It involved ABRI troops that consisted of Indonesian Army, Indonesian Navy, Indonesian Air Force, and police force. The whole troops took important roles in supporting the pro-integration groups against FRETILIN group who is contra-Indonesia, but Indonesian Air Force (TNI-AU) was the most dominating in succeeding Seroja Operation. Considering the landscape of East Timor which was dominated by rocks and hills, the role of Air Force is crucial. This research aimed to identify the role of Indonesian Air Force in Seroja Operation. The Air Force was the key to the success of Seroja Operation in East Timor, like the deployment of Parako (Para Komando) soldiers, deployment of Special Forces Command from Air Force, even the deployment of the aircrafts of Air Force. The focus of this study was discussing the implementation of Seroja Operation in East Timor and the involvement of Indonesian Air Force in the operation in 1975-1979. The period of 1975-1979 was chosen because that was the year when Seroja Operation started under the command of Komando Tugas Gabungan (Kogasgab). In 1797, Seroja Operation was anounced to be finished because East Timor had declared as safe and ABRI had reigned the whole area of East Timor. II. METHOD This reseach employed Critical Historical Research by Kuntowijoyo. The writing process took five stages of historical method: (a) topic selection, (b) sources obtaining, (c) verification (criticism, history, and validity of sources), (d) interpretation: analysis and syntetic, and (e) historiografi or history writing [1]. The author used three kinds of approaches. The first was geographical approach to analyse the landcape and natural condition of East Timor in 1975-1979. Geographical information was important as one of consideration in the The Role of Indonesian National Air Force (TNI-AU) in Seroja Operation in East Timor (1975-1979) Brilliantoro Yusuf Ervanda, Akhmad Fakhrurroji, and Zulkarnain International Journal of Culture and History, Vol. 3, No. 1, March 2017 44 doi: 10.18178/ijch.2017.3.1.076