Question: Arnold Tucker was an officer in a warfare service branch that was formed under which act ?

Context paragraphs:
Eritrean Air Force: The Eritrean Air Force (ERAF) is the official aerial warfare service branch of the Eritrean Defence Forces and is one of the three official uniformed military branches of the State of Eritrea.

Republic of Korea Navy: The Republic of Korea Navy (ROKN; Korean: 대한민국 해군 ; Hanja: 大韓民國海軍; Revised Romanization: "Daehanminguk Haegun"), also known as the ROK Navy, is the naval warfare service branch of the South Korean armed forces, responsible for conducting naval operations and amphibious landing operations.  The ROK Navy includes the Republic of Korea Marine Corps, which is a quasi-autonomous organization.  Established in 1945, the ROK Navy is the oldest branch of the South Korean armed forces.

Arnold Tucker: Arnold Tucker (born January 5, 1924) is a retired United States Air Force officer who graduated from the United States Military Academy at West Point, New York in 1947.

United States Air Force: The United States Air Force (USAF) is the aerial and space warfare service branch of the United States Armed Forces and one of the seven American uniformed services.  Initially part of the United States Army, the USAF was formed as a separate branch of the U.S. Armed Forces on 18 September 1947 under the National Security Act of 1947.  It is the most recent branch of the U.S. Armed Forces to be formed.  The USAF is the largest and one of the most technologically advanced air forces in the world.  The service articulates its core functions as Nuclear Deterrence Operations, Air Superiority, Space Superiority, Cyberspace Superiority, Command and Control, Global Integrated ISR, Global Precision Attack, Special Operations, Rapid Global Mobility, Personnel Recovery, Agile Combat Support, and Building Partnerships.

Philippine Navy: The Philippine Navy (PN; Filipino: "Hukbong Dagat ng Pilipinas"; Spanish: "Armada Filipina") is the naval warfare service branch of the Armed Forces of the Philippines and one of the three uniformed services of the Philippines.  It has an estimated strength of 24,000 active service personnel, including 7,500 marines.

Somali Navy: The Somali Navy Force (SNF), (Somali: "Ciidamada Badda Soomaaliyeed" , Arabic: القوات البحرية الصومالية‎ ‎ ), is the naval warfare service branch of the Somali Armed Forces.  Before independence in 1960, the Somali Navy was established in conjunction with the Italian Navy, the latter of which also helped maintain security in Somali waters.  During the post-independence period, the Somali Navy mostly did maritime patrols so as to prevent ships illegally infringing on the nation's maritime borders.  The Somali Navy and Somali Air Force also regularly collaborated.  In addition, the Somali Navy carried out Search and Rescue (SAR) missions.

United States Navy: The United States Navy (USN) is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States.  The U.S. Navy is the largest, most capable navy in the world, with the highest combined battle fleet tonnage.  The U.S. Navy has the world's largest aircraft carrier fleet, with eleven in service, one in the reserve fleet, and two new carriers under construction.  The service has 322,421 personnel on active duty and 107,577 in the Navy Reserve.  It has 276 deployable combat vessels and more than 3,700 operational aircraft as of 2017 .

Iraqi Air Force: The Iraqi Air Force (IQAF or IAF; Arabic: القوة الجوية العراقية, "Al Quwwa al Jawwiya al Iraqiya") is the aerial warfare service branch of the Iraqi Armed Forces, responsible for the policing of international borders and surveillance of national assets.  The IQAF also acts as a support force for the Iraqi Navy and the Iraqi Army and it allows Iraq to rapidly deploy its developing Army.

Royal Cambodian Navy: The Royal Cambodian Navy (Khmer: កងទ័ពជើងទឹកកម្ពុជា ) is the naval warfare service branch of the Armed Forces of Cambodia and one of the three uniformed services of the Kingdom of Cambodia.  It has an estimated of 4,000 active personnel and operates 228 boats/ships in active service.  It is commanded by Admiral Tea Vinh and sails under the jurisdiction of the Ministry of National Defense.

Turkish Air Force: The Turkish Air Force (Turkish: "" ) is the aerial warfare service branch of the Turkish Armed Forces.  The Turkish Air Force can trace its origins back to June 1911 when it was founded by the Ottoman Empire, however, the air force as it is known today did not come into existence until 1923 with the creation of the Republic of Turkey.

Supporting paragraphs: Arnold Tucker United States Air Force
Answer: the National Security Act of 1947