Originally operated by the Romanian Air Force's 135th Jet Fighter Regiment based at Caransebes, the aircraft was flown to Yugoslavia by Mihail Diaconu, who requested political asylum as soon as he landed.[N 1]
The jet had all its markings removed and was put trough a rigorous flight test program by the VOC (Testing and Evaluation Center), including weaponry trials (the Yak-23 had two NR-23 guns in the lower nose, 23mm caliber with 90 rounds each). Three different Yugoslav pilots, Captains Vodopivec, Prebeg and Todorovic flew 21 sorties totaling 9 hours.
Sometimes in October 1953, Yugoslavian authorities contacted the local CIA residence, offering the Yak for evaluation. The CIA, in its turn, called upon the ATIC (Air Technical Intelligence Center) at Wright-Patterson AFB, thus “Project Alpha” was born. The crated Yak was airlifted by a C-124 belonging to the 4th Troop Carrier Squadron, 62nd Troop Carrier Wing based at Larson AFB, Washington; the last leg of the mission being flown from a US base near Munich to Yugoslavia at night. Three Yugoslavian personnel accompanied the dismantled Yak to Wright-Patterson AFB, Ohio.
Chief of the “Project Alpha” was an USAF civilian employee, named I.H. Herman. The pilot for the Yak was Captain H.E. “Tom” Collins (the same who flew a few weeks earlier for the first time on the North-Korean MiG-15 bis #2057 delivered by No Kum Sok), while Lt. Col. Fred Wolfe flew the chase plane. The ground crew chief was Ray Gardiner with two other mechanics: Stan Kulikowski and Ronnie Wilcoxin, most likely aided by the Yugoslavs flown in together with the plane.
The Flora was given removable USAF markings and serial FU-599.[N 2] For those outside the program who asked, it was the Bell X-5 prototype. A total of 8 test flights were performed, with the first on 4 November and the last on 25 November 1953. After this last flight, the US markings were removed, the plane disassembled and crated for transport back to Yugoslavia. Another C-124 (tail no. 0097) from the same unit as above, flown this time by Captain Leroy D. Good was called upon to deliver the crates. Apart from the crew, 6 to 12 foreigners (almost certainly Yugoslavs) and an unidentified USAF Colonel boarded the plane at Wright Patterson. The route was the same – flying to the USAF base near Munich, than at night to Yugoslavia, where they were intercepted and led by two prop-driven fighters. Cpt. Good believes he landed at Pancevo, where the Yak and the foreigners disembarked. The C-124 took off soon after and flew to Orly, France for refueling, that being also the place where the colonel left the plane to its crew.
The ATIC summary report stated that “There is a minimum amount of equipment installed in the aircraft. ... The outstanding features of the aircraft are its takeoff, climb, and acceleration capabilities, which are excellent. ... Lack of cockpit pressurization, a 0.8 Mach No. restriction, and poor directional stability above 325 knots IAS [indicated air speed] are its major drawbacks.”
Yugoslavia had most to gain – they got the opportunity to test an aircraft which was still used as a frontline fighter by Romania and Bulgaria, two of its potential enemies. The gesture of providing it to the USA certainly paved the way for the delivery of T-33, F-84 and F-86 to the Yugoslav Air Force.