less-powerful AL-31FP engine, which was essentially an AL-31F engine that had the AL-100 vectoring nozzles of the AL-37FU. The aircraft was rolled out in May. Two months later, the temporary engines were replaced with AL-37FUs; its nozzles could only deflect 15 degrees up or down in the pitch axis, together or differentially. Apart from the addition of thrust-vectoring nozzles, the Su-37 did not outwardly differ much from the canard-equipped Su-27M. Instead, engineers had focused on the aircraft's avionics. Unlike previous Su-27Ms, the Su-37 had a digital (as opposed to analogue) fly-by-wire flight control system, which was directly linked to the thrust-vectoring control system. Together with the aircraft's overall high thrust-to-weight ratio and the engine's full authority digital engine control feature, the integrated propulsion and flight control systems added maneuverability at high angles of attack and low speeds. The aircraft's weapons-control system had also been improved, as it included an N011M Bars (literally "Panther") pulse-Doppler phased-array radar that provided the aircraft with simultaneous air-to-air and air-to-ground capability. The radar was capable of tracking twenty aerial targets and directing missiles toward eight of them simultaneously; in comparison, the Su-27M's baseline N011 could only track fifteen aerial targets and engage six of them simultaneously. The aircraft retained from the Su-27M the N012 self-defence radar located in the rearward-projecting tail boom. Considerable improvement had also been made to the cockpit layout. In addition to the head-up display, the Su-37 had four Sextant Avionique multi-function colour liquid crystal displays arranged in a "T" configuration; they had better backlight protection than the Su-27M's monochrome cathode ray tube displays. The displays presented to the pilot information about navigation, systems status, and weapons selection. The pilot sat on an ejection seat that was reclined to 30 degrees to improve g-force tolerance. Painted in a disruptive sand and brown scheme, the aircraft was given the code 711 Blue, later changed to 711 White. Following ground checks at the Gromov Flight Research Institute, the aircraft made its maiden flight on 2 April 1996 from Zhukovsky Airfield outside Moscow, piloted by Yevgeni Frolov. The nozzles were fixed during the first five flights. Due to the lack of funding from the Russian Air Force, Sukhoi was compelled to finance the project with its own funds; according to Simonov, the company channelled revenue from the exports of the Su-27s to China and Vietnam towards the project. The aircraft was publicly unveiled at Zhukovsky