The Kurnass 2000 was the lsraeli name given to an upgrade program applied to IDF/AF Phantoms that was designed to extend their service lives by 15 years. The Phantom was already known as Kurnass (Heavy Hammer) in IDF/AF service, and the upgrade project became known as Kurnass 2000, implying that the goal was to extend the effective life of the IDF/AF Phantom well into the next century.
IDF/AF Phantoms subjected to this upgrade were fitted with a new Kaiser wide-angle heads-up display, a mission computer, a display computer controlling new multifunction displays, a heads-up display video camera, new radios, and major improvements to the electronics. Various parts of the aircraft structure were strengthened and fuel tank leaks were fixed. The converted aircraft were fitted with fixed inflight refuelling probes that were plumbed externally into the boom refuelling receptacle on the upper fuselage behind the second crewman
A small strake was added above the air intake flanks on each side to improve combat maneuverability. Canards were also considered, but were not actually fitted.
The first Kurnass 2000 conversion was carried out at the IDF/AF's Central Maintenance Unit. The first example took to the air on its maiden flight on July 15, 1987, and was formally accepted by the IDF/AF on August 11, 1987. Further upgrades were carried out by the Bedek Aviation Division of Israel Aircraft Industries, with planes being converted as they came in for their D-level maintenance overhauls. Conversions began in April of 1989.
The Kurnass 2000 was originally to have been fitted with the Norden Synthetic Aperture Multi-Mission Radar System. This system was originally designed for the Grumman A-6F upgrade and was to have used technologies that were developed for the A-12. The cancellation of both the A-6F upgrade and the A-12 project caused serious delays in the Norden radar, and plans to use the system in the Kurnass 2000 had to be put on hold. However, a few test sets were delivered in 1992, and plans are to fit the Norden radar in all Kurnass 2000 conversions in the coming years. The core of the Kurnass 2000 aviation package is an Elbit ACE-3 mission computer which is integrated with the Norden/UTC APG-76 synthetic aperature multi-mode radar. There are Elbit heads-down displys in both cockpits, and the pilot is provided with a Kaiser/El Op holographic HUD. A hands-on-throttle-and-stick control system is fitted. An ASX-1 TISEO electro- optical targeting system is fitted to give the Kurnass 2000 the ability to fire the Rafael Popeye ASM.
Another part of the Kurnass 2000 program was to have been a change of engines. In 1986/87, Bedek fitted first one and then two Pratt & Whitney PW1120 turbofans into an IDF/AF F-4E. The aircraft was initially flown on July 30, 1986 with a single PW1120 in the starboard nacelle only, but was flown with two turbofans from April 24, 1987. This re-engined aircraft was initially intended as a test bed for the IAI Lavi project. A similar sort of conversion had been planned for the abortive Boeing-originated "Super Phantom"--in fact Boeing is rumored to have played a cooperative role in this project, although the true extent of IAI-Boeing collaboration is unknown. The re-engined Phantom was able to exceed Mach 1 without using afterburner, and had a combat thrust-to-weight 17 percent greater than that of the standard F-4E. The sustained turning rate was 15 percent greater, the climb rate was 36 percent faster, and medium-level acceleration was 27 percent greater. The re-engined Phantom was displayed at the 1987 Paris Air Show wearing the civilian registration 4X-JPA. However, plans to re-engine the entire IDF/AF Phantom fleet with PW1120 turbofans were abandoned due to budgetary constraints. In any case, since most IDF/AF Phantoms were already high-time aircraft, such an ambitious conversion program would not have been very cost effective.