Saudi Arabia signed a $29.5 billion letter of offer and acceptance (LOA) for 84 new and 70 upgraded F-15 Strike Eagles last week. The deal, which took 18 months to conclude, is by far the biggest foreign military sale in U.S. history.

Citing “industry experts,” the State Department claimed that the agreement would support more than 50,000 jobs at 600 suppliers in 44 states. U.S. government officials said it would help ensure secure and stability in the Gulf region.

The F-15SA (Saudi Advanced) configuration remains as stated in the October 2010 notification to Congress. Compared with the latest production F-15SGs for Singapore, the F-15SA includes the same Raytheon APG-63(v)3 AESA (active electronically scanned array) radar and GE F110 improved-performance engines worth $7 billion, but adds a fly-by-wire flight control system and a digital electronic warfare system from BAE Systems.

U.S. officials repeated earlier assurances that the package would not erode Israel’s “qualitative military edge.” Of note, therefore, the F-15SA does not include the low-observability modifications that Boeing has been marketing as the “Silent Eagle.” The package also does include the Lockheed Martin AAS-42 infrared search and track system and a large array of weapons, including Boeing AGM-84 Block II Harpoon anti-ship missiles.

Upgrading of the Royal Saudi Air Force (RSAF) fleet of 70 F-15S aircraft will begin in 2014, followed by deliveries of new F-15SAs built at St. Louis starting in 2015. Some 5,500 Saudi personnel will receive training, much of it alongside U.S. forces, a Pentagon official said.

The RSAF is expected to retire its fleet of older F-15C/Ds, of which 120 were delivered in the 1980s.

A Boeing spokesman told AIN that the sale would extend F-15 production until the end of the decade, as well as help the Strike Eagle compete in the forthcoming FX-III evaluation by Korea.

The spokesman also confirmed that Saudis had signed an LOA for 36 AH-64D Block III Apache helicopters destined for their National Guard. The company expects Saudi LOAs for a further 34 AH-64Ds, in addition to 36 AH-6i Little Bird helicopters, to be signed shortly. These sales were announced at the same time as the F-15SA package in October 2010, together with 72 Sikorsky UH-60M Black Hawks and 12 MD-530Fs.