The Defense Department said recently it awarded Boeing [BA] a $1.8 billion contract to provide Saudi Arabia with upgrade kits to convert its F-15s to its F-15SA variant.

The sole-source Foreign Military Sale will provide 68 F-15 to F-15SA conversion kits, Country Standard Time Compliance Technical Order (CSTCTO) development, CSTCTO integration and testing, fabrication of trial kits to support validation and verification activities and installation of four base stand-up kits.

Boeing spokeswoman Lori Moore said in a statement the company is committed to executing the program on cost and on schedule.

“Boeing looks forward to working with the U.S. government to provide the Kingdom of Saudi Arabia with development of Country Standard Time Compliance Technical Order’s procurement of conversion kits, and installation of base stand-up kits,” Moore said. “The acquisition will enhance the long-term relationship between Saudi Arabia and Boeing and help assure the Royal Saudi Air Force’s ability to defend the Kingdom against regional threats. Boeing is committed to executing this program on cost and schedule while ensuring we consistently meet the needs of the RSAF warfighter.”

Work is scheduled to be completed by Dec. 31, 2013.

The conversion kit includes wings, tail booms, a forward fuselage and other supplies necessary to convert the F-15S aircraft to F-15SA, according to a Justification for Other than Full and Open Competition notice posted on Federal Business Opportunities. The base stand-up kit includes sufficient spares and support equipment needed to achieve initial operating capability and maintain this capability until follow-on supply support is established.

DoD justified the sole source contract in the notice, saying Boeing is the only known source capable of performing this “highly specialized” conversion effort for the F-15S and is a “consistent extension” of the work performed under previous and current government contracts for the F-15, F-15E and F-15S aircraft. DoD also said selection of a new source would require duplication of extensive effort over several months and result in unacceptable program delays of approximately 30 months and a cost increase of $500 million if certain program components were competed.

This deal is part of the Saudi Arabia F-15 Fleet Modernization Program (FMP).