The first Bell AH-1Z set to receive the Structural Improvement Electrical Power Upgrade (SIEPU) modification to be provided by Bell Textron Inc., under a contract with the U.S. Marine Corps, has arrived at Bell’s Amarillo Assembly Center.  SIEPU modifications optimize the aircraft to improve mission capabilities, aircrew safety, and interoperability by increasing the electrical power capacity on the aircraft and support the integration of additional cabin capabilities. SIEPU marks the start of the next chapter in the life of domestic H-1 helicopters, following the completion of the U.S. Marine Corps Program of Record in November 2022.

"The Bell AH-1Z Viper and UH-1Y Venom provide the backbone of attack and utility aviation support in the various battlespaces in which they are used, so SIEPU comes at an important time for the future strategic implementation of this platform,” said Mike Deslatte, Bell H-1 senior vice president and program director. “SIEPU will be immediately beneficial for today’s operations and also sets the H-1 up to quickly support future operational needs, some that may not even be conceived of yet."