Question: An American twin-engine attack helicopter that was developed for the United States Marine Corps as part of the H-1 upgrade program is also called what when based on the ICAO phonetic alphabet pronunciation of it's variant letter? 
Sentence (from "Bell AH-1Z Viper"): The AH-1Z features a four-blade, bearingless, composite main rotor system, uprated transmission, and a new target sighting system.
Relevant evidence: No