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? 

Related documents: [0]  [DOC] The International Radiotelephony Spelling Alphabet, commonly known as the ICAO phonetic alphabet, sometimes called the NATO phonetic alphabet or spelling alphabet and the ITU radiotelephonic or phonetic alphabet, is the most widely used radiotelephonic spelling alphabet. Although often called "phonetic alphabets", spelling alphabets are unrelated to phonetic transcription systems such as the International Phonetic Alphabet. Instead, the International Civil Aviation Organization (ICAO) alphabet assigned codewords acrophonically to the letters of the English alphabet, so that critical combinations of letters and numbers are most likely to be pronounced and understood by those who exchange voice messages by radio or telephone, regardless of language differences or the quality of the communication channel. [END] 
[1]  [DOC] The Bell AH-1Z Viper is an American twin-engine attack helicopter, based on the AH-1W SuperCobra, that was developed for the United States Marine Corps as part of the H-1 upgrade program. The AH-1Z features a four-blade, bearingless, composite main rotor system, uprated transmission, and a new target sighting system. The AH-1Z, one of the latest members of the prolific Huey family, is also called "Zulu Cobra", based on the military phonetic alphabet pronunciation of its variant letter. [END]  
Answer: Zulu Cobra
Zulu Cobra