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? 

Context paragraphs:
HMLAT-303: Marine Light Attack Helicopter Training Squadron 303 (HMLAT-303), is a United States Marine Corps helicopter training squadron stationed at Marine Corps Base Camp Pendleton, California.  Known as the "Atlas", HMLAT-303 trains newly commissioned Naval Aviators, conversion pilots, refresher pilots, and enlisted aircrew on the new Bell UH-1Y Venom and Bell AH-1Z Viper helicopter as well as the Bell AH-1W SuperCobra.  It is part of Marine Aircraft Group 39 (MAG-39) and the 3rd Marine Aircraft Wing (3rd MAW).

Bell AH-1 SuperCobra: The Bell AH-1 SuperCobra is a twin-engine attack helicopter based on the United States Army's single-engine AH-1 Cobra.  The twin Cobra family, itself part of the larger Huey family, includes the AH-1J SeaCobra, the AH-1T Improved SeaCobra, and the AH-1W SuperCobra.  The AH-1W, the backbone of the United States Marine Corps's attack helicopter fleet for decades is being replaced by the next generation Bell AH-1Z Viper attack helicopter.

HMLA-469: Marine Light Attack Helicopter Squadron 469 (HMLA-469) is a United States Marine Corps helicopter squadron consisting of AH-1W Cobra attack helicopters, AH-1Z Attack helicopters (As of November 2016) and UH-1Y Venom utility helicopters.  The squadron is based at Marine Corps Air Station Camp Pendleton, California and falls under the command of Marine Aircraft Group 39 (MAG-39) and the 3rd Marine Aircraft Wing (3rd MAW).  The squadron was activated on June 30, 2009.

NATO phonetic alphabet: 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.

HMLA-369: Marine Light Attack Helicopter Squadron 369 (HMLA-369) is a United States Marine Corps helicopter squadron consisting of AH-1Z Viper attack helicopters and UH-1Y Venom utility helicopters.  The squadron, also known as the "Gunfighters", is based at Marine Corps Air Station Camp Pendleton, California and falls under the command of Marine Aircraft Group 39 (MAG-39) and the 3rd Marine Aircraft Wing (3rd MAW).

HMLA-269: Marine Light Attack Helicopter Squadron 269 (HMLA-269) is a United States Marine Corps helicopter squadron consisting of AH-1W Super Cobra attack helicopters and UH-1Y Venom utility helicopters.  Also known as "The Gunrunners", the squadron is based at Marine Corps Air Station New River, North Carolina and falls under the command of Marine Aircraft Group 29 (MAG-29) and the 2nd Marine Aircraft Wing (2nd MAW).

H-1 upgrade program: The H-1 upgrade program is the United States Marine Corps's program to develop the AH-1Z Viper and UH-1Y Venom military helicopters to replace its aging fleets of AH-1W SuperCobras and UH-1N Twin Hueys.  The contract was awarded in 1996 to Bell Helicopter, the original manufacturer of both aircraft, to design the new airframes as modernized attack and utility helicopters with considerable design commonality, to reduce operating costs.

Bell AH-1Z Viper: 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.

Americanist phonetic notation: Americanist phonetic notation, also known as the North American Phonetic Alphabet or NAPA, is a system of phonetic notation originally developed by European and American anthropologists and language scientists (students of Neogrammarians) for the phonetic and phonemic transcription of indigenous languages of the Americas and for languages of Europe.  It is still commonly used by linguists working on, among others, Slavic, Uralic, Semitic languages and for the languages of the Caucasus and of India (however, Uralists commonly use a variant known as the Uralic Phonetic Alphabet).  The term "Americanist phonetic alphabet" is misleading because it has always been widely used outside the Americas.  For example, a version of it is the standard for the transcription of Arabic in articles published in the "Zeitschrift der Deutschen Morgenländischen Gesellschaft", the journal of the German Oriental Society.

Bell UH-1Y Venom: The Bell UH-1Y Venom (also called Super Huey) is a twin-engine, medium-sized utility helicopter, built by Bell Helicopter under the H-1 upgrade program of the United States Marine Corps.  One of the latest members of the numerous Huey family, the UH-1Y is also called "Yankee", based on the NATO phonetic alphabet pronunciation of its variant letter.

Supporting paragraphs: Bell AH-1Z Viper NATO phonetic alphabet
Answer: Zulu Cobra