4. Bell AH-1Z Viper
The American Viper is a third-generation descendant of the legendary Bell AH-1 Cobra, the ancestor of all modern attack helicopters. The US Marine Corps was the first to use the asset in 1965. The latest model in the class-defining design, the Viper, has proven to be a capable and long-lasting platform. The Marines intend to deploy 189 Vipers, which were first deployed in 2010. The platform is still going strong after 55 years, with new orders coming in from Bahrain and the Czech Republic.

4. Bell AH-1Z Viper
