Fei Long Hua Dao (飛龍化刀)

Drawing of a Fei Long Hua Dao rocket, from 'Huo Long Jing (《火龍經》)'.

Fei Long Hua Dao (飛龍化刀, lit. 'Flying dragon turning into knives') is a highly unusual and viciously designed—if not terribly effective—rocket. Recorded in famous Ming military treatise Huo Long Jing (火龍經), this is a one zhang five fen long spear-sized rocket with a two chi long bamboo rocket motor as well as two Du Huo (毒火) poison smoke-cum-incendiary warheads, which by itself isn't anything unusual. What set Fei Long Hua Dao apart from other rockets is that it is fitted with secondary rockets designed to be engaged at the same time as poison smoke warheads detonate. Known as Hua Dao Tong (化刀筒, lit. 'Knife-changing tube'), these stickless secondary rockets are two chi five cun long gunpowder-filled tubes fitted with three poisoned blades on both ends, and are said to be able to cover an area dozens of zhang wide, literally shredding anything they hit.

Long Fei Hua Dao Zhen (龍飛化刀陣)

Layout of Long Fei Hua Dao Zhen, from 'Huo Long Jing (《火龍經》)'.

The author of Huo Long Jing also created a military formation for the rocket, called Long Fei Hua Dao Zhen (龍飛化刀陣, lit. 'Dragon flying changing into knives formation') or simply Long Fei Zhen (龍飛陣, lit. 'Dragon flying formation'). The formation is designed to inflict maximum mayhem with the rockets to create an opening that allows a trapped unit to break out of encirclement, and is best deployed during cloudy but windless weather.

Long Fei Hua Dao Zhen consists of thirty-two rocket teams armed with ten Fei Long Hua Dao rockets each. These rocket teams are arrayed in a checkerboard-like formation, with eight teams serving as vanguard, twelve teams as wings, four teams at the centre, as well as eight teams as rearguard. Nevertheless, it is not known what purpose does such a specific formation serve other than for firearms safety, as Fei Long Hua Dao has a long enough range that such arrangement wouldn't be necessary.