This effect consists of two parts:

Requires JetPropulsor to work.

A ParticleSystem prefab called JetParticleSystem is included with the asset under NWH ⇒ Aerodynamics ⇒ Effects ⇒ Particles ⇒ Prefabs ⇒ JetParticleSystem.prefab and can be a good starting point to configuring the exhaust ParticleSystem.