Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Low Polygon Sci-Fi Helicopter Free.
Low Polygon Sci-Fi Helicopter v1.0b
A very detailed model with low polygon count.
All texture maps are very detailed and worked on, so you should get a very nice look on this thing with no effort.
This model is divided on five parts; Body, interior, blades, small lights and the main spotlight.
All the things together sum up in just around 5k polygons.
For easier animation setup, the helicopter is rigged.
Source files are included in this package, so the whole object is editable to fit your needs.
Please, feel free to mail me all your questions!