Brightly colored guides extend out of a helicopter (or airplane) at landing. They are placed one foot from blades. Guides are parallel to the blades, stable and porous (designed not to affect airflow). A loud and visible alarm is activated at contact.
It is an instrument that acts as Fillipers' eyes in the sea and Concords' eyes in the sky.
It shows the position of the airplane exactly (North-South-East-West-Up-Down-Artificial horizon), even loop, roll or bank movements in two ways!