The phrase "as a directional" is correct and usable in written English.
It can be used in contexts where you are referring to something that serves as a guide or indication of direction.
Example: "The sign was placed as a directional to help drivers navigate the complex intersection."
Alternatives: "as a guide" or "as an indicator".
As a directional antenna concentrates the transmit power into the main lobe direction, the radiation intensity in the main lobe direction is larger than that in other directions and its in that direction is much larger than zero.
"It can be good as a directional tool".
The MNR serves also as a directional relay.
Gayden, T., Cadenas, A. M., Regueiro, M., Singh, N. B., Zhivotovsky, L. A., Underhill, P. A. et al. The Himalayas as a directional barrier to gene flow.
Tai, G., Reid, B., Cao, L. & Zhao, M. Electrotaxis and wound healing: experimental methods to study electric fields as a directional signal for cell migration.
The system consists of a transmitting antenna, a receiving antenna, a power divider as a directional coupler, and a mixer.
By itself, neither is satisfactory as a directional reference, but a combination of the directional gyroscope with a magnetic compass gives the pilot complete and stable directional information.
As a directional evening option, the floorlength trouser – which has to be actually floorlength, an inch above is totally cheating – can be wide and fluid (see McCartney) or a precise, embroidered showpiece flare (see Giambattista Valli).
The device is a hand-held Global Positioning System, better known by its initials, G.P.S., and it is used as a directional tool to help pilots of small planes fly from one point to another.
Stryzinski's numbers do not indicate that he will be an upgrade -- he was second worst in the league last season with a 37.8-yard average -- but he is known as a directional punter who limits returns.
In the future, this method could serve as a directional liquid wave source in applications used in hydraulic and ocean engineering for the concentration of wave energy.
