The phrase "active flight" is correct and usable in written English.
It can be used in contexts related to aviation, aerospace, or any situation where something is currently in the process of flying or operating.
Example: "The aircraft is currently in active flight, navigating through the airspace as planned."
Alternatives: "in-flight" or "currently flying".
There are 7,500 active flight attendants and 2,500 on furlough.
Only with active flight have the resources of the aerial habitat been successfully exploited.
Migration may occur by active flight or, as in aphids and locusts, largely directed by the wind.
In the evolution of modern birds from an Archaeopteryx-like form, the development of active flight must have occurred early.
Model builders were forced to employ automatic stability, but those experimenters who built and flew gliders had to develop active flight controls.
Oddly enough, the one early vocal dissenter to this view at the time considered pterosaurs to be the ancestors of birds (a position we now know is incorrect) and hence pushed for a theory of active flight (Seeley, 1901).
GPS points were plotted using Google Earth Pro©, which in combination with acceleration data analysed in e-obs visualisation tool allowed the determination of active flights to foraging locations or to a roosting site.
By the age of five, for example, excessive stress sets up a lifetime with an overly active fight or flight response, a decreased ability to handle adversity.
In addition to the bats that are capable of active powered flight, various passive gliders like flying squirrels, sugar gliders and the so-called "flying lemurs" have all independently evolved some extension that that helps to support a membranous wing.
And while foreign drone activity was the starting point for Van Houtryve, a US lawsuit filed by Electronic Frontier Foundation under the Freedom of Information Act revealed multiple active drone flight zones across the US while this project was under way.
The ruckus involving 19,500 active American flight attendants began after 5,000 of them based in the Northeast got a memo from John M. Tiliacos, a regional managing director for the airline.
