The phrase "are to fully" is correct and usable in written English.
It can be used in contexts where you are indicating a requirement or expectation to complete something entirely or comprehensively.
Example: "The participants are to fully engage in the workshop activities to gain the most benefit."
Alternatives: "are expected to completely" or "are required to thoroughly".
Most Balanchine ballets are to fully orchestral scores.
American troops are to fully withdraw by Dec. 31 after nearly nine years of war.
We members of our great nation's armed forces are to fully expect to stand ready to defend what we have.
If we are to fully support these exceptional individuals then more unity is needed in our efforts.
But as my own political imprisonment exemplifies, we still need unyielding international encouragement and pressure, if our nations are to fully realise their democratic destinies.
"That's a really crucial piece of this, because it's going to tell us finally how close we are to fully solving the problem".
If we are to fully harvest the potential sustainable yield of fish from the ocean, we cannot follow the utopian dictum that no stocks may be overfished.
We and the international community need to make sure we work more closely with, and empower, women and girls with disabilities if we are to fully realise their rights.
Listening to these stories may offer us new possibilities, but if our new life stories are to fully emerge, we must also challenge the underlying myths and prejudices that limit us.
If we are to fully realize the opportunities we seek, and to make the American Dream a part of our lives, we must make an intentional effort to naturalize all who have planted new roots here in the United States.
Backing new nuclear energy can only be done at appalling cost and at the expense of renewable energy – the last thing that Scotland needs if we are to fully harness our enormous renewables potential.
