Nope. June 1916 is perfect.
The air war only just begins to become a lethal business, and we will witness all important stages.
In the beginning, the Germans only have Fokker Eindecker scouts, but their time is over, and the
Entente has the better fighters. But soon, in August, the Germans may equal the balance with the
Halberstadt; and then in September they will gain superiority with the Albatros D.II for a while.
Starting in June 1916 will bring us most intetesting ups and downs for both sides IMHO.