Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

The establishment of Ottoman military aviation dates back to between June 1909 and July 1911. The Ottoman Empire started preparing its first pilots and planes, and with the founding of the Aviation School (Tayyare Mektebi) in Yeşilköy on 3 July 1912, the Empire began to tutor its own flight officers. The founding of the Aviation School quickened advancement in the military aviation program, increased the number of enlisted persons within it, and gave the new pilots an active role in the Ottoman Army and Navy. In May 1913 the world's first specialized Reconnaissance Training Program was started by the Aviation School and the first separate reconnaissance division was established.[citation needed] In June 1914 a new military academy, the Naval Aviation School (Bahriye Tayyare Mektebi) was founded. With the outbreak of World War I, the modernization process stopped abruptly. The Ottoman aviation squadrons fought on many fronts during World War I, from Galicia in the west to the Caucasus in the east and Yemen in the south.
What was the first date that the Ottoman empire had an air-based military unit?