The flight school is owned by a popular driving school, where many Beijingers learn to drive. They had a series of Sunward propeller planes when I visited last night, where it was confirmed the plane took off from. The police appeared to have raided the company offices.
Police presence at the flying school where the plane took off from in east Beijing. When I visited tonight there were five police vans, gathering intel at Eastern Pioneer flying school.
Full update on the FT: