Well safety comes first, though it will not exactly be an inspiring show without aircraft showing off to their capability to both the public and trade visitors.
As trade days are a way to show off your wares to potential customers and get them on the first rung of becoming a client, it must be an uphill struggle if you cannot show them what your combat aicraft can do in real life when shown against its competitors.
The last Airshow I can think of when straight and level runs wowed the crowds must have been Kittyhawk 1903.
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