I'd be interested to know if the Warthogs were 'electronically aware' they were under surveillance. I realise it could be dependent on what 'devices' the pilots had switched on.
I'm just curious, it was a nice tracking shot.
Round here (Peak District, Derbyshire, UK) the C130s do low speed, thus quiet, low level practicing by flying down the valleys. You can be standing on the hillside (hills not mountains) and certainly be level with them as they drift past.
In broad daylight it's impressive, in the night I wouldn't know they were there.
Regards.