FAA Regulation

30 days. 10 days.  90 days.

55 lbs. or less. 55 kg or less. Less than 55 lbs. 

No, the other people in the park are not on notice.  Yes, as long as the park is not busy enough that it would be considered an open-air assembly of human beings.

ensure that the human beings who are not participating in the operation are under a covered structure or inside a non-moving vehicle. ensure the sUAS is equipped with a parachute make sure the area is closed or restricted-access.

The owner of the aircraft. The operator of the aircraft. The manufacturer of the aircraft.

The Remote Pilot in Command (RPIC). The owner of the aircraft. The FAA.

Civil and public aircraft operations. Public and military operations. Civil operations. 

No more than three as long as the Remote PIC maintains visual line of sight. As many as he/she can handle. No more than one. 

is required to receive ATC authorization.  must use a visual observer. is required to file a flight plan.

100 mph 100 kts 87 mph