[/url]
Yes there is lots of uncertainty about what actually is a UAV (UAS)
.
Also the NPRM from the FAA for UAS does muddy the water (full summary in the link below):
https://www.faa.gov/regulations_policies/rulemaking/media/021515_sUAS_Summary.pdf
Unmanned aircraft must weigh less than 55 lbs. (25 kg).
Visual line-of-sight (VLOS) only; the unmanned aircraft must remain
within VLOS of the operator or visual observer.
At all times the small unmanned aircraft must remain close enough to
the operator for the operator to be capable of seeing the aircraft with
vision unaided by any device other than corrective lenses.
Small unmanned aircraft may not operate over any persons not directly
involved in the operation.
Daylight-only operations (official sunrise to official sunset, local time).
Must yield right-of-way to other aircraft, manned or unmanned.
May use visual observer (VO) but not required.
First-person view camera cannot satisfy “see-and-avoid” requirement
but can be used as long as requirement is satisfied in other ways.
Maximum airspeed of 100 mph (87 knots).
Maximum altitude of 500 feet above ground level.
Minimum weather visibility of 3 miles from control station.
No operations are allowed in Class A (18,000 feet & above) airspace.
Operations in Class B, C, D and E airspace are allowed with the
required ATC permission.
Operations in Class G airspace are allowed without ATC permission
No person may act as an operator or VO for more than one unmanned
aircraft operation at one time.
No careless or reckless operations.
Requires preflight inspection by the operator.
A person may not operate a small unmanned aircraft if he or she knows
or has reason to know of any physical or mental condition that would
interfere with the safe operation of a small UAS.
Proposes a microUAS option that would allow operations in Class G
airspace, over people not involved in the operation, provided the operator certifies he or she has the requisite aeronautical knowledge to perform the operation.
Also some clarification from the FAA[/url] re model aircraft:
[url=https://www.faa.gov/uas/model_aircraft/]
https://www.faa.gov/uas/model_aircraft/