Since the term "Microlight" tends to be associated with mainly 2-seat trikes, and "ultralight" with 3-axis sub-GA aircraft, (both of which are getting heavier all the time), "Nanolight" was coined to describe the return of the simple, basic single-seat powered aircraft based on a production hang glider wing.
As a rule of thumb, a nanolight is generally below 70kg (155lb) empty weight. There's a good reason for that. Here in Australia, anything below 70kg doesn't have to be registered. Back in the early 1980's the UK had a sub-70kg class which flourished briefly before misguided officialdom banished the genre due to misinformation that such a light machine was too flimsy. (I have heard that this was largely spread about by folks with a vested interest in selling certain 2-seat trikes).
Nanolights tend to come in two flavours
- either motorised harnesses or 
lightweight trikes.
although there are a few unusual variants as well. Most of
the motorised harnesses are variants of the groundbreaking(?) Mosquito
sold by Swedish Aerosports. Almost all of these use the Radne
Raket 120cc 14hp engine, with varied claims to better thrust using
special props and exhaust systems.
The lightweight trikes come in many flavours with a variety of engines. In general the lighter trikes come from Europe, with most US machines opting for more power. But then, Europe is the birthplace of the trike - the USA flirted briefly with it in the late 1970's but trikes have only really started getting popular again there since the mid 90's.
In general, since nanolights will be used with "production" hang glider wings, the weight of undercarriage/motor/harness and pilot should not exceed the maximum recommended pilot weight for that wing when certified.
- Plans for a "Minimum" type power
system (with 2-wheel steering and direct drive Solo)
from John Walmsley (Australia) Approx 25 pages A4 size,
International: $US35 including postage, or Australia:
$AUD35+postage
email: jwalmsley@aapt.net.au
- PULMA2000: The French PULMA (Planeurs Ultra Legers`a Motorisation Auxiliaire) club sell plans for a nanolight trike using a Solo for power
- More trike plans for the "Eagle" and "Tukan" trikes (not nanolights) that
maybe useful at http://www.trikeplans.com/
Nanolight
Legalities
In Australia, at present, the Hang
Gliding Federation allows its members to fly sub-70kg aircraft, both
powered and unpowered, without registration of the aircraft. You
will require a powered hang gliding endorsement, however. This is
not the same as a microlight licence, although you can do the
endorsement itself at most microlight schools. For Australian
non-HGFA members, the options are limited. You will need a
full ultralight licence from the Australian Ultralight Federation, and
the aircraft will need to be registered under CAO 95.10 or
similar. ... We'll keep you
posted!
Overseas, in the UK, foot launched units don't have to be registered/certified, but anything with wheels does. In the USA of course, pretty much anything goes and usually does.
