Start with two surfaces facing opposite directions like the
blades of a helicopter.
Connect them together with a rod that prevents them flying
apart or getting too close, but doesn't resist twisting
Instead, to control the pitch of each blade/wing, each has a
separate elevator behind
it like on the tail of an aeroplane.
Also, instead of centrally driving the rotor like on a
helicopter, have a propeller on each blade/wing (again like
it's an aeroplane), to pull it around the central point.
Start up the propellers and the wings spin around like
Normally (in helicopter mode) the wings point in different
directions, but if you tilt them both all the way up to
vertically up or all the way down to vertically down, they're
both pointing in the same direction. This is aeroplane
where together they function like an aeroplane instead of a
helicopter. You'd keep them pointing mostly the same
direction, adjusting both together to pull up or down, or
pointing them slightly differently to roll/bank the pair of
wings (rotating it much slower than you'd spin the blades of
The propellers are not expected to have enough power to
maintain vertical flight upwards in aeroplane mode -
attempting this would risk a stall.
Say both blade/wings are pointing straight down, you can
then pull up so the combined aeroplane is flying
instead of downward. In lieu of a rudder, turning is done by
Also while in helicopter mode, you can adjust the wing
to tilt the virtual helicopter rotor away from pointing
- you can tilt it to horizontal before transitioning to
aeroplane mode if you want.
There could also be an intermediate mode where the wings
are spinning at a moderate rate but it's more like a spinning
aeroplane than a helicopter.
This should have some sort of computerised control
translating the pilot's intentions into elevator movements,
rather than just having the pilot directly control the two
elevators. There could be two sets of controls, one for
aeroplane mode and one for helicopter mode.
Carrying a central load:
As a small-scale remote control toy this isn't needed, but
more rods or cables can be added to the blade-connecting
rod, to connect a central load to each point where the
connecting blade-connecting rod attaches to the blades
(making a triangle). There is a bearing to allow the blades
and triangle of connectors to spin freely without the load
spinning, and then further joint mechanisms to allow the
Comparison to other aircraft:
Compared to a helicopter it can fly better at high speed (by
going into aeroplane mode).
Compared to an aeroplane, it can do vertical takeoff and
landing (I haven't specified any landing gear, but it could be
attached the same way as a central load).
When I went to put this idea on the halfbakery there were
two similar ideas already (so I've used a similar name) but
they didn't quite match my vision.
Compared to the aircraft in "Who needs a runway? Every
airplane can be a helicopter II", the wings are mounted
like helicopter blades, so there is not a central fuselage
has to spin around together with the blades when in
helicopter mode. Also the wings aren't symmetrical front-
back as they each have the elevator behind them to control
Compared to "Who needs a runway? Every airplane can be
a helicopter" the two halves do not need any mechanism to
separate and reconnect, and they can be simpler as they do
not need to function independently (each separate wing has
no left-right steering, and probably no landing gear, though
we could add that to eliminate load on the connecting rod
during takeoff and landing)
Autogyro: unfortunately the craft has no autogyro mode. It
can auto-rotate like a helicopter though, if it runs low on
power to run the propellers. I'd been kind of obsessed with
autogyros when I was thinking of this idea.