Electrically Powered Ultralight Aircraft

Electrically Powered Ultralight Aircraft

Below is a report of an electrically powered ultralight aircraft.
Further down is information about Sonex's electrically powered
home-built aircraft, and below that is information about Royal
Aeronautical Society's 2007-8 design competition (submissions close
May 2, 2008).

Personally, I'd like to see an electrically powered parachute
(http://skyhighflying.com/homepage.html) design attempted. Surly the
lighter weight would require less power. It would seem that
lithium-ion polymer batteries are a potential enabling technology.


AVGAS? WHO NEEDS IT? TRIKE RUNS ON BATTERIES
(http://www.avweb.com/eletter/archive...ll.html#195816)
While concerns over price, availability and environmental impact
have aviators worried about the future of fuel, one ultralight
flyer in New Jersey has already solved that problem. Randall
Fishman has been testing lithium-ion polymer battery packs to
drive the prop on his ultralight trike, and he says they work
great. They are powerful, smooth, sturdy, safe and quiet, Fishman
claims. "The closest thing to a magic carpet ride ever," he says
on his Web site (http://www.electraflyer.com/). The quiet is not
only enjoyable for the pilot, it improves relations with
neighbors, he notes. The batteries will run for up to two hours
and cost about 60 cents to charge via a standard electric outlet.
However, the batteries are expensive -- $3,800 to $7,500,
depending on size.
http://www.avweb.com/eletter/archive...ll.html#195816

First attempted takeoff video:
http://www.youtube.com/watch?v=Wksx-jmhY7c


Brochu
http://www.electraflyer.com/brochure.pdf
Technical Specifications:
Motor - 18 H.P. High Torque - 90% Efficient at Cruise
Controller - Electronic, Pulse Width Modulation, For High
Efficiency and Smooth Control
Battery Packs - Custom Built, Lithium Ion Polymer, Super High
Capacity Choose the Size You Want
Voltmeter - To Monitor How Much Power Is Available
Ammeter - To Monitor How Much Power You Are Using
Thrust - With Folding Prop - 140 Pounds
With Big, Ultra Quiet Prop - 155 Pounds
Duration - Up to Two Hours Depending on Battery Pack Chosen, Total
Weight and Efficiency of the Wing - 1 to 1.5 Hour Flights Most
Common
Total Weight - 210 to 250 Pounds Complete With Wing and Battery
Packs The ElectraFlyer is a True Legal Part 103 Ultralight

Electric Aircraft Corporation
Randall Fishman, President
phone: 561-351-1190
website: www.ElectraFlyer.com
email:


http://www.electraflyer.com/52_53_womf.pdf
An EAA MEMbEr First...
The ElectraFlyer, an Electric-Powered Trike!


http://www.electraflyer.com/lightsport.pdf
Light Sport and Ultralight Flying July 2007






================================================== =
Sonex web site: http://www.sonexaircraft.com/

Photo of Sonex e-flight electric aircraft:
http://www.sonexaircraft.com/news/im...flight_058.jpg

Photo of electric powerplant:
http://www.sonexaircraft.com/news/im...light_5947.jpg

Diagram of e-Flight powerplant:
http://bioage.typepad.com/.shared/im.../25/sonex1.png

Pricing: http://www.sonexaircraft.com/kits/pricing.html


Article:
http://www.greencarcongress.com/2007...aft-.html#more

http://www.sonexaircraft.com/press/r...pr_072407.html
Sonex Aircraft, LLC and AeroConversions Unveil E-Flight Initiative for
Sport Aircraft Alternative Energy Research & Development

Electric Power; a new mission: The contemporary E-Flight electric
project will benefit greatly by the maturation of technology since our
initial studies. Using a purpose-built AeroConversions brushless DC
cobalt motor, controller, and highly efficient battery and charging
system, the E-Flight electric systems will be able to power a larger
aircraft to higher top speeds with greatly increased endurance.
E-Flight’s proof-of-concept prototype will use the flight proven Waiex
airframe, flown single pilot only, so that the emphasis can be placed
solely on powerplant research and development. Initial top speeds will
reach approximately 130 mph, and endurance is expected to range
between 25-45 minutes or longer, depending upon power usage on each
individual flight.

The initial emphasis for the E-Flight proof-of concept aircraft has
been shifted away from immediate pursuit of FAI speed records,
although the possibility remains that those records could be obtained
in short-order after successful first flight. With the advanced state
of the technologies concerned, the goal of the project is to develop
and prove the application of the technology and pave the way for
near-term electric powerplant Sonex and AeroConversions products for
sale to the sport aviation marketplace and beyond.

The current state and growing popularity of electric powered model RC
aircraft leads the layman to assume that an electric powered aircraft
of this type is simply a matter of hooking a bigger battery to a
bigger motor, charging it up in an hour or two and taking-off. While
that is essentially true in raw principle, the reality of this project
is that scaling-up these technologies in a viable manner presents
significant challenges.

• Electric Power; AeroConversions Electric Motor: Brushless DC cobalt
motor technology has advanced significantly since 1994’s Flash Flight
study, allowing the design team to now consider their use, however,
just like before, a suitable brushless DC cobalt motor of this level
of power output with an acceptable size and weight does not exist and
can not be built and provided by a third party vendor without
incurring unacceptable costs. As a result, the design team, in
collaboration with Bob Boucher of Astro Flight, Inc., has designed and
built a completely new AeroConversions motor.

This motor is the most powerful, lightest-weight, and efficient unit
of this type ever produced. It is a 3 phase, 270 volt, 200 amp motor
that will be over 90 percent efficient. It uses elegantly designed CNC
machined anodized aluminum and nickel-plated steel parts in
combination with “off the shelf” bearings, races, snap rings, magnets,
etc.

The prototype AeroConversions motor is slightly larger than a 35 ounce
coffee can and weighs approximately 50 pounds. The motor is a
modular, scalable unit. The motor core’s design has modular sections
that can be reduced to a lower-output, smaller motor (shortened in
length), or added upon to make a larger motor with a higher power
output.

• Electric Power; AeroConversions Electronic Motor Controller:
Electronic motor controllers for brushless electric motors are quite
commonplace today, mostly used in the electric RC market. A suitable
controller for a 270 volt, 200 amp motor does not exist. Running such
high current requires much larger components. Although there are a
handful of third party vendors who could design and build the
appropriate controller for this project, it would take 6-7 months lead
time and cost 20-50 Thousand Dollars. The time and cost associated
with acquiring such a controller was deemed unacceptable and the
research and development team, in cooperation with a key electronics
expert, began designing a proprietary AeroConversions electronic motor
controller.

The controller can commutate the motor in two different ways: using
Hall effect sensors to determine the magnet core’s position in
relation to the coils, or using the motor’s back-EMF to sense rotor
position, eliminating the need for Hall sensors. The AeroConversions
controller will initially employ a Hall effect sensor-equipped motor,
but back-EMF controlling will also be explored to potentially further
simplify the AeroConversions motor design. The AeroConversions
controller will also provide in-cockpit monitoring of battery power
levels to the pilot.

• Electric Power; AeroConversions Battery System: Most contemporary
electric powerplants for gas-electric and pure electric cars and
previous generations of RC electric vehicles utilize Lithium Ion
battery technology. While much improved in power density and discharge
rate over lead-acid and NiCad batteries, Li-Ion batteries still do not
offer enough power discharge-to-weight ratio to support an electric
powerplant for an aircraft that is based on battery power alone and
has a market-viable endurance. Newer RC electric vehicles, cell phone,
laptop computers and other mobile devices have been moving toward
Lithium Polymer cells. Li-Poly battery cells can safely discharge at a
rate of 25 times their capacity, or “25c.”

With all the extra energy of a Li-Poly cell, however, comes extra
volatility. The E-Flight design team has engineered and constructed 10
battery “safe boxes” intended to contain 8 Li-Poly battery packs per
box and consolidate their charge/discharge and balancing wiring into
two sets of multi-pin connectors. The Boxes will accommodate natural
cell expansion and contraction while safely securing each cell pack
and facilitating cell cooling with “cooling foam” padding. Cooling
will further be aided by heat sink surfaces on each box that will have
cooling inlet air directed over them. Additionally, the boxes are
designed to contain and safely direct fire or explosion within the box
through a “blow hole” in the box that will be connected to a small
exhaust manifold.

For the proof-of-concept aircraft, the battery boxes will be removed
from the aircraft and charged individually. The charging units need to
be configured to safely keep all cells balanced during charging.
Lessons learned from the proof-of-concept systems will lead to the
design of more advanced charging and balancing systems allowing safer
battery handling by consumers, including a single-plug charging system
that may remain in the aircraft at all times, featuring easy exchange
of battery boxes to enable consecutive back-to-back flights in a short
period of time by pilots who wish to invest in spare batteries.

Future generations of safer, more powerful Li-Poly batteries show the
near-term possibility of further extended flight duration while
personal electronics and transportation will undoubtedly continue to
push improvement of the technology in years to come.

“By developing a viable electric motor and controller system for this
proof-of-concept aircraft, we will open a door to future flight that
we have only been able to dream of,” comments Monnett. “Self-launching
electric powered gliders already exist. The potential of electric
power goes beyond that single use and relates directly to sport
flying, aerobatics and high altitude flight in purpose-built
airframes. It is essential that our proof-of-concept vehicle is a
conventional aircraft that the majority of aviation enthusiasts can
relate to.”

One remarkable reality about the E-Flight electric aircraft project is
that, by necessity, the entire R&D project for the proof-of-concept
stage of the project will cost less than the price of the average
ready-to-fly LSA aircraft available today. This project undeniably
highlights the spirit of EAA in that it is truly a grass-roots effort
to push technology for advancement of our sport and improvement of our
planet’s ecosystem and it has been accomplished, not by a large
aerospace firm or government agency, but by EAA members on an
extraordinarily cost-effective budget.


http://www.aeroconversions.com/

--------------------------------------------------------------------------------
The official daily newspaper of EAA AirVenture Oshkosh

Volume 8, Number 4 July 25, 2007

--------------------------------------------------------------------------------

Sonex rolls out electric plane
By Randy Dufault

Jeremy Monnett shows off the electric motor and mount employed in a
proof-of-concept Waiex airframe to demonstrate the potential of
compact electric power and advanced-technology batteries. Photo by
Dave Higdon

With the price of oil rising faster than an F-15 in an unrestricted
climb and the potential for $6 per gallon self-serve avgas a real
possibility, alternate ways of powering aircraft, ways that require
much less fossil fuel, are going to be important to the future of
sport aviation.

On Tuesday, Sonex Aircraft LLC took the wraps off its previously
secret e-Flight initiative.

"This is an exciting announcement and one that you are really going to
appreciate," EAA President Tom Poberezny said at the beginning of the
press conference. He added, "It addresses the grass-roots research
that is important to the integrity of EAA and the homebuilt movement.
More importantly, it is growing aviation by making it more
economical."

The most visible aspect of e-Flight right now is a Sonex Waiex
airframe equipped with a proof-of-concept prototype electric
powerplant. The aircraft, which is expected to fly later this year,
will be used to further develop the motor, along with the requisite
control systems, charging systems, and of course, battery systems.

"It was [apparent] that once we started down this path to developing
an alternative power source for the airplane, that we had to do it in
very specific steps," John Monnett, Sonex founder and president, said
when he introduced the electric plane. "The whole object of [the
proof-of-concept] is to come up with a powerplant that is equivalent
in weight and in power to our AeroVee-powered Sonex and Waiex
[models]."

Monnett went on to add the sole mission of the airplane displayed here
is to develop the technologies that will ultimately result in
production systems. The test-bed airplane is also expected to test
other, as yet unspecified, electric power sources.

The prototype powerplant uses brushless, cobalt motor technology and,
according to AeroConversions, is the most powerful, lightest weight,
and efficient motor of the type ever produced. It was developed with
the help of Bob Boucher of Astro Flight Inc. Astro Flight is a major
producer of electric radio-controlled model motors.

The 200-amp motor is 90 percent efficient and operates on 270 volts of
direct current electricity, as advertised by the Waiex’s tail number,
N270DC.

According to Pete Buck, Sonex’s chief engineer, the motor was
manufactured in-house. He added that Sonex expects to construct
virtually all of the components of the future production systems
themselves. Production systems, unlike the current AeroVee engine,
likely will not be offered as kits, due to the critical tolerances and
potential dangers with some of the electrical components.

Monnett pointed out that a couple of technologies are key to making
electric flight a reality. Of course, powerful and light batteries are
a must, but a motor controller capable of managing the high power
involved also is required. A charging system, capable of replenishing
the batteries in a reasonable amount of time, is another must. Sonex
is developing both technologies.

Target flight duration for the proof-of-concept airplane is 25 minutes
to 45 minutes. Production systems are expected to allow for one-hour
flights. Buck says an hour’s endurance is difficult right now but
ultimately is very possible as both the system and the available
technologies are further developed.

In addition to the electric Waiex, Sonex’s e-Flight initiative also
involves two other aspects: the practical use of ethanol fuels in the
AeroConversions AeroVee 2.0 engine and developing other enhancements
to the AeroVee, improving its already-impressive efficiency.

Sonex partnered with Wisconsin-based Renew Fuel Stations, a
distributor of E85, a blend of up to 85 percent ethanol and 15 percent
gasoline, to develop an AeroVee engine configuration that can use the
fuel. Renew’s interest in the project is expansion of the market for
ethanol fuels. Testing is under way right now.

The idea of electric flight is not new to Sonex. It dates back to 1994
when Monnett and Buck looked into the possibility of building an
electric plane specifically for the purpose of establishing speed
records for a new class of aircraft. Although the project was deemed
to be practical, Sonex put the project aside to further develop its
current set of kit airplanes and to support their customers. The
company is committed to completing the effort this time, though
Monnett stated firmly that the e-Flight program will never detract
from Sonex’s commitment to its customers.

Sonex is financing the entire effort itself.

Once production systems are available, Sonex plans to make them
available to the experimental market for installation on other
airframes.

Sonex will present a forum on the e-Flight project Wednesday at 11:00
a.m. in Forum Building 11. More information about the project is
available on the web at www.AeroConversions.com/E-Flight.


================================================== ========



The RAeS General Aviation Group aims to encourage the development of
light aviation through the promotion of technologies, in particular
those that minimise its impact upon the environment.

The 2007-8 design competition therefore offers awards for technical
developments that can include:

• whole aircraft design
• propulsion
• operational methods
• specific technologies within the aircraft.

The competition is open to any individual or group; entries are
particularly encouraged from teams from educational institutions or
RAeS corporate members.

Entries should be received by Friday 2 May 2008 and consist firstly
of a 10 page report , showing how it works, its benefits both to
light aviation and to the environment, and who is responsible for the
entry.

A shortlist of entrants will then be selected, who will be invited to
give a 20 minute presentation at a special event at RAeS Headquarters
in London during mid June 2008. At that event, a judging panel will
select the final winning entries; prizes and final award categories
will be announced nearer to the entry deadline.

Judging criteria will be based upon feasibility, originality,
reduction of impact upon the environment and the potential benefits
to light aviation overall. Final presentations will also be judged
on presentation quality and response to questioning.

The judging panel will consist of highly qualified light aviation
professionals – including representatives from industry, regulatory
authorities and academia.

Further Details:
General Aviation Group
Royal Aeronautical Society
No.4 Hamilton Place
London, W1J 7BQ, UK