The Dawn of Electric Aircraft

With the cost of aviation fuel soaring, I’m not surprised to see engineering efforts to find alternatives to conventional aircraft fuel, either jet or piston-powered. Previously I wrote on this blog about efforts to find replacement aviation fuels, either by Virgin Atlantic looking at biofuel as an alternative for jet fuel, or a small start-up company, Swift Enterprises, working on a synthetic substitute for general aviation gas. While it will be interesting to watch these efforts to see if they ever become practical fuel replacements, some folks are looking at completely different power sources for aircraft, including hydrogen and electric power.

With technology allowing for lighter, more powerful and longer-lasting batteries (thanks to the general public’s appetite for ever-smaller portable electronics, such as laptops, cell phones and music players), you are starting to see the fledgling attempts to power a light aircraft with electric power alone. The radio controlled scaled aircraft industry has been building electric powered aircraft for a number of years, as has the UAV industry. Of course the technology is nowhere near advanced enough to allow large aircraft such as airliners to fly on electric power, but some smaller companies are attempting to see if electric power is practical for light general aviation airplanes. Though human-carrying electric aircraft have flown before, they have basically been experimental, very unique aircraft. The successful ones have used aircraft-mounted solar cells to provide power to the electrical motor instead of on board batteries. Such aircraft include the Solar Challenger, developed by pioneering aeronautical engineer Dr. Paul MacCready, that successfully flew across the English Channel in 1981. Another solar powered aircraft is the SunSeeker, which used solar panels and soaring flight techniques to fly across the U.S. successfully in 1991. Taking the design of a piloted solar powered aircraft to the extreme, a European team is developing an aircraft, called Solar Impulse, that they hope to fly non-stop around the world. Since this effort will take several days, the aircraft will require some type of on board batteries that can be charged during the day so they can power the electric motor during nighttime.

Although these solar-powered aircraft are great aerospace engineering achievements, the cost of solar panels and the need for steady sunshine still make them impractical as everyday aircraft. The next step we are starting to see is the development of battery-powered electric aircraft. It started with self-launching motor gliders, such as the AliSport Targa 2, and the Antares 20E. Putting an electric motor in a sailplane is a good place to start, since sailplanes are the most aerodynamically efficient flying vehicles. Getting to an altitude to begin soaring doesn’t require a large engine or much fuel, so it was the logical place to add an electric power system for self-launching.  The next step in electric aircraft development is to go beyond providing enough power (usually only about 10 minutes)  for self-launching, to providing enough energy for sustained horizontal flight of at least one hour or more. This would make a piloted electric aircraft more practical for local fun flying or short cross country flights. Several such planes now under development include Sonex Aircraft’s E-flight Initiative, the ElectraFlyer-C and the Pipistrel Taurus ELECTRO, the latter two which have already flown. In fact interest in electric-powered aircraft is increasing so rapidly that a recent technical symposium was held in San Francisco to discuss the latest technical achievements in electric flight.  These promising developments have also lead to the Experimental Aircraft Association (EAA) to petition the FAA to authorize electric motors in ultralights and light sport aircraft.

We are still a long way from having electrically-powered commercial (i.e. carrying passengers for hire) aircraft. However, these recent encouraging developments indicate that it may not be too long before pilots will be able to safely fly a less costly, environmentally friendly, electric aircraft for sport and recreation purposes.

How Aerospace Can Help Solve Energy Demands

I recently received a brochure for the International Energy Conversion Engineering Conference (IECEC), and it got me thinking how the aerospace industry has much to contribute when it comes to helping to solve the energy crisis. Organized by the American Institute of Aeronautics and Astronautics, the forum allows presentations and discussions on such topics as “21st Century Space Solar Power”, “Fuel Cells and the Hydrogen Economy” and “Synergies Between Space and Terrestrial Photovoltaics”.  The aerospace industry has long been involved with alternative power sources, developing and using fuel cells to provide electrical power for the spacecraft used on the Apollo program, and the near universal use of solar panels to provide power for most satellites and the huge international space station. This space technology has been perfected over a 50-year period, and much of the technology is directly applicable to uses on earth. There are now discussions of taking some of this technology even further by collecting, converting and beaming solar energy from space to earth receiving stations, where it could be added to the national power grid. Solar panels in space are more efficient, as the energy from the sun isn’t “diluted” by the earth’s atmosphere.

Other areas where the aerospace industry can contribute to reducing reliance on oil is aerodynamics and advanced light-weight materials. One of the most visible applications of aerodynamics to terrestrial applications are wind turbines, which are basically
refined aircraft propellers that convert wind energy into electricity.  You are starting to see them pop up in numerous windy areas, such as mountain passes and ridge tops. There are even plans to place them offshore to take advantage of the strong, steady winds found over the ocean. Some of the best ways to make a vehicle go further on a gallon of gas is to make it more aerodynamic, and lighter. Weight has always been a concern for aircraft engineers, so the aerospace industry has been at the forefront of developing strong, light-weight materials such as advanced composites. Many of these advanced materials can be applied directly to the design of new cars and trucks, giving them the same or better strength as steel, but at a lower weight. Also, many of the major car companies now have their own wind tunnels for refining the aerodynamic characteristics of their new models. Just a slight change in the roof, side-view mirrors, or hood design can provide less wind drag, and thus greater mileage for a car.

One of the first scientists to recognize the benefits of applying aerodynamic efficiency from aircraft to ground vehicles was Dr. Paul MacCready. MacCready was the famous aeronautical engineer who designed the human powered aircraft the Gossamer Condor, which won the Kremer prize in 1977. MaCready’s wind tunnel studies on tractor-trailers lead to the streamlined shrouds you see today on
the top of just about every tractor-trailer cruising the
highways. These shrouds help reduce the drag of the trailer, thus increasing
the miles-per-gallon and saving money for the long-haul trucker.  MaCready went on to start AeroVironment, an engineering firm that specialized in developing products that use aerodynamics to make them more efficient.  MacCready also had a hand in the aerodynamic design of the infamous GM EV-1 electric car that was the topic of the documentary “Who Killed the Electric Car”.  It’s not stretching the truth to say that MaCready was one of the first to successfully prove that aerodynamics could be used to successfully develop and sell products other than aircraft.

As the energy crisis becomes more acute, I believe the aerospace industry will play a larger role in developing cost-effective, environmentally safe alternatives to carbon-based fuels. The IECEC conference is scheduled for July 28-30, 2008 in Cleveland, Ohio.

Beautiful Photos of Bush Plane Flying in Alaska

I recently came across a web site with some great aerial photos of light plane flying in Alaska.  The pictures were taken by the late Shaun Lunt, who was tragically killed in the crash of his Piper Super Cub single-engine aircraft earlier this month. Shaun was an anesthesiologist by profession, but in his free time he loved to fly his Super Cub to Alaska to explore the wild parts of the state. Even though he had only been flying in Alaska for about a year, he took some amazing photos during his Alaskan adventures. They show the rugged beauty, on the ground and from the air, of a state where light aircraft are still the best way to travel.

Sadly I remembered reading about Lunt in a May 2008 Air & Space Magazine article about learning to fly light planes “off airport” in Alaska. The article features bush pilot Loni Habersetzer and his course for teaching pilots how to land and takeoff on beaches, sand bars, mountain meadows, river banks, etc. Lunt is quoted as one of Habersetzer’s students in the article. In fact, at the time of his accident, Lunt was flying his plane along side of Habersetzer’s Super Cub.  Accident reports indicate Lunt was circling at low altitude to get a better look at some whale bones on the beach when his plane went down.

Lunt was only 33 years old at the time of his death, but his photos
showed a talent for great aerial photography. It makes you wonder how many
more beautiful images he would have taken during his wilderness flying
adventures if his life hadn’t been cut short.

First Take: Discovery Channel Mini-series “When We Left Earth”

I finally got around to watching the first two episodes (saved on my DVR) of the Discovery Channel’s new mini-series, “When We Left Earth”, and so far I have to say I’m impressed. I’ve watched many TV specials, movies and documentaries about the U.S. space program (see my previous review of “In the Shadow of the Moon” ), most of them showing the same recycled NASA footage of the Mercury, Gemini and Apollo missions. “When We Left Earth” not only uses many images I’ve never seen before, but the inclusion of new recollections by many of the astronauts still living adds a personal touch missing from the previous films I’ve watched. Fortunately “When We Left Earth” includes comments by the normally reclusive Neil Armstrong. One of my major complaints with “In the Shadow of the Moon” was the absence of  Armstrong, the first person to walk on the moon. Not including Neil Armstrong’s thoughts and recollections on one of man’s biggest engineering achievements is like making a documentary on the Rolling Stones and not interviewing Mick Jagger.

Some of the film that I hadn’t seen before included more footage of astronaut Ed Whites first spacewalk by an American, and closeup shots of Gemini capsules 6 and 7 practicing the first rendezvous maneuvers ever attempted in space. The capsules are so close that you can clearly see astronauts Wally Schirra and Tom Stafford in Gemini 6 waving to Jim Lovell and Frank Borman, in Gemini 7, through the capsule windows. The fact that Discovery has transferred the archival NASA color footage into the high definition format made the blackness of space, the exterior details of the capsules, and the deep blue of Earth below even more spectacular on my high definition TV. 

Some of the footage shown of the astronauts training on the U.S. Navy
human centrifuge at Johnsville, PA, brought back nostalgic memories for
me. I worked in that centrifuge building for 15 years as a crew systems
engineer for the Navy, and my office was on the ground floor directly
below the cavernous room that held the astronaut-carrying gondola on the end of a 50-foot rotating arm.
(Sometimes when they weren’t running the centrifuge, we would play
basketball in the room using a portable backboard, or in the winter use
it as an indoor track to get some exercise during lunch.) That building
was built so well (and placed on solid bedrock), that most of the time I
could hardly tell when the centrifuge was running. However, ever few
years the bearings  on the main electric motor would start to wear, and
then I could notice a slight vibration in my office walls and ceiling
until new bearings were installed. There were reminders of the
groundbreaking human spaceflight research  done with this centrifuge throughout the
building.  Pictures of Mercury and Gemini astronauts who rode the
centrifuge, such as Neil Armstrong, Alan Shepard, and Gus Grissom hung
on the walls. I also remember going up to the “attic” area above the
main centrifuge room and found some of the original custom-fit
“couches” that each astronaut had made for their high-g runs, with
their individual names on them. I’m not sure what happened to those couches, but I hope some of them wound up in a museum. Alas, the history-making centrifuge at
Johnsville was eventually shut down when the Navy closed the base in 1996. It was too expensive to
operate, and had been replaced by more modern equipment for training Navy and Marine pilots in high-g environments. The building and the centrifuge are still there in Johnsville, PA and there has been talk recently of making it into a
museum to reflect it’s historical significance in the training of the first U.S. astronauts.

My congrats to the Discovery Channel and NASA for working together to producing a visually beautiful recap of the space program, along with relevant commentary from some of the astronauts, flight controllers, and engineers who made it happen.  If the remaining four hours of this mini-series continue with the high quality of footage and first-person commentary, I may be tempted to buy the series when it comes out on DVD. Though I may wait until it is released on Blu-Ray DVD to take advantage of the high definition format as seen on the broadcast.

Air Force Releases B-2 Crash Findings, Mishap Video

Last week the U.S. Air Force released the findings of the investigation into the cause of the mishap that destroyed a B-2 stealth bomber in February.  The accident investigation board concluded that the flight control computers, which essentially keep the aircraft stable throughout the flight envelope, received erroneous information due to moisture in the air data system. This lead to an uncommanded pitch-up during takeoff, and subsequent low speed, low altitude stall. The two crewmembers successfully ejected as the left wing of the B-2 scraped the runway just prior to ground impact.

The ejection system, which I wrote about in a previous blog entry about the crash, worked perfectly, and shows the capability of modern ejection seats to provide successful emergency escape even at very low altitudes. The video below, which was released by the Air Force along with the final report, shows the escape hatches being jettisoned, then the copilot leaving the aircraft first, followed quickly by the pilot. The ejection seats are the ACES II model manufactured by Goodrich Corporation. The video apparently was taken by a security camera, probably located on or near the control tower at the air base in Guam. As I wrote about in a blog entry on a wild A320 crosswind landing in Hamburg, Germany, the B-2 crash clip shows the importance of having video coverage of takeoffs and landings at major airports to aid in mishap investigations.

As a final note on the crash, the Air Force report states the B-2 destroyed in this mishap had a value of $1,407,006,920. The B-2 is truly a billion dollar+ bomber.