We’re still early in attempts to set world records with electric airplanes.  Jean-Luc Soullier, a friend of the blog, held many of them a decade ago, flying a little Colomban MC-30, an ultralight designed by one of Concorde’s engineers.  At the other end of the size scale, Solar Impulse set many records on its globe-girdling treks.  Now, a five-member mostly German team hopes to set seven world records “in one fell swoop” as they electrically traverse 700 kilometers (435 miles) between the Schanis, Switzerland airport and Norderney Airport on Germany’s North Sea.

Friends of Electric Mobility

The five have interesting professional lives beyond their love of flight.  “Futurologist Morell Westermann, Swiss pilot Marco Buholzer, the Norderneyer brewer Tobi Pape, the video and music producer Tom Albrecht and the podcaster Malik Aziz, who founded the association ‘Friends of Electric Mobility’ want to start on August 31,” according to Electric-Flight.eu.  They will fly Pipistrel’s recently certified Velis Electro.  The team adds, “Above all, we want to prove its suitability for everyday use. That is why we do not fly prototypes specially designed for such record missions that only work under laboratory conditions.

700 kilometers (435 miles) by air -considerably farther by car: 1,246 kilometers (772.5 miles)

They hope to achieve their records during the planned three-day flight, including:

  • Lowest energy consumption (kWh / 100 km) over 700km
  • Highest average speed over 700 km (km / h)
  • Highest flight altitude ever reached with an electric aircraft (meter above main sea level)
  • Fastest climbing performance from 0-1000m / 1000-2000m / 2000-3000m (m / s)
  • Fastest average speed over 100km (km / h)
  • Lowest number of stops at 700km distance (number of stops)
  • Longest electrically flown route in 24/48/56 hours (km)

The team’s Velis, based at the Schanis, Switzerland airport (LSZX), will make a three-day flight of the 700 kilometers.   That’s an average of only 144.6 miles per day, which may not seem all that adventurous.  Flying a light airplane over the Alps certainly counts, and finding chargers along the way adds to the venture.

Comparing This to a Nissan Leaf’s Trip

Only 8 years ago, your editor wrote about Tony Williams, a then unemployed airline pilot who drove his daughter from Baja, California to Victoria, B. C. in his Nissan Leaf for a relative’s wedding. Early editions of that car managed around 100 to 125 miles on a charge, so Tony counted on the still-under-development network of charging stations along the I-5 to ensure that stops would be productive.  Today, motels, restaurants, gas stations, and Kohl and Walgreen’s parking lots have chargers.

Tony Williams’ Baja to B.C. Nissan Leaf was highly recognizable on its journey up the I-5

The sparseness of charging stations meant Tony had to plan carefully.  Similarly, our Swiss pilots will need to be prepared for a paucity of airports with the necessary support gear.

Overcoming the obstacles of terrain, aircraft range limitations (not too different from the 2012 Leaf) and relative lack of airport accommodations for electric craft today, the crew hopes to prove five big points.

  • “Electric flying is 4x more efficient than fossil drives
  • “E-planes are as efficient as e-cars
  • “CO₂-neutral flying is already possible today
  • “Electric flying is considerably quieter
  • “No contrails, exhaust fumes and kerosene stank” (We all need to add this to our descriptions of fossil-fuel fumers, ground-bound or aerial.)

 “Climate friendly, quiet and a little bit crazy” (their words)

The partners compare their adventure to that of Charles Lindbergh, who managed a solo flight across the Atlantic in 1927, winning the $25,000 (about $370,000 today) Orteig Prize, the largest such award up to that time.  The partners, however, have calculated they will have to pungle up between 50,000 and 80,000 euros to pull off their expedition.  Part of that will finance their application for the Guinness World Records acknowledgements.  Here your editor thought the Guinness folks showed up with plaques and medals when someone did something noteworthy.  It turns out they have to be lured to the scene and rewarded themselves.  Needless to say, they are looking for willing funders.

“Flying is not necessarily harmful to the climate”

The Friends of Electric Mobility will attempt to set seven world records in one flight

Pilot Marco Buholzer explains the grander goal.  “Flying with kerosene is extremely harmful to the climate. Aviation currently accounts for around five percent of the global warming, and the trend is increasing. The emissions at high altitude are a particular problem that arise from air traffic. We want to show that there are alternatives, even if we don’t manage the whole route in one go, CO₂-neutral flying is already possible today!”

Brewer Tobi Pape adds, “Most small planes fly distances shorter than 200 kilometres anyway, you could do that electrically.

Marco emphasizes, “On August 30th we will prove with our extraordinary flight that the time of electric planes has come.”  The landing is scheduled for September 1st.

Flight Following

The blog will follow this adventure and those playing at home can track the flight beginning August 30 here or here.  Stay tuned.


SolarStratos Returns to Service

SolarStratos, a mission envisioned by Raphaël  Domjan and an airplane designed by Calin Gologan,  returns to the skies after suffering a literal break in its program in 2018.

During a series of tests that put increasingly heavy loads on the wings, its left wing broke with what was called a “technical damage.”  This type of breakage during stress testing is not uncommon, especially on what are special machines such as SolarStratos and Solar Impulse.  Solar Impulse 2 suffered a similar break when its newly-designed wing was being tested.  As noted, this type of setback takes the team back to the drawing board, but also besets them with new reflections on their ongoing decisions.  If it were easy, everyone would be doing it.

“This pioneering spirit involves a real technological challenge, and takes us to unknown territories. Risks are an integral part of such a project, even if our objective is to anticipate them as well as possible; this is why we carry out many tests.”


Building a 24.9-meter (81.69-feet) wing for a powered aircraft that will gross only 450 kilograms (992 pounds) is a great challenge, but one that designer Calin Gologan has faced with his range of solar-powered vehicles.

As noted here five years ago, The airplane will carry two “big” pilots in tandem and 30 kilowatt-hours of batteries.  With the entire craft weighing only 200 kilograms (440 pounds) empty and 450 kilograms (990 pounds) loaded, the HPD-25D dual motor (32 kilowatts/43 horsepower) will be able to loft the efficient airframe to its goal altitude in about an hour, according to Calin.   The motor contributes a mere nine kilograms (19.8 pounds) to the airplane and Calin notes that the dual motor controllers are each the size of a deck of cards, enhancing the craft’s light weight.

The aircraft foregoes pressurization, helping make it a great deal lighter than the Perlan 2 sailplane, which weighs in at around 1,800 pounds.  SolarStratos will have to hoist two pilots with pressure suits, though, about 44 percent of the airplane’s gross weight.

 A Visit to Patagonia

Following the August, 2018 break in their wing, and waiting for the new design, Raphaël Domjan, Frank Bormann and Raphael Javet visited the Perlan Mission 2 team quartered at Al Calafate International Airport in Patagonia.  The two groups, both headed toward stratospheric goals, were able to discuss the challenges involved, “and Raphaël was able to gain the detailed insights of a highly motivated and dynamic team.”

Perlan acted as an inspiration for SolarStratos, with the power team reporting, “While the SolarStratos team was in Argentina, Perlan II broke a new record under tow, climbing to more than 40,000ft (12,192 m), beating the 30,000 ft (9,144 m) former record. An historic moment!

“Since the 27 August, the glider has broken the record again, posting an all-time altitude record for a glider of 76,000 ft (over 23,000 m) – a monumental achievement for this extraordinary aeronautical project.”

Miguel Iturmendi

Miguel A. Iturmendi, “Holds degrees in Aeronautical Science, Space Studies and Flight Test Engineering, and graduated as a Test Pilot from the National Test Pilot School.”  He was part of the Perlan team in Argentina, and flew with Jim Payne to 65,000 feet in 2018 in the Perlan 2.  Having flown over 160 different aircraft types, perhaps the most unique are the Perlan and the SolarStratos he is now test flying.

Miguel will have achieved record heights in both sailplane and power plane mode, with pressurization coming from a sealed cabin in Perlan and from a Russian-designed pressure suit in the SolarStratos. Both types of flights will share temperatures below -40° F or C (both identical at that temperature).

Resuming Flight

Miguel helmed the first flight of the re-designed and rebuilt SolarStratos on July 23.  The organization reports on the early morning flight.  “The aircraft soared effortlessly on its elegant new wings equipped with winglets at 800 meters (2,625 feet) above the Payerne aerodrome for twenty minutes before touching down again.”

Its new wings and wingtips catching the light, SolarStratos awaits the full light of the sun

Raphael Domjan expressed happiness with the results.  ““The plane is more stable and reliable than during our first round of test flights. Today we are beginning a new chapter that will allow us to reach extraordinary goals, to make the public dream and to convey a positive message on the potential of solar energy to fight climate change.”  Miguel and As flight testing continues, we will continue to report on the team’s progress.

Your editor as delighted to see a true pioneer in solar-powered craft counted as a member of the SolarStratos team.


Fred To was the first solar airplane designer, successfully designing and flying Solar One in late 1978.  SolarStratos, considerably advanced technologically, has the benefit of much better solar cells, batteries and motors than were available to Fred.

Fred reflects, “These are exciting times; from the humble beginnings in the 1970’s solar powered flight has come a long way. The pioneering spirit and dedication of Raphaël Domjan and team is now raising solar powered flight to a new and important level. I wish Solarstratos every success in this challenge.”  From the inspired inception of the concept Fred To gave us in 1978 to the sophisticated platform Raphael Domjan is using to explore extreme altitudes, it all seems of a wondrous thread tying past, present, and future together.


Electric Aviation Group Goes Big

Emulating bird flight has been a big part of man’s desire to fly through the years.  The latest in ornithological look-alikes comes from the Electric Aviation Group in the United Kingdom.  Their creation seem to be an outgrowth of last year’s somewhat controversial Bird of Prey concept displayed by Airbus at several prominent airshows.

Designed to have a “certain ‘Wow’ factor,” the model took its cues from hawks and eagles, including a high-arched wing blended into the upper fuselage.  It featured wingtips much like a bird’s, with primary feathers ostensible capable of morphing to control banking and even adverse yaw in a turn. Even its patriotic tail feathers were indeed feather-like and added to the avian quality of the aircraft.

Sailplane designers in the 1930’s tried similar imitation, with craft like the German Fafnir reaching an arch-winged perfection.

High-aspect ratio wing with distinctive bird-like shape helped German Fafnir glider achieve several world distance and endurance records.

Its flight, at least in this video, would be a model of grace and smooth, flowing motion – a bit dreamlike.

Hybrid Electric Regional Aircraft (HERA)

The British have always been good at giving their aircraft mythological appellations.  According to Greekmythology.com, “Hera is the wife of Zeus, the Queen of Olympus, and the Olympian goddess of marriage. As such, she is also the deity most associated with family and the welfare of women and children. Her marriage, however, was an unhappy one, since Zeus had numerous affairs. Jealous and vengeful, Hera made sure to give each of his consorts some hard time.”

Others have used the acronym, with one example four years ago from Imperial College in London.

Substantially different in configuration and with a distributed electric approach to propulsion, this aircraft has the same basic mission and requirements for quiet, economical, clean operation as the EAG proposal.


Perhaps short for EAGle, the resurrected design seems to be a more plausible version of the Bird of Prey, and has solid corporate and aerodynamic backing.

Mission parameters include reducing carbon dioxide emissions 75 percent per passenger kilometer over regular jet aircraft, dropping nitrogen oxide emissions 90 percent, and lowering noise by 65 percent.  EAG embraces these goals enthusiastically, seeing a slowdown in cleaning up existing craft.  “While the sector has made substantial progress over the last 50 years in addressing some of these factors, the pace of improvement is slowing as opportunities to do so on existing aircraft diminish and we remain a long way from reversing the impact on the environment. Hence it is time for the industry to embrace a paradigm shift. If we are to realize improving emissions that are moving towards the 2050 targets, then this paradigm shift needs to be embraced now and wholeheartedly.”

EAG’s HERA will have a tail perhaps inspired by aerodynamicist Bruce Carmichael rather than that of the earlier birdlike Airbus design

According to notes released for the beginning of the (virtual) Farnborough International Air Show, EAG’s HERA will be endowed with the following virtues:

  • Whisper-quiet operation reduces noise pollution
  • Innovative airborne battery regeneration to minimize turn-around time
  • Efficient battery integration
  • Thermal management of motors and power electronics
  • Gear Assisted Take-Off Run (GATOR) gives rapid acceleration for a quick lift-off reducing energy requirements
  • Short take-off-and-landing (STOL) performance enables new route opportunities affording greater profitability to operators
  • Cabin-flex design enables passenger operation during the day and cargo operation at night
  • Suitability for operating from regional airports brings convenience to travelers and gives increased proximity to warehouses, enabling private sector cargo to optimize last-mile terrestrial logistics and delivery systems and reduce carbon emissions
  • Future-proof design to accommodate alternative energy sources if available before 2030
  • Flexibility to transform into an all-electric or carbon-neutral as the battery density improves or alternative fuels and associated powertrain technologies mature and become affordable.

The design, has received additional support from EAG’s JetZero consortium, which includes some of the UK’s leading engineering and manufacturing organizations and senior academic advisors.

There will be competition, perhaps.  With larger and longer-range craft such as Jeff Engler and EasyJet’s Wright 1  making headway, HERA will find itself in a new and competitive environment.  Its medium size and medium-range capabilities should make it a desirable aircraft for that part of the market.


Honeywell’s New UAM Business Unit

Honeywell, long involved in avionics and other aviation-related instrumentation and equipment, has created an entire, new business unit devoted to unmanned aerial systems (UAS) and urban air mobility (UAM).  If any indication is necessary to show that urban air is not a passing fad, it’s the investments being made by major entities – from Toyota to Honeywell, from NASA to Mercedes.

Honeywell’s contributions to future UAM flight include avionics – devices that combine aviation with electronics.  Honeywell’s portfolio includes a miniaturized fly-by-wire system, electromechanical actuators to take the place of traditional control cables and pushrods, and systems to help integrate the UAM into existing and future air traffic control systems.

These systems will work for electric Vertical Take Off and Landing (eVTOL) machines or more conventional fixed-wing configurations, represented by Tine’ Tomazic from Pipistrel in the following video.

Multi-rotor craft can benefit from Honeywell’s lightweight auto-pilot and fly-by-wire systems.  Integration into the overall aircraft enables precise control and the ability to program systems and components for heightened efficiency, as shown with this Vertical Aerospace proof-of-concept vehicle.  You can find a white paper on the collaboration between the designers and Honeywell here.

Flight control passes to electro-mechanical actuators, another part of the Honeywell component lineup.  Having everything come from one source means more secure integration of those control systems and components.

Within the UAM and within the airspace in which that UAM flies, a maze of mission requirements and government regulations require the aircraft designers to integrate their craft into a complex flow of other vehicles.  That could be daunting in the not-too-distant future, with Uber, GrubHub, and Dominoes pizza deliveries competing for airspace.  Honeywell has thought about that future and launched a response.

Honeywell’s Consolidation of Resources

Mike Madsen, president and CEO of Honeywell Aerospace sees UAMs and UAS’s as a vital part of Honeywell’s future.   “Urban Air Mobility and Unmanned Aerial Systems will play an increasing role in the future of aerospace, with potential applications in all-electric urban air taxi vehicles, hybrid-electric unmanned cargo drones, optionally piloted airplanes, delivery drones and everything in between.”

Honeywell has chosen a skilled entrepreneur to lead the business unit, Stéphane Fymat, who your editor knows through his work with the Perlan Project.  Perlan holds the world altitude record for sustained, unpowered flight at over 76,000 feet.  This rarified atmosphere and almost unexplored height is significantly different from the low-altitude, potentially crowded urban airspace of the UAM world.  He did, as noted in his Perlan Project biography, found “Smartplane Inc. in 2011, a company developing a semi-autonomous personal aircraft.”  That experience will help him integrate well with his new business unit.

unmanned aerial systems (UAS) and urban air mobility (UAM)

The Perlan Project Biography

Stéphane Fymat : Board Member: Biography

“Stéphane has 25 years of experience in the aerospace and computer industries. He began his career as an engineer for Aerojet-Electrosystems, now a subsidiary of Northrop Grumman Corporation. At Wang Laboratories, he was part of the founding team of its document imaging software business unit which grew from $0 to $50M in 3 years, when it was carved out and sold to Kodak for $260M. He then joined cyber-security company Passlogix as Vice President. As part of the executive team, he lead the company from start up to mature market leader with #1 market share and 20M licenses sold to the largest companies worldwide. Passlogix was acquired by Oracle. He founded Smartplane Inc. in 2011, a company developing a semi-autonomous personal aircraft, and is its Chief Executive Officer. He has an MBA from Columbia University and a B.S. in Mechanical Engineering and Computer Science from UCLA. He is a private pilot, and sits on the ASTM F44 committee for FAA Part 23 Certification. He has two patents issued and one pending in avionics.”

Even more apropos to the needs of the AUM/UAS world, his work with the ASTM (American Society for Testing and Materials) F44 committee will be invaluable.

“This Committee addresses issues related to design and construction, systems and performance, quality acceptance tests, and safety monitoring for general aviation aircraft (also known as Part 23) that is less than 19,000 pounds and 12 passengers.”

It will be fascinating to see how Stéphane will expand his horizons and those of his employer in coming years.  Best wishes to all.


HyPoint and Hydrogen Flight

Their web site proclaims, “HyPoint, Inc. is developing the next generation hydrogen fuel cell system with zero CO2 emissions and game-changing energy performance for the air transportation and urban air mobility market.”  Pointing out a “fundamental barrier at a chemistry level” for lithium-ion batteries, the fuel cell maker launches some seemingly outrageous claims.

HyPoint states, “Our patented technology increases operational time and utilization rate while decreasing TCO (total cost of operation) of any flying platform.”  They claim “5X operational time, 10X utilization rate, 20X faster charge,” and a TCO 90 percent of equivalent battery-powered systems.

As we have reported here, demonstrated outputs for lithium-ion cells are around 350 Watt-hours per kilogram, and about 260 Whr/kg at the pack level.  HyPoint says it can already demonstrate a system-level specific power of 1,000 Watts per kilogram and an energy density of 530 kW-hr/kg.   The company points to its next generation of “turbo air-cooled” units to produce even more power and show better energy density.

These improvements would make the fuel cell a candidate for aircraft use, according to HyPoint.  Already collaborating with ZeroAvia and Urban Aeronautics, HyPoint hopes to supply airworthy systems by next year.

Urban Aeronautics, which is pioneering the next generation of eVTOL aircraft for commercial air taxi and air rescue roles, and HyPoint, a leader in next generation, high power (HTPEM) hydrogen fuel cell systems, will explore the development of an advanced version of Urban Aeronautics’ CityHawk eVTOL powered by HyPoint’s cutting-edge, hydrogen fuel cell stack technology. As currently designed, CityHawk relies on hybrid propulsion. 

  True Costs of Operation?

Mass-produced,HyPoint’s current fuel cells would cost about $800 to $1,000 per kilowatt.  The cost per kilowatt-hour would depend on the cost of hydrogen flowing through the cell.  HyPoint is apparently counting on their new “turbo air-cooled” units to lower that cost, although they are reluctant to disclose what the cell costs will be.

Tesla’s “Roadrunner” project aims to lower battery prices to $100 per kilowatt-hour.  For battery electric vehicles, that is a set rate (increasing slightly over time as the battery capacity is reduced in use).  Charging costs should decline over time, as solar cells and wind turbines become more efficient and less costly.

Several sources challenge the idea that hydrogen power can operate cars (or airplanes) more cheaply than electricity stored in batteries.  Inside EVs, for instance, reports that Volkswagen is trending toward batteries exclusively, stating somewhat provocatively, “In the case of the passenger car, everything speaks in favor of the battery and practically nothing speaks in favor of hydrogen.”

The efficiencies in comparison, as described by Volkswagen, which has a preference for batteries. Would another comparison from a different perspective yield a different preference?

Fred Lambert, writing in Electrek predicts, “Though hydrogen certainly has more potential with semi-trucks than passenger cars, it’s still not likely to triumph over batteries for powering the next generation of zero-emission transport.

“As we have often explained before, the entire end-to-end process from production to consumption is 3x times more energy efficient for battery-powered vehicles than hydrogen fuel cell vehicles.”  This was written three years ago, and things in both battery and fuel cell worlds have changed considerably.  It’s interesting that Lambert felt enthusiastic enough about his ideas at that time to use no less than four exclamation points in his caption to the diagram below.

What hope is there for hydrogen fuel cells in aircraft if the numbers tend to favor large stationary installations or their use in large vehicles such as buses or class 8 trucks?

Use in Aircraft

As we described 11 years ago, “Gerard Thevenot, a long-time championship-level hang-glider pilot, celebrated the centennial of Louis Bleriot’s flight across la Manche (the French name for the English Channel) by flying his hydrogen-powered La Mouette hang glider over roughly the same route Bleriot took between Calais and Dover on August 6, 2009.”  Later reports showed the flight used 755 grams (1.66 pounds) of H2, a great deal less than the amount of fuel a howling two-stroke engine might have consumed.

At current prices for hydrogen, at $1 to $1.40 per pound liquefied and transported to the user, the trip would have cost $1.66 to $2.33.  Try flying 22 miles any cheaper than that.

Today, several firms are exploring H2 aviation.  ZeroAvia, flying both Hollister, California and Cranfield, England, is using avgas and hybrid setups so far, but will switch its proof-of-concept Piper Malibus to hydrogen power in the near future.  They are partnered with HyPoint, so we look for flight tests by next year.

The Alaka’i Skai is intended to fly on H2 from the beginning.  The four-rotor UAM will have a range of hundreds of miles, rather than dozens like its battery-powered competition.

Reported in New Atlas, Rafi Yoeli, CEO of Urban Aeronautics says, “We look forward to collaborating with HyPoint on the integration of the next generation of hydrogen fuel cell systems for eVTOL transportation and the urban air mobility market. As a high-power, 100 percent environmentally friendly fuel, hydrogen is key to the future of eVTOL aircraft.”

Red Jensen shared this photo of a strange craft at Mojave Airport.  One Redditor speculated, “The tail number N971YT is registered to Toyota. It’s an electric aircraft which I find interesting considering their vehicle’s are known to favor hydrogen fuel cells as their alternative fuel choice instead of electric.”

Toyota promotes fuel-cell-powered trucks and its Mirai passenger car.  It gave Joby Aviation $394 million in January, so one wonders about the direction future flight might take with this partnership.

Where Will This All Go?

Obviously, proponents on both sides of the fuel cell/battery debate are well dug-in on their positions.  We need to do a less biased, more measured look at the trends and potential for each system.  In coming entries, we’ll try to give as objective a look as possible at these energy sources.


Wisk Tests Cora in US, New Zealand

Recently renamed Wisk (formerly KittyHawk) has resumed flight testing of its Cora eVTOL (electric Vertical Take Off and Landing) machines following a cautionary corona virus shutdown.  It’s already got a fleet, with several prototypes in the U. S. and at least four in New Zealand.

Four Cora’s on the ramp

New Zealand seems to have a lock on flight testing for unpiloted aircraft, with Pyka and Cora both finding amenable administrators willing to allow flight tests.  Boeing and Wisk are collaborating on achieving urban air mobility with the two-seat machine, and getting a lot of positive vibes from the locals.  Partly from the NZ government, partly from local businesses, and partly from indigenous Maori tribes’ people, Wisk and Cora have found wide-spread acceptance down under.

Government Support

Research, Science and Innovation Minister Megan Woods announced last October that, “The Government is establishing an Airspace Integration Trials Program to support the safe testing and development of advanced unmanned aircraft and accelerate their integration into the aviation system.”

The Ministry of Business, Innovation and Employment (MBIE), “Is committed to supporting the growth of an innovative unmanned aircraft sector in New Zealand. We’re creating opportunities to test and develop these emerging technologies to help make this happen.”

Working Zephyr Airworks, the New Zealand affiliate of Wisk, the MBIE has transferred $2.1 million to the Civil Aviation Authority to “build capability” and hire technical experts.  The Ministry gave an additional $900,000 to the Ministry of Transport to “support policy development related to regulatory settings.”

The government will also partially reimburse 4,000 aircraft owners for the costs of installing ADS-B (Automatic dependent surveillance–broadcast) transponders in their airplanes.  Such units will become essential as the number of autonomous craft grows.

Maori Support

Wisk reports (as of October, 2018), “Our time in New Zealand has also empowered many other important milestones. We have achieved seven hundred flight tests globally (now well over 1,000)–– a major step forward toward ensuring Cora is one of the most reliable and advanced aircraft ever to take to the sky.

“We have built lasting bonds with the community. The young leaders of Ngai Tahu Iwi (a Maori tribe in New Zealand’s South Island) recently visited our headquarters in sunny California. And we have benefited from hiring incredible local talent as the Kiwi cohort on the Cora team grows.

Kids, chalk, and Cora – a great outing for the family

Recently, we also celebrated the opening of our hangar in New Zealand. It was an exciting moment. The hangar will serve as our first base of operations as we grow our fleet of Coras and build toward the world’s first electric, autonomous air taxi service.”

In a hangar opening ceremony attended by Minister Woods, local school children, and Maori tribes people, “We were privileged enough to have Ngai Tahu bless our hangar. They led us on a procession in a timeless ceremony for invoking wellbeing and prosperity. It was one of the many priceless opportunities we have had to engage with the rich tikanga of the Māori culture… Together, we are building a world where the freedom and power of the sky connects all our lives.”

Cora Itself

An outcome of a decade’s development, Cora takes off vertically with no less than 12 propellers, apparently on pivoting mounts, paired on six under-wing booms.  Wisk describes the safety factor inherent in the design: “Rotor Safety System: Our vertical lift system features 12 independent rotors. Each direct drive motor combination has only one moving part: the fan. Flight tests have shown that an issue with one rotor is automatically handled with no discernible change in the flight path.”

Autoblog has a somewhat unique take on the “flying taxi.”  The Kittyhawk offerings are no longer available.

To keep things on a planned course, triply redundant flight controllers process navigation.  If any one encounters a problem, the other two maintain the plan.

Finally, in the Hail Mary type of safety measure all UAMs seem to choose, a total failure of all power plants on Cora would enable use of a ballistic parachute that would lower Cora and its occupants safely to the ground.  Your editor has a nit to pick with this, even though most UAM makers extol its virtues. It may be great for the craft and its passengers, but what about the unsuspecting groundlings who may have even the lightest of craft land on them – however slowly?

Cora has one saving grace in this, with its aerodynamics enabling controlled forward flight even with all power off.  A pilot (or an autoland system) could still maneuver Cora to a relatively safe landing.

Wisk does not elucidate on the power of the large pusher motor, or of the 12 fans.  It lists only the 400-pound payload, allowing us to make some admittedly loose speculations about the rest of the package.  The 12 fans will have to produce at least 100 – 135 pounds of thrust each to lift a 1,200 -1,600 pound Cora and passengers.  That gross weight will probably be more, so thrust will need to be greater.  Let’s guess 15-to-20 kilowatts (20-to-27 horsepower) per fan.  That’s 180-to-240 kilowatts total (240-to-324 horsepower).

Wisk lists Cora’s range at, “Initially about 25 miles (40 kilometers) plus reserves.  This is less than eVTOL News’ endurance listing of a flight time of 19 minutes with a 10-minute reserve.  At 110 mph cruising speed, 19 minutes would take the craft 34.8 miles (not counting power required to gain cruising altitude and set back down).  Let’s guess that cruising on the one pusher motor takes much less power than that required for vertical lift.  Just for fun, let’s add two minutes of total power lift and two minutes of total power descent.  (All these assumptions and calculations are open to scrutiny, of course.)

Four minutes of full power and 25 miles of 70-percent power would require 16 kilowatt hours for lift and descent and about one kilowatt-hour per minute in level flight or 29 kWh (with reserve).  16 + 29 = 45 kWh for the 19-minute flight.   We’re basing the power required for level flight on that for a Cessna 152, a roughly equivalent but radically different craft.   To lift the 400-pound payload, aircraft structure and motors, and batteries keeps the range short, and the total weight probably close to that of a 152 – 1,670 pounds.

Wisk Cora’s FAA application drawing

George Bye of Bye Aerospace has what are probably the highest power battery packs (as of now) on his eFlyer aircraft.  They are rated at 260 Watt-hours per kilogram.  If equally efficient packs were installed in Cora, it would take 981 pounds of batteries to maintain 29 minutes of full-power lift.  This would be inconceivable – if not impractical.

For the 19-minute flight noted above, batteries to obtain the 45 kWh would weigh around 173 kilograms, or 380 pounds.  That’s close to the one-third total weight that would make this a viable flying machine.

Wisk is doing a great job in promoting its aircraft, involving talent in both hemispheres, and being a good corporate citizen.  Its examples now flying are showing their merit and we may see the skies filled with their machines sooner than later.


Pipistrel Velis: Part of an Electric Heritage

The Pipistrel Velis is the culmination of 13 years of electric aircraft development and the first to gain certification by the European Union Aviation Safety Agency (EASA) on June 10.

Pipistrel has been in the electric airplane business since 2007 when it announced the Taurus Electro motorglider, which entered service in 2011.  That aircraft went through several iterations, and is still part of the Pipistrel lineup of electric planes, which includes the Alpha Electro Trainer, the Panthera Hybrid, and the new Velis.

Alpha Electro Trainer in SoCal

An electric version of the Alpha Trainer, the Electro has been in production since 2015.  With an empty weight of 615 pounds (279 kg) and a maximum take-off weight of 1,212 pounds (550 kg), it is a bit heavier than the Rotax-powered gas version, and carries about 100 pounds less payload.  Both have similar performance, though, with rates of climb around 1,200 feet per minute.

Joseph Oldham started a well-organized, well-intentioned operation to bring electric flight to California’s Central Valley.   His Sustainable Aviation Project aims to train low-income young people in electric training craft and give them a different direction in life than otherwise might be possible.  Beth Stanton, an aerobatic pilot and writer for the Experimental Aircraft Association’s Sport Aviation, flew with John in an Alpha Electro recently and wrote about it in the July issue of EAA’s magazine.

Pipistrel velis electro in flight

Michael Coates republished it in the Pipistrel USA newsletter number 130, where it details the careful planning and execution of getting four Electros through 100 hours of flight in the heat of the Central Valley.  Oldham even went to the trouble of creating an air-conditioning hookup to keep batteries from overheating.  His efforts allowed him to achieve 175 hours in different Electros, 111 in one example.  That batteries survived the long, hot days of summer was a major victory, although the air-cooled motor controllers often reached the limits of their operating temperatures.  Pilots applied limits to keep things cool, but the airplanes still performed better than one might expect.

Beth reports, “At full throttle, the Alpha Electro jumped off the runway faster than the gas-powered version. As we cruised around the valley, I noticed that it had more docile handling characteristics compared to the gas-powered version. Joseph said that the electric motor has smoother power than a four-cylinder combustion engine. I was careful to keep coordinated flight, as any tiny amount of drag decreases efficiency (and time aloft). It was surreal to glance at the SOC reading as opposed to the familiar fuel, engine, and oil gauges.”  She has vowed to return for further training, “Once these babies are certified for instruction, I’m going to be first in line to get checked out to fly them.”

A Liquid-Cooled Solution

The new Velis has added liquid cooling to its motor, controller, and batteries to enable its use even in hotter climes outside its Slovenian homeland.

As part of the Type Certification, Pipistrel demonstrated that Velis Electro achieves the highest levels of safety, even surpassing those required for conventionally powered aircraft.

“Velis Electro is a full-electric derivative of the proven Virus SW 121, which is already type certified by the European Union Aviation Safety Agency (TC No EASA.A.573). It is equipped with a Pipistrel type certified electric engine E-811-268MVLC (TC No. EASA.E.234), developed with partners EMRAX and EMSISO, and Pipistrel’s three-bladed composite fixed pitch propeller P-812-164-F3A.

“The 57.6kW liquid cooled electric engine provides power to the aircraft.

Pipistrel’s E811 type-certified motor in its Velis mount.  Note charging port behind starboard side of motor

“The power is delivered by 345 VDC electric system built around a liquid-cooled in-house developed high performance battery system, which includes two Pipistrel PB345V124E-L batteries connected in parallel, installed in a redundant 2-unit arrangement, total nominal capacity 24.8 kWh. Crashworthy, thermal runaway inhibiting, HIRF/EMI tolerant.

Pipistrels 60 kilogram, liquid-cooled battery packs

“One battery pack is located in the nose of the airplane and the second behind the cabin. This ensures redundancy of the power source: in case of battery failure, the malfunctioning battery would get automatically disconnected from the system. A single battery is capable of standalone operation and has enough power capability to support climbing and continuation of flight.

“The liquid-cooling system consists of a radiator and two electrically driven pumps installed in series, located behind the rear battery pack. An air inlet for the radiator is located on left side of the fuselage, and the warm air leaves the fuselage at the bottom. Two high power axial fans are installed behind the radiator in order to allow battery cooling during charging. The fans are automatically controlled and monitored by the BMS for seamless operation.

“Batteries can be charged via an onboard charging port using a Pipistrel electric charger. The whole operation is overseen by the Main computer, which displays the status of all systems on the Pipistrel EPSI 570C.”

The controller receives torque command via CAN bus and adjusts the motor current input accordingly through the engine’s high voltage AC bus. The motor reacts instantaneously and without hesitation

The upgrades in the Velis ensure that it will have a long service life, operational safety, and the cost benefits of electric aircraft operation.  Pipistrel claims a one euro ($1.13) per hour battery cost.  Beth’s article notes a $4 per hour battery charging expense.   Neither comes close to the costs associated with avgas consumption.

Current pricing for a standard configuration Velis Electro is 159,000 euros (about $179,000).  This is at the top of the range for Light Sport Aircraft, and the price is offset by the low operating and maintenance costs one can expect.

It looks like a winning approach to lowering the cost of flight instruction and bringing more potential pilots into the new world of electric aviation.


Eric Raymond Shares a Vision

Eric Raymond is a real pioneer in electric aviation.  Decades before Solar Impulse made its epic flights Eric navigated his solar-powered Sunseeker I across the United States in 21 hops, traveling from Desert Center, California to Kitty Hawk, North Carolina.

Sunseeker 1 departing Desert Center, California from which cross U. S. trip began in 1990

He flew over the Matterhorn on his way from Germany to Italy in Sunseeker II.  He and his wife Irena build the world’s first two-seat solar-powered airplane, the Duo, which they regularly fly over Italy and Switzerland.  He shared the promise and mystique of such flight with the readers of Travel Forward recently.

Sunseeker 2 looking back at Matterhorn after successful crossing


The Future is Electric: Exploring the World in a Two Seat Solar Powered Airplane

MAY 18, 2020


While Tesla and other car manufacturers are changing the way we commute, prototype electric airplanes are set to change the way we fly in the future.

Aviation has become the last frontier to become more environmentally friendly, even though technology devolved for electric vehicles can be adapted for aircraft. Since 1975, many airplanes have been powered with electric motors, with ever-increasing capabilities.  Since batteries can give power only for a limited time, the first airplanes to take advantage of electric motors have been gliders.

Eric and Irena Raymond in Sunseeker Duo, having just flown over Matterhorn on trip from Italy to Switzerland, 2015

After taking off and climbing with the power from the on board batteries, they can turn off the motor and fly peacefully over land for hours. A lot of us may have a preconceived image of what a solar panel looks like, never dreaming they could be part of an airplanes structure. However, they fit neatly onto gliders, enabling the recharging of batteries whilst in the air! This saves not only petrol and fuel emissions entering the atmosphere but also allows the motor to run with full batteries several times per flight.

The experience of soaring like a bird, comfortable and silent, through the air with no noise from a motor to spoil it, is a dream! Note that you are never in doubt with the added security of an electric motor to climb when needed. The technology capabilities in aviation are close to limitless, and crafts like the SUNSEEKER DUO, show promise for short and medium range commuter aircraft in the near future. Adding hybrid propulsion to an electric aircraft can greatly improve the range, while retaining most of the benefits of a pure electric aircraft.

A Typical Day Flying in an Electric Airplane

The cockpit is so quiet that no headsets are used.  Conversation between the two people on board and for radio communication is at a normal sound level.  The electric motor cannot be heard from the cockpit at all, just the swish of the propeller, far behind on the tail.  Unlike most small planes, the motor is in back to give the best flying experience for the pilots in the cockpit.  The view forward is excellent since the motor and propeller are not in the front.  The bubble canopy allows for a breath taking views and has a dark tint to keep the passengers cool, sitting in the sun.  Large air vents bring in fresh air, and for an outdoor feel, the large side windows can slide open, allowing pilots to touch the air as they fly!

Sunseeker Duo over alps

Built for touring, this light solar-electric airplane can fly all day long in good weather, over the clouds, often at 3000 – 5000 meters altitude.  The solar power gets stronger and stronger at high altitudes, its height limit is still unknown.

Solar Flight Inc. have plans that could inspire electric aircraft manufacturers all over the world, from Canada to South America: travelling and offering rides to locals to view their land from above in an airplane that does not disturb anyone or anything! Success of this demonstration flights should lead to inspiration for every game player in the industry to invest in electric and solar solutions.

By Eric Raymond, Founder and President of Solar Flight Inc.


Terrafugia in Transition

Terrafugia, a company started by a group of inspired college friends, has made it a mission to bring a flying car to the marketplace.  Quite literally – it’s in their mission statement: “Terrafugia’s mission is to create the ultimate mobility solution – flying cars.”  Even though the term is somewhat decried in current parlance – things like urban air taxis or sky taxis that would provide Urban Air Mobility being preferred.

The Transition

Their first craft, the Transition, earned a high hype score, with even Hammacher-Schlemmer including the flying car in their catalog.  It flew at AirVenture in 2013, demonstrating its folding wings and reasonable Light Sport Aircraft performance (even with a waiver for its “heavy LSA” gross weight).

In some respects, the Transition is like Molt Taylor’s famous Aerocar, the first such vehicle certified for land and air travel.  It’s a great deal simpler to operate, though, not requiring a trailer like the Aerocar to haul the wings and empennage.  It doesn’t require assembly and disassembly to transition from aerial to terrestrial travel.  Molt found that the number of licenses kept his craft from greater acceptance.  Imagine the paperwork involved with applying for airworthiness certificates, aircraft, automobile and trailer licenses and one begins to get the idea.  Only two Transitions have been built to date, possibly for reasons that limited Aerocar’s success.

The T-FX

In 2013, Terrafugia introduced the T-FX, a radical flying car.  It doesn’t seem to have progressed beyond the computer-generated video stage, though.  Some of the anticipated specifications seemed implausible to your editor, including a 500 mile range at a cruising speed of 200 mph.  Its cost was to “be consistent with high-end luxury cars,” but one wonders how high?  Million-dollar Bugattis, perhaps.  The one-megawatt power output from unleaded auto gas would not make it a truly green machine.

Purchase by Zhejiang Geely

Chinese firm Geely Holding Group explains a managerial transition for Terrafugia two years ago.  “Terrafugia was founded in 2006 by five award winning MIT graduates that had a vision and a passion to change the way human’s move around their environment.

“On November 13th 2017, Terrafugia became part of Zhejiang Geely Holding Group in an industry changing transaction, mixing Geely Holding’s entrepreneurial and innovative spirit with Terrafugia’s passion and vision.”

Geely has been on a spending spree that last few years, fetching Lotus cars, Volvo, and rights to the classic London taxi, which they have electrified.  Their growing line of automobiles, including electrification of Volvo in their Polestar line and an exotic, $2.1million Lotus Evija that can do zero to 186 mph in nine seconds shows an intent to cover all price and performance levels.

The TF-2 in Several Iterations

Terrafugia introduced a series of computer-generated videos for a new product called the TF-2, more like a flying mini-van than a flying car.

Starting with the pre-Geely-acquisition version, TF-2 has gone through a few iterations.  To help sort that out, the data-driven folks at eVTOL News keep a directory of all the actual and projected designs for Urban Air Mobility.  In this recounting, there are two basic versions of the TF-2, the TF-2 Tilt Rotor (since abandoned) and the  TF-2.0 Lift + Push .  Since then, they have introduced a smaller UAM/Uber-possible machine, the TF-2A, a two-seat sky taxi not unlike the Wisk Cora.

Terrafugia tf2-tiltrotor, no longer a viable design

Terrafugia TF-2 Lift + Push configuration

The TF-2A, tested in a reduced-size version, has a wingspan of 4.5 meters (14.8 feet) carrying 60 kilograms (133 pounds) at about 100 kilometers per hour (62 mph).  The full-size version will carry two passengers up to 100 kilometers (62 miles) and a cruising speed of 180 km/hr (112 mph).  The Geely press release includes a video of the reduced-size test machine.

Terrafugia TF-2A two-seater designed as UAM

Between Terrafugia’s willingness to accept risks and Geely’s ability to fund visionary ideas, the pairing might come to market with exciting machines sooner than one might expect.


Hydrogen Malibu’s on Two Continents

Tuesday, June 23, ZeroAvia flew a hydrogen-powered Piper Malibu from Cranfield Airport in England., eight time zones from ZeroAvia’s home base in Hollister, California.

Flown by Andrew Dixon, that and a subsequent flight gained extra publicity for “a James Bond stunt pilot*” helming the first electric aircraft capable of carrying passengers from a United Kingdom airport.  Dixon reported that the battery-powered Piper Malibu needed 10 per cent less distance for take-off and climbed faster than normal.

The Airplane Was the Real Star

Reflecting the high-flying status of the test pilot, the airplane, part of a government-funded “HyFlyer” project, flew two missions on two days of 15 and 25 minutes each.  Its two automotive-based batteries easily carried the six-passenger aircraft on its tours of the Bedfordshire countryside.

The second of two Piper Malibus to be converted by ZeroAvia, the craft will be converted to hydrogen power before an October or November “300-mile flight from Orkney to an airport on the Scottish mainland.”This would be a predecessor to a line of fuel-cell aircraft that could include a 19-passenger medium-range commuter craft.

ZeroAvia Malibu lifts off under English skies

Business Green.com reports that, “Having demonstrated its new electric drive train the company intends to develop a hydrogen fuel cell powertrain and convert a 19-seat aircraft to run on hydrogen that could be in commercial use as early as 2023.”  The report add, “Yesterday’s test flight came on the same day an EU-backed study assessed the potential for hydrogen-powered flight in Europe, predicting that with supportive regulatory, investment, and policy signals the technology could become a major player for short to medium haul plane journeys within 10 to 15 years.”

ZeroAvia is partnering with the European Marine Energy Centre Ltd. and Intelligent Energy, manufacturer of what they claim to be the lightest and most powerful H2 power systems.  Over a decade ago, IE was promoting a fuel-cell scooter, and later tested the system with the Metropolitan Police in London.  They have developed small-scale systems for unmanned aerial vehicles (UAVs) and are collaborating with ZeroAvia on larger units.

Valery Miftakhov

Valery Miftakhov’s company biography shows a unique skill set and background that enables his work with ZeroAvia. “Val Miftakhov, ZeroAvia Founder and CEO, is a serial cleantech entrepreneur who knows how to scale technology for use by existing transportation industries. Val’s previous venture, eMotorWerks, developed smart vehicle-grid integration hardware and software, and was acquired in 2017. eMotorWerks’’ JuiceBox Smart EV charging station is the best selling product in its category in the United States for the last 5 years. Before eMotorWerks, Val held executive business strategy & operations positions at Google, McKinsey & Company, and Nielsen. He also launched and managed three startup companies, in all of which he held the CTO positions. Prior to his industry experience, Val was a high energy physics researcher at Stanford Linear Accelerator, a Department of Energy facility. Val received his PhD in Physics from Princeton University and his MS in Physics from Moscow Institute of Physics and Technology. He was a two-time winner of the Nationwide Russian Physics Competitions. In whatever spare time he gets, Val tries to get good use out of his airplane and helicopter pilot licenses.”

To help promote his company’s mission, he has authored to sponsored articles in Forbes Magazine.  “Is Electric Flight Aviation’s Next Era of Innovation?” reviews the startups and companies “…already already creating promising products and prototypes,” including, of course, ZeroAvia.  “Aviation Is The Driving Force Of Hydrogen” explains “Requirements for extreme energy density, high cycle frequency and lack of biofuel scalability will make hydrogen-based aircraft propulsion a virtual necessity in our carbon-neutral future.”


ZeroAvia is not in this effort alone, being funded by the UK government agency Innovate UK and the Aerospace Technology Institute (ATI).  Dr Simon Weeks, chief technology officer at ATI, praised the program.  “The ATI is delighted to see the first flight of ZeroAvia’s battery-electric aircraft at Cranfield.  This exciting ATI funded project is the next step in an effort to develop a commercial zero emissions hydrogen fuel cell powered commercial aircraft in the UK.”

European Marine Energy Centre will provide clean hydrogen for future flights, “made by an electrolyzer powered by wind turbines, so there will be no greenhouse gas emissions.”This is similar to the vision of Pipistrel, which foresees cheap H2 made by non-fossil-fuel means.

Academic and practical assistance will come from Cranfield University, which has a significant aeronautical department.  “Cranfield Aerospace Solutions (CAeS) will assist with integrating ZeroAvia’s powertrain into the Piper airframe and host the ZeroAvia team at their hangar facilities. With its expertise in airframe integration and modification as well as whole aircraft design, CAeS brings the best of the UK aerospace industry into this collaboration.”

ZeroAvia seems well on its way to its goals, having secured an Experimental R&D certificate at its Hollister headquarters necessary permits and certificates in the UK.  The company feels it’s “on track for commercial operations in 2022.”  Suddenly, hydrogen, which has always been the fuel of the future, seems much more imminent.

*Besides acting as a training captain on Sally B, the last airworthy B-17 in Europe, Dixon has flown stunts on the Father Brown TV series, and in the James Bond films Spectre and Quantum of Solace.