Common Sense vs. E-Everything
Austin Meyer here from Laminar Research. I wrote the flight simulator X-Plane and I am currently using it to evaluate a number of eVTOL aircraft, including several that I am consulting or otherwise working on.
Jason Baker recently wrote a blog here titled “Common Sense vs. E-Everything” In this blog, Jason asked five questions, each of which I shall now answer.
1: Where do we get the lithium for these batteries and at what environmental and human expense?
Answer: From the ground and at the expense of digging. There may be barriers to electric airplanes, but lack of lithium isn’t one of them.
2: Can we shoot non-recyclable batteries into outer space?
Yes, we can shoot many things into space. Including cars. For fun. But it’s smarter to employ used batteries on the ground to stabilize the power grid during swings in supply and demand. This is called leveling the grid. The lively secondary market for batteries awaits only sufficient volume of used cells.
3: Will we be capable of paying constantly increasing electricity bills?
That depends. Do you pay more than $3 per hour for fuel for your airplane? Because that’s the electricity cost of a Pipistrel Electro. Compare that to fossil fuels. Which is cheaper?
4: Will temperatures fall measurably by banning gasoline and fossil-fuel burning engines from primarily personal transportation, while completely ignoring much larger environmental abuses?
Yes, and who said anything about ignoring other problems?
5: Where will we find work for millions of people displaced from their source of income when and if this E-hype continues?
It’s not hype if it actually displaces millions of jobs, is it? And to answer the question, the jobs will obviously be found in the new electric industry.
So Jason’s questions all have blatantly obvious answers, but now let’s look at what REALLY matters for electric aviation.
We’ll start with the most critical and limiting factor: The batteries. Batteries store far less energy per pound than jet fuel, and this limits endurance and range compared to fossil fuels… BUT is battery energy density good enough to get a transportation job done?
Tesla has already proven that batteries are good enough for ground transportation. They’ve proven it 900,000 times and counting, in fact.
So that’s fine for DRIVING, but what about the power-intensive world of aviation?
Let’s look at what the batteries talk to when it’s time to spin a prop: Electric motors. As it turns out, electric motors unlock certain secret weapons that Lycomings, Continentals and Pratts have never given us… and THESE are the secret weapons that will help unlock the next level of aviation.
Secret weapon #1: Instant torque. As every Tesla driver—and countless fossil-burners looking at their tail-lights in a drag race—have discovered, electric motors give torque instantly. Helicopters are dogged by their complex, expensive, maintenance-intensive cyclic, collective and anti-torque systems. But drones with e-motors can change their rotor spin so quickly with instant torque that their simple one-piece plastic props can both stabilize and maneuver the craft. Complexity and cost are slashed. I’m currently involved in a flight test program that has tested this in hovering and forward flight on a manned eVTOL that weighs 3,600 pounds… with nothing but one-piece, fixed-pitch props. So this effect is now proven valid up to the weight of a Cirrus SR-22.
Secret weapon #2: 95 percent efficiency. At best, gas-burners run at about 33 percent thermodynamic efficiency, turning only a third of their fossil-fuel energy into power. Electric drive systems, though, run at about 95 percent efficiency, delivering three times the energy to the prop for each unit of energy consumed. This effectively triples the energy on board compared to any gas-burning engine. The gas-burner energy advantage just got cut by a factor of three.
Secret weapon #3: Silence. If you just operate close to the ground only within airport bounds, then the noise of an airplane can usually get a grudging pass from the community: Your noise is largely limited to the airport area. But what if we wanted to fly from the airport to the middle of downtown? Suddenly, the engine and prop noise would be a deal-breaker. Electric motors solve this problem for engine noise, and with proper sizing or gearing, can turn a prop slowly enough to hugely reduce the prop noise as well.
Secret weapon #4: Zero emissions. An obvious benefit for everyone near the airplane… and if that energy comes from a grid fed by solar, wind, or nuclear power, then it’s a benefit for everyone. This is a requirement for community and public acceptance, as it should be.
Bonus secret weapon: Rapidly-improving battery technology.
A gallon of 100LL will be the same next year as it was in 1950.
Batteries, however, have demonstrated that they can carry an airplane about 100 miles (airplanes under construction now may double that) with energy density improving at about 7 percent per year.
This is a race fossil fuels can only lose and here’s how fast they’ll lose it: Take 100 or 200 nautical miles and compound it at 7 percent interest. As that number grows over time, it will displace fossil-fuel airplanes for FLIGHT MISSIONS OF THAT RANGE OR LESS. This point has already been passed for almost all uses of cars… my wife’s Tesla goes 390 miles on a charge, much further than 100% our families’ ground-based missions.
So, we have a propulsion system with a quartet of new characteristics and a steady upwards push in battery capability. The REAL question is: Where can that take us?
With a motor that provides instant torque, we have vertical takeoff and landing flight with almost no moving parts, allowing affordable access to… everywhere.
With a motor running at 95% efficiency, we turn almost all of our energy into power-at-the prop: Not noise and heat.
With a motor that makes little noise and no pollution, we have an aircraft that will have public acceptance at more places than just… airports.
So we have a powertrain that enables affordable, quiet, zero-emissions, politically acceptable three-dimensional access to almost any location within an (initially short) radius that increases by about 7 percent per year.
Will a new market be unlocked by that capability?
Is there a new market that is enabled by affordable, efficient, quiet, zero-emissions, AIRPORT-INDEPENDENT, short-range, three-dimensional, travel above traffic?
You see, the electric airplane doesn’t HAVE to weight a million pounds and hurtle across the Atlantic Ocean at Mach 0.85 to work…. it just has to get you from LaGuardia to Central park in 5 minutes.
And it will.
And then it will do more… about 7% more each year.
Poll: Should the NTSB Make More Safety Recommendations for GA?
- Absolutely! They should go through all the existing government regulations, tax laws, and practices to ensure that anything isn’t causing accidents. First do no harm needs to become a standard for our government.
- I’ve watched the NTSB/FAA duel on accident investigations. Based on those investigations, I’d even trust the FAA before I’d trust the NTSB—at least in GA accidents. Unless it is a major crash, involving many NTSB experts—some of the NTSB people are not well-versed in even General Aviation.
- No. The NTSB should stick to accident investigation only. Adding recommendations from a group that by and large are not pilots nor active in GA makes for an adversarial relationship with the FAA and General Aviation as a whole.
- Less regulation, combined with more personal responsibility/accountability seems to be a better way to go to me. Heaven forbid someone would actually be held responsible for their own bad decision, rather than the nanny state trying to legislate common sense out of Aviation?
- Yes, they need to issue more recommendations and we need to ensure those recommendations are researched and executed by the FAA.
- No. More regulation does not fix bad piloting.
- Any NTSB recommendation will lead to higher costs, more equipment, less privacy, and a higher burden, and any safety improvement will come from the standpoint that “the safest airplane is the one that doesn’t fly.”
- Yes and there must be an FAA deadline for implementation. Too many good ideas linger for years until public pressure forces change. Good policy is never a bad idea.
- No, GA is at an all-time low for accidents.
- No, practice what you have already, no use adding more confusion.
- Military accident investigators routinely prepare accident investigation reports in about a month. The NTSB should do the same.
- No. No room for politics.
- It’s real easy to make recommendations when you don’t have to consider economics, regulatory impact or industry capability.
- Address situations as they occur. No knee jerk reactions.
- Let GA self-regulate.
- Are you crazy??!?
- No, NTSB should investigative only. Find and report the cause. Let FAA decide, via committee with GA involved, any necessary changes needed.
- The NTSB usually goes overboard in their recommendations.
- Collaborate, yes. Common sense can be the outcome.
- No way!
- I don’t have problems with recommendations.
- No, no, no.
- Focus on training not technology.
- No. They’re doing it wrong.
Annex 13 to the Chicago convention says that the investigator should issue safety recommendations IF APPROPRIATE. Living in a country with a small fleet, I’ve seen quite a few knee jerk reaction recommendations that nobody cared to question.
After a crosswind related incident in which the nose gear collapsed in soft soil, the investigator recommended and the authority put in force a requirement for one-time nose gear inspection on ALL GA aircraft. Being owner of two tail wheel aircraft I received two letters to inspect my nose wheels and report findings.
Another not so funny example was after a wing separation of an experimental that have identical certified version. The authority grounded ALL experimentals asking owners to do “spar inspection per maintenance manual” and didn’t bother to address the certified version in any way.
As an airport manager, I’ve watched both FAA and NTSB conduct accident investigations. I’m no fan of the FAA, but they ARE far better at GA accidents than the NTSB. We had a young Private Pilot land here at 2 a.m. after a 4-hour flight across the Dakotas in a Skyhawk. Almost out of fuel, he ran off the runway. The NTSB “investigator”–a Private Pilot, laid the blame on “fuel imbalance.” Yes, there WAS a fuel imbalance–one tank had 4 gallons in it, and the other one was empty–hardly an issue.
A hospital helicopter (Bell 222 with fixed skids instead of wheels) landed here to pick up a patient. Pilot had been in only 2 hours before. A number of us watched the approach (two of us are also helicopter pilots). We saw a cloud of black smoke from one of the engines–then a steep drop–then the blades cone–an autorotation. He attempted a run-on landing, but hooked a skid on the edge of the pavement. The helicopter rolled over, but no injuries.
I passed out a tablet to each of the 6 witnesses and asked them to go off by themselves and record what they saw. The pilot phoned his company–who notified the NTSB. NTSB said “don’t allow ANYONE near the wreckage–INCLUDING THE FAA.” When the FAA showed up, I told them about the NTSB request, and they went home. I did have the witness sheets–all filled out by aviation professionals. The NTSB agent said “You know what I don’t like about this? They all have the same account.”
Within half an hour–he came back with “I’ve solved the issue. There were two flight attendants on board (one was a trainee). There is also an entertainment system on board. Note that it was selected on the audio panel. I think that the pilot was out to impress the women, listening to the entertainment system and ditty-bopping–and maybe doing a steep approach–lost altitude awareness, and hit hard.”
I countered with “Perhaps you haven’t noticed, but ALL of the audio panel switches were selected. Do you REALLY THINK that the pilot was listening to BOTH Comm radios, BOTH Nav radios, the ADF, the DME, the company HF radio, AND the entertainment system?” And there is one other problem with your theory–THIS IS A HELICOPTER, AND HE WAS FLYING FROM THE RIGHT SEAT!”
Attempting to extricate himself from his aviation faux pas, he opined “I don’t see any evidence of an engine failure. I pointed to the scorched paint aft of the right engine.
He asked “how did this aft fuselage get 100′ and 90 degrees to the rest of the wreckage?” I pointed to the tail rotor–asking which way the thrust was pushing the tail. The blades severed the tail–and looking at the gouges in the asphalt, they were on a uniform length–exactly the same distance apart as the span of the tail rotor.
I received a nice letter from the clinic AND one from the pilot–“I’m SO GLAD that there were helicopter pilots watching the accident!”
It’s bad enough that we have untrained personnel in these positions of authority–making judgements that may impact a pilot’s job or insurance coverage. It’s even worse that WE PAY THEM!
Electric cars are quiet, but the propellers on multirotor VTOL aircraft are far from quiet. How many YouTube videos have you watched where they play the sound of the aircraft instead of playing music or talking over it?
Just a question, why not use ducted fans instead of propellers? electric motors aren’t as limited by RPM and ICE’s are, typically using less current with higher RPM. Doesn’t the duct also serve to contain/direct any blade noise?
Electric VTOL faces even more limitations than normal engine powered VTOL.