Aviation

[NeilT]

this work and I read parts I am just not sure if I have much to say about it.

It was more about the extensive work done with materials and their properties, strength's and strength to weight ratio's for use in this kind of application.

You don't have to apply it to his use case of a vacuum airship.  I felt that applied in another use case that work would save a whole lot of design.

[SteveMDFP]

Most people fly to get somewhere so minimal flight time is preferred. Dream about zeppelins all you like but it is not a current aviation thing. It is not going to be relevant in the near future to aviation emissions etc.

For mass market demand, you're right.  However, assuming price for freight is significantly lower than jets, plenty of stuff needs to be transported faster than ships, but doesn't need the speed of jets.  And quite heavy or large items may be well suited for this mode, like large construction equipment, turbine blades, etc.  For moving people, the niche is likely smaller.  But if there are serious policy moves to make air travel eco-responsible, jet travel could become substantially more expensive.

Imagine you're directing development of a substantial population, divided among a dozen archipelago islands.  You need to build a couple of hospitals and a lot of schools. And roads, and water and sewer, housing, etc.  Current "port facilities" consist of docks.  What other mode of transportation can practically fill this need?

My take is that there are more than enough niches to get the industry started, and then reasonable prospects for growth.

[NeilT]

Don't ignore the business market.  Most businessmen can now work on the move and do work on the move.

I spent years getting up at 2am on Monday morning to get a flight out at 6am.  However when I was going Edinburgh-London I had an alternative until they took it away.  I could get the Caledonian sleeper train.  Go to the local town 10 minutes away, drop the car in the parking where I could park for a week at the price of one day in Edinburgh.  Get on the train at 10pm on Sunday night, arrive relatively fresh at 08:30 in Euston on Monday morning.

It was very popular even though it was much more expensive.  Until Easyjet killed it off.  It is back now but at such a high price it is only for senior business execs.

People do look for alternatives to the rush and crush of modern air travel.  Colleagues and I call it "travel shock".  Tourists who fly in high holiday season just call it a nightmare.

As pressure comes to bear on aviation, taxes are applied to both the journey and the fuel, economies of scale start to fall with the reduction in fuel production, then air travel is going to be looking for alternatives.

Electric?  For the mass transport of time sensitive journeys?  Not without a level of breakthrough which I see no news of.

[kassy]

Most people fly to get somewhere so minimal flight time is preferred. Dream about zeppelins all you like but it is not a current aviation thing. It is not going to be relevant in the near future to aviation emissions etc.

For mass market demand, you're right.  However, assuming price for freight is significantly lower than jets, plenty of stuff needs to be transported faster than ships, but doesn't need the speed of jets.  And quite heavy or large items may be well suited for this mode, like large construction equipment, turbine blades, etc.  For moving people, the niche is likely smaller.  But if there are serious policy moves to make air travel eco-responsible, jet travel could become substantially more expensive.

Yes it should become more expensive. The easiest way to do that in theory would be to agree to prize in the carbon on all flights worldwide. This will make tickets more expensive but not that much.

An even better way would be to track flights per user per year (so frequent flyers pay more).

Hefty extra taxes on private planes are optional but a good idea.

Most people don´t fly that much and variety 1 would not add that much cost.

For freight, maybe but it is still niche. So i doubt if it will ever be a thing but it is surely not relevant for the transition.

[NeilT]

For freight, maybe but it is still niche. So i doubt if it will ever be a thing but it is surely not relevant for the transition.

It depends whether the freight delivers a compelling enough reason to develop the solution and then the solution can be reversed into the transition.

That, I guess, nobody knows.

[Sigmetnow]

EPA finds small planes’ lead pollution threatens human health

The Environmental Protection Agency Wednesday announced it has determined that lead emitted from airplanes is a danger to public health, opening the door for the agency’s first-ever limits on lead fuel in aviation.

The move puts the Biden administration in the middle of a brewing fight over how long airports — particularly smaller ones — can continue selling leaded gasoline, despite the health hazards from this powerful neurotoxin. More than 170,000 smaller planes, known as piston-engine aircraft, still use leaded gasoline, according to the EPA, and there is an ongoing dispute about how quickly this form of fuel can be phased out at thousands of airports nationwide.
…
“The science is clear: exposure to lead can cause irreversible and lifelong health effects in children,” the EPA Administrator Michael Regan said in a statement. “Aircraft that use leaded fuel are the dominant source of lead emissions in our air.”
…
Commercial jets do not use leaded fuel, so the rules would affect only smaller planes that fly two to 10 passengers, the EPA said. On average these aircraft are nearly 50 years old. While the planes are only a small subsection of the aviation industry, the agency said they still pose risks near their airports, many of which are mostly in or near poor or minority communities.

https://www.washingtonpost.com/climate-environment/2023/10/18/lead-aviation-fuel-epa-toxic-pollution/

[vox_mundi]

BETA Technologies delivers first manned electric aircraft to USAF
https://breakingdefense.com/2023/10/beta-technologies-delivers-first-manned-electric-aircraft-to-usaf/



WASHINGTON — BETA Technologies, a Vermont-based electric aircraft startup, today deployed its ALIA aircraft to Eglin Air Force Base in Florida — in what the company and Air Force are saying is the first manned electric aircraft to be delivered to the service.



The ALIA trudged its way from Vermont down the East Coast, which involved what the company says is the first flight of an electric aircraft in Washington, DC airspace. Now at Duke Field, an auxiliary airfield of Eglin, the aircraft will begin a minimum three-month test campaign, with possible extensions.



“The involvement of the military massively augments our velocity on the commercial side because the military’s expectation of an airplane is fundamentally the same as the FAA’s. They want a safe, reliable, repeatedly produced aircraft,” Kyle Clark, BETA founder and CEO, said in a Wednesday interview with Breaking Defense ahead of the ALIA’s arrival.

https://www.beta.team/aircraft/

The Air Force’s Agility Prime program, which is run through the service’s innovation arm known as AFWERX, has been helping cultivate new aircraft like the ALIA to seize upon a burgeoning electric-powered aircraft market. Earlier this month, Joby Aviation, a separate electric vertical takeoff and landing (eVTOL) startup, delivered its own aircraft to the Air Force as part of the Agility Prime effort. (The Joby aircraft for the time being is remotely operated, though the Air Force plans to bring pilots on board next year.)

https://afwerx.com/divisions/prime/agility-prime/

[Sigmetnow]

Rolls-Royce puts flying taxi business up for sale
Tue, Nov 28, 2023

… Despite this, he insisted Rolls is not abandoning electric flight power altogether, as he said hybrid systems making use of battery power for better engine efficiency are still being developed by the company.

He said sustainable aviation fuel will help decarbonise the travel sector over the next 15 to 20 years, which will serve as a boost to Rolls’ civil aviation division.
…
The latest announcement also revealed ambitions to re-enter the engines market for smaller “narrowbody” passenger jets, such as the Airbus A320 and Boeing 737, which ferry passengers around Europe.

It stopped making these engines in 2011 but it will now seek partners to resume manufacturing. …

https://finance.yahoo.com/news/rolls-royce-sell-1-5bn-102739443.html

[morganism]

Changing Flight Altitudes Reduces Climate Impact of Aviation

(...)
 The key innovation explored in this study was the 'avoidance' procedure, implemented on alternate days when weather forecasts indicated the potential formation of long-lasting contrails at typical flight altitudes. During these days, flights were redirected either higher or lower by 2000 feet (approximately 660 meters). The researchers then used satellite imagery to assess the presence of long-lasting contrails. Comparing these days to the reference days when flights followed their usual paths, the research team found that long-lasting contrails occurred less frequently.

Aviation's climate impact extends beyond carbon dioxide emissions, encompassing what are known as non-carbon-dioxide effects. These effects are particularly pronounced in air transport because aircraft emit pollutants at altitudes where their impact differs from ground emissions and can significantly affect the climate.

Among these effects, contrails and contrail cirrus clouds play a pivotal role. They can either warm or cool the atmosphere, with a warming effect prevailing. The extent of their climate impact depends on various factors, including geographical location, altitude, emission timing, solar positioning, and weather conditions. This complexity presents an opportunity to mitigate aviation's climate impact by optimizing flight routes and altitudes, a concept known as climate-optimized flight trajectories.

Several prerequisites must be met to implement climate-optimized flight trajectories successfully:

+ Reliable Climate Impact Prediction: Weather services must accurately predict the climate impact of individual flights to ensure that rerouting air traffic leads to a genuine reduction in climate impact.

+ Integration into Flight Planning Tools: Non-carbon-dioxide effects must be integrated into operational tools and flight planning processes, requiring a system capable of calculating the climate impact of flights with precision during the planning phase.

+ Capacity and Safety: When rerouting flights in higher airspace for climate considerations, it's essential to ensure the continued safe and orderly handling of authorized air traffic, as these adjustments can potentially lead to airspace capacity constraints and delays.

Unlike other non-carbon-dioxide effects, controlling the formation of long-lasting contrails is feasible through sophisticated statistical methods. The collaborative effort between DLR and EUROCONTROL/MUAC has demonstrated the practical viability of contrail avoidance in real air traffic. This promising development marks a significant step towards more climate-friendly air travel.
(more)

https://www.energy-daily.com/reports/Changing_Flight_Altitudes_Reduces_Climate_Impact_of_Aviation_999.html

[kassy]

Moved from cloud feedbacks in science because that is a more general topic and this is a ´solution´ for aviation.

[vox_mundi]

Santa Claus, like all pilots, gets regular visits from the Federal Aviation Administration, and it was shortly before Christmas when the FAA examiner arrived.

In preparation, Santa had the elves wash the sled and bathe all the reindeer. Santa got his logbook out and made sure all his paperwork was in order.

The examiner walked slowly around the sled. He checked the reindeer harnesses, the landing gear, and Rudolf’s nose. He painstakingly reviewed Santa’s weight and balance calculations for the sled’s enormous payload.

Finally, they were ready for the checkride. Santa got in, fastened his seatbelt and shoulder harness, and checked the compass. Then the examiner hopped in carrying, to Santa’s surprise, a shotgun. “What’s that for?” asked Santa incredulously.

The examiner winked and said,

[Sigmetnow]

Mach 2 OPENFOAM simulation of Santa and his reindeer

Lemme just put this in layman's terms: I'm concerned about Santa here

12/24/23, https://x.com/drchriscombs/status/1739044650135015730

➡️ pic.twitter.com/hn6jryXmIT  20 sec model animation.

[Sigmetnow]

90-seat Elysian E9X airliner: 800-1,000-km range on batteries alone
Relatively small-diameter electric props on low-mounted wings with upturned tips

A Dutch startup says everyone's hugely underestimating the potential of battery-electric aircraft – that it's possible to build large battery-electric airliners covering distances most assume we'll need hydrogen for. Elysian plans to prove it.

The company doesn't believe it'll need some giant leap in batteries to do it, either; it says it can take 90 passengers some 800 km (497 miles) using a pack with 360 Wh/kg. Amprius, meanwhile, was shipping 450-Wh/kg cells back in 2022, and Chinese giant CATL launched a 500-Wh/kg "condensed" battery last year. Assuming some improvements, Elysian says it'll hit 1,000-km (621-mile) range figures, at which point the E9X aircraft could feasibly cover around 50% of all scheduled commercial flights.

It's quite a leap from the conventional thinking, which assumes that batteries are far too heavy to build airliners around, and really only suitable for small aircraft flying sub-400-km (250-mile) routes. Indeed, most of the action in clean aviation over the last several years has been in the gaseous hydrogen space, with liquid hydrogen a few years behind that and other solutions like ammonia popping up around the fringes.
…
But Elysian says batteries will do just fine. The company cites a couple of TU Delft studies (albeit studies whose lead author, Reynard De Vries, is also Elysian's Director of Design and Engineering) as evidence. According to Venturebeat, the company says the industry's mental block is the result of modern airline designs, which make maximal use of the highly efficient, mature powertrains they run.

When dealing with heavy energy supplies like batteries, the company says you need to go back to the 1960s for inspiration; the first-gen narrow-body aircraft of the day were horribly inefficient, so they needed to carry a lot more fuel than today's big birds to cover long distances.

Thus, the Elysian E9X design features a relatively small fuselage and longer wings than current jets. Its low-mounted wings, complete with upswept tips, house most of the battery mass, as well as the rear landing gear. Elysian says these considerations save a lot of airframe mass, and should also reduce drag by around 15% for a corresponding range boost.

Batteries make vastly more efficient use of energy than hydrogen, in any of its forms. Indeed, the company says you'll get some five times further per unit of energy with a battery-electric airliner than with any hydrogen or SAF-powered aircraft. And indeed, that could well be a consideration as the world moves all of its energy away from fossil fuels and into renewables.

Elysian says the E9X will "take to the skies" in 2033, and the startup has developed it to this point with the help of some US$10 million in backing from Panta Holdings, which also currently owns the historic Dutch Fokker brand.

Now, time for a bucket of cold water.
If Elysian is really planning to design, prototype, test, certify and go into serial manufacture on a quirky new airframe for a 90-seat commercial airliner, the company will need to dig up billions – probably even tens of billions – of dollars to get there. Even prototyping a beast of this size is no joke; it's not a relatively cheap retrofit you can throw into a second-hand Q400 you picked up for $12.5 million in pocket change.
 
…
And then there's what happens upon landing; battery-electric airliners are going to need some seriously large packs. Charging infrastructure at airports will not be a trivial matter, especially if it's got to turn the plane around and get it back airborne quickly; you're probably talking about pushing several megawatts. …

https://newatlas.com/aircraft/elysian-electric-airliner/

 
How passenger electric planes could become a reality within the next decade
The Elysian E9X will be able to hold 90 people and fly up to 500 miles without having to stop to recharge.

… Prior to this design, the consensus among industry experts has been that battery-electric air travel would be confined to small planes only -- aircraft that could hold a maximum of 20 passengers and travel less than 200 miles without having to land, Jayant Mukhopadhaya, a senior researcher at the International Council on Clean Transportation (ICCT), told ABC News.
…
Instead of trying to electrify a modern propeller plane, Elysian looked to first-generation aircraft, which were designed for very long distances,De Vries said.

"If you really design a large passenger aircraft on batteries, you can actually fly further than a small electric aircraft if you do the design property," De Vries said.

The wing is extremely large relative to the body of the plane, especially when compared to conventional aircraft. But the large wing allows for increased aerodynamic efficiency, De Vries said. The engineers also added folding wing tips to ensure that a large wing can fit in the current gate infrastructure.* …

https://abcnews.go.com/Business/passenger-electric-planes-become-reality-decade/story?id=106223258
 
*Note:  Those fancy wingtips aren’t for style, or to “make the airplane fit at the gate.”
Folded wingtips act to eliminate the drag created by wingtip vortices, which are generated by air flowing from the higher pressure under the wing (lift), around the wingtip to the lower pressure on top of the wing — essentially this makes the wing infinitely long.

 
===
Second image below is from 2016, the Solar Impulse 2, a very light, single-pilot, solar-and-batteries aircraft that flew around the world (in several legs). “Flying day and night without fuel”

https://forum.arctic-sea-ice.net/index.php/topic,1150.msg47971.html#msg47971

https://forum.arctic-sea-ice.net/index.php/topic,1021.msg74614.html#msg74614

[gerontocrat]

*Note:  Those fancy wingtips aren’t for style, or to “make the airplane fit at the gate.”
Folded wingtips act to eliminate the drag created by wingtip vortices, which are generated by air flowing from the higher pressure under the wing (lift), around the wingtip to the lower pressure on top of the wing — essentially this makes the wing infinitely long.

When I was a kid in the mid-1950's and making paper aeroplanes I found out that bending the wingtips made it fly for further and made it more stable.

Parhaps I should have patented it.

[Sigmetnow]

Interesting comment from 𝕏:

Alex ⁦‪@alex_avoigt‬⁩
 
I would be willing to pay double the price knowing it's an all-electric flight without any emissions and I believe I'm not alone.

1/12/24, https://x.com/alex_avoigt/status/1745742122869789144

[Sebastian Jones]

Interesting comment from 𝕏:

Alex ⁦‪@alex_avoigt‬⁩
 
I would be willing to pay double the price knowing it's an all-electric flight without any emissions and I believe I'm not alone.

1/12/24, https://x.com/alex_avoigt/status/1745742122869789144

Alex is not alone.
Not only would I be prepared to pay double for an e-flight, I think all plane flights should double in price- both to make e-planes more viable sooner, and to drive people away from frivolous flying.

[vox_mundi]

Xwing and U.S. Air Force Demonstrate Fully Autonomous Cargo Aircraft
https://www.therobotreport.com/xwing-air-force-demonstrate-fully-autonomous-cargo-aircraft/

[John_the_Younger]

Just noticed this press release from last July: a high-flying (very long wingspan) drone...

BAE Systems has conducted the first successful stratospheric test flight of its High Altitude Pseudo-Satellite (HAPS) drone platform.

The defense company said its PHASA-35 drone achieve altitudes of more than 66,000 feet [20 km] in a 24-hour flight, reaching the stratosphere above New Mexico before landing successfully.

[Freegrass]

This is a pretty new YouTuber, but I like the way he explains things.
This is a second video of him that I just watched and liked. I had no idea we're so close already to regional electric flights.

[NeilT]

So the short version is that a viable local commuter plane needs to be a hybrid until battery power densities rise significantly.

I could see this as a very useful plane for island hops where the only alternative is going by sea.

Beyond that it is going to find it hard to compete.

[Freegrass]

So the short version is that a viable local commuter plane needs to be a hybrid until battery power densities rise significantly.

I could see this as a very useful plane for island hops where the only alternative is going by sea.

Beyond that it is going to find it hard to compete.

I agree, hybrid seems to be a great solution for emergency capacity and weight reduction. In most cases it will hardly be used, but it's there when you need it. Good idea. Especially if they use a biofuel.

Island hopping sounds like a great idea. Maybe they could make an electric water plane? When out of juice, land on the water, and wait for a boat to fill up your batteries?

[Linus]

Harbor Air has been trying to bring this to reality for years Freegrass!

In aviation, regulatory certification is the biggest hurdle. Just because you can build it and fly it, doesn’t mean that you can quickly get it certified to carry paying passengers. New technology is extremely difficult to bring to market.

https://www.aerotime.aero/articles/harbour-air-says-electric-dhc-2-beaver-is-delayed-to-at-least-mid-2025

[Sigmetnow]

At this week’s London news conference, the first questioner asked, “Is this a new way for rich people to kill themselves?”
 
Halo Space reveals design for stratospheric tour capsule

If and when passengers climb into Halo Space’s capsule for a ballooning trip to the stratosphere, they’ll find cushy seats, fold-down receptacles for food and drinks, floor-to-ceiling windows that provide an astronaut’s-eye view of the curving Earth below — and a snug toilet to get them through the hours-long flight.
…
Halo Space is aiming to begin commercial service by 2026 with ticket prices starting at $164,000. It’s one of several companies targeting the stratospheric tourism market, a lineup that also includes World View, Space Perspective, Zero 2 Infinity and Zephalto.

Although these stratospheric tours are typically marketed as spaceflights, they wouldn’t go anywhere near as high as the suborbital rocket ships built by Blue Origin and Virgin Galactic — 20 to 25 miles for Halo Space, as opposed to 50 miles for Virgin Galactic. On the plus side, the trips would be much less expensive, and arguably less risky.

Halo Space has already conducted five flight tests of prototype capsules, and plans to do the sixth test in Saudi Arabia in June. The company is working with regulatory agencies to set up bases in Saudi Arabia, the U.S., Australia and Spain — in desert-like places that Mira characterized as being “in the middle of nowhere” with open skies. …

https://cosmiclog.com/2024/04/12/halo-space-reveals-design-for-stratospheric-tour-capsule/

>> The Karman line, 100km/62 miles above the earth’s surface, is commonly considered the “boundary of space.”

⬇️ A cutaway illustration shows the layout of Halo Space's Aurora capsule, with a toilet in the center.

[John_the_Younger]

New Yorker article on flying cars
https://www.newyorker.com/magazine/2024/04/22/are-flying-cars-finally-here

Some quote from deep in the article:

... Dubai seems poised to begin offering services; China’s regulatory body just approved the mass production of an eVTOL for commercial use. But for such plans to become a widespread reality, let alone the future of transport, regulatory agencies will have to be coaxed into an overhaul of the way that airspace is structured and administered. We would need foolproof, digital detect-and-avoid systems to prevent collisions. eVTOLs might not be helicopter loud, but they are noisy. Engineers think that this issue can eventually be ameliorated, but, if it can’t, no one will be happy with an insistent mosquito buzz in the background. And then there’s the sheer number that would be needed. Before the pandemic, about four hundred thousand people a day crossed the Hudson River into Manhattan. Aerial commuting would require tens of thousands of drone taxis operating on regular, reliable schedules, with flawless safety records. David King told me, “So all of a sudden you’re into the realm of, ‘Why didn’t we just build a train?’ ”

One design for early automobiles, known as Horsey Horseless, featured an artificial horse head mounted on the front of the chassis, so that it would resemble something familiar to other horses on the road. Wisk took a similar approach in the test. It was using a Boeing drone that was not being flown autonomously but by pilots in regular communication with air-traffic control; the pilots simply happened to be on the ground rather than in the cockpit. This was quite a big step for commercial aviation, in which virtually all procedures are based around the presence of an onboard pilot, but the accomplishment was buried under a barrage of bureaucratic acronyms: they hoped to do B.V.L.O.S. for an R.P.A. under I.F.R. conditions in C.T.A. ...

and ends

I was now ready, they told me, to fly for real. As I took off into a hover, I twisted the stick to the right, turning away from everyone below, and lit out in the direction of the hills. Once I levelled off, the propellers quieted to a much softer hum, and all at once I had a feeling of lightness and agility in the air. Below me were muddy ponds, glistening patterns of water and grass, a cluster of black cows. I crested through a long, slow turn over the base of the foothills, and the machine felt alive to my touch. The company had disabled cruise mode, limiting me to an airspeed of about thirty miles an hour—something they said they’d done to prevent me from accidentally slipping into higher gear. But I knew now that, if cruise weren’t disabled, I would have pushed the craft to whatever speed was available to me; I would have flown in the direction of the hills and the sky and never come back; I would be up there still. There was the sense that the vibrating craft was an extension of my limbs. It was no wonder that the disembodied march of software had left so many technologists longing for the experience of living inside the circuitry. Entirely forgotten was the banality of commuting to work. The delirium of flight was enough. I glanced at my viewscreen, began the slow, gradual descent I’d practiced on the simulators, and, with great reluctance, triggered the sequence to land. ♦
Published in the print edition of the April 22 & 29, 2024, issue, with the headline “Flight of Fancy.”