maybe because leehamnews is not so far from the truth:
leehamnews.com
The fact that the CEO Omer Bar-Yohay and executive chairman Roei Ganzarski both left the company in surprise departures earlier this year, well after the company starting claiming that the first flight was only a handful of good weather testing days away back in January, is also worrying...!
New Signs First Flight of Eviation’s All-Electric Alice May Be Near - FLYING Magazine
A test article for the nine-passenger aircraft has been undergoing ground tests at Moses Lake, Washington.www.flyingmag.com
A quick summary of what we know so far about the first flight of the aircraft and the long road this project has to travel to get certified. A lot of articles still quote the 440nm range without realizing that it's just the ferry range in ideal conditions with light winds. The fact that the company remains tight lipped about what the range will be with a full payload with IFR reserves is worrying.
I didn't realise that the 440nm range was so conditional. Do you have a source?
www.eviation.co
www.ainonline.com
newatlas.com
www.seattletimes.com
www.thedrive.com
www.flyingmag.com
leehamnews.com
If that true, they should not have build them tangent to the fuselage. Any positive attitude could prevent to reach vacuum conditions at the outlet. Vents have to be designed with that in mind.Yes, there are markings on the side of the fuselage that says 'burst disc keep clear' so I presume they are vents for battery thermal runaway - presumably to try to minimise the gas ingress in to the cabin.‘We’ve ... made aviation history’: All-electric airplane takes flight above WA
Eviation’s all-electric prototype plane made its first flight this week. The design of the production models will differ substantially. Certification is 5 years out.
I never noticed this before. Are these openings at the underside of the fuselage designed to help vent the batteries in case of a thermal runaway event ?
It seems, they committed that they do have range problem and they depend on others (battery suppliers) to solve it.Electric Commuter Aircraft 'Alice' Has Flown For The First Time
After months of delays, Alice's first flight could be a major step toward future electric-powered air travel.
Eviation’s 'Alice' Electric Demonstrator Flies for the First Time - FLYING Magazine
Eviation’s electric commuter airplane test article Alice has flown for the first time. What’s the story behind this sleek, nine-seat, zero-emission aircraft?
UPDATED: All-electric Eviation Alice takes 1st flight - Leeham News and Analysis
By Bryan Corliss Sept. 27, 2022 © Leeham News: The battery-powered Eviation Alice has flown for the first time. The nine-seat aircraft, powered by twin electric propeller motors assembled by Eviation’s sister company, magniX, rotated up and took... Read More
Some interesting nuggets of information quoted from the articles above :
“It’s the first Part 23 aircraft that’s all fly-by-wire,” Bar-Yohay says. “It was a very, very painful aspect of the development of this system. It makes the system much more complex and it takes a long time and a lot of money to do this right.”
"The fractional weight of the battery system is roughly 50 percent of the MTOW of the aircraft. The battery is very big. In fact, Bar-Yohay says the “battery itself functions as a structural part of the aircraft. Meaning the plane cannot fly without the battery there, from a load bearing perspective.”
"Over the past seven years, Eviation considered several design options before it settled on this one. “We looked at canards. We looked at box tail designs,” Bar-Yohay says. “We looked at the wingtip propellers and we landed with something that is very avant-garde, while still being a plane.”
“The biggest technical challenge that Eviation has to overcome is the development of batteries,” he said. “We really do need the industry to boost the energy density.” Because of that, Davis said he doesn’t expect that Alice will win regulatory approval until 2025, and won’t be carrying paying passengers until 2027"
"The plane that flew this morning was Eviation’s “proof of concept” aircraft, Davis said. With a five-year gap before the expected entry into service, and with technologies developing rapidly, “we absolutely will make evolutions to the aircraft,” he said."
The misconception comes from the fact that fuel fumes are not lethal and the burst disk on Airbus planes won't act to prevent fuel odor to be detected in the fuselage.Who knows, a burst disc could be made to burst open with a vent that gets around the tangency issue. The escaping gas pressure could be high enough to exit in to the airflow anyway. They might have figured out they'll only have a problem on the ground. And so on...If that true, they should not have build them tangent to the fuselage. Any positive attitude could prevent to reach vacuum conditions at the outlet. Vents have to be designed with that in mind.Yes, there are markings on the side of the fuselage that says 'burst disc keep clear' so I presume they are vents for battery thermal runaway - presumably to try to minimise the gas ingress in to the cabin.‘We’ve ... made aviation history’: All-electric airplane takes flight above WA
Eviation’s all-electric prototype plane made its first flight this week. The design of the production models will differ substantially. Certification is 5 years out.
I never noticed this before. Are these openings at the underside of the fuselage designed to help vent the batteries in case of a thermal runaway event ?
As a comparison, burst discs on airbus wings I am familiar with are flush to the wing lower surface and do not incorporate any features to help extract internal air or liquids.
This is not an A320. Those are not fuel tanks. This is what we are discussing.That doesn't change anything I said. Prob best to let this go Tomcat - I know what those burst disks do on the A320, and I know why.The misconception comes from the fact that fuel fumes are not lethal and the burst disk on Airbus planes won't act to prevent fuel odor to be detected in the fuselage.Who knows, a burst disc could be made to burst open with a vent that gets around the tangency issue. The escaping gas pressure could be high enough to exit in to the airflow anyway. They might have figured out they'll only have a problem on the ground. And so on...If that true, they should not have build them tangent to the fuselage. Any positive attitude could prevent to reach vacuum conditions at the outlet. Vents have to be designed with that in mind.Yes, there are markings on the side of the fuselage that says 'burst disc keep clear' so I presume they are vents for battery thermal runaway - presumably to try to minimise the gas ingress in to the cabin.‘We’ve ... made aviation history’: All-electric airplane takes flight above WA
Eviation’s all-electric prototype plane made its first flight this week. The design of the production models will differ substantially. Certification is 5 years out.
I never noticed this before. Are these openings at the underside of the fuselage designed to help vent the batteries in case of a thermal runaway event ?
As a comparison, burst discs on airbus wings I am familiar with are flush to the wing lower surface and do not incorporate any features to help extract internal air or liquids.
Batteries outgasing byproducts, on the contrary, do kill. When you've a fire, it's already too late.
See the diagram of the system as installed on A320:
View attachment 684735
The overpressure breaches the disc and the tangent airflow only helps in the evacuation.
When they get better batteries, they will gain reasonable range, as say a 10% improvement is 44 miles, but that goes on the 250 VFR range, so now 294, almost a 20% improvement.
www.forbes.com
www.bloomberg.com
aviationweek.com
www.flightglobal.com
Completing a single 8 minute test flight in September (a full 8 months after teasing "we are about 5 to 6 days away from starting the flight campaign" back in January.....) and now they are another 6 months down the line and NO further flight time logged...
Yes It's remarkable, though in retrospect perhaps not a massive surprise that range is significantly below initial projections/deluded marketing claims. Did they really expect that battery density would improve that quickly?!
www.prnewswire.com
