You may have heard of EHang, the Guangzhou, China-based drone and autonomous aerial vehicle manufacturer, which has been pushing its unmanned electric VTOL technology in the urban air mobility market. EHang says its two-seat, 16-rotor 216 AAV has made over 2,000 passenger test flights, mostly in China. The company is seeking FAA approval for its aircraft and its first U.S. flight test took place in January.
EHang also went public last December on the Nasdaq, raising $43 million. The stock has fallen from its IPO price of $12.50 a share to about $8.65. The drop in valuation for an early-stage UAM company isn’t surprising given current events and the fact that in the first half of 2019, EHang had a net loss of $5.5 million and net operating cash outflows of $5.8 million.
Not surprisingly it’s trying to show investors signs of progress. In early August, EHang said it will implement a trial UAM operation in Linz, Austria, but more attention-getting was a July 31 announcement that the company has developed a bomb-throwing, fire suppressant-spewing version of the 216 air taxi (216F) for fighting high-rise building fires.
The associated publicity exercise may outweigh the 216F’s value as a commercial venture, at least in the West.
Essential Firefighting Equipment
In its release, EHang says that the autonomous firefighting 216F could “become essential equipment for thousands of fire stations across China and eventually those around the world.”
EHang showed off the aircraft at a launch ceremony in Yunfu, China, with a demonstration of its ability to extinguish a high rise-fire. According to the company, the firefighting version of the 216 has a ceiling of 1,968 feet, a curb weight of 1,376 pounds and can carry up to 40 gallons of firefighting foam and six “extinguisher bombs”.
As can be seen in EHang video of the high-rise fire demonstration, the 216F uses an optical zoom camera to identify the location of fire. “It then hovers precisely in position and uses a laser aiming device to fire (in succession) a window breaker, the fire extinguishing ‘bombs’ and then a full-range spray of firefighting foam. Multiple 216Fs can be deployed to rapidly extinguish the fire.”
The press release also pictures a pair of 216Fs in the fire engine bays of a Chinese fire station. EHang posits deploying the craft to urban fire stations to assist in firefighting within a 3 mile radius. Their autopilot and dispatch management capability would enable rapid response “even before the firefighters arrive.”
EHang’s demonstration video might look impressive at first glance. But to expert eyes, like those of Timothy Sampey, deputy commissioner of the Chicago Fire Department, it raises questions. It also looks strangely familiar. Chief Sampey says he’s seen something like this on the Internet before. Turns out he’s right.
In 2017, a Turkish firm called Dahir Insaat showcased its own high-rise aerial firefighting eVTOL concept in a YouTube video. Founded by by Russian engineer and inventor, Dahir Kurmanbievich Semenov, the company has floated many concepts, frequently criticized as wildly impractical. Perhaps EHang was watching?
Regardless, Sampey’s reaction to EHang’s release and demo was one of caution. “I wouldn’t say it solves the [high-rise fire] problem. It’s an interesting concept but if you take the 10,000-foot view, I’m not sure it overcomes our concerns.”
Those concerns begin with the 216F’s use of a projectile to break a high rise window.
“If you’ve ever been to a Chicago high-rise, I don’t know that a little wand like that would break one of the windows. Secondly, I don’t know that I would want the window broken.”
Sampey points out that Chicago building codes require high strength windows for “Windy City” high rises. Designed to withstand bird strikes and bullets, the sturdy windows force firefighters to use sawzalls, drills and suction cups to penetrate them. That is, if they want to penetrate them. The Chicago Fire Department has studied high rise airflows and the potential of wind-driven fire with the National Institute of Standards and Technology (NIST) and the Illinois Fire Service Institute.
“By ventilating too soon and without enough agent to suppress the fire, I’m creating more harm than good,” Sampey says.
The natural wind swirling around cityscapes can indeed fuel fires, particularly when funneled through a window. Chicago’s number two firefighter cites incidents in large cities like New York where a high-rise fire window-breach and resulting wind-driven fire incinerated an NYFD crew in a hallway.
He adds that while EHang may use an effective Class A firefighting foam, 40 gallons may not be enough to put out a blaze. If it comes through a narrow window opening, it may also only touch a portion of the fire. Its effectiveness might differ for commercial or residential high rises with different architectural compartmentalization.
EHang suggests capacity issues could be overcome by employing multiple AAVs. “Multiple drones means they’re fighting air currents together in proximity,” Sampey observes. He’s not a fan of multiple window breakage exacerbating the wind-driven fire issue or of the resulting glass debris which can float and travel before landing on ground, potentially injuring firefighters or others.
The chief points out that the building in the video is not particularly tall or located in proximity to other high rises. The stability of the AAVs for spraying fire retardant, their ability to do so using laser targeting in smoke or at night are other questions as is their use of “extinguisher bombs.”
The CFD conducted experiments with bombs filled with chemical suppressant at a location near O’Hare Airport several years ago.
“We had very limited success,” Sampey says. “And we did not advocate for [the method] because we’re not fans of using anything explosive if we’re not sure there aren’t victims in there.”
The idea of essentially armed drones residing in an urban firehouse in a city like Chicago where there has been recent civil unrest raised flags for Sampey as well. And as a manager, he says he’d have to think about resources needed.
“I’m not saying this is totally impractical but how much does it cost to give me 40 gallons of foam? How much would five or six of these cost?”
According to EHang, the non-firefighting version of the 216 rings the bell at about $336,000 per copy.
In Search of a Market
Some UAM observers have raised questions about EHang’s quality and American resistance to acquiring and employing a Chinese system, including UAM Geomatics, a subsidiary of northern Virginia-based investment banker Nexa Capital Partners. UAM Geomatics aids startups and OEMs including Piasecki Aircraft Corporation, which UAM’s Phillip Dyment says is soon to announce a new eVTOL product.
With respect to EHang’s potential, Dyment is cautious. “Philosophically, we think there’s nothing to buy or fly in this [UAM] industry for several years. There is $4.5 billion coming into it from private and government capital sources but the U.S. is not eager to see China dominate the urban air mobility space. Programs like Agility Prime [a USAF effort to support investment in eVTOL] suggest that companies like EHang are not likely to be welcome players in North America.”
With nothing like mature demand for UAM transport on the horizon, EHang is, like other eVTOL players, shifting to ancillary applications, markets with shorter potential timelines. But a 1,300-pound bomb throwing, foam spewing, aerial robot may say more about EHang than about firefighting.