L2 Aviation expects to receive an STC in the first quarter of 2021 for its new Halo Cabin Air Monitoring System. The company is looking to integrate air sampling technology that has been in use in buildings such as schools to measure potentially toxic chemicals in the air—or even detect illicit vaping—for aviation purposes. As such L2 has entered into a joint venture with the product developer IP Video on the Halo system.
While airlines have had to deal with cabin air quality virtually since the start of commercial aviation, Halo project manager with L2 Mike McConnell said there has been no way to quantitively measure it until now. “One of the big areas in aircraft that the airlines are very interested in is the chemical detections, so, ammonia, carbon monoxide, carbon dioxide, and ozone, we’re integrating into the sensor suite,” he told AIN. “If you have any reduced respiratory function, ozone can trigger an asthma attack, so the ability to detect ozone is important for those people in the cabin.”
The Halo units may come online at an especially crucial time, as aircraft operators have relied on a variety of products, methods, and equipment over the past year in efforts to sanitize, or at least appear to sanitize their aircraft before, during, and after flights—all in an effort to allay the fears of their customers during the Covid pandemic. Some of those products can have unexpected effects on cabin materials or even cause degradation over prolonged use McConnell noted.
“You don’t even know what the effect of all this [stuff] is,” he said. “All those chemicals that are being sprayed, they’re going to be in the air and that becomes an air particulate and it can absolutely be measured.” Other air contamination events can occur when cabin air becomes polluted with breakdown products from heated engine oil or hydraulic fluid, or even from de-gassing by lithium-ion batteries.
McConnell noted that the system must first be calibrated. “You have to first find a baseline of what a healthy cabin looks like," he explained. “That could either come from a new airplane or it can come from an airplane that has been sitting for a while, where there has been no introduction of airflow, recycled air, and humans.” Once that baseline is determined and cataloged, when a signature on an in-service aircraft matches a known contaminant, Halo’s smart sensor is triggered to measure any deviation from that baseline. In case of smoke, the device can not only detect it but can determine what that smoke consists of to help the crew determine whether the problem is a galley microwave food fire or something more serious.
Ultimately, L2 intends for Halo to be fully integrated into the aircraft. “That is our intent, but some airlines are requesting that it not be,” said McConnell. “They want a portable unit that they can take on and off and put on other aircraft, and also a faster time to market.”
For the past several months, the company has been flight testing several units mounted in armored carry cases, secured in the cabin, and plugged into regular 115-VAC outlets. For larger commercial airliners, L2 is still working to determine the optimal number of sensor units required, but McConnell believes five would be recommended, starting with three in the cabin.
“What we’re investigating is putting one behind the pressure bulkhead in the outflow valve area to measure all the air coming out,” he said. The customer could then decide if they wish to place a unit in the cargo hold as well. “The way that we are initially designing the alerting is a simple light in the cockpit that says where that alert is coming from and then it's automatically streaming that data in very high fidelity to say what exactly one of these detection units is saying compared to what is normal in the baseline.”
“We’re initially targeting the Boeing and Airbus airframes due to the large numbers and the airlines' immediate challenge of recapturing trust in their customers,” McConnell said. “Our roadmap absolutely [includes] the large-cabin business jets from Gulfstream, Dassault, and Bombardier.”