NASA Studies Sources of Ice Crystals in High Places – Is It Up Thanks to That?

From NASA

A team of NASA researchers are once again using NASA’s DC-8 Aerial Laboratory to study ice crystals – and more – inside large thunderstorms to improve jet engine design and increase flight safety.

This work is part of NASA’s High Ice Water Content (HIWC) research operation, which has previously conducted two flight research campaigns: the first out of Florida in 2015and the second place besides Florida, California and Hawaii in 2018.

Now, the team is back at it again, conducting a flying operation in July off the southeastern coast of the United States and the Gulf of Mexico.

This time, the team – which includes the Federal Aviation Administration (FAA) and Japanese partners – is using Cecil Airport in Jacksonville, Florida, as their base of operations.

“For this campaign, we are doing something a little different. Our priority is to conduct flights in regions with man-made aerosols to better understand their impact on the growth of highly concentrated ice crystals,” said Thomas Ratvasky, HIWC principal investigator said. NASA’s Glenn Research Center in Cleveland.

Spray bottle 101

Aerosols are small particles in the atmosphere that are the result of many types occur naturally and man-made sources. Fossil fuel burning, industrial emissions, and agricultural activity are just a few examples.

These contaminated aerosols, once released into the air, move through the atmosphere, and may eventually be released into the ocean.

Once they interact with convective systems, one theory is that they can increase the concentration of ice crystals present in a thunderstorm – although exactly how this complex interaction works is often unknown. well known.

During these storms, especially in mid-level convection systems, high concentrations of ice crystals form. As an airplane flies over them, the power and efficiency of its jet engines can drop.

That’s why HIWC researchers have been collecting data on ice crystals, their prevalence, and their effect on jet engines.

With this additional flight campaign aimed at aerosol research efforts, HIWC is closing the gap in existing data that regulators will use to review new safety standards to reduce crystals. ice.

“We wanted to make sure that environments with a lot of aerosols were represented in this dataset. Many engines today are not required to demonstrate the ability to fly in these conditions of ice crystals, says Ratvasky, but future engines will.

Don’t Cool Your Jets

Over the past 30 years, there have been more than 170 reported incidents of power failure and engine damage in commercial transport jets such as airplanes when flying over convection systems.

Here’s how it happens: the jet flies over an area with a high concentration of ice crystals. Some ice crystals come in the core of the engine – where its power is generated.

Under some conditions, ice crystals form a viscous layer of water inside critical components such as compressors. Heat transfer from the motor into the ice groove causes freezing in the compressor. When this ice peels off, the motor can be lost or damaged.

Elsewhere on the plane, equipment that collects information important to the pilot, such as the plane’s speed, can also be obstructed by ice crystals, resulting in false and inaccurate readings. body in the cockpit.

To investigate the role of aerosols in the growth of high concentrations of ice crystals that affect aircraft performance, HIWC is using NASA’s DC-8 Aircraftbased NASA’s Armstrong Flight Research Center in California, and flew through storms with large amounts of both ice crystals and aerosols.

Flight Lab

The HIWC team has improved NASA’s DC-8 with their data collection tools and other technologies, allowing on-board researchers to study the environment in real time.

On the DC-8’s left wing and nose are instruments that measure the total water content of the clouds the aircraft flies over, as well as a probe to measure smaller cloud-sized droplets.

Meanwhile, the right wing is home to particle devices capable of measuring the size and shape of larger ice particles.

Inside the nose is a modified weather radar, used in collaboration with researchers at NASA’s Langley Research Center in Virginia, to detect storm conditions ahead of DC-8’s flight path.

A new device added to the aircraft for this flight operation is a passive aerosol spectrometer probe. This canister-like device measures the number of aerosols in the air.

Nagoya University in Japan owns and operates this and other aerosol devices and is collaborating with HIWC on the research.

On the right side of the plane is an inlet that directs air into the plane itself, where it flows through a series of devices before exiting the aircraft downstream.

Inside the DC-8 are monitor stands, monitors, and other stations where researchers sit and watch data as they fly.

Each flight lasts about seven hours and thousands of miles at various speeds and altitudes.

In a typical flight configuration, the group flies at the same altitude as the airliner to fly over the ice crystals. They then descend to very low altitudes – even less than 1,000 feet – to hunt for aerosols before they ascend during storms and interact with clouds and ice crystals.

Rest assured; Safety is paramount. The plane is in the hands of experts who know what to expect and how to deal with ice crystals.

“We are not flying anywhere other than the aircraft will fly so we can get data that applies to normal operations. Our pilots and the entire team are aware of the risks to engine performance and aeronautical data systems posed by HIWC, and we use procedures to minimize those risks. ,” Ratvasky said.

High-flying partnership

The close collaboration between a number of organizations, who contributed both expertise and funding to the project, makes HIWC’s work possible.

“We could not have done this without NASA’s internal and external cooperation. We have the science team from Langley, the icing team from Glenn, and the airplane from Armstrong. The FAA is supporting the instrumentation, and Nagoya University and the Japan Meteorological Agency have provided their expertise and aerosol measurement equipment,” said Ratvasky.

Following the flight campaign, the next step is to process the data then pass it on to the FAA and other agencies such as the Ice Crystal Icing Aviation Rules Advisory Committee.

Once researched, relatively new standards for jet engine certification will be evaluated and could eliminate all power outages caused by ice crystals in convection systems.

John Gould
Aviation Research Mission Directorate

Last Updated: July 29, 2022

Editor: Lillian Gipson