
Credits: NASA / John Gould
A team of NASA researchers are once again using NASA’s DC-8 airborne laboratory to study ice crystals – and more – within the heart of large thunderstorms in a bid to improve jet engine designs and increase flight safety.
The work is part of NASA’s High Ice Water Content (HIWC) research activity, which has previously conducted two flight research campaigns: the first out of Florida in 2015, and the second out of Florida, California, and Hawaii in 2018.
Now, the team is back at it again, conducting a flight campaign during July off the southeast coasts of the United States and the Gulf of Mexico.
This time, the team – which includes Federal Aviation Administration (FAA) and Japanese partners – is using Cecil Airport in Jacksonville, Florida, as their base of operations.
“For this campaign we’re doing something a little different. Our priority is to conduct flights in regions with human-made aerosols to better understand what effect they have on the development of high concentrations of ice crystals,” said Thomas Ratvasky, HIWC’s principal investigator from NASA’s Glenn Research Center in Cleveland.

Credits: NASA / John Gould
Aerosols 101
Aerosols are tiny particles in the atmosphere that result from a variety of both naturally occurring and human-made sources. Burning of fossil fuels, industrial emissions, and agricultural activity are just a few examples.
These pollutant aerosols, once released into the air, move through the atmosphere, and eventually can be carried out over the ocean.
Once they interact with convective systems, one theory suggests they can increase the concentrations of ice crystals present in a thunderstorm – although exactly how this complex interaction works is generally unknown.
In these storms, specifically mesoscale convective systems, high concentrations of ice crystals form. When an aircraft flies through them, its jet engines’ power and performance can decrease.
That’s why HIWC researchers have been gathering data on ice crystals, their prevalence, and their effect on jet engines.
With this additional flight campaign attempting to study aerosols, HIWC is bridging a gap in the existing data that regulatory bodies will use to consider new safety standards for mitigating ice crystals.
“We want to make sure that high-aerosol environments are represented in this dataset. Many of today’s engines were not required to demonstrate capability in flying in these ice crystal conditions, but future ones will,” Ratvasky said.
Don’t Cool Your Jets
During the past 30 years, there have been more than 170 reported incidents of power loss and engine damage in commercial transport jets such as airliners when flying through convective systems.
Here’s how it happens: jets fly through an area with a high concentration of ice crystals. Some of the ice crystals enter the core of the engine – where its power is generated.
In some conditions, the ice crystals form a layer of slushy water inside critical components such as the compressor. The transfer of heat from the engine into the icy slush causes ice to build up in the compressor. When this ice sheds, engine power loss or damage may occur.
Elsewhere on the aircraft, instruments collecting important information for pilots, such as the aircraft’s speed, also can be obstructed by ice crystals, leading to erroneous and inaccurate readings in the cockpit.
To learn the role aerosols play in the development of high concentrations of ice crystals affecting an aircraft’s performance, HIWC is utilizing NASA’s DC-8 aircraft, based out of NASA’s Armstrong Flight Research Center in California, and flying through storms with a high amount of both ice crystals and aerosols.

Credits: NASA / John Gould
The HIWC team has souped-up NASA’s DC-8 with their data-gathering instruments and other technology, allowing onboard researchers to study the environment in real-time.
On the DC-8’s left wing and nose are devices to measure the total water content of the clouds the aircraft flies through, as well as a probe to measure smaller cloud-sized droplets.
Meanwhile, the right wing is home to particle instruments capable of measuring the size and shape of the 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 up ahead of the DC-8’s flight path.
A new instrument added to the aircraft for this flight campaign is the Passive Cavity 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 instruments and is collaborating with HIWC in the research.
On the aircraft’s starboard side is an inlet that directs air into the aircraft itself, where it flows through a series of instruments before being exhausted out of the aircraft further downstream.
Inside the DC-8 are racks of monitors, displays, and other stations where researchers sit and view the data as they fly.
Each flight lasts approximately seven hours, and thousands of miles are flown at a variety of speeds and altitudes.
In a typical flight profile, the team flies at the same higher altitudes as airliners to fly through ice crystals. Then, they descend to very low altitudes – even below 1,000 feet – to hunt down aerosols before they have risen into the storm and interacted with cloud and ice crystals.
Rest assured; safety is paramount. The aircraft is in the hands of experts who know what to expect and how to deal with ice crystals.
“We’re not flying anywhere different than an airliner would fly so we can get data that is applicable to normal operations. Our pilots and the entire team are aware of the hazards to engine and air data system performance caused by HIWC and we utilize procedures to minimize those hazards,” said Ratvasky.

Credits: NASA / John Gould
High Flying Partnerships
Close cooperation among several organizations who contributed both expertise and project funding make HIWC’s work possible.
“We could not do this without all the collaboration both internal and external to NASA. We have the science group from Langley, the icing group from Glenn, and the airplane from Armstrong. The FAA is supporting instrumentation, and Nagoya University and the Japan Meteorological Agency have provided their expertise and aerosol instrumentation,” said Ratvasky.
Following the flight campaign, the next step is to process the data then pass it on to the FAA and other bodies such as the Ice Crystal Icing Aviation Rulemaking Advisory Committee.
Once studied, the relatively new standards for jet engine certification will be assessed and could all but eliminate power loss incidents due to ice crystals in convective systems.
John Gould
Aeronautics Research Mission Directorate
Last Updated: Jul 29, 2022
Editor: Lillian Gipson
Ohh, Ahh. pencil pushing pin heads are studying how aerosols impact ice crystal formation! But wait, duhhhh – aircraft of any type or size are normally not flown into known convective activity. Pilots avoid CB’s like they are carrying the plague. (CB= CumulonimBus)
Furthermore, mankind’s aerosol production is entirely dwarfed by what nature routinely does:
https://www.foxweather.com/weather-news/tracking-saharan-dust
For the past almost 2 weeks, and continuing an humongous Saharan Dust cloud is impinging on the Atlantic, Caribean, and Gulf of Mexico, with Florida in the mix. It is estimated to contain 180 million tonnes of dust:
https://astronomy.com/news/2022/06/gargantuan-saharan-dust-plume-blowing-across-the-atlantic (As of June 6, 2022, the plume stretched from Africa to South America and even reached Puerto Rico. All told, it covered more than 2.2 million square miles (5.7 million square kilometers) of the tropical Atlantic Ocean.)
That one dissipated, and now there is another one as large or larger.
So smart guys at NASA, how is it this aerosol cloud made by nature, supresses convection, reduces water content and does not promote ice crystal formation (because there are almost no thunderstorms)? But you contend man made aerosols increase ice crystal formation in thunderstorms? Or did you just tack on the “man made” aspect to secure funding by ticking the green nutbar subscriber check box?
Yet strangely, in other parts of climate science, dust particles create clouds and rain.
Epic rant btw, somebody who knows their own mind and, contrary to how it will be ‘taken’ by the pin-heads, NOT out of their mind
I luvz it
Again: Everything in this world is now wrong.
Thanks, but it’s an epic rant due to actual knowledge and experience with flying and understanding the extreme danger of CB’s or any convective activity. I am a pilot.
You would rather they just use models to study how weather works?
We and they already know how this aspect works. What I disagree with is saying or insinuating that man made aerosols are the drivers of ice formation in CB’s Essentially without aerosols or condensation nuclei there would be no rain, let alone ice crystals – so stop making natural necessary features of the real world into some man made monster!
D Boss,
“ Pilots avoid CB’s like they are carrying the plague. (CB= CumulonimBus)”
Probably doesn’t give enough emphasis, based on my Father’s hatred of them. He was shot down – French Anti-Aircraft, he thought – over Dunkirk in 1940, but managed 4,400 hours flying before his Golden Bowler..
Didn’t talk all that much [to me] about his service, but I gathered that ‘plague crossed with rabies’ – with a side of anthrax – would be closer to his dislike of Cb.
From sea level – my vantage point – Cb is magnificent, and can be useful if you’ve just had a passel of shitehawks perched on your foc’stle, and need a deck wash. But radars on.
Auto
Aye mate. Cleaning the foc’astle and fertilizing plants by releasing nitrogen are some of the benefits of CB’s on the ground level. Not to mention they are the air conditioners for the planet as many posit on this site.
I like your addition to the pilot’s view of CB’s – plague crossed with rabies with a side of anthrax – that about sums up how a towering cumulonimbus is viewed by sane pilots!
I would think their results would be applicable to explaining a little better how the weather works.
Passive Cavity…
Indeed
What’s the footprint of a 7 hour flight?
3 Al Gores (my new metric)
I thought that was a measure of volume, not length.
Volume of hot air actually.
And when expelled, this is known to give some people the vapours.
Density. An AlGore is a unit of density, equivalent to 1Gigathunberg.
Since NASA is part of the gubmint bureaucracy, they probably snatch up any
“extra airframes” that were part of the military’s order, which may be how
they got this DC-8. They then load it up with sensors to collect data they &
other users want. If they were a private research company, they’d probably
be using modified drones equipped with sensors that would relay data to
ground stations. It’s much cheaper, safer, cleaner & takes less time but
NASA is stuck in the bureaucratic framework where “Das ist verboten!
This DC-8 pictured probably has the same turbofan engines used to
upgrade the KC-135 refueling tanker, which itself had problems caused
by flights through rain and hail that were eventually resolved. The original
turbojet engine pictured below left a cloud of smoke upon take off, like the F-4.
https://www.nasa.gov/centers/armstrong/aircraft/index.html
170 incidents in thirty years?
In 2019 there were over forty million airline flights plus many additional cargo jet and private jet flights.
I guess one can’t be too careful.
Statistically insignificant — unless you or a loved one happens to be on one of those 170 flights. Relativity rules the universe.
Air France 447 crash over the Atlantic (1992) was a high-visible incident of the hazards of inadvertent convection penetration with icing protection (pitot tube anti-ice) turned off. The Air Florida 90 crash into the Potomac River in Washington DC (1982) was another example of failure to use engine anti-icing protection. Aircraft already have protection against these icing situations…they just have to be used.
Aircraft are not designed to fly through thunderstorms. NASA should reconsider if the data is actually needed and use alternative methods to collect this data if needed.
The DC8 would be better employed flying Nancy to Taiwan.
How about a Slow Boat to China?
One-way and leave her in Beijing.
“Burning of fossil fuels, industrial emissions, and agricultural activity are just a few examples.These pollutant aerosols, ” ….
Gotta stop the plebs from eating ,traveling etc …
Unlike all the other “garbage research” that is actually nothing more than
staying in the office & designing more useless models, these folks are
actually collecting REAL WORLD data that they can do REAL analysis on
that hopefully can be used to improve weather forecasting & flight safety,
two REAL WORLD needs. While they have the usual Green spiel, it’s still much, much better than all of NASA’s wasted time & $$$ spent on social justice programs!
Deliberately fling any aircraft into an electrical storm is abso-bloody-lutely ridiculous.
These are the stark raving idiots who are trying to place our younger generation into continuous states of fear.
Ludicrous.
Unlike the phony baloney Fear Porn™ The Team™ feeds our youngsters,
real lightning can zap you 25 miles from the thunderstorm.
This, unlike climate, falls withing NASA’s purview as described in its original charter. It has not been given proper attention because of mission creep into more profitable research.
profitable research or propaganda research?
Just by weather watching you get clues about whats going on in the upper air.
Yesterday afternoon here in England l saw a ‘mock sun’, these turn up more often during the winter months. As it needs very cold air for them to form. So this one turning up yesterday told me that the upper air above England must have been very cold for the time of year.
I have no idea whether this study is practical or useful but when I read this,
“With this additional flight campaign attempting to study aerosols, HIWC is bridging a gap in the existing data that regulatory bodies will use to consider new safety standards for mitigating ice crystals.”
I got suspicious and less interested.
Oh wow, I wasn’t finished reading when I spotted this one: it says there that
“aerosols are tiny particles in the atmosphere that result from a variety of both naturally occurring and human-made sources. Aerosols can increase the concentrations of ice crystals present in a thunderstorm, although exactly how this complex interaction works is generally unknown”.
Well, now I feel stupid here, because this is NASA high end flying research lab saying this, but we chemists know from precipitation principles that particles are excellent promoters of crystallization because they act as seeds. The surface area attracts by Van ser Walls forces the molecules of the chemical to be crystallized. We do this on purpose in organic chemistry when you want to make powder of a drug; you can add a bit of previously-crystallized amount to what we call the mother liquor of the new crystals to form. We chemists grow complex structures of drugs in solid state at different pH values, and organometallic complexes of heavy metals, which work as semi and superconductors.
I don’t get how highly-technological NASA doesn’t have clear the chemical logical argument that atmospheric water crystals are seeded by aerosols, is that a mystery to them?? This is easy to prove! Take samples of the crystals and do chemical analyses with stuff like HPLC/GC-MS, IR, Uv/Vis spectroscopy, NMR, X-ray crystallography; detect aerosol chemicals in crystals of water. That’s standard analytic chemistry.
I’m going to read the rest, trying to see something clearer about this “mystery”. If the chemistry proves right, they should be already making statistical analysis of how much water crystallization is caused by human aerosols versus how much by nature; add to that a study based on altitude too.
Isn’t that kind of thinking standard in NASA??
I’m just an almost unemployed chemist.
JBVigo, PhD
This icing condition only occurs where water vapor accumulates on warmer surfaces within the engine nacelle then migrates to where it isn’t wanted. Drainage is problematic as the drain paths keep freezing too. From these studies we learn that this condition, firstly is an issue, and subsequently how to avoid it.
Lower altitude icing conditions are also more common and dangerous. Ice buildup is quite damaging to lift as it collects on wings and flight controls, both reducing lift and adding weight.
Sorry guys they are testing at much higher altitudes than most Cb’s go. Cb’s usually top out around 30k ft (9500 m) but can go higher. They are looking at high and dry (relatively) ice clouds at above 1000 m (35f ft) typical of airliner cruising altitudes.
Real design surprisingly needs real data.
Humm … based on history (e.g. weather studies in the ’50’s being U-2 spy flights), this seems like it could be a cover for a different “secret” venture. Not saying that it is, but …