Anh-Thu Nguyen, 44, died in a plane crash in Greenwood, Indiana, on July 30. About a month later, the National Transportation Safety Board has released its preliminary report, revealing new details about the crash. Nguyen, a Purdue University graduate, wanted to be the first Vietnamese woman to complete a solo flight around the world.
Nguyen was on the second leg of her journey when her plane suddenly fell out of the sky shortly after she took off from the Indy South Greenwood Airport.
Her plane crashed on a hill near a small creek behind a Circle K gas station, less than a mile away from the airport. She was the only person killed in the crash.
The NTSB report revealed new details, but it did not provide any information regarding what may have caused the crash.
On July 30, 2025, Nguyen was planning to travel from Greenwood to Quakertown Airport in Quakertown, Pennsylvania, which was about a 640-mile trip, according to the NTSB preliminary report.
There were a few clouds in the sky that morning, with the temperature sitting at about 86 degrees Fahrenheit, according to the report.
At 10:45 a.m., Nguyen took off in her Lancair IVP airplane from runway 19 at the Indy South Greenwood Airport. After takeoff, her plane began to climb in a left turn.
About 30 seconds later, data captured by surveillance-broadcast systems on board showed that Nguyen was decreasing in her turn, when the plane suddenly began to rapidly descend to the right.
Frank Williams, a witness to the crash, said the airplane was quietly spiraling as it fell from the sky.
The total duration of the Nguyen’s flight was about 1 minute and 30 seconds, according to the NTSB preliminary report.
Plane data showed that the engine was fully activated and steadily running throughout the duration of the flight, according to the NTSB preliminary report.
An aviation professor explains how the NTSB conducts investigations
Cary Grant, a professor in the aviation department at Embry-Riddle Aeronautical University, spoke with IndyStar a few days after Nguyen’s crash to explain the National Transportation Safety Board’s approach to investigations.
“There won’t be anything about what caused the crash in the preliminary report. It’s just the facts,” said Grant.
It may be two years before the NTSB releases its full report, he said.
“The full report takes a while because the NTSB is evaluating several factors.”
The NTSB usually has a team that evaluates the training qualifications of the pilot, the meteorological conditions at the time of the accident, and air traffic control, among other possible factors, Grant said.
The NTSB also evaluates each part of the plane to determine if there may have been a point of failure on the plane, and in some cases, the NTSB will invite third parties like the Federal Aviation Administration or the manufacturer of the plane and engine to help with its investigation.
Grant did not provide an opinion on what may have caused Nguyen to crash.
He expressed concern that Nguyen’s plane may not have had sophisticated flight data recorders, as they are not required to have them installed.
“But now with modern glass panel displays and instruments, there’s a lot of information that can be forensically pulled off the data chips that are on board the airplane,” Grant said.
“While they are not designated as flight data recorders, they are recording conditions of the airplane at that time.”
Who was Anh-Thu Nguyen?
Nguyen, a 2015 Purdue graduate, wanted to inspire other Asian women to become pilots.
She started Asian Women in Aerospace and Aviation Inc., a nonprofit 501(c)(3) organization, in 2018 and became the chief flight instructor at Dragon Flight Training Academy in Georgia.
Nguyen was born in Vietnam, moving to the United States when she was 12 years old. She received a bachelor of science in math and a master’s in aeronautics and astronautics engineering from Purdue University. She received a doctoral degree in aeronautics and astronautics engineering from Georgia Institute of Technology.
“As an Asian woman, I faced many obstacles and challenges to get to where I am today, especially adapting to a new culture, language, and life in the United States. I wanted to give back and inspire the next generation,” she told Purdue University.
Nguyen originally conceived the idea of becoming the first Vietnamese woman to complete a solo flight around the world in 2019, but due to a number of issues, her plans were pushed back.
On July 27, 2025, Nguyen officially started the journey when she flew out of Oshkosh, Wisconsin, toward Indiana.
On July 30, before Nguyen left the Greenwood airport, she posted an update about her journey on social media.
“I just completed the first leg of my solo flight around the world,” she said. “This is more than just a flight. It’s a mission to inspire the next generation of Asian female pilots and aerospace engineers and STEM professionals.”
Noe Padilla is a Public Safety reporter for IndyStar. Contact him at npadilla@indystar.com, follow him on X @1NoePadilla or on Bluesky @noepadilla.bsky.social.
This article originally appeared on Indianapolis Star: NTSB releases preliminary report about Greenwood plane crash that killed Purdue graduate
Reporting by Noe Padilla, Indianapolis Star / Indianapolis Star
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