William Langewiesche, a magazine writer and author who forged complex narratives with precision-tooled prose that shed fresh light on national security, the occupation of Iraq and, especially, aviation disasters — he was a professional pilot — died on Sunday in East Lyme, Conn. He was 70.

Cullen Murphy, his longtime editor at The Atlantic and Vanity Fair, confirmed the death, at the home of a friend, saying the cause was prostate cancer.

Mr. Langewiesche (pronounced long-gah-vee-shuh) was one of the most prominent long-form nonfiction writers of recent decades. He was an international correspondent for Vanity Fair, a writer-at-large for The New York Times Magazine and a national correspondent for The Atlantic.

For 10 years running, from 1999 to 2008, his pieces were finalists for the National Magazine Award, and he won it twice: in 2007 for “Rules of Engagement,” about the killing of 24 unarmed civilians by U.S. Marines in 2005 in Haditha, Iraq; and in 2002 for “The Crash of EgyptAir 990,” about a flight that went down in the Atlantic Ocean in 1999 with the loss of all 217 people aboard.

He chose to write often about calamitous events, piecing together a meticulous explanation for what went wrong while portraying the human subjects under his microscope with sympathy.

“At his best there’s a sort of cinematic omniscience in the way he writes,” Mr. Murphy said in an interview. “And so you feel almost as he feels, with your face pressed up against the window watching something unfold, often very rapidly, and often wishing that things would unfold very differently but knowing there’s nothing that can be done.”

Mr. Langewiesche’s account of the EgyptAir crash in 1999, which was profoundly enriched by his own aviation background, blamed a suicidal co-pilot. Egyptian officials refused to accept that conclusion, a response, he wrote, that was rooted in political and cultural chauvinism.

Mr. Langewiesche learned to fly as a boy and worked as a commercial pilot early on to support his literary ambition. He drew on his aviation expertise in a number of articles and books that laid out highly technical subjects in lucid prose.

Writing about Capt. Chesley B. Sullenberger III’s famous landing of a commercial airliner in the Hudson River in 2009, Mr. Langewiesche made the case that that injury-free belly flop was a testament more to modern airplane technology than to the heroism of the pilot.

Captain Sullenberger took issue with that account, telling The New York Times that Mr. Langewiesche’s book about the episode, “Fly by Wire,” contained “misstatements of fact.”

Reviewing “Fly by Wire” in The Times, the book critic Dwight Garner wrote, “Written quickly, it lacks some of the eloquence and steely control of Mr. Langewiesche’s earlier books.” Mr. Garner called Mr. Langewiesche “the Steve McQueen of American journalism,” referring to the author’s muscular prose style and often gripping subject matter.

In other projects — pursued thanks to editors who allowed him months for reporting and writing — Mr. Langewiesche wrote an account in The Atlantic in 2006 about how terrorists might obtain a nuclear bomb; another article, also in The Atlantic, in 2004, dissected the sinking of a ferry in the Baltic Sea a decade earlier.

His 2002 book, “American Ground: Unbuilding The World Trade Center,” based on a three-part series in The Atlantic, was reported over six months at ground zero as he meticulously covered the cleanup after the terrorist attacks of Sept. 11, 2001.

Not all of his work described life and death dramas. His profile of Robert M. Parker Jr. in The Atlantic, “The Million-Dollar Nose,” opened with the enticing line: “The most influential critic in the world today happens to be a critic of wine.”

Closer to form, he wrote about another aviation mystery: the disappearance of a Malaysia Airlines flight with 277 passengers over the Indian Ocean in 2014, an article that generated enormous readership for The Atlantic.

The plane remained aloft for hours after someone in the cockpit shut down its communication signals, then plunged into the Indian Ocean.

Mr. Langewiesche hypothesized a scenario in which a pilot intent on murder-suicide had asphyxiated his passengers by climbing to 40,000 feet while depressurizing the cabin, then cruised onward until the fuel ran out and the plane plummeted.

“The scene would have been dimly lit by the emergency lights,” Mr. Langewiesche wrote, imagining those hours in chilling detail, “with the dead belted into their seats, their faces nestled in the worthless oxygen masks dangling on tubes from the ceiling.”

Of the captain, the last living soul in the plane, he wrote, “The cockpit is the deepest, most protective, most private sort of home.”

William Archibald Langewiesche was born on June 12, 1955, in Sharon, Conn. His mother, Priscila (Coleman) Langewiesche, was a computer analyst. His father, Wolfgang Langewiesche, a German-born émigré, was a test pilot for the maker of the Corsair fighter used by the U.S. Navy; he wrote a classic book on flying, “Stick and Rudder,” in the 1940s.

William, a late child, had an adult sister and brothers when he was growing up. His father taught him to fly before the boy could see over the instrument panel. Later, as an undergraduate at Stanford University, Mr. Langewiesche helped pay his way through college by piloting air taxis and charters.

After earning a degree in anthropology, he moved to New York City and worked for Flying magazine. But he quit the job because he aspired to write literary nonfiction, in part inspired by The New Yorker writer John McPhee. While struggling to be published, Mr. Langewiesche supported himself as a corporate pilot.

“Other people trying to break into writing have to work as waiters,” he told Aviation News in 2001, “and I considered myself as having a technical skill — like a welder — that I could use to support myself.”

His breakthrough came in 1991, when The Atlantic published as its November cover story his article “The World in Its Extreme,’’ a 17,000-word travelogue and natural history of the Sahara Desert. He went on to write for the magazine as a national correspondent for 15 years. In 2006, he became an international correspondent for Vanity Fair, where he contributed two to four lengthy articles a year through 2019.

Mr. Langewiesche married Anne-Marie Girard in 1977, and they had two children. The marriage ended in divorce in 2017, and the following year, he married Tia Cibani, who survives him.

In addition to his wife, he is survived by his son Matthew and his daughter Anna Langewiesche, both from his first marriage; his son Archibald and his daughter Castine Langewiesche, from his second marriage; and his sister, Lena Langewiesche. He lived in North Salem, N.Y., in Westchester County.

In a 2007 interview with Mediabistro, an online career site for designers and writers, Mr. Langewiesche described his method. Instead of reading exhaustively about a subject and writing questions for interviews in advance, he preferred to plunge right into a subject “with very little preparation, intentionally somewhat naïve about it.”

“I just talk to people and listen carefully and respond to what they’re saying and try to give of myself as much as I’m asking them to give of themselves, so that a true conversation can develop,” he said. “These conversations typically will go on for weeks, on and off. Sometimes I take notes.”

The real work, he said, came later when he sat down to write.

“Writing is thinking; writing is a form of thought,” he said. “It’s difficult for me to believe that real thought is possible without writing.”

Ash Wu contributed reporting.