And like most of America's problems, it has its roots in Ronald Reagan.
On the afternoon of July 2, a Southwest Airlines pilot had to abort a landing at Louis Armstrong New Orleans International Airport. A Delta Air Lines 737 was preparing to take off on the same runway. The sudden maneuver avoided a possible collision by seconds.
Nine days later, in San Francisco, an American Airlines jet was accelerating down the runway at more than 160 miles per hour when it narrowly missed a Frontier Airlines plane whose nose had almost jutted into its path. Moments later, the same thing happened as a German airliner was taking off. In both cases, the planes came so close to hitting the Frontier aircraft that the Federal Aviation Administration, in internal records reviewed by The New York Times, described the encounters as ''skin to skin.''
And two and a half weeks after that, an American flight to Dallas was traveling at more than 500 m.p.h. when a collision warning blared in the cockpit. An air traffic controller had mistakenly directed a United Airlines plane to fly dangerously close. The American pilot had to abruptly yank the Airbus A321 up 700 feet.
The incidents highlighted in preliminary F.A.A. safety reports but not publicly disclosed were among a flurry of at least 46 close calls involving commercial airlines last month alone.
They were part of an alarming pattern of safety lapses and near misses in the skies and on the runways of the United States, a Times investigation found. While there have been no major U.S. plane crashes in more than a decade, potentially dangerous incidents are occurring far more frequently than almost anyone realizes a sign of what many insiders describe as a safety net under mounting stress.
So far this year, close calls involving commercial airlines have been happening, on average, multiple times a week, according to a Times analysis of internal F.A.A. records, as well as thousands of pages of federal safety reports and interviews with more than 50 current and former pilots, air traffic controllers and federal officials.
The incidents often occur at or near airports and are the result of human error, the agencys internal records show. Mistakes by air traffic controllers stretched thin by a nationwide staffing shortage have been one major factor.
In addition to the F.A.A. records, The Times analyzed a database maintained by NASA that contains confidential safety reports filed by pilots, air traffic controllers and others in aviation. The analysis identified a similar phenomenon: In the most recent 12-month period for which data was available, there were about 300 accounts of near collisions involving commercial airlines.
The number of such near misses in the NASA database which is based on voluntary submissions that are not independently corroborated has more than doubled over the past decade, though it is unclear whether that reflects worsening safety conditions or simply increased reporting.
''Honestly, this stuff scares the crap out of me,'' a longtime airline captain, who previously was a carrier fighter pilot, reported to NASA in November. An air traffic controller had cleared the pilots flight to land on what looked like ''a collision course'' with another passenger plane. (NASA redacts entries identifying details, such as the airlines and pilots names.)
''This has really opened my eyes to how the next aviation accident may play out,'' another pilot wrote to NASA after a close call on a runway in January.
''Is it going to take people dying for something to move forward?'' a controller wrote the same month after barely preventing a midair collision.
One problem is that despite repeated recommendations from safety authorities, the vast majority of U.S. airports have not installed warning systems to help prevent collisions on runways.
But the most acute challenge, The Times found, is that the nations air traffic control facilities are chronically understaffed. While the lack of controllers is no secret the Biden administration is seeking funding to hire and train more the shortages are more severe and are leading to more dangerous situations than previously known.
As of May, only three of the 313 air traffic facilities nationwide had enough controllers to meet targets set by the F.A.A. and the union representing controllers, The Times found. Many controllers are required to work six-day weeks and a schedule so fatiguing that multiple federal agencies have warned that it can impede controllers abilities to do their jobs properly.
''The staffing shortage is beyond unsustainable. It has now moved into a phase of JUST PLAIN DANGEROUS,'' one controller wrote to the F.A.A. last year in a confidential safety report that The Times reviewed.
''Controllers are making mistakes left and right. Fatigue is extreme,'' the report continued. ''The margin for safety has eroded tenfold. Morale is rock bottom. I catch myself taking risks and shortcuts I normally would never take.''
The controller concluded, ''It is only a matter of time before something catastrophic happens.''
For planes that can move at hundreds of miles per hour, distances that seem substantial can vanish in seconds. The F.A.A. therefore requires planes to maintain large buffers between one another. (The size of the buffers varies depending on factors like flight conditions and the type of plane.)
The F.A.A. and NASA records that The Times reviewed, as well as interviews with controllers and pilots, indicate that those standards are routinely breached. Only some of those violations are regarded as significant but they are happening with regularity.
They included a series of incidents that became public early this year. At Kennedy International Airport in New York in January, an American Airlines flight crossed into the path of a Delta flight that was accelerating for takeoff. The Delta pilot slammed on the brakes, barely avoiding a crash.
Three weeks later, on a foggy morning in Austin, Texas, an air traffic controller cleared a FedEx plane to land on the same runway as a departing Southwest flight. The planes, both moving at more than 150 m.p.h., came within less than 100 feet of colliding.
Over the next few weeks, there were similar incidents in Sarasota, Fla.; Burbank, Calif.; and Boston, where a JetBlue Airways flight aborted its landing to avoid colliding with a charter plane that was taking off without clearance from air traffic control.
In an attempt to improve safety and restore public confidence, federal officials opened investigations into the incidents, urged the aviation community to exercise ''continued vigilance'' and convened a safety summit.
''The absence of a fatality or an accident doesnt mean the presence of safety,'' Jennifer Homendy, chairwoman of the National Transportation Safety Board, said at the summit, in March. She added, ''These recent incidents must serve as a wake-up call for every single one of us before something more catastrophic occurs, before lives are lost.''
While the string of headline-grabbing incidents was unnerving, there were other significant ones that have not been publicly reported. Preliminary descriptions were included in what are known as the Administrators Daily Alert Bulletins, which are distributed to a select group of F.A.A. employees and which The Times reviewed.