Indian envoy warns of 'big red line,' days after charges laid in Nijjar case
India's envoy to Canada insists relations between the two countries are positive overall, despite what he describes as 'a lot of noise.'
People living in and around Washington experienced a rare, if startling, sound that has a rich history in American aviation and possibly a muted future: A sonic boom.
The boom was heard Sunday after the U.S. military dispatched six fighter jets to intercept an unresponsive business plane flying over restricted airspace.
The Air Force gave the F-16s permission to fly faster than the speed of sound -- something civilian aircraft rarely get to do -- as the jets scrambled to catch up with the Cessna Citation. The result was a thunderous rumble that resonated across a metropolitan area that's home to more than six million people.
The business jet eventually crashed in rural Virginia, killing the pilot and three passengers.
Below is an explanation of what sonic booms are, their history in the U.S. and their potential future.
Sonic booms are heard on the ground when airplanes overhead fly faster than the speed of sound. That speed is typically about 760 mph near sea level, but can vary depending on the temperature, altitude and other conditions, according to the Congressional Research Service.
As the plane speeds through the air, molecules are pushed aside with great force, "and this forms a shock wave, much like a boat creates a wake in water," according to NASA.
"When this line of shock wave passes by, listeners on the ground hear a very loud noise," according to an explanation from Australia's University of New South Wales.
The F-16s flying over Washington on Sunday were "probably trying to go as fast it could to catch up" with the wayward Cessna airplane, said Anthony Brickhouse, an associate professor of applied aviation sciences at Embry-Riddle Aeronautical University.
The F-16 Fighting Falcon can fly 1,500 mph or twice the speed of sound, known as Mach 2, according to the Air Force.
In 1947, test pilot Charles "Chuck" Yeager became the first person to fly faster than sound in an orange, bullet-shaped Bell X-1 rocket plane. His exploits were told in Tom Wolfe's book "The Right Stuff," and in the 1983 film it inspired.
In the movie, someone on the ground asks, "What's that sound?" as Yeager's plane flies above the Mojave Desert and breaks the sound barrier.
Interest in supersonic flight initially focused mostly on military planes, according to the Congressional Research Service. But it grew to include supersonic civil aircraft in the 1960s.
For example, the Soviet Union became the first country in 1968 to fly a supersonic passenger plane, the Tupolev TU-144. But a fatal crash at the 1973 Paris Air Show ended that ambition.
In 1963, the U.S. government announced a major program to develop a supersonic passenger aircraft. But serious problems soon surfaced, including massive development costs and doubts about financial viability. The program was terminated in 1971.
During the 1960s, NASA was tasked with helping to develop commercial supersonic aircraft and researched the effects of sonic booms. It found that people who experienced them were not happy with the loud sounds, describing them as "annoying," "irritating" and "startling."
In 1973, the Federal Aviation Administration prohibited supersonic flights over land, "based on the expectation that such flights would cause a sonic boom to reach the ground," the Congressional Research Service wrote.
The Concorde, an Anglo-French supersonic jetliner, saw success for a number of years after making its first commercial flights in 1976. However, its ear-rattling sonic booms irritated people on the ground and led to restrictions on where the jet could fly.
In the U.S., the plane flew mainly over the Atlantic to New York and Washington. It could fly at twice the speed of sound. And it promised to revolutionize long-distance travel by cutting flying time from the U.S. East Coast to Europe from eight hours to three and a half hours.
The Concorde never caught on widely. The plane's economics were challenging, and its sonic booms led it to be banned on many overland routes. Only 20 were built; 14 of which were used for passenger service.
In 2003, British Airways and Air France both stopped Concorde service.
Sonic booms are still heard in the U.S. from the nation's military aircraft. In 2021, a sonic boom from F-15 fighter jets caused widespread concern that there was an earthquake on the Oregon coast.
In 2018, the Congressional Research Service noted a revival of interest in supersonic aircraft, with startups hoping new technology could make them quieter and profitable.
Since then, American Airlines and United have bought supersonic jets from manufacturer Boom Supersonic. The aircraft are still on the drawing board and years away from flying -- an not all industry observers believe they'll be profitable.
Meanwhile, NASA's X-59 airplane is designed to fly faster than sound -- but with drastically reduced noise -- over land, according to April blog post from the agency.
"People below would hear sonic `thumps' rather than booms, if they hear anything at all," NASA wrote.
India's envoy to Canada insists relations between the two countries are positive overall, despite what he describes as 'a lot of noise.'
With Donald Trump sitting just feet away, Stormy Daniels testified Tuesday at the former president's hush money trial about a sexual encounter the porn actor says they had in 2006 that resulted in her being paid to keep silent during the presidential race 10 years later.
The U.S. paused a shipment of bombs to Israel last week over concerns that Israel was approaching a decision on launching a full-scale assault on the southern Gaza city of Rafah against the wishes of the U.S.
Footage from dozens of security cameras in the area of Drake’s Bridle Path mansion could be the key to identifying the suspect responsible for shooting and seriously injuring a security guard outside the rapper’s sprawling home early Tuesday morning, a former Toronto homicide detective says.
A chicken farmer near Mattawa made an 'eggstraordinary' find Friday morning when she discovered one of her hens laid an egg close to three times the size of an average large chicken egg.
Susan Buckner, best known for playing peppy Rydell High School cheerleader Patty Simcox in the 1978 classic movie musical 'Grease,' has died. She was 72.
Accused killer Jeremy Skibicki could have a challenging time convincing a judge that he is not criminally responsible for the deaths of four Indigenous women, a legal analyst says.
A Calgary bylaw requiring businesses to charge a minimum bag fee and only provide single-use items when requested has officially been tossed.
Two Nova Scotia men are dead after a boat they were travelling in sank in the Annapolis River in Granville Centre, N.S., on Monday.
An Ontario man says he paid more than $7,700 for a luxury villa he found on a popular travel website -- but the listing was fake.
Whether passionate about Poirot or hungry for Holmes, Winnipeg mystery obsessives have had a local haunt for over 30 years in which to search out their latest page-turners.
Eighty-two-year-old Susan Neufeldt and 90-year-old Ulrich Richter are no spring chickens, but their love blossomed over the weekend with their wedding at Pine View Manor just outside of Rosthern.
Alberta Ballet's double-bill production of 'Der Wolf' and 'The Rite of Spring' marks not only its final show of the season, but the last production for twin sisters Alexandra and Jennifer Gibson.
A mother goose and her goslings caused a bit of a traffic jam on a busy stretch of the Trans-Canada Highway near Vancouver Saturday.
A British Columbia mayor has been censured by city council – stripping him of his travel and lobbying budgets and removing him from city committees – for allegedly distributing a book that questions the history of Indigenous residential schools in Canada.
Three men in Quebec from the same family have fathered more than 600 children.
A group of SaskPower workers recently received special recognition at the legislature – for their efforts in repairing one of Saskatchewan's largest power plants after it was knocked offline for months following a serious flood last summer.
A police officer on Montreal's South Shore anonymously donated a kidney that wound up drastically changing the life of a schoolteacher living on dialysis.