Virgin Atlantic's Boeing 787-9 Dreamliner broke speed records.

Virgin Atlantic's Boeing 787-9 Dreamliner broke speed records.

A Virgin Atlantic plane accidentally flew at the speed of sound during a record-breaking flight from LA to London

A Virgin Atlantic flight from Los Angeles to London reached the ground speed of 1289km/h with the help of strong winds, according to reports.

The blistering speed was reached while at 35,000 feet, or 10.7km, above Pennsylvania. The Boeing 787 twin-jet aircraft was given a boost by a furious jet stream, the high-altitude air current along which storms travel, Fox News reported.

"Never ever seen this kind of tailwind in my life as a commercial pilot," tweeted Peter James, a jet captain.

Monday's record was above the speed of sound which is 1234km/h - however, whether air travel breaks the sound barrier is dependent on its airspeed, not ground speed. Commercial aircraft are not designed to fly at supersonic speeds.

The Virgin Atlantic flight arrived in London 48 minutes early. The Boeing 787 airliner has reached top speeds of 1248km/h before and has a cruising speed of around 9.3km/h, The Washington Post reported.

Several other high speeds were recorded in the United States on Monday. A flight from Los Angeles to New York City hit 1091km/h at 39,000 feet, or 11.9km, over Ohio, while a 737 aircraft en route from Chicago to New York passed 1126km/h on Tuesday morning.

The jet stream was so strong, flight times from Dallas to Boston dipped below three hours.

This article originally appeared on Fox News and was reproduced with permission.