Boom Supersonic's XB-1 jet breaks sound barrier 3 times on final test flight (video, photos)

[Admin]

Boom Supersonic's XB-1 pathfinder vehicle went out in style on Monday (Feb. 10), breaking the sound barrier three times on its 13th and final test flight.

Boom Supersonic's XB-1 jet breaks sound barrier 3 times on final test flight (video, photos) : Read more

 

[Woodboy12]

Boom Supersonic's XB-1 pathfinder vehicle went out in style on Monday (Feb. 10), breaking the sound barrier three times on its 13th and final test flight.

Boom Supersonic's XB-1 jet breaks sound barrier 3 times on final test flight (video, photos) : Read more

An impressive achievement! However, I believe transitioning from a single-pilot aircraft to a certified commercial airliner is quite a significant leap.

 

[Unclear Engineer]

Seems strange that the aircraft would make only one test flight at supersonic speeds. I would think that it would be used to better define an envelope of flight conditions that produced acceptable levels of boom at various ground elevations and temperature conditions. We have terrain that exceeds 7,000' altitude, for instance. La Paz, Bolivia, is a city at 12,000 feet.

 

[larryc55]

An impressive achievement! However, I believe transitioning from a single-pilot aircraft to a certified commercial airliner is quite a significant leap.

All it will take is about $30-$50B and 20+ years. They are VERY close. They'd be better off trying to mod this thing into a Bizjet for billionaires.

 

[ChrisA]

People are asking why the test program ends so early. I think because the entire point of the test flight was to validate the company's aerodynamic simulation software. If the plan flies exactly as the software predicted it would fly, now they are confident the software works. So as said, they can freeze the design of the airliner.

If you are very confident in your ability to model a plane in software you reduce development risk in the next design. They can be very sure their bigger plane is "just work"

 

[Unclear Engineer]

Good point about validating the software.

But, 3 short duration supersonic flight segments on the same day in the same location might not be sufficient to capture the range of atmospheric conditions that might affect sound levels at the ground across the entire nation in all seasons.

And, I would think that the maneuverability of the aircraft at supersonic speeds would also be a design consideration, particularly for off-normal situations. It is an unusual airframe design.

 

[Classical Motion]

Perhaps some kind of Lidar or other sensor could sense the reflective altitude. The measurement would be detected earlier than the boom ETA. And depending on reflective change rate, might be mitigated with course/altitude changes.

What prevents us from flying higher and faster now? Is it the structure and stress(pressure/temp cycles) ….. or the fuel efficiency?

 

[Unclear Engineer]

My experiences in Montana with sonic booms were at elevations of 5,000 to 8,000 feet. The booms were LOUD, and we never saw the planes that made them, so we assumed they were quite high - and long gone by the time the shock wave got down to us.

So, my expectation is that the major effect on boom reduction is the airframe design, and the atmospheric part is secondary.

What happens to the shockwave directed towards the ground when the plane banks at supersonic speeds? When it descends? Etc?

 

[Classical Motion]

The shock wave is one she bang. If a structure could slice that up into a thousand little sequential she bangs...... we might not hear it.

A puff boom.