Boom Supersonic Blog

Great to see so much innovation in aerospace. Boom has said they're going to reduce noise, but they've also said they'll only fly supersonic over water with buffers between supersonic zones and populated areas. So the 'boom', as it were, is still a concern.

I'm super interested to see how quiet their planes are at subsonic. If you ever saw the Concorde flying subsonic, it was unbelievably loud. Nothing to do with being supersonic - their engines were just obnoxiously loud. Came into Cape Town a long time ago and made the whole town rumble on final.

In this blog post: https://blog.boomsupersonic.com/booms-principles-of-sustainability-2f4a7b638f48

..Boom says: "Today’s subsonic commercial aircraft are 80% more fuel efficient than those of the 1960s, and noise footprints have shrunk up to 90% in the last 50 years. This technological progress has fueled Boom’s efforts to design a supersonic airliner that makes economic sense for airlines and their customers. "

However, the innovation that enabled this is high bypass turbofan engines. Turns out if you move more air slower, it's way quieter and more fuel efficient because physics. Boom can't take advantage of this - at least directly, because they have to go supersonic. A high bypass turbofan engine is huge, by it's very nature. At supersonic speeds this presents a lot of drag. That's why I'm super curious how they plan to be quiet and fuel efficient while also being supersonic.

i'm in no way qualified to give any praise/criticism, it just caught my attention (from the linked post on their cockpit/fuselage bonding https://blog.boomsupersonic.com/20-hour-bonding-event-speeds-xb-1-toward-first-flight-b50a682d924 )

"It’s the following morning and bonding appears to be successful, but it’s essential to confirm that the bond lines are shaped correctly or “filleted.” A member of the engineering team, who is certified in the process, begins non-destructive tap testing to audibly listen for voids such as air bubbles within the bond. With several decades experience, he knows what to listen for. Using specialized tools, he taps all bond lines and listens for different and unusual noises. He confirms that bonding is a success."

In general it seems that their main fabrication cost is labor, and it would probably be very hard to scale for production. I wonder why wouldn't they choose titanium - the price of material doesn't seem to matter here, and while it is hard to work with than say steel, i'd think it is still more mass production friendly than carbon fiber.