BeechTalk - BT - XB-1 Takes Flight

Username Protected · **Posted:** 25 Mar 2024, 17:02

Dad has talked about racing Eastern in the CV880. Fuel was cheap then. MMO .88

Username Protected · **Posted:** 25 Mar 2024, 17:09

Username Protected wrote:

And the Boom plane is expected to only be able to do ~4,000nm, so that takes the ultra-long haul option off the table. That can maybe do Seattle-Tokyo, but probably not with a headwind.

The winds die down significantly at FL600.

Here is FL390 (top) versus FL600 (bottom) now over the Paris to JFK route:

Attachment:

fl390-fl600-winds.png

As you can see, the winds are essentially a non factor for a supersonic aircraft, but for the subsonics in the 30s, it is a huge factor.

Mike C.

Username Protected · **Posted:** 26 Mar 2024, 09:51

Username Protected wrote:

And the Boom plane is expected to only be able to do ~4,000nm, so that takes the ultra-long haul option off the table. That can maybe do Seattle-Tokyo, but probably not with a headwind.

The winds die down significantly at FL600.

Here is FL390 (top) versus FL600 (bottom) now over the Paris to JFK route:

Attachment:

fl390-fl600-winds.png

As you can see, the winds are essentially a non factor for a supersonic aircraft, but for the subsonics in the 30s, it is a huge factor.

Mike C.

Username Protected · **Posted:** 26 Mar 2024, 10:02

A reusable rocket can make that flight in a hour or so.....but the cost is much higher. :peace:

Username Protected · **Posted:** 26 Mar 2024, 10:07

Username Protected wrote:

I can't stand to watch videos that jump around every 1/10 of a second. If you have something to show me - SHOW ME, don't over-dramatize it with jumpy screen shots which tells me nothing. Nobody UNDER 40 looks at the world that way...

Dan

Fify.

Edit. Added the under 40 part

Username Protected · **Posted:** 26 Mar 2024, 16:35

Username Protected wrote:

A reusable rocket can make that flight in a hour or so.....but the cost is much higher. :peace:

Or we can just take a hypersonic scramjet powered vehicle and not worry about exoatmospheric flight. Can stay down in the 60,000 ft range. :peace:

Username Protected · **Posted:** 26 Mar 2024, 17:12

Username Protected wrote:

A reusable rocket can make that flight in a hour or so.....but the cost is much higher. :peace:

Or we can just take a hypersonic scramjet powered vehicle and not worry about exoatmospheric flight. Can stay down in the 60,000 ft range. :peace:

Username Protected · **Posted:** 26 Mar 2024, 22:13

Its an interesting question at what average speed a rocket is more efficient than a scramjet.

Hypersonic flight is extremely inefficient, with L/D ratios in the ~4:1 area, and somewhere above about Mach 5 the stagnation temperature is hither than any structural material can tolerate long term.

A suborbital rocket is a lot simpler.

Scramjets and hypersonic flight are fantastic - I really want them to be the answer, but I'm not sure they are

Username Protected wrote:

A reusable rocket can make that flight in a hour or so.....but the cost is much higher. :peace:

Or we can just take a hypersonic scramjet powered vehicle and not worry about exoatmospheric flight. Can stay down in the 60,000 ft range. :peace:

Username Protected · **Posted:** 26 Mar 2024, 23:06

Username Protected wrote:

the biggest technical limit to expanded Concorde use was due to sonic boom, but in the 80s/90s was there a desire to get Concorde on a domestic (e.g. JFK-LAX) route for faster transcontinental?

It wasn't just the sonic boom, Concorde was also very loud on takeoff, measured at 119.4 dB. That killed any possibility of adding routes to more airports.

Username Protected · **Posted:** 27 Mar 2024, 00:26

The only thing I ever heard that matched Concorde in volume was a British Vulcan.

Username Protected · **Posted:** 27 Mar 2024, 07:32

Username Protected wrote:

I just looked up the range of Concorde and it is listed as 3,900 nm. That's 350 nm less than what Boom is trying to do, so realistically they could fly the same routes.

Concorde would make tech stops at Shannon when needed; from what I recall in Bannister's book, they were sometimes constrained by CG and fuel burn when going westward.

Username Protected · **Posted:** 27 Mar 2024, 08:25

Username Protected wrote:

Its an interesting question at what average speed a rocket is more efficient than a scramjet.

Hypersonic flight is extremely inefficient, with L/D ratios in the ~4:1 area, and somewhere above about Mach 5 the stagnation temperature is hither than any structural material can tolerate long term.

A suborbital rocket is a lot simpler.

Scramjets and hypersonic flight are fantastic - I really want them to be the answer, but I'm not sure they are

Quote:

Or we can just take a hypersonic scramjet powered vehicle and not worry about exoatmospheric flight. Can stay down in the 60,000 ft range. :peace:

Keep in mind that despite the low L/D, with a scramjet, one does not need to carry all that oxidizer, so depending on the mission/flight profile, a scramjet powered vehicle maybe more efficient as a function of range and/or endurance.

Username Protected · **Posted:** 27 Mar 2024, 10:42

Username Protected wrote:

I just looked up the range of Concorde and it is listed as 3,900 nm. That's 350 nm less than what Boom is trying to do, so realistically they could fly the same routes.

Concorde would make tech stops at Shannon when needed; from what I recall in Bannister's book, they were sometimes constrained by CG and fuel burn when going westward.

Username Protected · **Posted:** 10 Apr 2024, 01:42

Mike - May your business grow until you need a G-V or G550 and another pilot so you can tell us about Mach 0.925 and FL510 as well as how nice it is to take a nap in the back.