It doesn't talk about the sonic booms, which was the main problem with Concorde (and the fees resulting from it)
Boom (YC W16) – Supersonic Passenger Airplanes
161–170 of 488 posts
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#162Pretty amazing that materials science (lighter, carbon-fiber aircraft; hotter, more efficient/powerful turbines) has made this economic. Concorde never was. NYC-LON seems like the one market where this enables something fundamentally new (well, Concorde did); single-day business trips between two major business centers which were otherwise a full day apart. Transpacific flights would be nice, too, but cutting an alre…
> single-day business trips between two major business centers which were otherwise a full day apart. Was the LON-NYC flight time the problem, though? I think that to go door-to-door right now you spend 50% of the time in the air and the other 50% on the ground. With this company, you'll be spending 3.5 hours in the air and 8 hours getting to and from airports and through security.
Vastly expidited security lines have been available for purchase for a while. It's not even that expensive. Pre, Global Entry, etc.
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#163As tangent, instead of focusing on NYC to London, a Mach 2.2 travel actually will make travel from Americas to Asia more comfortable. US to India and US to China routes benefit the most, and perhaps where people will be interested in paying top-dollar vs. Europe.
I believe the problem with those was always the sonic boom created by flying at > 1 Mach. It shattered windows on the ground. Could be wrong tho
Mythbusters tested the sonic boom myth. An F/A-18 flew ridiculously low (200 ft AGL) before the window cracked with a supersonic flyby.
A sonic boom from a fighter jet above around 10,000 ft usually doesn't break any windows. In one case, a General flew a F-22 in supercruise just off the Florida coast at over 50,000 ft and nobody "reported" the boom until the media story ended up on the news.
For low level supersonic flight, what typically happens is the pressure wave created either overflexes the window pane, or the window frame isn't strong enough and the glass falls out.
For a larger aircraft like the Concorde flying above 40,000 ft they wont break windows. People complain about the noise.
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#164Earlier quoted context omitted.
> single-day business trips between two major business centers which were otherwise a full day apart. Was the LON-NYC flight time the problem, though? I think that to go door-to-door right now you spend 50% of the time in the air and the other 50% on the ground. With this company, you'll be spending 3.5 hours in the air and 8 hours getting to and from airports and through security.
I would think that the people that can afford this have Uber helicopter service to/from the airport and all the line skipping extras paid for already. Not sure it is really 8 hours to and from airports/security.
At one point in New York, it was pretty routine for first class passengers on Pan Am to take a helicopter from JFK to the Pan Am building, which had a helipad on the roof. The service may even have been included as part of the fare. (This service was discontinued after an accident though, at least for a time, I believe there was still service to a helipad next to the East River.)
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#165Pretty amazing that materials science (lighter, carbon-fiber aircraft; hotter, more efficient/powerful turbines) has made this economic. Concorde never was. NYC-LON seems like the one market where this enables something fundamentally new (well, Concorde did); single-day business trips between two major business centers which were otherwise a full day apart. Transpacific flights would be nice, too, but cutting an alre…
The issue with it is that supersonic flight (due to noise) is only allowed over non-populated areas so a business jet variant is less useful unless you spend most of your time flying over the ocean (and not coast-to-coast for instance).
> The issue with it is that supersonic flight (due to noise)
Actually it's with the technology currently in use with supersonic flight that there is this large amount of noise. It's technically possible to reach supersonic without the boom and NASA is currently working on it with some contractors. I hope it pans out well; I would love to be able to fly between BWI and SFO in 2 hours.
http://www.sciencealert.com/nasa-is-building-a-jet-that-brea...
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#166Pretty amazing that materials science (lighter, carbon-fiber aircraft; hotter, more efficient/powerful turbines) has made this economic. Concorde never was. NYC-LON seems like the one market where this enables something fundamentally new (well, Concorde did); single-day business trips between two major business centers which were otherwise a full day apart. Transpacific flights would be nice, too, but cutting an alre…
> has made this economic. That remains to be seen. They don't even have an engine yet, so this is still firmly in the "we'll see" category.
Seriously. People here are way underestimating the costs to develop and certify a major commercial airframe, especially across the multiple regulatory regimes inherent to international flight. You're probably talking about on the order of a billion dollars even if you're playing it cheap. If you want to start re-engineering components instead of buying off the shelf, that number will go uphill rapidly.
This is not a field that's amenable to "disruption". Cutting corners means that dozens of people plummet to their deaths, not to mention the abrupt end of your airline as their families sue you into oblivion. If you try to play this like Uber and flout the regulations, the FAA and EAA will ground and impound your gear so fast your head will spin, and rightly so. Even a test aircraft is a gigantic tank full of explosive fuel hurtling through the air on a couple flimsy wings. When things go wrong people die, and the FAA does not play games.
Airlines are an incredibly low-margin business in the best case, and supersonic airliners in particular are a very niche market and have immense operating expenses (to purchase and maintain the airplane and to slake its immense thirst for fuel). The Concorde's operators could never make it profitable.
Never say never, but this just seems like fantasy. Supersonic airliners are a problem domain that has been pored over by engineers for decades, six engineers are not going to pull a rabbit out of a hat and solve all the technical problems, then get it certified, then start an airline. Each of those is a problem that requires a national-scale corporation to handle.
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#167Earlier quoted context omitted.
You may not have minded your entire house shaking, but most would probably quickly grow to resent such unnecessary disruption. It's a good way to kick everyone in a large region out of their zone. If this was a constant occurrence, work may quickly cease, or become greatly diminished.
Sure, but these were 1980s-era fighter/trainer jets flying at probably 1000 ft., and it only shook the whole house when they flew pretty close. Other times one might only hear the boom when outside. I think a passenger craft of recent design of recent materials, flying at 40k ft. could do much better, even before routing to avoid populated areas. I don't think anyone, even those who live on ranches in the Dakotas, re…
I could have sworn the Concorde was still glass-breaking loud at 40,000. Reardless, NASA is working on getting rid of the sonic boom http://www.sciencealert.com/nasa-is-building-a-jet-that-brea...
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#168Earlier quoted context omitted.
Speed only matters for the cruise part of the flight. The first and last 45 mins, plus airport time are not different. The slowdown portion of a Mach 2.2 flight will be even longer. (edit: maybe not much on the slow-down: see Concorde data via link below)
They likely accelerate much faster, and slowing down from mach 2.2 is also fast.
Data from an actual Concorde flight shows slowdown-to-land of around 45 mins, so around the same as a regular flight.
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#169Earlier quoted context omitted.
If they could make it quiet enough to go over land, transcontinental US flights would be great; LA/NY in 2.5 hours would likely have a pretty high demand. [edit] As someone who flies LA/DC fairly regularly I do have to mention my favorite record of the SR-71 doing that flight in under 65 minutes.
I doubt the cost would be low enough to support demand. Transonic (approximately Mach 0.80 - 1.2) flight uses significantly more fuel than subsonic flight does. Business jets like the Gulfstream G550 burn more fuel at M0.9 than regional Boeing 717(MD-95) at M0.75 with 4 times more passengers. The F-22 Raptor can supercruise at M1.6, with half the range compared to cruise at M0.85 similar to other fighters. If Boom ca…
The Boeing 747 has one of the lowest cost/passenger mile (CPM) of any aircraft, and cruises at Mach 0.85. Different aircraft have been optimized for different speeds, and while it is true that a supersonic aircraft will likely have a higher fuel cost than a comparable subsonic aircraft, the difference may not be as large as we currently think.
There has never been a supersonic passenger aircraft built with modern turbofan engines.
Re: Boom (YC W16) – Supersonic Passenger Airplanes
#170Earlier quoted context omitted.
If they could make it quiet enough to go over land, transcontinental US flights would be great; LA/NY in 2.5 hours would likely have a pretty high demand. [edit] As someone who flies LA/DC fairly regularly I do have to mention my favorite record of the SR-71 doing that flight in under 65 minutes.
Yes- due to the time change, heading east from coast to coast is practically a day away as well.
Yeah, flying West to East, more speed wouldn't be a great help. I lose 2 hours getting there, 3 hours in time zones, an hour upon arrival. So red-eyes are the way to go. But if the reverse could be improved, that'd be a big help. I could fly West in the morning, get there the same time as I left, do a days business, and take the red-eye home. All in a day.