I’m perusing a story on CNN about a vehicle that can fly at Mach 6, or more than 4,500 miles/hr. While that seems like a crazy speed, my response is, what took so long?
I think about that almost every time I board a plane these days. It took the same six or so hours to fly across the US 20 years ago that it does now. I know that the cockpits have changed significantly, and other improvements have been made, but flight times haven’t budged. And yes, I’m aware of the whole Concorde thing, and it’s really a shame that the program had to be cancelled.
Back to the story on CNN. Does it mean that we’re actually going to see faster commercial airplanes? Not likely, or at least not anytime soon. The Pentagon’s X-51A Waverider hypersonic flight test vehicle is just that -- a test vehicle.
Later today, the 25-foot-long vehicle will be dropped off of the wing of a converted B-52 bomber off the California coast. It will attempt to fly for five minutes at Mach 6. Remember, Orville and Wilbur’s first flight only last a few seconds. According to the story, “The technology could eventually bring missiles or airplanes to the other side of the planet in minutes instead of hours.”
If successful, the test plane will simply fade into the Pacific Ocean and not be recovered. The Air Force claims that it’s prohibitively expensive to try to recover the planes. The cost of the program was not disclosed.
What's getting in the way of speed? Is it just cost or is it, like usual, government regulation? Even in its heyday, the Concorde was only allowed to fly at its advertised speed over open ocean. I think it was "illegal" for them to fly a New York to LA route at those speeds.
Yes, Rich, I also saw that CNN article, andI too was surprised. I was under the (perhaps mistaken) impression that speeds exceeding 600 mph would cause sonic booms that would be unacceptable to residents. And thus, there was a wall against faster speeds. Yet at 4,500 mph, why no sonic booms?
I believe you are correct about the sonic booms. They had to be over the ocean before going to hyperspeed. The test run by the Pentagon today was also over the ocean.
OK, that explains a lot. When I read the article -- which didn't address sonic booms -- I wondered whether the small size of the craft negated the sonic booms. Maybe they just take the boom over the ocean and move on.
Exceeding 660 miles per hour above sea level creates the boom. Once an aircraft breaks the sound barrier, it creats an extended boom that is heard by anyone who is near the supersonic craft. So it isn't just one single boom -- it's continuous as long as the craft is exceeding the the sound barrier, even if those on the ground experience it as a single boom. So, on a flight from L.A. to N.Y that exceeds the sound barrier, everyone on the ground between the two cities would experience the window-shaking (and sometimes window-breaking) boom.
NASA, however, is looking at strategies for taking the boom out of high speed aircraft:
From my understanding, faster speed = high fuel consumption. During the days of the Concorde, high fuel consumption wasn't seen as a problem. Today, consumers and the market are more focused on things that, at least, appear to be good for the environment.
@Jon Titus--I, too, have questions about acceleration. Would this require pressure suits for passengers, or perhaps some sort of encapsulated seat that would react to the G-forces?
A transcontinental flight takes about five hours, wheels up to wheels down. Five hours to go 3000 miles is not too shabby, and there's no shock wave to be of concern.
I am constantly dismayed at the amount of time it takes, when using air travel, that is not actually in the air.
The airlines tell you to arrive 75 to 90 minutes before your departure, and you could spend up to 45 minutes waiting for your luggage at the other end. Tack on an additional 20 minutes or so taxiing to and from the gate. Call it 2-3/4 hours going effectively ZERO miles per hour.
Your average speed for your transcontinental flight isn't 600 miles per hour, it's 387, just two thirds the real speed of the plane.
Think about it. Sure the speed is the same as it was 40 years ago. The passenger loading process hasn't changed one bit for almost a century! It seems insane to load everyone single file through ONE door! The time a passenger jet spends on the ground not moving people is wasted revenue to an airline. An airline should be able to cut the turnaround time by at least 40% if more than one door is used. Sometimes that's done on jumbos, but it's still from ONE SIDE ONLY!
A widebody has two aisles. Why not load from both sides of the plane? And why not load from the rear as well? A jumbo could effectively be loaded from a four doors on two aisles.
Even a single aisle aircraft could be loaded from front and back. I've seen a single aisle aircraft unloaded a few times in this manner at the San Jose airport in California (Alaska Air), and that gets the plane empty fast.
Time is money. Cut the load / unload time, and make millions.
Jack, in this case there is a reason for the regulation. The sonic boom will break windows and cause lots of other problems when flown over land, unless you are at a very high altitude (think SR-71). The military also has to be careful when doing that. Frankly, supersonic speed is great for catching up to someone or getting away from someone (I am thinking military jets). On the other hand, you can't shoot or turn very tightly at supersonic speed. For transport it would be great, but the cost is very high. Those safety and other regulations are important in this case.
We looked at a number of sources to determine this year's greenest cars, from KBB to automotive trade magazines to environmental organizations. These 14 cars emerged as being great at either stretching fuel or reducing carbon footprint.
Researchers at MIT and Sandia National Labs have observed a reaction in lithium-air batteries that could help improve the design of these cells for electric vehicles and other applications.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 3
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
8 
