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Oh, Your Private Jet Is Just Subsonic?
zerogeewhiz writes "Found this article here at The Sydney Morning Herald . It seems that Bill and his mates need to move a bit quicker these days and for a cool US$80 million, you too can overtake the Concorde on a dash to Harrods for dinner.
As described in the article, the main complaint about Concorde is that it can only fly supersonic over water and creates those nasty sonic booms that punch holes in buildings and shatter windows. They reckon they can get rid of these waves by making the plane longer. These are gonna be fast but hideous. 737-700s are suddenly passe as a corporate jet..."
The original Telegraph article is much longer and talks about the economics of production, and other developments in the fast-plane industry.
I seem to remember Bill flew in Coach class until his well-known appearance made that a non-starter, so I don't think Bill's that great a candidate.
.80 and you can get up to Mac .93 on a Cessna Citation X. So it might not be worth the extra money to go supersonic unless you're doubling or tripling the speed of sound (as you do with the Concorde). The long and thin design also might not be as comfortable as the Gulfstream.
Larry Ellison, on the other hand, will buy the first one available, the microsecond it comes up. And Warren Buffet will buy a few for his Executive Jet fleet.
You can charter a Gulfstream V for $8,500 per flight hour, which means a transcontinental flight would cost about $ 38,000. Skyjet.com reports round trip charters on an IV at $60,000 for the same flight. Ownership is, of course, mind-bendingly expensive; a Gulfstream V is in the $45 million range, and the Citation X (fastest bizjet around, but less luxurious and with half the passenger capacity) is $18m. You also need a full-time pilot and copilot, together with very expensive maintenance, all of which amounts to an overhead of tens of thousands of dollars a month.
After being squeezed in like a sausage in the USAIR tourist class cabin, I can very much see the appeal of having your own jet. I'm sure that if I was as rich as Bill or Larry, a jet would be one of the first things I'd get. Bear in mind that the Gulfstream has a top speed of Mach
The aforementioned Citation X is about 100 knots (or 25%) faster than a typical commercial flight, and you can arrive at a general aviation airport about 15 minutes before takeoff. Since general aviation airports are most likely a lot closer to you than commercial ones, you can save literally hours by just getting there in ten minutes and taking off almost immediately instead of taking an hour to get to the airport and taking off an hour later. This speed and flexibility is the jet's main advantage compared to, say, simply buying a first-class ticket on a scheduled airline.
In other words, if your time is worth a lot, you probably want a jet. And if you can fill it to capacity, it's not that much more expensive than first-class airfare. A Gulfstream IV can fit 19 people; first-class airfare coast to coast is about $3,068 for a non-stop flight. So if you're paying $60,000 for your round trip flight, you're paying $3,157 per person instead of $ 3,068 for first class; not too shabby.
(I spent quite a bit of time flying with a friend who owned a small propeller plane, so I can attest first-hand to the ease and convenience of general aviation airports. Sadly, I have yet to fly on a private jet).
D
The government takes a dim view of sonic booms over the US land mass.
i tl e_14/14cfr91_00.html
http://www.access.gpo.gov/nara/cfr/cfrhtml_00/T
91.817 Civil aircraft sonic boom.
(a) No person may operate a civil aircraft in the United States at a true flight Mach number greater than 1 except in compliance with conditions and limitations in an authorization to exceed Mach 1 issued to the operator under appendix B of this part.
(b) In addition, no person may operate a civil aircraft for which the maximum operating limit speed MM0 exceeds a Mach number of 1, to or from an airport in the United States, unless --
(1) Information available to the flight crew includes flight limitations that ensure that flights entering or leaving the United States will not cause a sonic boom to reach the surface within the United States; and
(2) The operator complies with the flight limitations prescribed in paragraph (b)(1) of this section or complies with conditions and limitations in an authorization to exceed Mach 1 issued under appendix B of this part. (Approved by the Office of Management and Budget under control number 2120-0005)
It's Linux, damnit! Pay no attention to renaming attempts by self-aggrandizing blowhards.
Short lesson on high-speed aerodynamics follows:
:-)...
* The "intensity" (read: energy) of a boom is proportional (roughly) to the speed of the aircraft and the angle of attack of the wing or fuselage.
* To lower the energy wasted in a sonic boom, you can either go slower (neah...) or lower the angle of attack. For a wing, this is kinda easy: either sweep it back (notice a how much further back a fighter's wings are than an airliner's?) or make it thinner (so that the cross-sectional angle of attack, so to speak, is less).
* For a fuselage it gets trickier: a fighter need only fit one person, and you can extend the nose long enough to lower the leading angle of attack. And you don't care about traling shocks or really shocks at all, because you're in a fighter. You're supposed to terrify people.
* But for a commercial jet, you will have to take care of both ends of the fuselage, and the only way is to make them longer, and have them taper out smoother. Look at the Concorde's absurdly long nose (so long, it has to be pivoted so that the pilots can see the runway at take-offs and landings) and its thin tail. Now, you know why they're there.
Supersonic business jets have always been possible. However, new, more efficient engines and cheaper high performance materials are only now making them affordable (well, relatively at least
This article had an annoying lack of details. These stories have more information on why this is being explored now:
aviationnow
and
savannahmorningnews
People's lives are at stake with the equipment in an aircraft, so you don't want to upgrade simply to make everything look cool.
But you still want to upgrade. Reducing pilot stress is one main factor in improving safety and those cockpit's from the 60's and 70's suck. You should see the cockpit of the infamous Comet, pity I don't have a link... Modern avionics are just as reliable as old dials, but pilots don't like the feel of not having control. I used to fly airplanes (ok, Piper Cherokees) and if I could have a dial showing me tire temperature or rudder angle I'd surely want one, yet usefulness would be highly questionable.
The Concorde is a weird beast, and most things about that airplane are are different. Let me give you two examples:
Cruise flight in a modern airliner is boring. You just supervise a few systems and sip your coffee (or actually sleep, as many pilots acknowledge. Some other things they won't acknowledge...). Not in a Concorde. That airplane burns lots of fuel considering its size, which means weight and CG change considerably during a trip. The flight engineer has to monitor the fuel in the many tanks and transfer it from here to there to maintain the CG where it's supposed to be, which also depends on how the plane is loaded in each trip. Lots of calculations, lots of monitoring. Also, the lighter the airplane, the highest it will fly at optimum fuel consumption. In normal jet aviation you're given a flight level and during the trip you are tipically allowed to switch to a higher level two or three times. The Concorde flies high, above 40.000 ft, where airspace is not controlled, so the pilot can gradually increase altitude during the trip. Actually one *has* to, if consumption is to be kept to the minimum. These are two tasks that should be handled by computers in my opinion, drawing attention from the crew only if something goes out of pre-established parameters.