What is the probability that a plane by Boeing or Airbus will encounter a flight problem in its first flight that would be noticeable to the general public?
Huh. I'm on my phone, so I can't view the site, but I saw a 787 go over my head at about 7:30 this morning as I left home in west Seattle, which is just northwest of Boeing field.
Strange that they're saying it's 10am. Then again, maybe I was mistaken. But full-size jets that look just like 787s don't land at boeing field every day.
Quite possible it was - makes sense to me that they'd make private test flights before the first public one. Good to reduce the chance of any serious issues getting widespread publicity.
first flight is huge event for every airliner, media and spotters were camping out next to Paine Field days before it. I'm pretty sure it would have been spotted if it was flying before it was supposed to ;)
In the design highlights, it has a diagram of the materials used in each section of the plane. The pointy part at the back is the only part made of titanium in the whole plane, does anyone have any idea why that would be?
My guess is that it's the exhaust for the Auxiliary Power Unit [1]. The APU is essentially a small gas turbine generator, so the exhaust temperature is approximately 1000°C. This is way above the melting temperature of composites, and even aluminum.
This site [2] has a very good discussion about the Boeing 737 APU and APU exhaust (which they call an "Educator").
Meh, it looks the same as any other airliner. Where're the radical designs, a la Concorde (delta), Comet (engines in wings) etc etc? Boeing's just making tweaks to a basic design that's been around since the 1960s.
Neither approach (delta wings, in-wing-engine) worked out well.
Delta wings are great in supersonic flight, but not so in shorter distances and for takeoff and landing. The Concorde is a beautiful machine, but not a terribly practical one. I miss it, BTW.
Comet-style in-wing engines cannot use silent and efficient turbofan designs and would need fat wings to accommodate the engines, increasing drag. The position of the engine exhaust also limits the efficiency of the wing and the effectiveness of the control surfaces.
Radical designs require more engineering than any airplane manufacturer can afford right now. It's not like airlines will dump all their 747s and 380s (and all other 7x7s and A3xxs) just because there is a more efficient plane rolling out of the factory line. Airplanes are horribly expensive and have a very long service life.
The radical design is under the skin. OK, in and under the skin. "Its materials (by weight) are: 50% composite, 20% aluminum, 15% titanium, 10% steel, 5% other."
http://en.wikipedia.org/wiki/787_Dreamliner#Features
The Concorde had a delta wing so it could fly supersonically with acceptable range (fuel economy vs. tankage). The trade-off for that speed was horrible fuel economy and poor takeoff and landing characteristics (extremely high drag - it had to use afterburners to get airborne).
WRT the Comet, airframers don't put engines in wings because they are a bugger to service there.
A big part of the reason for hanging the engines is actually because it means you can make the wings less robust.
If you have in-wing engines they generally have to be near the root (where the wing connects to the fuselage) because engines are large, wings taper and wings shouldn't be too fat. Under wing engines can be hung wherever you like, within reason.
If you simplify things a bit you can think of a wing as a cantilever which supports half the weight of the plane, balanced by an equal upwards force spread out along the whole wing.
By shifting weight towards the middle of the wing, as you can do by moving an engine outboard, some of your weight is no longer at the end of the lever but instead is closer (on average) to where the upwards force is being applied. This decreases the load you have to design for even though the weight remains the same.
Engines are not just "hanged wherever one likes". There's an optimal point along the wing where airflow entering the engine will provide optimal performance, and it's not near the wing root.
It's pretty much a given that anything you read about aerodynamics on an Internet forum will be a massive generalization made to illustrate a simplified version of the point.
Look at the rubbish people keep on repeating about the reasons for inherent instability for a prime example!
Your comment is a good example of how not to communicate effectively.
You pose a "question" in such a condescending and dismissive tone that leaves no room for fallibility in your assumptions or your knowledge, no reasonable answer other than "hurr, of course you're right and Boeing is teh dumbs" is possible without introducing conflict. If instead of taking a confrontational tone you took an inquisitive, deprecatory route of acknowledging that you lack perfect knowledge of aerospace design and are curious exactly why the 787 is considered so radical a design, given the seeming lack of outward differences of appearance from existing planes, you would perhaps start an engaging, informative discussion.
Boeing shopped the Sonic Cruiser concept extensively to the airlines. The premise of the Sonic Cruiser was a 15-20% increase in speed (Mach 0.95-0.98) without increasing the fuel burn rate.
The airlines said "no thanks, give us 15-20% lower fuel burn rate at the current speed" (Mach 0.85). The 787 was the result... the form follows the function.
You think Boeing should design planes based on how cool they look? Myself, I'd rather that any plane I travelled in was designed by competent auronautical engineers.
look closer! you don't have to know anything about composite structure etc. just take a thoughtful look and you'll understand that it's not your usual airliner (although it is very similar in many ways)!
I'm sure they have plenty of supersonic airliner designs lying around, but I'm afraid you're not prepared to pay for a ticket to fly on one ;)
Radical designs are in manufacturing (ie, massive use of composites) rather than aerodynamics.
And that "basic design" has had a lot of efficiencies made to it in the last 50 years. I'd be highly surprised if there were any potential design changes left that could make a visible difference. (Ignoring things like lifting bodies that would drastically change the passenger experience.)
While it would be awesome to see a canard design, which would be the most logical choice given fuel costs and safety, the odds of a struggling airline manufacturer introducing something so risky are extremely low.
The Dreamliner cabin was included in the Cooper-Hewitt's 2006 Design Triennial. It looked pretty nice, but only a handful of airlines have any taste when it comes to their interiors.
It's ugly. Just look at its nose from the side - it's evilish and ugly. The most beautiful thing Boeing has ever designed is 747. Or compare it to A380.
"Chicago-based Boeing now is struggling to avoid missed deadlines and their resulting costs in dollars and reputation. Airbus, for example, is running an embarrassing 22 months behind on production of its new A380 super-jumbo jet, its flagship product. Those delays caused management shake-ups, canceled orders and costly payments to customers."
Boeing and the world gave Airbus a lot of grief for the schedule slippage of the A380. Boeing has subsequently gotten its share of grief for 787 slips. Interestingly, I've seen comments holding the A380 up as a success vs. the 787 by people who have already forgotten the A380 schedule slips.
First flight is a bit more than 2 years late according to Wikipedia.
However that's not bad for a project this complicated, being built in so many different places. I know more than a few aerospace engineers who would be delighted to deliver their projects only 2 years late.
For the frequent fliers here I'd recommend this wing load testing video http://www.youtube.com/watch?v=pe9PVaFGl3o - it's from the 777 program but it's pretty interesting.
Personally I think the A380 will be more successful due to the increase in the number of Chinese residents able to afford flights and their population density making big city to big city routes a larger component of demand. However there's clearly space in the market for both as they have different roles.
"However there's clearly space in the market for both as they have different roles."
Agreed, they serve very different markets in many ways. In addition, I see the A380 and 787 as radically different approaches to the same problem: fuel economy. The A380 approach is to use a lot of fuel but to haul as many bodies as possible. By amortizing the fuel over more bodies, it gives good fuel economy per body.
The 787 uses a very efficient aerodynamic design and reduced weight to use less fuel per aircraft, thus amortizing less fuel over the (fewer) bodies it hauls.
The weakness of the A380 approach is load factor: if the plane isn't full, it will use more fuel per body.
The weakness of the 787 approach is that they must hit their weight targets to achieve all of their projected fuel savings. They are currently overweight compared to their wishes (some of the first flight delays were caused by a need to reinforce parts - that means more weight).
The A380 also gets cost savings from sharing the landing fees, taxes and slot costs between more passengers.
That's more applicable for busy airports though - I'd bet that a lot of the traffic at LHR and ATL will switch over to A380s, while it's not as necessary for places like IAH.
