SchorschStill from a purist point of view, you don’t want wing tip rails. If you have a wing that requires wing tip missiles to control wind flutter, the problem is in the wing, your wing is not well designed then. You have to return to the drawing board and redesign the wing. You want things as clean as possible for both aerodynamics and RCS. You never want a design that has hacks from the start.
ECM capability can be embedded inside the wing or fuselage.
I disagree.
A wing is a compromise. Withstanding high G-loads and being of low structural weight is something completely different, for example.
As an example: when the F-18 flies without wing tip AIM-9 the drag index actually increases!
So, from a purist point of view many things might look good that are actually not.
SchorschSlightly (well) OT, but why didnt over-wing pylons ever become poppular? As far as I know only the Jags and Lightenings used them. Too mouch drag, or was there something else?
– negative effects on aerodynamics
– cumbersome loading of the station
– difficult to jettison
– interference with spoilers and flaperons
– problem with payload use (cannot drop)
SchorschOr they can cause extreme vibrations. That’s the reason why the F-16 is almost exclusively seen with AMRAAM on the tips these days.
Depending on airspeed, Mach number, G-load and other variables I guess they may also serve as damper. Negative I think is the aerodynamic loads created with pressure point forward of the 25% line, creating a torsion moment.
But depends on the aircraft, I could think that the F-18 has an issue with that (due to its rather flexible wings).
SchorschAs a design feature, you really should move away from them when it comes to future designs. They add to the radar signature, add drag to the wings and add flexing to the outer wing.
Generally wing tip missiles have favorable effects: They act as mini wing let and reduce lift-induced drag. Additionally, it is the method of minimum drag to place a missile.
Disadvantage is surely the added weight, that especially at high G-loads causes noticeable wing bending. But an AIM-9 weights about 90kg, add another 10-20kg for the pylon. Depending on the design, the weight can be actually helpful as anti flutter balance.
Winglets don’t make sense on low aspect ratio supersonic aircraft.
SchorschNot just that industry. I see the same elsewhere. Technically skilled project managers who had an understanding of how much work was actually needed to do things have gone, to be replaced by MBAs & spouters of management-speak who think that if something is on a plan, it has been achieved. Progress chasers are now called project managers, & no longer understand what they should be doing (i.e. monitoring, chasing up, facilitating), but imagine that if they produce Gantt charts & Powerpoint presentations, they’ve done their job. Vital skills & corporate memory are thrown away without a moments thought, on the assumption that you can always buy them in when wanted. 😡
That is what I read with horror in the Airbus presentation that “leaked” to the general public recently: the manufacturers cooperating with Boeing had in some cases only limited experience, and needed to hire lots of staff, sometimes very specialized people.
Now, it is natural that new things need new people. But how could someone at Boeing make the decision, to pass large proportions of work to subcontractors and not precisely monitoring progress, or at least make the schedule more flexible to account for problems?
I looks like the people that decided about that not really grasped the difference between aircraft and coffee machines.
The problems that led to the A380 issues are now widely known: problems in communication between German and French sites, issues with software within the company, insufficient resources for cabin R&D.
SchorschWith all “Schadenfreude” some people might feel (and I confess I feel it, too), such disaster on a prestigious main line program should ring some alarm bells. It looks like neither Airbus nor Boeing are able to properly plan and execute a program. If subcontractors failed to deliver doesn’t count as excuse, Boeing is responsible for its product.
Strange is that 10/20/30 years before the situation actually seemed better. Now, with Six Sigma, MS Project and lots of MBAs in the process, the whole things seem to stall regularly.
Can it be that the industry got stupid?
SchorschFirst flight delayed until second quarter 2009. Sigh. Why oh why did they have to call it dreamliner…
It flies in our dreams, but nowhere else.
SchorschRemember that there also are actual USD for promised jets. Depending on the contract terms, the airlines that cancel might not see their deposits back, while Boeing sells off the whitetails.
The American launch customer of 787, the recently bankrupt Primaris, cancelled their 787 orders long time ago. Did they get their deposits back?
Yes, but a cancellation based on delays or performance shortcomings will most likely be without penalty. I guess airlines have terms allowing them to cancel if Boeing fails to fulfill the contract (with some margin of course).
That is BTW one of the risks Boeing has now: basically all of its customers will see delays, and so all have the option to cancel. Boeing basically has to renegotiate the terms of the contract, this time with a competitor in the background.
SchorschI have heard that the customer airliners of Boeing 2707 actually paid some deposits which they didn´t get back…
There are refundable and not refundable deposits. It is no federal law and depends on the type of contract. Generally, the better and more powerful the customer, the higher the chance he has favorable conditions (like refundable or very small deposits, compensation for delays, right to defer or change orders, right to change definition of the aircraft …).
Given the magnitude of some orders plus the relative smallness of the customers, it is dubious if every customer paid real deposits (it is also unlikely that Emirates paid 25% deposit for each A380 they ordered).
SchorschEven though the first one hasn’t been delivered to the dealer’s showroom yet? C’mon folks. This is new, cutting edge technology! Did anyone (anywhere, especially here) honestly think there wouldn’t be troubles with it? The thing hasn’t even flown and you’re ready to call it a failure? And, oh by the way, it’s already the most successful new airliner EVER, in HISTORY!?!
C’mon already. Let’s have a little reality party, shall we?
Sheesh..
JH
Yes and no.
What exactly did Boeing sell?
Boeing sold a promise. Airlines believed this promise as Boeing is the benchmark in commercial jet aviation.
Now, the question is: did Boeing promise too much?
They did in terms of schedule. OK, that is accepted.
But do they get the performance they promised? That is currently not the question, but will be the more interesting one. How is Dreamliner supposed to reduce seat mile costs?
The real question is, how much margin Boeing had in its promises. Airframers always promise things, and normally a sound business case should have margin to prevent running into problems. Normally commercial programs do, as they are state-of-the-art (military programs are often not, so normally afford no margin). We can only hope that the total lack of conservatism that befall the senior Boeing management did not also take effect in this area. If so, we could truly see some cancellations. But the truth in this issue will not be told before ~mid to end 2009, when first flight is accomplished, early envelope opening, loads flight tests and handling qualities are through and LN003 and LN004 do performance tests. Then we should also see how much of the weight gain can be compensated, and can sense the pain when we hear news on B787-9 schedule (the later it comes, the bigger the issues are).
So, just because airlines ordered it, it is not by default fulfilling the promises.
I don’t doubt the B787 looks like a commercial success so far, but do not mix “promised USD for pormised jet” with “actual USD for actual jet”. To this date the B787 has made no single USD of profit for Boeing.
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According to WSJ the initial deliveries are deferred to summer 2010. Although no Boeing source is given, WSJ was quite right the last times it announced such schedule changes.
SchorschAs djcross said, but this is an example of what the U.S. defense infrastructure can expect under Obama.
Putin must be smiling.
Yes, because for a short time frame the relative gap of capability is not widening but stays merely constant. Fortunate for Putin is further, that the thing called “microprocessor” is unknown to the majority of Russians defense equipment.
So they cannot get obsolete!
Capability-wise the USAF could do nothing for 10 years and still be ahead of the competition by margin.
Apart from that, now that oil prices break down and bubbles burst, real economic power is what counts. That is basically:
(People * Money * Education)^Ideas
Following that equation Obama can start spending money again at the end of his term.
SchorschYou guys are funny. You are starting to see China as the next big boogie man yet continue to buy whole container ships worth of goods worth trillions of dollars from them. :confused: Who supports their economy more than yourself?
We fuel their economy, make the Elbe river deeper (so more DVD player fit on one ship), battle the evil pirates off the Somali coast so the PS3 is here on Christmas.
At the same time China is living of our wallets. Let’s put it this way: if we stop all trade we are running short of DVD players and they run short of money. It is a bit more complex though as many Western products have Chinese content these days (yes, even those fancy SUVs from Slovakia).
Long story short: China is already so deeply in the Western trade system, that no one can afford a real war. Period.
Being a major trading partner does not exactly mean security from an armed conflict. When Nazi Germany invaded the Soviet Union in 1941, the leading panzer units were passing Soviet trains carrying grain into Germany, in fact, the USSR was one of Germanys main trading partners prior to Barbarossa.
While Hitler actually wanted to get control over all the resources he got delivered, and that in a very short time (basically 6 to 8 weeks). Also, “main trading partner” of the German Reich in 1941 was not that difficult to become, as Germany was either cut off from other nations or seized them.
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I think most possible opposing air forces nowadays employ tactics and doctrine based originally on Russia Air Force. Different maybe with Iran (US influence), while you may ask if they have any “American” heritage left after nearly 30 years.
SchorschI’ll try to find a link but SpI is reporting through anonymous sources of 1 month delay on first flight (now october) due to complexity of integration . EIS is still claimed to be the same .
Here we stand, 15 month later, and can say: another month delay to first flight.
Delivery 2nd half of 2010.
Average delay of first 250(!) aircraft can be estimated somewhere between 2 and 3 years.
Looks like the B787 is now at eye level with the A380.
Remember that originally Boeing forecasted 120 new Dreamliners in 2010.
I now bet a box of beer on a second assembly line, however, it looks like the partners are not really in the mood of additional investment.
SchorschAs following aircraft will be late, too, due to resources being focussed on LN001 (and Boeing generally does not have so many resources in Seattle), the flight test program will need 10 to 12 month if everything procedes rather well. First deliveries are to be expected in second quarter ’09. I guess Boeing will not deliver more than 50 aircraft in ’09, in general 100 delivery slots or ~12-14 billion USD are lost.
I would expect consequences for B747-8 program, too.
Hey, I was right.
SchorschOnce again, a flight test of an all-new aircraft needs minimum 10 to 12 month if all 6 test aircraft flight-worthy in short succession. That is if only few problems occur.
The idea of a 9-month test campaign was big bullock from the start.
Airbus – the other noticeable manufacturer of medium and large passenger jets – assumes 18 month test periods.
EDIT:
Moderator says nothing of the sort, you rascal!
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