A380
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They know!
Reversers are only effective at high speeds and are generally stowed at aprox 80-60 kts. A380 probably dont land at higher speeds than other heavy jets but will most likely only operate the largest airports in the world. That means verry long rwys and most often wide(60m). If you are not able to stop on a 3700m+ RWY due to poor BA, there are far more severe problems to deal with, like x-wind..
And I do operate on snowy RWY´s
And I do operate on snowy RWY´s
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You did realise the 380 will touch down at 138kt, much the same speed as a 320, where the 748 will be 160+ like a 777.
Last edited by False Capture; 13th Mar 2006 at 00:30.
Lame boeing driver 
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Still, one thing's for certain - it's not exactly a looker! Reminds me of some northern birds on a night out, lots of flesh on show and wedged into a miniskirt 
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how quickly we forget...reversers out and working properly and on time for that southwest at midway would have been helpful.
If we are depending on the relatively meager stopping force of reverse thrust to make or break (should I say brake....) the landing,maybe the entire exercise should be re-thought.
Still, one thing's for certain - it's not exactly a looker! Reminds me of some northern birds on a night out, lots of flesh on show and wedged into a miniskirt
Last edited by vapilot2004; 12th Mar 2006 at 11:34.
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Originally Posted by Zeke
You did realise the 380 will touch down at 138kt, much the same speed as a 320, where the 748 will be 160+ like a 777.
They have seen the light, the 748 will now be FBW as well.
They have seen the light, the 748 will now be FBW as well.
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Most pilots act like they own the Airbus or Boeing aeroplanes they fly and some seem to have serious issues with one manufacturer or the other.
What you need as a pro pilot is a safe aeroplane to fly and away from any likes or dislikes one may have is what aeroplane will make money for your airline-period. You are hired to fly whatever is available. Make sense????
What you need as a pro pilot is a safe aeroplane to fly and away from any likes or dislikes one may have is what aeroplane will make money for your airline-period. You are hired to fly whatever is available. Make sense????
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The "new" 748 is starting to sound more and more like the 745&746 boeing offered years back, and nobody wanted to buy.
with new engines, systems and wing, it is going to cost a lot of money to develop. the cost could aproach half the cost of the A380 program and still they are offering the old airframe!!! does not make sense to me.
with new engines, systems and wing, it is going to cost a lot of money to develop. the cost could aproach half the cost of the A380 program and still they are offering the old airframe!!! does not make sense to me.
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Sqwak7700 : Does anyone know what those doors are under the inboard leading edges of the wings, close to the fuselage? I thought I had heard that the packs are in the wings, so maybe they are pack inlet doors?
left outflow doors closed, right doors opened, same for the inlets
Moving the packs to the wing and kinking the wings front spar backwards enlarges the front cargo hold significantly. This is quite important for an airplane having two decks with passengers and just one for their luggage...
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Originally Posted by Packsonflight
The "new" 748 is starting to sound more and more like the 745&746 boeing offered years back, and nobody wanted to buy.
with new engines, systems and wing, it is going to cost a lot of money to develop. the cost could aproach half the cost of the A380 program and still they are offering the old airframe!!! does not make sense to me.
with new engines, systems and wing, it is going to cost a lot of money to develop. the cost could aproach half the cost of the A380 program and still they are offering the old airframe!!! does not make sense to me.
This is the first time that a civil aircraft program is going to be launched on the back of cargo aircraft orders/requirements
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Originally Posted by False Capture
You didn't realise that the touchdown speed of a B777-200 at maximum landing weight and full flap is 138kts.
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I believe that the number of thrust reversers has a lesser effect on landing roll distance as it is increased. For a simplified model of a 4-engined aircraft under poor runway conditions (ice/snow) the reduction in landing roll length for 2 thrust reversers is approx.30-40% but increasing the number of thrust reversers from 2 to 4 results in only a further 10% reduction. If weight or other factors are critical then getting rid of two of your thrust reversers does not present such a big landing performance degrade. I believe the VC-10 was originally designed with 4 reversers but then dropped to two after it was found that in service the stopping performance of two was satisfactory.
As previously stated by another poster i think the most likely reason for selecting to keep the reversers on the inboard engines is to minimise lateral moments should one reverser fail.
As previously stated by another poster i think the most likely reason for selecting to keep the reversers on the inboard engines is to minimise lateral moments should one reverser fail.
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As previously stated by another poster i think the most likely reason for selecting to keep the reversers on the inboard engines is to minimise lateral moments should one reverser fail.[/QUOTE]
This is a valid point. From experience on the B707 and DC 8 we normally used only the inboard reversers. However we used to deploy all the four reversers but used idle reverse on the outboards and up to full reverse on the inboards. The reason for deploying all four was that in case there was an inboard reverser failure and stopping became a problem then full reverse was available on the outboards.
This is a valid point. From experience on the B707 and DC 8 we normally used only the inboard reversers. However we used to deploy all the four reversers but used idle reverse on the outboards and up to full reverse on the inboards. The reason for deploying all four was that in case there was an inboard reverser failure and stopping became a problem then full reverse was available on the outboards.
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Well, at least th 380 saved the weight of the outboard reversers, since the aircraft is overweight already.
We'll see how it does in service. Maybe it will garner a few more orders if it does well. It'll make a great hajj cattlecar. But, Airbus has sunk a lot of money into the thing. Don't they have a breakeven point of something like 350 aircraft, and so far it's way short of that in any kind of orders.
The A340s? The 777 has far outsold the 340. The A350 is coming into the niche way later than the 787.
Maybe Airbus can snuggle-up to the Arab sheiks and get some more orders.
We'll see how it does in service. Maybe it will garner a few more orders if it does well. It'll make a great hajj cattlecar. But, Airbus has sunk a lot of money into the thing. Don't they have a breakeven point of something like 350 aircraft, and so far it's way short of that in any kind of orders.
The A340s? The 777 has far outsold the 340. The A350 is coming into the niche way later than the 787.
Maybe Airbus can snuggle-up to the Arab sheiks and get some more orders.
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Packsonflight, Fropilot;
It should be very creative to come up with such development costs that would bring a cost of derivative close to cost of a new project. Ratio is much closer to 1:10.
Even if you want to be conservative you go with 20% which is really high. Assuming that some of the cost will be offset to 787 work already done it is not surprising that Boeing is trying to spread the new stuff to its current programs.
747 is the logical example since it has the good capacity and fact that they sold cargo prior to passenger does not mean it is carried by the cargo version.
it is simply question of who reacted first, in this case. Cargo a/c are seeing boom in the last few years so there is a lot more demand form them then for pax a/c.
Cheers,
It should be very creative to come up with such development costs that would bring a cost of derivative close to cost of a new project. Ratio is much closer to 1:10.
Even if you want to be conservative you go with 20% which is really high. Assuming that some of the cost will be offset to 787 work already done it is not surprising that Boeing is trying to spread the new stuff to its current programs.
747 is the logical example since it has the good capacity and fact that they sold cargo prior to passenger does not mean it is carried by the cargo version.
it is simply question of who reacted first, in this case. Cargo a/c are seeing boom in the last few years so there is a lot more demand form them then for pax a/c.
Cheers,
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Originally Posted by Fish Out of Water
Another glitch - what a great a/c. The 748 will skin it alive! The question is where are the planes going to go to when more cancel the orders! Vive la boeing
Yes, I know it only has two engines - thus making the point that if you only need it on two, only fit it on two.
Protoype VC10s had four reversers - tests proved that only two were needed so that's all the production model got.
One advantage of fitting it to the inboards is that there will be smaller yawing moments in the advent of an asymmetry.
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Originally Posted by Roadtrip
Don't they have a breakeven point of something like 350 aircraft, and so far it's way short of that in any kind of orders.
Still, Boeing fans can content themselves with the thought that, like the 300, 310, 320 and 330 it will be a flop!
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I still think the 380 should have all 4 reversers. The bean-counters let money blind them sometimes. The minimal drag effect of the 2 outboards (assuming it's accurate data) is still batter than none at all.
What's cheaper, replacing 2 outboards because of FOD, or replacing the plane after it runs off the runway and into the water?
What's cheaper, replacing 2 outboards because of FOD, or replacing the plane after it runs off the runway and into the water?
Originally Posted by Check Airman
I still think the 380 should have all 4 reversers. The bean-counters let money blind them sometimes. The minimal drag effect of the 2 outboards (assuming it's accurate data) is still batter than none at all.
What's cheaper, replacing 2 outboards because of FOD, or replacing the plane after it runs off the runway and into the water?
What's cheaper, replacing 2 outboards because of FOD, or replacing the plane after it runs off the runway and into the water?
I guarantee you that there will be less planes off the runways into ditches by leaving off the outboard reversers.
I am not sure about the CAA requiring reversers as suggested by GEnxsus. I attended a number of the early A3XX working groups (before it became the A380) for my then employer in the late 90's and the reverser issue was raised by Airbus.
As others stated Airbus preferred the no reverser option to save weight and complexity and maintenance costs plus there were so many wheels that could be braked however the airline working group recommended Airbus go with the inboard reverser option. The reason was, if I recall correctly, in one scenario put forward by Airbus the required runway length was very long thus possibly preventing a max gross weight TO on a wet/slippery runway at some airports.
As others stated Airbus preferred the no reverser option to save weight and complexity and maintenance costs plus there were so many wheels that could be braked however the airline working group recommended Airbus go with the inboard reverser option. The reason was, if I recall correctly, in one scenario put forward by Airbus the required runway length was very long thus possibly preventing a max gross weight TO on a wet/slippery runway at some airports.
