Expert: Ray Wilkinson - 9/23/2006

Question
I've seen the A380 get off the ground and fly and im very amazed. I have several questions regarding the brand new plane and its structure. What kind of stresses are applied on a plane that size on the ground and at flight? Does it have fly-by-wire technology? What is its cruising altitude? What is its max g load? Is it safer to build bigger airplanes? How many hyrdraulics systems does it have? Will a plane that large be hard to maintain? I think thats about it. Sorry i ask alot..im just very curious. Thank you.

Answer
Kevin

I like curiosity...

I had the pleasure of visiting Toulouse last September, although they wouldn't let me on the A380 (I did see the production line and got close to them, though). However, I managed to get a look around inside the display aircraft at Farnborough this year.

When you refer to 'stresses' I guess you mean 'loads', as they're different. The aim of the designers is to get the STRESSES as high as possible within material limits, because that means the materials are being used efficently, saving weight. The LOADS vary a great deal, but of course the wing has to generate a little more lift than the weight of the aircraft, which is around 560 tonnes maximum. It's a big wing, though, so there's plenty of material in there. The g limits for this aircraft are 2.5 up and -1 down, which is the standard requirement for large airliners. However, there are also short-term loads associated with gusts and landing shocks that may be a little higher than this (not much higher).

Yes, it does have FBW technology, togehter with a stack of computers to manage flight. The pilot uses a small sidestick controller to send demands to the computers, which then send the correct signals out to the control surfaces. However, the control surfaces are simpler than a 747, which has a complex mixer for inboard and outboard ailerons and spoilers.

It cruises at around 35000-38000 feet, depending on its weight, and has a ceiling of 43000 feet.

It is safe to build big planes, but the danger with all planes is flying them ;-) The A380 should be one of the safest aircraft generally, as it is less affected by gusts and turbulence. However, there is always a greater risk of accident with any new aircraft, especially with human error. It still has a loose nut on the controls!, and new aircraft mean new maintenance procedures. However, flying one A380 gives only half the chance of an accident compared to 2 smaller aircraft, once the system is mature. You just kill twice as many people if you bang it into something!

There are only two hydraulic systems on the A380, compared to 4 on the 747, but the flying controls also use 2 electrical systems, giving 4 overall. This is unique, and makes the aircraft simpler and safer. For this reason,and the fact that it uses new technology, the A380 is relatively easy to maintain.

When the 747 first flew, people said it was just too big, and would be dangerous, yet it has one of the best safety records around. I'm sure the A380 will enjoy a similar record. BTW, you have more chance being killed driving to the airport than on the flight.

I love it!

Regards

Ray