Ah. Carry on, then.
What was new about the A380 (other than bigness)? I vaguely recall that it was the first FBW widebody but that doesn’t seem right.
Most of the innovation was down in the innards & not real obvious to the traveling public.
Off the top of my head …
The interior, galleys, etc. broke a lot of new ground in weight & bulk reduction. The air conditioning & pressurization system also had a lot of new tech. At the time, the engines were the largest and most advanced ever built, although they’ve since been eclipsed by even larger & more advanced derivatives for 777-300 and A350.
A bunch of the innovation was on the factory floor, not in the delivered product. And this is where they stumbled the worst. Which produced a bunch of delay in the early deliveries which in turn really moved the payoff point out to the right.
honestly I think both cars and airplanes have followed a similar track. modern airliners don’t look all that different from the 707 and DC-8. It’s been a continual improvement in tech which has made them more efficient, economical, and (most importantly) a hell of a lot safer to operate. Modern cars aren’t all that different from a '57 Chevy, they’ve gone through continual progress making them more efficient, economical, and (most importantly) a hell of a lot safer to operate.
What are the advantages/disadvantages of having the engines on the wings like in larger airliners versus engines on the rear of the fuselage like on smaller business jets?
Thanks!
Mostly noise. The cabin is shielded from engine noise by the wing itself, plus the distance from the cabin. They also act as vortex generators and make the wing slightly more efficient, and it’s a lot easier to maintain them when they’re near ground level rather than way up. It’s also a safety benefit; an exploding engine on a wing won’t damage the fuselage the way an exploding fuselage-mounted engine could.
I once went to a lecture on the early days of flight. They played a movie taken from a Wright Flyer in Europe around 1910. The lecturer said afterward - “Notice the horizon going up and down? The Wright aircraft was dynamically unstable as a canard, the pilot was continuously adjusting the forward stabilizer up and down.”
Another large improvement, I suspect coming - what better place to convert to hydrogen fuel? The fuel is consumed in copious quantities by a limited number of craft between a limited number of major destinations. The aircraft has to accommodate a very large thermos bottle, and it’s cylindrical already.
The downside is that the fuselage may end up containing a large liquid hydrogen thermos, which should make the passengers feel good - “any future accidents involve the ‘baked Alaska’ scenario”. However, for cargo it’s an ideal concept. The other downside is that fracking and the drop in oil prices have likely put off the urgency to convert away from petroleum products.
Hydrogen has a high energy density versus conventional electric batteries, but relatively low energy density versus petroleum derivatives. You’d need something like five times the volume of hydrogen to fly the same distance as you could on AvGas. Fuel can be up to half the takeoff weight of a 747 already.
Hydrogen is a bit more energy-dense than petroleum in terms of weight, but much less dense in terms of volume.
So you gain all the disadvantages of cryogenics, need huge tanks which weigh lots, and don’t gain hardly anything in return.
The big gain is in pollution production. If carbon gets regulated enough we may have to go to hydrogen. But not before. IMO.