This is an extremely open and broad comment that is open to everyone but in my mind I don't think that the aviation world is developing and advancing the way it should. It is almost like manufactuers are holding back or hiding the great developments of the times.
In the mid 70's the 747sp first flew. In the mid 80's the 747-400 first flew. Both of these airplanes have quite similar flying characteristics and stats. Now obviously many updates were in the 400 and obviously it is a totally different airplane in numerous aspects over the SP but from a pilot's view they are almost the same. The 400 only has about 500-1000 mile longer range. How is this such a vast improvement over the SP. The 400 was supposed to be quite superior to anything on the market and yet besides looks and weights the 400 isn't much different. Now the 400 can carry more due to its higher takeoff weight and difference in size but as far as differences in range the 400 doesn't seem like it is the best that Boeing could of done. Same with the 400ER. It is allowed a higher takeoff weight so that it can hold more fuel and thus the range is extended. Could of Boeing done better I would think so. Now obviously I could be wrong but from my perspective what they did was not a failure but just doesn't seem like the best they have to offer.
The same for the Concorde. I am definitly not saying that the Concorde was a failure or not the best because I believe that it was the best that the world could offer. But how could this amazing design and concept just disappear with no replacement waiting to take over when it retired. The Concorde was made with 1960's technology. Please don't tell me that the world hasn't advanced since then. Why hasn't Boeing or Airbus or somebody made a supersonic airliner? Most people will say that the market is not right or no one will buy them but airlines will spend billions on planes that fly at the same speeds and distances as one another. Where has that pioneering spirit gone in the aviation world. If you make it I can guarantee that someone will buy it. The world needs that new plane. The 747 of the 21st century. Who will make that plane, who knows?
The 767 family is not that different from one another. Same with the 777 family except for the LR but that has yet to prove itself. It seems that if you by one 737 you have bought them all. They all fly alike but one has newer gauges and luxury seats. Who cares. If one can fly at 70,000ft and has a range of 4500 miles then maybe you have an advancement, not if instead of going from New York to Denver now you can go to LA. That does not deserve a rollout ceremony or new designation. This does not just apply to Boeing but Airbus to. Most new planes just have a 500 mile increase in range and a new interior. Take the A340-600 and 500. The 500 can carry 67 less passengers 1000 miles further. It is like the the 600 and 500 are the same plane except one is shorter and lighter and thus can go farther. Is that really an amazing plane. That would be like me striping down a van so that it is lighter and thus it has better performance. This obviously works but seems like the easy way out and that not enough effort is being made to push the envelope of design.
This might offend some but to me it is true that the aviation world seems to have slowed in technology or at least at the commercial level. It is like the business world won't go forward just so that they can keep making replacements for the older planes. They make new designs not much different than the old ones just so they can replace the old ones without the fear of airlines not replacing their fleets due to a superior design.Feel free to comment on my post, but think about what developments have came about and their impact, not that much recently. The only two major designs in my mind have been the 777 and the A380. One obviously for its sheer size and the other for making two engines as powerful and efficent as two. Let me know what you think.