A completely misguided statement, Greg.
1. out of production quicker than any other Boeing jet...
I don't think so. I think the respondent above has it with the 747SP. The 757 has been in production for 22 years!
2. still has competitors that have a backorder for basically the same type of aircraft (A321).
The A321 is NOT the same type of aircraft. While the pax capacity may be similar, the 321 is designed for short-haul. the 757 was designed for trans-con. Similar sized planes, entirely different jobs.
3. is being replaced by a design that is essentially at least 15 years older....(737-900).
Two incorrect statements in one sentence. First, the 739 is an entirely new airplane. New wing, cockpit, systems, engines, everything. The only thing similar is that it has a similar fuselage design.
Next, the 739 does not replace the 757. Firstly, it also is designed for short-haul, though some airlines push the limits of its range. Next, the pax capacity doesn't match the 757. You know what the 739 competes with? The A321. Not the 757. The 739X was the proposed 752 replacement, but with the 7e7 out now, boeing may likely terminate the 739X plan, and go with a 7e7 hybrid instead.
how successful can it be judged if it's production has been terminated only two years after a derivative launched (753).
Was the DC-9 successful? By your logic, the 717 would be the same as a DC-9 because it looks the same and has a similar design. The 717 hasn't sold well, so does that mean the whole DC-9 family was a failure?
Here's a better example.
The 767 will be out of production soon. The 764, launched only a few years back, has had only two customers. Does this mean the entire 767 family is a failure? OR
that one particular design just didn't make it in today's market?
The 747SP was a failure...does that mean that the entire 747 line was a failure too?
See, bad logic. You say the 757 program was not a success, because the 753 didn't garner enough orders to keep the line open. By that logic, Boeing's entire jetliner family has been just one big failure after another.
[Edited 2004-05-12 02:11:55]