American Airlines management is continuing to pressurise the major airframers to come up with a new generation narrowbody aircraft by around 2016 but concedes that such an outcome is looking increasingly unlikely.
The carrier, which still operates some 260 Boeing MD-80s, is now likely to see most or all of those replaced by Boeing 737s unless their retirement rate slows significantly.
But American executive VP operations Bob Reding is among those urging Airbus and Boeing to make early decisions on their programmes.
Reding says: "I understand the 737 is selling very well and the same with the Airbus product line. They are really overwhelmed with new products too and focused on delivering the aircraft into the marketplace. So I fully appreciate that they have to do that and sometimes there are some challenges in doing that.
"We on the other hand really need a replacement narrowbody and will continue to look at all alternatives that give us good economics and emissions and noise.
"I understand their perspective but they must not put blinders on and they must be 10 years ahead because it will take that long to introduce into the marketplace."
Reding says American's fleet plan stretches out 20 years and he adds: "We continue to reassess particularly as the timeframe gets shorter and shorter. We have 260 MD-80s currently flying in 2009. Even if I replace at a 40-rate - and it will be 39 in 2010 - then you are looking at six or seven years. So 2015-2016 is where the OEMS are saying we have an airframe/engine combination, and now we will get experience with the geared turbofan on non-Boeing/Airbus aircraft [with the Bombardier CSeries]."
American senior VP planning Henry Joyner, presses home the message, adding: "There is a tension because of the decisions of the engine-makers and airframers and airlines, who are in different parts of the world and are in different places on their replacement timing.
"But we and some others in the US have much bigger near-term replacement needs. The MD-80s came in here quickly in the 1980s and the tyranny of age means we have to replace them.
"Our vision still says that our replacement needs are very big and the fact that you have to do that in a prudent way means we have to think about it to have continuity to it and build in flexibility."
"We can choose to fly MD-80s longer while we wait on the next generation aircraft or financing, through our relationship with Boeing. But the second part is when is the next generation narrowbody going to be here?"
The widebody fleet development presents fewer difficulties until the time comes to address the top end of the fleet. Meanwhile, although the introduction of the Boeing 787 is still contingent on reaching an acceptable deal with the pilots, Reding says: "We hope we will find a way to be able to competitively operate our 787s and execute the options.
"We have high confidence that we will be able to do that. I have every expectation that we will find common ground."
Joyner adds: "The 787s are first and foremost 767 replacements and the 777 will play a role for a very long time to come. Then we have to understand what the biggest size variant of the A350/787 will look like."
Finally there is the question of an aircraft in the 70+ seat category, over which American is in difficult negotiations with its pilots on the scope clause which currently restricts their operation.
The current deal allows American Eagle to operate another 23 of the 25 Bombardier CRJ700s that it has on option, and Reding says: "[The pilots'] proposal is pretty restrictive, which is 'no' to scope. We are just trying to be competitive. We always look to have the greater flexibility, but we also recognise that it is a bargaining issue."
And despite suggestions from the pilots that the airline wants to introduce Embraer E-170s, Joyner notes: "I put a high value on fleet simplicity."