It’s always been hard to make the case fo re-engining commercial airliners.  The government does it because their aircraft see far fewer cycles and are therefore used for a much longer duration. After 20 years, the government may well have another 20 years of service life left in the aircraft and re-engining makes sense.

I can’t honestly think of a re-engine program on a commercial airliner that was a financial success and that’s why both Boeing and Airbus are backing away from this idea.  Admittedly, Airbus isn’t exactly backing away yet but it is growing quieter and quieter about the subject.

Boeing has openly discussed building a new design as a 737 replacement and several airlines have openly expressed interest in the idea.  It is the obvious pathway to go forward on but the timeline is what is giving manufacturers fits.

Boeing and Airbus want to offer a quantum leap in efficiency with new aircraft and they sense that they don’t have the right technologies to make that happen on a small, single aisle aircraft yet.   It is going to be very difficult if not impossible to offer 30%+ gains in efficiency on the next airliner.  There has been too much learned in the art of making an airliner efficient now and that means the gains will be incrementally smaller as time goes forward. 

The engines are close enough to make that call.  With a firm build committment, engine makers could make an engine that would be a leap ahead of the rest in time for first flight.  It would require a big investment and hard work to make that happen but it is possible at this point.  Of course, the numbers of aircraft that would use these engines make the business case for that investment so the likely road block on engine development going into high gear resides with Boeing and Airbus. 

We already know quite a bit about wings and there isn’t much to be gained there.  Use of new materials could help with weight and that will help a bit but huge gains from new wing designs are likely a thing of the past.

Fuselages are one area that everyone speculatese about.  We see the gains to be had from CFRP (carbon fibre reinforced plastic) in the 787 project and assume we can get those in a 737 project.   Well, with the existing technology, those gains aren’t quite there.  That solution doesn’t “scale down” to a single aisle, 150 to 190 seat aircraft very well.  In addition, Boeing and its partners haven’t quite gotten their production to scale “up” to a level that would support high volume production that a 737 replacement would require from day one.

There are newer technologies emerging that may be satisfying for such a project’s fuselage but we’re not quite there yet and this is where the delay is coming from, I think.   I don’t think that Boeing and Airbus quite have a handle on whether or not the technologies are viable enough to pursue for production and I think that is requiring more study and thought before a committment.   The fuselage (and interiors) are the last place to make big gains and the “efficiency” needed is going to have to be won from that area. 

At the end of the day, it isn’t engines that is driving these decisions, it’s fuselages and their weight.  The manufacturers want to offer everything they can because this is an aircraft they’ll likely be building for decades and you want to have what people want when you make that kind of committment.

Filed under: Airline Fleets by ajax