Modularity seems like a useful step forward IF the value of the improved turnaround time is high enough to justify it.
Expansion of ground facilities on existing airports ranges from difficult to near impossible, with major cost inevitably attached. This might be where the desired financial leverage is greatest, but for the problem that the airport operators don't pay for the aircraft themselves, so increasing the capital costs for air carriers to reduce them for airport operators represents an unwelcome (and impractical) transfer of wealth between fundamentally different types of organization -- and away from spending it on the next generation of Pilots .
Unlike, say, railroad carriages, the pax and freight modules for aerial use will need to tolerate some unforgiving mechanical and operational constraints relating to the precision and security of fit (to avoid destruction by undamped vibrations), fatigue life (ditto), well-mated coefficients of thermal expansion (for repeated enviro changes of (100 C in a matter of minutes), etc. To endure the frequent insults of ground handling they will have to be tough in certain spots and inexpensively repairable all over.
If one looks at the distribution of manufacturing cost in an airframe, the engines, avionics, controls, and wiring are high cost items one does not want to repeat. The backbone structure of gear and fuselage and wings, and the ever-so-carefully contoured and attached skins are also fairly expensive. It's best to keep these elements together as a unit, because disrupting the mechanical and electrical integrity of the aircraft structures is surely a path to increasing trouble as the airframe ages, and probably is also more costly to build that way at the onset because the cost of reliable interface hardware (mechanical, electrical, plumbing, etc connectors) is humbling.
So, what comes into focus from this pile of assumptions and constraints is a modular airframe system with something that looks a bit like the C5A for the flying part, loading up cargo modules that resemble passenger busses for the revenue.
Question is, HOW do the economies justify the added expense?
Last edited by arcniz; 1st Aug 2002 at 16:51.