It looks like Southwest Airlines may have fallen into a growth trap: "Among all other influences, the desire to grow has perhaps the most perverse effect on strategy" - M.E. Porter<p>Southwest competes on cost, and this cost position hinges in large part on the rapid turnaround of aircraft. Rapid turnaround lowers Southwest's equipment and labor costs; its aircraft, pilots, and flight attendants are "doing work" for longer periods of time each day (rather than sitting idle on the ground).<p>A variety of activities contribute to Southwest's ability to rapidly turnaround aircraft, but some of the key activities include:<p>- Southwest's culture, where everyone pitches in to turnaround aircraft<p>- Using a single type of aircraft (737s), enabling simplified service and maintenance<p>- The point to point route structure, avoiding the issue of synching the schedules of hub and spoke aircraft<p>- Operating at less congested airports to avoid traffic delays<p>From my vantage point, it seems the AirTran acquisition threatens each of these activities:<p>- Integrating AirTran's distinct culture with Southwest's<p>- Expanding beyond 737s to operate 717s<p>- Divergence from the point to point structure to a hub and spoke<p>- Entry into congested airports, such as Hartsfield-Jackson (ATL), which was ranked #20 in 2010 for on-time departure performance by the Bureau of Transportation Statistics<p>In short, this acquisition is problematic from a strategic standpoint and appears to threaten the basis of Southwest's cost advantage.