OPNLguy From , joined Dec 1969, posts, RR:
Reply 2, posted (15 years 2 months 3 weeks 4 days 12 hours ago) and read 2010 times:
I looked at the weather from MDW yesterday, and as it was clear all day, it sure doesn't appear to be a weather diversion.
Most likely, it was some type of mechanical problem (hydraulic system failure, engine shutdown, unsafe gear indication, etc.) that was incompatabile with MDW's rather short runways. Some 737-200 mechanical problems require the use flaps-15 for landings, and that setting requires faster landings speeds, and thus more runway, which MDW doesn't have.
Another possibility is that (assuming Vanguard even serves ORD) was that a MDW flight "flag-stopped" ORD to pick-up passengers from another Vanguard flight that had mechanical problems. It does happen, but again, that assumes that in this case that Vanguard serves ORD.