Originally Posted by
expert7700
I've read the steps that happen in near real-time when a station like BWI closes and traffic is diverted to several other airports. Truly amazing that a group on the ground can handle this in real-time.
OPLNguy, I'm curious if the Southwest always includes "alternate+45min" airport fuel in their planning. It seems the FAA allows (in 135.223) carriers to skip alternate fuel if weather is forcast good 1hr before and after scheduled arrival time?
It seems like you'd need to land with 1.5 of fuel remaining on some routes to satisfy this, depending on how far it is to an alternate airport. In some cases the closest/best might be a round trip back to the departure airport more than 45 minutes away.
FAR 135.223 wouldn't apply to a Part 121 carrier, and the appropriate reg for us is 121.619,. FAR 135.223 also includes the things that are covered in 121.639. FAR 121.619 is commonly refered to as the "1-2-3" rule. The default is that one needs to list an alternate for the destination, but if the weather is above 2000-3 (That's a 2,000 foot cloud ceiling and 3sm visibility) +/- 1 hour of a flight's ETA, one can technically forgo the alternate. It's not as cut-and-dried as all that, since one still has to consider the items in the other reg I mentioned, namely 121.647, and we have additional internal considerations.
If one is planning no alternate, we're still carrying holding and/or contingency fuel, in addition to the required 45-min reserve, so if Mother Nature throws us a curve with the weather once a flight is in the air, we can still name an alternate. It might be a close-in "offline" airport (one we don't fly into), but they're still viable alternates. For example we frequently use IAH for HOU, but seldom do we have to actually divert there.