I figure if I want to maintain the moral high ground with respect to my slogan, "Where nothing is off topic," I figure I should write about something other than politics now and again. So here's an interesting bit o trivia about Air Force One.
You may have read in the news that Barack Obama's last flight aboard Air Force 1 had to divert from Palm Springs to March Air Force Base because of bad weather. Actually, it wasn't Air Force One -- it's only called that if the president is on board, and at that point Obama was no longer president. So the flight was called SAM44: Special Air Mission (or something like that) for the 44th president. But it was the same aircraft that is used to transport the president.
But that's not the interesting part.
The interesting part is that PSP was reporting ceilings of 900 feet at the time SAM44 had to divert. They had to divert because they were flying the VOR/GPS-B approach which has minimum around 2000 feet, not even close to being able to make it in with a 900 foot ceiling. But there are two other approaches, the RNAV (RNP) Y RWY 31L approach and the RNAV (RNP) Z RWY 13R approach (which has one of the funkiest approach paths I have ever seen). Both of these have minimums of 734 feet, well below the reported 900 foot ceiling. Furthermore, the RNAV Z 13R approach would have aligned them with the prevailing winds at the time and allowed them to land straight in instead of circling.
So why didn't they fly that approach?
It's because the aircraft doesn't have the right kind of GPS.
Think about that: the airplane that carries the president of the United States is supposed to be chock-full of the latest super-secret military technology. It's supposed to be able to survive a nuclear attack with enough capability remaining to issue the order for a counterattack. But it can't land at Palm Springs if the ceiling is below 2000 feet because it lacks a GPS unit that you can put in a civilian plane for about $5000.
That's kind of mind boggling, but it turns out it's actually not so uncommon. Retrofitting older airplanes with newer avionics is really hard, sometimes impossible. Still, you'd think that for the president's plane they'd get it figured out somehow.