- The FAA specifies that the round-trip distance has to be more than 250 nm and has to include at least three different types of instrument approaches with reference to instruments only (i.e. no visual or contact approaches).
- We want to stay on the L-2 enroute chart and not have to drag along (or buy) a whole new set of charts for (say) Southern California, Southern Oregon, or Nevada.
- We want to maximise the amount of actual -- California's coastal summers give you a lot of chances for actual without thunderstorms or icing, so it's good practice. And I really enjoy the transition into and back out of actual.
- I want realistic traffic and routing conditions, to see what really happens once you're in the system (who do you call for a clearance at a place in the middle of nowhere? Will center vector you early for an approach instead of making you fly the full procedure? How do you cope with real pattern traffic at untowered airports out in the sticks? Etc..).
For the 250nm / three approaches bit, there's a huge choice of routes and airports here in Northern California, so there's also no problems with the second requirement. We don't have an IFR-capable GPS in the plane we'll be using (4AC), so I want something like an ILS, a VOR approach, and maybe either a localiser or LDA approach. I don't particularly want an NDB approach. And almost any decently-long trip here will satisfy the last requirement as long as we include an untowered airport somewhere away from the larger population centers.
The third requirement pretty much points to going up the coast -- the inland is usually totally clear at this time of the year (and desperately hot). Arcata (KACV) seems the obvious choice -- it's usually covered in low coastal stratus nearly all day at this time of year, and even though it's untowered, it has two ILS approaches (which should give you some idea of the likely weather without having to even look at the forecasts...). And -- conveniently -- the town of Ukiah (inland, up highway 101 from here) both has a decent localiser approach and is only a few miles out of the direct route to Arcata, a little under half way to Arcata from here. So making it an Arcata (ILS) / Ukiah (LOC) / Oakland (VOR/DME) thing seems a fairly easy decision. Especially since Arcata apparently has a decent restaurant in the main terminal, and I'm guaranteed to be pretty hungry by the time we get there....
The problem with this is that Arcata is -- by Cessna 172 standards -- a long way from here (Oakland). It's about 220 nautical miles direct, i.e. at least two hours flying over or past the Redwood Empire, the Lost Coast, the Trinity Alps, Humboldt Bay, the Mad, Russian, and Eel Rivers, and plenty of other typically evocative names (this is a wild, rugged, largely uninhabitted part of the world, especially above Mendocino). And the flip side to Arcata being under coastal stratus so much is that you need a decent alternative in case it goes below even ILS minimums (which it has several times in the last week -- I keep a close watch with DUATS). But there are no useful alternatives on the coast much this side of Oakland because of the stratus (if it's below minimums in Arcata, it's probably not much better fairly close by at Eureka or Fortuna, where the minimums are much higher; and Little River (Mendocino), down the coast, has no approach at all, and is a long way from Arcata -- and is usually socked in when Arcata is as well. And the weather only gets worse if you fly north (think Seattle)...
So you almost always need a decent inland alternate -- one that has a good chance of actually being used. Unfortunately, the nearest inland alternates with suitable approaches -- Ukiah or Redding -- are each at least 100nm from Arcata, and getting from Arcata to Redding means coping with an MEA of 11,000' to get over the Trinities. 11,000' in a 172 when the temperature at sea level is well over 40C just isn't a lot of fun (in fact, it's not far from the service ceiling when you do the density altitude calculations). So Ukiah is the obvious alternative (as well as being the planned second airport). But Ukiah's at least an hour's flying from Arcata without a headwind -- which puts us very close to the legal fuel requirements of being able to fly to Arcata, go missed, fly to Ukiah as an alternate, and still have 45 minutes reserve. Still legal and doable (4AC will theoretically do 4.5 hours on full tanks), but I have my doubts about how well I'll do after three hours continuously under the hood....
So I make two plans, based on the forecast ceiling at Arcata an hour before we depart (Ukiah will always be clear at this time of the year, so that isn't a factor). Firstly, if the forecast ceiling for our arrival time at Arcata is at least 500' higher than ILS minimums, and not forecast to get worse, we'll go straight for Arcata, refuel and eat there, then come back via Ukiah. Otherwise, if the weather looks really bad, we'll fly to Ukiah first, refuel, then head to Arcata; if we land there OK, we'll have lunch, refuel, then head back to Oaktown; otherwise, we'll go missed, head for Ukiah for fuel again (and do a different approach), and try to scrounge something to eat there (there's no on-airport cafe as there is at Arcata), then head back to Oakland. We'll amend the decision (and flight plan) in the air if Flight Watch give us a different forecast for Arcata as we get near Ukiah.
The route planning isn't hard, but I can't quite believe they'll give us the route we ask for, so I do two versions of them as well. The first looks like KOAK V107 PYE V27 FOT KACV / KACV HOCUT2.FOT V27 ENI KUKI / KUKI ENI V27 PYE V107 KOAK. These three routes are what we'll actually file (or obvious variants depending on whether we go up via Ukiah or direct), but as well as these routes I've programmed into my handheld GPS some variants that seem more likely to me based on my very limited experience. I'm prepared to jettison any of these routes as we go along -- my guess is that Center will vector us along short cuts to the approaches and possibly even enroute -- but they're fairly simple routes in any case. We shall see.
And yes, I could have done the whole Chico / Ukiah / Oakland or Fresno / Sacto / Oakland thing instead like everyone else, but where's the fun in that?