(Tacoma, WA) the sun comes up this morning for the last full day of Pacific Northwesting. Tomorrow’s Peoplenomics report will be posted this evening – and will be a discussion of the charts, Greece, and so on. But, in passing, I notice the world hasn’t ended…just as some of reprobate codger suggested would be the case.
One of our friends up here asked about the flight homed.
Because of expected weather in the Rockies. this is quite the planning game because there are three big “humps” and a lot of high country between here and low altitudes down along the bottom of the Midwest.
Wednesday morning, we will leave the hotel at 4:45. Arrive at the airport at 5 AM. Load the airplane, and while I top off fuel, Elaine will drop the rental car at the local transient aircraft emporium.
About 5:30 after a thorough check of all systems including inspect mirrors and fuel testing, we will wind ‘er up and take off.
We’ll “shoot the gap” between the north of the JBLM (McChord Field) airspace to the south and the floor of the SeaTac low approach to the north where permissible flight level drops to just 1,800 feet. By staying a bit south, we can bump along at 3,000 and below. More altitude means more options.
The first part of the morning, about 6 AM will be climbing up to 7,500 feet and over Snoqualmie Pass. Sun will be in my eyes, so flight following and a new hat are ready.
Around 6:30. we will have passed over Ellensburg, WA and will be turned Northeast and coming up on Ephrata where Boeing does a lot of flight test certifications. Shortly thererafter, Spokane International will pass by/.
The first tactical obstacle is Mullan Pass Idaho. The top of the radio beacon there is at about 6,073 feet and we’ve been watching the weather there like a hawk for a week, or longer.
Current weathers forecast may be found here.
Since we should pass there about 8 AM, we would expect (as of last night’s read) 30% cloud cover and a layer of clouds above. We can estimate about 3..5 degrees per thousand feet in this area. So with the Dew Point at 52 and the air temp at 66, we will see a spread of 14-degrees.
Divide the 14 by 3.5 and we would expect the cloud bases to be about 4,000 feet. But remember when flight planning that cloud heights are above terrain.
So when we get 6,073 of elevation and about 4,000 of clouds, we will be comfortably clear of clouds. To be sure, Thursday does look a little better, but two problems come up if we delay until then.
First is that on Thursday, while the skies will be clear, there is also a drop in air pressure. Airplanes like high pressure air. Easier to fly in and makes the effective altitude density lower. The drop isn’t much, but again, it’s something to think about.
We UPS’ed two big boxes of clothes back to the ranch which will reduce our payload by a lot (try 68 pounds!) and that directly translates into higher or faster, or both if needed.
By the time we fly into Missoula, we should be at 12,000 high clouds and nothing down low.
Thursday morning, we will get up early again (the column may be a bit wonky, depending on how closely we can pull off the schedule. Thursday forming was forecast to be clear and nearly idea except for the low barometric pressure. Again, all subject to change and we have live weather/ADS-B in so we can work around thunderstorms if needed.
This gets us to the second Big Bump on the way home: Going over the pass outside of Butte, Montana. Again,.