Saturday, March 01, 2014

Bag Lady

We've been working somewhere south of Grande Prairie, Alberta. Big flat land, a few hours work and then company tells us where the next job is. We're supposed to fly across the Rocky Mountains from Alberta to British Columbia. There is a lot of disorganized mid level cloud, with sufficient vertical development forecast above our service ceiling that it's not appropriate to take this airplane over the cloud. There will be a high concentration of supercooled water droplets lurking in the clouds, water that has remained liquid despite being cooled below the freezing point. All it needed in order to freeze is a good jolt, like being smacked into the wing or propeller of my airplane, where it could form a deadly coating. So going through the clouds is out. Under the clouds, however, is not out of the question. There is a chance that clouds or intense rainshowers with downdrafts could block the passes, but there are actually quite a few ways through. There are also ridiculous west winds.

I set a westward course and study the charts, as I go, plotting out half a dozen possible routes, with contingency plans and turnback options. I note the GPS coordinates of the key points on each route from the map and enter them in the GPS, helping me to ensure I don't miss a turn. In the mountains it's so easy not to see the point at which you should have taken a different valley, or to think that what is actually a tiny blind canyon is the turn you needed to take. I brief my tech guy, a non-pilot crew member on the plan and adjust course slightly to head for the first planned option, near Grande Cache.

I haven't even properly entered the first valley there, when we encounter moderate turbulence, and I can see that clouds already make it challenging getting through here. I turn around, a no-brainer. Not only are the clouds an issue, but the turbulence which is uncomfortable and tiring for the people may be damaging for our electronic payload. Instead of trying the next option I planned, I abandon everything and head northwest, paralleling the mountain range. I've decided we need more fuel before we continue with what is going to be a long slow trip west with more false starts. I could get to Grande Prairie quite quickly, but with these winds I feel that it will be forever getting back, so I announce we're going to Dawson Creek for fuel. It's a fair ways north and the flight follower even asks why I am going there. I'm tell him it's to avoid coming back against the wind, but really that doesn't add up. I don't know one hundred percent why I chose that fuel stop. The mountains do get lower that way.

We fuelled up, checked the weather with some more sources and successfully made the slow, westward into-wind trek. Turbulence is nil to light and we only have to make a few turns and altitude changes to evade the clouds. While I'm en route flight services broadcasts an urgent SIGMET for severe turbulence. It covers pretty much everywhere I might have crossed south of my eventual route. A SIGMET is an update announcing severe weather that wasn't in the original forecast. I pretend that I used my elite pilot skills to deduce that the west winds would interact with the many folds of the mountains to create turbulence there and not here. But did I? How did I do that? Absent that knowledge, it was a weird decision. Was it luck? Was it some instinct that I acted on without fully communicating to myself?

They say a pilot starts out with two bags: one of luck, which starts out full, and one of experience, which starts out empty. The trick is to fill the experience bag before you run out of luck. But for this trip, I honestly don't know which bag I used.

13 comments:

Sarah said...

Wonderful post! Light aircraft flying in weather seems an artistic blend of intuition based on experience, and meteorology. And how does choice play into this? There we can get into some interesting, definitely fun solipsistic philosophy.

I mean by this "many worlds", something I've been thinking of a lot lately. For instance, slightly dark stories like this.

Anonymous said...

Clearly this was not really luck, but intuition born of experience. Good going, Aviatrix! Ben Read

Frank Ch. Eigler said...

How did the analysis/GFA charts look at the time?

Aviatrix said...

Frank: The turbulence was not on the GFA, hence the need for a SIGMET when it showed up. I can't say from memory what else was in it. Enough icing that I couldn't go over, Enough disorganized cloud that I felt I needed to plan multiple mountain routes, but not enough that I thought it was dangerous to attempt to go through. Summer mountains.

Sarah: That's great. I have read a lot of Golden Age science fiction in the Toronto area. I always find fiction more compelling when it intersects with a time or place or mindset where I've been. I love that some of the readers who commented are meeting science fiction concepts like parallel words, and aliens reconstituting humans after the death of the species, for the first time.

Frank Ch. Eigler said...

Aviatrix, it may be possible to extract those ancient GFAs/etc. from NavCanada, if you advise them that this is for flight-safety/instruction purposes. (Or you could double-pinky swear to write up these events within 24 hours of their occurrence, so they're not so ancient. :-)

saminacam said...

Enjoy your exploits as you work, would love to have had a job like your's but now way too old to learn to fly. However I enjoy the ride through your experiences and adventures. Now if you boss would only allow hitch hiker's........

majroj said...

A simple extrapolative use of Murphy's Law. We will henceforth dub it "Aviatrix's Foul Weather Corollary", to whit:

"If all else if blocked, you can predict the further progress of no-fly weather by carefully plotting the remaining route available when all else has become unavailable; this will describe the path of further fouls weather. (It is unclear if this is predictive, causative, or both)".

PS: There are three bags. The two you described, and the one the passengers use if the others are a little rocky.

majroj said...

PS: Aviation in SciFi: Read (don't watch) "Millennium".
click here

(hope that clicks)

townmouse said...

Slightly lower stakes, but being a cyclist in a UK city is a bit similar... especially the luck/experience judgement

Aviatrix said...

Frank, I recently had to order some old GFA data for a company internal safety investigation: $100, if you don't notify them within 24 hours to hold the data.

Even if I had the time to write things up same week, I wouldn't. I don't like it when people stalk us on FlightAware or the like.

Aviatrix said...

majroj: That looks cool. I like the premise.

World'sMostAnxiousPerson said...

The movie millennium has one of the best lines ever when the investigator is asked "what caused the crash?"

Best retort ever!!!

majroj said...

So what was the retort?
IMDB cites a quote from the movie (ugh) about a man and a woman riding an escalator and it stops. He says to her: " We may be stuck here or hours. Maybe we'd better get to know each other?" or words to that effect.