Monday, December 01, 2008

Endless Supply of North Winds

Next morning there is no respite on the winds, but the snow has swept through and left Alberta clear. It's threatening to drop the visibility here now, but that's something I can work around. We get a cab back to the airport in early morning darkness. There is no one at the FBO, but they have fuelled the airplane as requested, tied it down and chocked it against the wind. Loaded to the gills, it's still jumping around like a kite. I put my passenger on board and close the door while I do the walkaround with a flashlight, checking especially to make sure that nothing has has blown into the engine cowlings or other important apertures during the night. I untie the ropes, but leave the chocks behind the wheels so it doesn't go anywhere while I'm starting the engines. It's that windy.

The saving grace is that the wind is now blowing straight down the runway, so that all its force will go to shortening my take-off roll and none to trying to push me sideways off the runway. The only challenge is getting to the runway. I taxi very slowly, turning my ailerons at each turn so as to spoil the lift on the into-wind wing. It's a skill I learned as I first learned to taxi in a light little two-place airplane. I don't always do it in this airplane, but today it is needed. I wonder if there is a size of airplane at which you can just leave the ailerons neutral through taxi in any conditions. I wonder if Airbus 380 pilots turn their ailerons for wind anyway, because that's what you do.

I position at the very end of the runway, because that's what you do, complete my pre-takeoff checks and set power. It's an amusingly short take-off roll. I estimate I had seventy percent of rotation speed before I even released the brakes, and there's very little rolling resistance to acceleration at low groundspeed. I climb, but not too high, because this wind is forecast to be even stronger at higher altitudes. My initial heading is due west, because the area of the worst turbulence and of low visibility and snow is approaching from the north. I've chosen a point based on forecasts at which I should be able to head northwest and be clear of the weather.

It works like a dream. I give thanks aloud for modern weather forecasting technology. The passenger is unimpressed and I resolve to shut up about that sort of thing in future. Progress is unbelievably slow. I file a PIREP reporting minimal turbulence and sixty-five knots on the nose. Just as forecast. I watch the scenery go by very slowly. I file another PIREP because I know there will be a lot of people looking at weather reports and forecasts today, wondering if they should venture out.

The frequency on which one files a PIREP up here is 126.7, the same frequency as one makes air-to-air position reports for the benefit of other traffic. Another pilot on frequency recognizes my voice and checks to confirm that it's me. It turns out to be the fueller from one of the places I've stopped recently. He's working on his commercial pilot licence and is on his way back home after a cross-country trip. He too was grounded yesterday. He's headed in the same direction as I am. I shudder to think what his ground speed might be. He's in a C172. He might get to his destination faster by driving. I respect him for being up here at all, with obviously limited experience.

Total flight time for the two legs of the trip, not including time spent on the ground at my planned fuel stop, was six hours, thirty minutes. And I took a more direct route than the 4h 07 southeastbound flight. I once had a student ask, "so where does all that wind COME FROM? Isn't the north going to run out of air?" There's actually a circulation, such that there is a polar high, constantly subsiding and being resupplied by air that circles aloft at the subpolar low.

4 comments:

david said...

Aviatrix, my favorite thing about your blog is that you see everything as a challenge, not a problem. It inspires me to think differently about my own flying.

I once faced headwinds that strong on the nose in a Cherokee (NW winter winds), dropping my groundspeed into the 60s and changing a 2-hour flight into a 4-hour flight. I did drop down to driving speed, but hey, I had to get the plane home from Boston one way or another.

Anonymous said...

I fly an airplane with a max. takeoff weight of a little over 65000 lbs, and we don't position the ailerons/roll spoilers for wind during taxi (not just me- it just isn't done). Also, we frequently depart from intersections, rather than using the entire runway (with customized performance for each departure prepared by dispatch). With more than about 10-15 knots of xwind component for the takeoff roll, they will be positioned into the wind, but with only partial deflection to prevent excessive spoiler deployment (we're trying not to 'spoil' much lift during takeoff, obviously).

Flying Europe said...

Same thing here. During taxi, the flight control lock is in place. During t/o you correct a little though. Thanks for the nice post.

bam said...

little over 49t MTOW here.
we use ailerons during taxi.