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Decision making and turbulence

Pulling the pin!

I went out to the Cremona area this morning, intending to practice precautionary and forced approaches. Last time I went to practice them, it was not only busy in the practice area but there was also a small forest fire in the quadrant in which I was established, and couldn’t descend low enough to practice the procedures. As soon as I got close to 5000 feet the smoke smell became quite intense.  Since the ground in the area is around 4300′, I wanted to descend to 4800′ (I can only descend to 500′ feet above ground when flying by myself) to practice. But as soon as I hit 5000 it was already too much. That coupled with heavy traffic and a Bell helicopter that was returning flying at an altitude similar to the one I was using kept me busy. Eventually, I ran out of time and had to head back, and though I did one of each precautionary and forced, they weren’t quite that good.

Forest Fire near Cremona

So this morning I went to try again. So everything went great this morning and the forecast was good.  The airport was extremely busy at 10 am: the circuit was full of planes and there was a backlog of planes in the run-up bay, and the poor controller was asking planes that have lined up at the hold short line “okay, who is next?”  and lined up another plane behind me to try and get as many off the ground as possible.  He received his take-off clearance when I was airborne, and at 800′ feet above ground, I turned around and could see him behind me. Expeditious!

Once I was handed off to outer tower at Springbank I got a report that a pilot in a 172 had experienced severe turbulence between 6000 and 6500, 10 NM north of Cochrane above highway 22, exactly where I was flying.  I thought for a second and decided to keep going, feeling slightly disturbed.

Once I got handed off to Calgary Terminal I received another such report and warning.  I thought about it quickly “this might really suck if I go in there” …  I mean, moderate, okay, pretty bad since you have changes in attitude and altitude, but you can still control the plane positively at all times. Severe causes large, abrupt changes in altitude and attitude and large fluctuations in indicated airspeed, and the aircraft is momentarily impossible to control. Is it worth the risk?

I decided no, it’s not. I don’t know who is making the report and what their perception of severe turbulence is, so it could be someone over-reacting. But I didn’t think it was worth chancing it, and asked Terminal if I could turn around.  I was disappointed I couldn’t get out and do my procedure, but I would rather feel that than complete terror at being stuck in a small aircraft in those conditions.  This information was very good to know and I am thankful the controllers passed it on!

Here are what the different categories of turbulence are and how they affect your aircraft:

Turbulence Aircraft Reaction
Light Turbulence that momentarily causes slight, erratic changes in altitude and/or attitude.
Moderate Turbulence that causes changes in altitude and/or attitude, but with the aircraft remaining in positive control at all times. It usually causes variations in indicated airspeed.
Severe Turbulence that causes large, abrupt changes in altitude and/or attitude. It usually causes large variations in indicated airspeed. Aircraft may be momentarily out of control
Extreme Turbulence in which the aircraft is violently tossed about and is practically impossible to control. It may cause structural damage.

Ultimately, you are the pilot in command when flying solo and you have the authority to make these decisions, judgement calls, using your experience, skill and as well your risk tolerance. I am pretty conservative and would not put myself in that situation at this point.

When I landed and after I arrived back home I checked the PIREPs again, and sure enough, there was yet another report, this one at a lower altitude and even closer to Springbank.  And there you go there was something to it, and I think I did the right thing. Posted here. Can you decode it?

CYBW 330015 /TM 2047 /FL055 /TP RV7 /TB MDT-SEV 055-070 /RM TURB APRX 5 NM TO 15 NM NW CYBW