(David B. Cole) wrote
Approximately 30 miles NW of the airport we were lowered
to 2500. It was from there on out that I experienced the worst
turbulence I had ever experienced in a small plane. My head hit the
ceiling at least four times. I kept the airspeed below Va as the
plane essentially did what it wanted. We rolled 25-30 degrees
uncommanded on several occasions and once the sudden movement of the
yoke nearly took my wrist with it.

This was the first time I could say that I was somewhat nervous in
turbulence. The bigger boys going into Newark were reporting moderate
turbulence and before switching to the tower my instructor reported
that we had severe turbulence. Yet he remained calm and somehow I
still managed to keep altitude to within 100 feet, with the exception
of a few excursions down 150 feet.

Just FYI - if you were managing to hold altitude within 100 ft most of
the time, and the worst deviation was 150 ft, this was not severe
turbulence. Severe turbulence is when unsecured objects are flying
about the cabin, the airplane is often uncontrollable, etc. What you
experienced was moderate turbulence. As a rough rule of thumb, if you
are hitting your head on the ceiling, that's moderate turbulence.
Anything less is light. When you can't keep your chart on your lap or
the airplane on course and altitude, that's severe.

We were vectored for LOC Rwy 22 approach at CDW. I tuned and ID'ed
the localizer, but was so whipped that I forgot to set the OBS head
from GPS to Nav. When I finally figured this out, thanks to my
instructor, the needle was centered and I still had a 30 degree
intercept. To make a long story even longer, I eventually got on
course, although we were still getting smacked around fairly hard.
The surface winds were from 260 at 12 kts, so we circled to Rwy 27,
although I made the mistake of descending to the straight-in minimums.

The major hazard of moderate turbulence is fatigue, and fatigue is a
recipe for pilot error. You made several, but of course that's what
training is all about. I'm glat to see that your instructor point
this out for you, but I'm going to offer you a slightly different
perspective.

It's all very well to say that when you recognize fatigue you should
land, but the reality is you are eventually going to fly IFR fatigued,
just like you have driven in bad weather fatigued. You will sit in
some pilot lounge for several hours, being safety conscious and
waiting for the really bad weather to pass. You will then decide that
the weather isn't that bad anymore, and you're not that tired, and it
will all be OK. Then you will find yourself being beaten up, tired,
and needing to shoot an approach to get home - possibly with some
equipment failure. Of course you could always decide to only fly for
fun, and never fly when there's any pressure to be anywhere at any
particular time - but then what's the point of the instrument rating?
So assuming you are actually going to use the rating and stay current,
you need to be prepared for the day you will have to use it when you
are not at your best - without making the mistakes you did on that
last approach. How do you get to that point? Practice, man,
practice.

Michael