Every student has heard the admonition: don't fly the
airplane with any frost on the wings. At least we all hope
that message has been heard. Frost reduces lift and
increases drag. Even a thin layer as smooth as a fine
sandpaper grit can be detrimental. Here's my story.I was
visiting friends in Murphy, North Carolina several years
back. It's a gorgeous area, nestled in a valley in the Great
Smokey Mountains. The airport is wedged between two high
ridges with mountains a few miles off each end, directly on
the centerline. It's one of those airports where you spiral
for altitude if your ride lacks a healthy climb performance.
I had stayed over Christmas, and arrived at the
Andrews-Murphy airport around 9 a.m. on the 26th for my
flight back to Atlanta. My Cessna 182 had been on preheat
all night so it was ready to go except for a significant
layer of frost across the tops of anything metal - the
entire airplane. Although the morning sky was fully bright,
the sun had not yet climbed above the southeastern
mountains. There was no way I was going to get that frost
off until the sun came into view and melted it.
By 10 a.m. the sun had finally crested and I turned the
airplane tail first in its direction. This put the most
sunlight across the tops of the wings and tail.
Within 30 minutes, the outer half of the wings and all of
the tail surface was covered in slush. An icey job, but I
was able to sling it off with my bare hand. That only left
frost on the inboard halves of the wings. With some
repositioning of the aircraft, I was able melt the crust
from the trailing edges and flaps. That left just a crystal
covering on the area above the fuel tanks. Because the avgas
inside was still very cold, the frost above stubbornly clung
to life. I surveyed the runway.
The launch pad at Andrews-Murphy runs roughly east-west
and is 5,500 feet long. A mountain stands up off the
departure end, oh, something less than four miles out, I
think. Not a problem for 182. Possibly a problem for one
frosted up, however. I looked at the airplane.
My Skylane, a trusted mount for several years, climbs
very well. I operate it out of a 2,300 foot grass strip
without problems. I could take off and land three times on a
mile long stretch of paved runway. Under normal conditions,
that is. I looked at the airport's main building.
On the roof was a bright piece of blue plastic tarp.
Probably a roof repair in progress. It would be easy to see
on a takeoff roll and marked the approximate halfway mark on
the runway. I made my decision to depart.
On the runway, with the tail hanging out over the
threshold lights, I put in the throttle and held the brakes.
It took about two seconds to develop full power. As my feet
lifted from the pedals, I quickly eyed that blue tarp. If I
didn't have this airplane in the air by that point, I would
abort the takeoff.
The Skylane trundled down the pavement, picking up speed.
I watched the needle rotate. Sixty knots, seventy knots.
Seventy-five knots. The airplane was still on the ground. I
might be able to pull it up into ground effect, but what a
huge problem I'd have if I got there with no climb ability.
That mountain was dead ahead. And there was the tarp, abeam
my right wingtip. A glance at the airspeed indicator showed
us passing eighty knots and still on the ground. I
immediately pulled the power and lightly pumped the brakes.
A Cessna going eighty knots on the ground will sure roll
a lot further than I thought. As the runway end raced toward
me, I stood on the brakes harder. Just enough pressure so
that the tires didn't skid. The airplane came to a stop on
the departure end numbers. No smoking rubber, no swerving
off the centerline, but it did eat up the entire length of
runway.
By the time I taxied back and shut the engine down, the
sun was higher. In less than fifteen minutes, the frost over
the fuel tanks had turned to liquid and dripped away on its
own to the rear.
Now this little experiment was conducted safely and it
did have a good ending. It graphically showed the effects of
even a small amount of frost when maximum performance is
required. But it also showed me that I could be a victim of
go-itis, even if I rationalized carefully controlled
conditions and a firm backup plan.
I suppose I shouldn't have been surprised about the
effects of the frost. A couple of years earlier I had
experienced a much closer call.
Much of the southeast is covered with several species of
pine trees. The one thing these all have in common is that
they expel pollen in the spring in huge amounts. Giant
wafting clouds of yellow blow from these trees like the
water slung from a Labrador Retriever after a swim. It's a
huge mess and it's everywhere.
I have since built a hangar, but at that time, my
airplane was tied down on the ramp. I was off on a trip down
to the Kennedy Space Center to do some research and there
was my airplane, covered with sticky yellow pollen. I
remember looking it over and figured, "Eh, that'll blow
off." Not.
I put in the power at the end of our grass runway. The
manifold pressure came up and I released. Using the
short-soft technique that is common to grass pilots, I got
the airplane up into ground effect. And there it stayed.
Scarcely a thousand feet in front of me, a group of
offending pine trees stood erect, branches locked in a show
of solidarity. I could almost see them sneering in defiance
as I screamed toward them. The stall horn blared as I eased
up the nose.
I'll tell you now that I did clear those trees, but not
by much. It reminded me of a story I heard Chuck Yeager
tell. He once clipped a tree in a P-51 coming in on final.
After landing, his crew chief grumbled as he looked at the
damage.
"Must have been a bird strike," Chuck offered.
The crew chief looked at him squarely. "Yeah, and I guess
he was carrying a nest."
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