Flight Training - December 2019 - 10

FLYING CARPET BY GREG BROWN

Mountain airports require thorough preparation.
See GREG BROWN'S website for more Telluride
planning details.
GregBrownFlyingCarpet.com

MOUNTAIN AIRPORT
Some airports set a pilot's heart racing.

Our friends Steve and Molly recently invited us for a hiking weekend in southwest Colorado. This would be our first summertime visit to 9,070-foot-elevation
Telluride Regional Airport (TEX).
Telluride is surrounded on three sides by 12,000- to 14,000-foot mountains,
but we could approach from the west at 11,000 feet. Like most Telluride traffic
I planned to land on Runway 9 and depart Runway 27 to avoid maneuvering in
the dead-end canyon east of the airport. That required good visual flight conditions, and light winds
to preclude downwind
takeoffs or landings and
dangerous downdrafts
tumbling over the surrounding mountains.
Given suitable
weather, my main
concern flying our
nonturbocharged
Cessna 182 was safely
departing such a
high-elevation airport
in summertime. TemApproach to Runway 9 at Telluride Regional Airport, Colorado.
peratures of 48 degrees
10 FLIGHT TRAINING DECEMBER 2019

Fahrenheit to 75 degrees F sound pleasantly cool, but at 10,000 to 12,000 feet
density altitude we'd be lucky to get 65
percent of sea-level power at full throttle, and 300 fpm climb.
My performance charts indicated
the 7,000-foot runway was plenty for
takeoff, but at those density altitudes our
normally peppy Skylane might require
10 miles to clear a 1,000-foot ridge. Had
we needed to top terrain after takeoff
I would have canceled the trip. To the
west, however, the ground plunges into
the San Miguel River Canyon, meaning
we could even descend after takeoff if
necessary.
To optimize Telluride departure
performance, we needed to take off cool
and light. Jean and I packed minimally,
and rather than top tanks before leaving
Flagstaff, I loaded only precalculated
roundtrip fuel plus reserves. That staged
us 475 pounds under gross weight to
depart Telluride.
We launched on the two-hour flight
Friday morning, and sure enough, Telluride's density altitude was 11,400 feet
when we landed. Whether at sea level
or 10,000 feet, pilots should always
fly the same indicated airspeeds for
airport operations. True airspeed, however, increases by about 2 percent per
thousand feet of altitude, meaning at
Telluride you're covering ground nearly
20 percent faster than at sea level for
the same indicated airspeed. Pilots must
resist temptation to slow dangerously
below normal approach speed because
"this doesn't feel right." The airplane
will also touch down faster than usual,
use more runway, and require a greater
turning radius aloft-more reason
to avoid circling in Telluride's cozy
canyon.
Following two idyllic days trekking
with our friends among wildflowers
and waterfalls, we departed cool and
early Sunday morning at 10,200 feet
density altitude. I leaned the engine in a
full-power runup, accelerated in ground
effect to best-rate-of-climb speed, and
committed to flying by the numbers
regardless of poor climb performance
out the windshield. We easily cleared
the runway and climbed sluggishly
homeward. Anyone who thinks piloting
is dull should land at a high mountain
airport. FT

http://www.GregBrownFlyingCarpet.com

Flight Training - December 2019

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