Aero-Tips!
A good pilot is always learning -- how many times have you heard
this old standard throughout your flying career? There is no truer
statement in all of flying (well, with the possible exception of
"there are no old, bold pilots.")
Aero-News has called upon the expertise of Thomas P. Turner,
master CFI and all-around-good-guy, to bring our readers -- and us
-- daily tips to improve our skills as aviators. Some of them, you
may have heard before... but for each of us, there will also be
something we might never have considered before, or something that
didn't "stick" the way it should have the first time we memorized
it for the practical test.
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Aero-Tips 12.20.06
I was working the FBO at Sedalia, MO many years ago (before
Whiteman Approach covered KDMO, if any readers are familiar with
the area). The crew of a chartered King Air jumped up from the FBO
couch as a sedan pulled through the airport gate and onto the ramp.
Another quick-launch awaited the charter aircrew.
Skies were overcast, about 1500 feet above ground level (AGL).
The crew had filed IFR for a 50-mile hop to Columbia, MO, where
they would pick up another passenger and take everyone home. "We'll
pick up our clearance in the air," commented the captain as they
drew on their coats and exited the airport lounge.
I caught up with the copilot and told him he wouldn't be able to
pick up his instrument clearance below the clouds in that area, and
unless they wanted to cruise VFR at 1000 AGL all the way to
Columbia they should contact Flight Service over Sedalia's Remote
Communications Outlet (RCO) on the ground.
Minimum Vectoring Altitude
Minimum Vectoring Altitude (MVA) is the lowest altitude above
sea level at which an IFR aircraft will be vectored by a radar
controller, except as otherwise authorized for radar approaches,
departures, and missed approaches. MVA meets IFR obstacle clearance
criteria. It may be lower than the published Minimum En-route
Altitude (MEA) along an airway. It may be used for radar vectoring
only upon the controller's determination that an adequate radar
return is being received from the aircraft. Charts depicting
minimum vectoring altitudes are normally available only to the
controllers, and not to pilots.
To pilots MVA is therefore unknown and, seemingly, unknowable.
In most cases controllers can't activate a clearance in-flight
unless the aircraft is above MVA. That makes departing visually
from a nontowered airport without radar approach coverage risky
when clouds or visibility are tight by VFR standards. If you call
Flight Service for a weather briefing your briefer might be able to
provide MVA information, if you ask. If at all possible, though,
get your clearance with a void time by radio from the ground, or by
calling Flight Service by telephone, in such conditions.
Aero-tip of the day: Ask your briefer for the
MVA in your area, or get your clearance on the ground before
departing IFR into marginal weather conditions.