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.") It's part of what makes aviation
so exciting for all of us... just when you think you've seen it
all, along comes a scenario you've never imagined.
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, and as
representatives of the flying community. 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.
It is our unabashed goal that "Aero-Tips" will help our readers
become better, safer pilots -- as well as introducing our
ground-bound readers to the concepts and principles that keep those
strange aluminum-and-composite contraptions in the air... and allow
them to soar magnificently through it.
Look for our daily Aero-Tips segments, coming each day to you
through the Aero-News Network. Suggestions for future Aero-Tips are
always welcome, as are additions or discussion of each day's tips.
Remember... when it comes to being better pilots, we're all in this
together.
Aero-Tips 04.04.06
Arriving at a commercial-service airport in poor
visibility? Listening to ATIS (the Automated Terminal
Information System) you may hear "RVR"-- the Runway Visual Range.
RVR values are measured by transmissometers mounted on 14-foot
towers along the runway, 250 feet apart. A known-intensity of light
is emitted from the projector and is measured by the receiver. Any
obscuring matter such as rain, snow, dust, fog, haze or smoke
reduces the light intensity arriving at the receiver. The resultant
intensity measurement is then converted to an RVR value by the
signal data converter. These values are displayed by readout
equipment in the associated air traffic facility and updated
approximately once every minute for controller issuance to
pilots.
Minimum measured visibility is 600 feet (1/10th nautical
mile). Higher visibilities are reported in 200-foot
increments up to a maximum value of 6000 feet (one nautical
mile).
Note: this differs from other visibility
measurements, which are reported in statute miles.
Air Traffic Control Towers report RVR when:
- it is available,
- the prevailing visibility is one (statute) mile or less,
and/or
- the measured RVR is 6000 feet or less.
Instrument Approach categories with the corresponding
minimum RVR values:
AIM TBL 7-1-5
-
Category Visibility
(RVR)
- Nonprecision 2,400 feet
- Category I 1,800 feet
- Category II 1,200 feet
- Category IIIa 700 feet
- Category IIIb 150 feet
- Category IIIc 0 feet
Aero-tip of the day: Expect to hear "RVR"
values when landing at a large airport in poor visibility.