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时间:2010-05-10 19:29来源:蓝天飞行翻译 作者:admin
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of the arrival.
VISUAL APPROACHES
When it is operationally beneficial, ATC may authorize
pilots to conduct a visual approach to the airport in lieu
of the published IAP. A pilot or the controller can initiate a visual approach. Before issuing a visual approach
clearance, the controller must verify that pilots have
the airport, or a preceding aircraft that they are to follow, in sight. In the event pilots have the airport in sight
but do not see the aircraft they are to follow, ATC may
issue the visual approach clearance but will maintain
responsibility for aircraft and wake turbulence separation. Once pilots report the aircraft in sight, they
5-44
assume the responsibilities for their own separation
and wake turbulence avoidance.
A visual approach is an ATC authorization for an
aircraft on an IFR flight plan to proceed visually
to the airport of intended landing; it is not an IAP.
Also, there is no missed approach segment. An aircraft unable to complete a visual approach must
be handled as any other go-around and appropriate
separation must be provided. A vector for a visual
approach may be initiated by ATC if the reported
ceiling at the airport of intended landing is at least
500 feet above the MVA/MIA and the visibility is
3 SM or greater. At airports without weather reporting service there must be reasonable assurance (e.g.
area weather reports, PIREPs, etc.) that descent and
approach to the airport can be made visually, and the
pilot must be informed that weather information is
not available.
The visual approach clearance is issued to expedite the
flow of traffic to an airport. It is authorized when the
ceiling is reported or expected to be at least 1,000 feet
AGL and the visibility is at least 3 SM. Pilots must
remain clear of the clouds at all times while conducting
a visual approach. At an airport with a control tower,
pilots may be cleared to fly a visual approach to one
runway while others are conducting VFR or IFR
approaches to another parallel, intersecting, or converging runway. Also, when radar service is provided, it is
automatically terminated when the controller advises
pilots to change to the tower or advisory frequency.
CONTACT APPROACHES
If conditions permit, pilots can request a contact
approach, which is then authorized by the controller. A
contact approach cannot be initiated by ATC. This procedure may be used instead of the published procedure
to expedite arrival, as long as the airport has a SIAP or
special instrument approach procedure (special IAPs
are approved by the FAA for individual operators, but
are not published in Part 97 for public use), the reported
ground visibility is at least 1 SM, and pilots are able to
remain clear of clouds with at least one statute mile flight
visibility throughout the approach. Some advantages of
a contact approach are that it usually requires less time
than the published instrument procedure, it allows pilots
to retain the IFR clearance, and provides separation from
IFR and SVFR traffic. On the other hand, obstruction
clearances and VFR traffic avoidance becomes the
pilot’s responsibility. Unless otherwise restricted, the
pilot may find it necessary to descend, climb, or fly a
circuitous route to the airport to maintain cloud
clearance or terrain/obstruction clearance.
The main differences between a visual approach and a
contact approach are: a pilot must request a contact
approach, while a visual approach may be assigned by
ATC or requested by the pilot; and, a contact approach
may be approved with 1 mile visibility if the flight can
remain clear of clouds, while a visual approach requires
the pilot to have the airport in sight, or a preceding aircraft to be followed, and the ceiling must be at least
1,000 feet AGL with at least 3 SM visibility.
CHARTED VISUAL FLIGHT PROCEDURES
A charted visual flight procedure (CVFP) may be
established at some airports with control towers for
environmental or noise considerations, as well as
when necessary for the safety and efficiency of air traffic operations. Designed primarily for turbojet aircraft,
CVFPs depict prominent landmarks, courses, and recommended altitudes to specific runways. When pilots
are flying the Roaring Fork Visual RWY 15 shown in
figure 5-32, mountains, rivers, and towns provide
guidance to Aspen, Colorado’s Sardy Field instead
of VORs, NDBs, and DME fixes.
Pilots must have a charted visual landmark or a preceding aircraft in sight, and weather must be at or above the
published minimums before ATC will issue a CVFP
clearance. ATC will clear pilots for a CVFP if the
 
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