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2.  Circling MDA.

 The circling MDA will 

provide 300 foot obstacle clearance within the area 
considered for obstacle clearance and may be lower 
than the LNAV/VNAV DA, but never lower than the 
straight in LNAV MDA. This may occur when 
different controlling obstacles are used or when other 
controlling factors force the LNAV MDA to be higher 
than 250 feet above the LNAV OCS. In FIG 5



the required obstacle clearance for both the LNAV 
and Circle resulted in the same MDA, but lower than 


13 provides an 

illustration of this type of situation. 

3.  Vertical guidance (LNAV/VNAV).

 A line is 

drawn horizontal at obstacle height until reaching the 
obstacle clearance surface (OCS). At the OCS, a 
vertical line is drawn until reaching the glide path. 
This is the DA for the approach. This method places 
the offending obstacle in front of the LNAV/VNAV 
DA so it can be seen and avoided. In some situations, 
this may result in the LNAV/VNAV DA being higher 
than the LNAV and/or Circling MDA. 

h.  The Visual Descent Point (VDP)

, identified by 

the symbol (V), is a defined point on the final 
approach course of a nonprecision straight


approach procedure from which a stabilized visual 
descent from the MDA to the runway touchdown 
point may be commenced. The pilot should not 
descend below the MDA prior to reaching the VDP. 
The VDP will be identified by DME or RNAV 

track distance to the MAP. The VDP distance 

is based on the lowest MDA published on the IAP and 
harmonized with the angle of the visual glide slope 
indicator (VGSI) (if installed) or the procedure VDA 
(if no VGSI is installed). A VDP may not be 
published under certain circumstances which may 
result in a destabilized descent between the MDA and 
the runway touchdown point. Such circumstances 
include an obstacle penetrating the visual surface 
between the MDA and runway threshold, lack of 
distance measuring capability, or the procedure 
design prevents a VDP to be identified. 


VGSI systems may be used as a visual aid to 

the pilot to determine if the aircraft is in a position to 
make a stabilized descent from the MDA. When the 
visibility is close to minimums, the VGSI may not be 
visible at the VDP due to its location beyond the 


Pilots not equipped to receive the VDP should 

fly the approach procedure as though no VDP had 
been provided. 


On a straight-in nonprecision IAP, descent 

below the MDA between the VDP and the MAP may 
be inadvisable or impossible. Aircraft speed, height 
above the runway, descent rate, amount of turn, and 
runway length are some of the factors which must be 
considered by the pilot to determine if a safe descent 
and landing can be accomplished. 


A visual segment obstruction evaluation is 

accomplished during procedure design on all IAPs. 
Obstacles (both lighted and unlighted) are allowed to 
penetrate the visual segment obstacle identification 
surfaces. Identified obstacle penetrations may cause 
restrictions to instrument approach operations which 
may include an increased approach visibility 
requirement, not publishing a VDP, and/or prohibit-
ing night instrument operations to the runway. There 
is no implicit obstacle protection from the MDA/DA 
to the touchdown point. Accordingly, it is the 
responsibility of the pilot to visually acquire and 
avoid obstacles below the MDA/DA during transition 
to landing. 


Unlighted obstacle penetrations may result in 

prohibiting night instrument operations to the 
runway. A chart note will be published in the pilot 
briefing strip “Procedure NA at Night.” 


Use of a VGSI may be approved in lieu of 

obstruction lighting to restore night instrument 
operations to the runway. A chart note will be 
published in the pilot briefing strip “ Straight-in Rwy 
XX at Night, operational VGSI required, remain on 
or above VGSI glidepath until threshold.” 


The highest obstacle (man-made, terrain, or 

vegetation) will be charted on the planview of an IAP. 
Other obstacles may be charted in either the planview 
or the airport sketch based on distance from the 
runway and available chart space. The elevation of 
the charted obstacle will be shown to the nearest foot 
above mean sea level. Obstacles without a verified 
accuracy are indicated by a 


 symbol following the 

elevation value. 

k.  Vertical Descent Angle (VDA). 

FAA policy is 

to publish a VDA/TCH on all nonprecision 
approaches except those published in conjunction 
with vertically guided minimums (i.e., ILS or LOC 
RWY XX) or no-FAF procedures without a 
step-down fix (i.e., on

airport VOR or NDB). A 

Arrival Procedures