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AIM

10/12/17

5−4−20

Arrival Procedures

VDA does not guarantee obstacle protection below

the MDA in the visual segment. The presence of a

VDA does not change any nonprecision approach

requirements.

1. Obstacles may penetrate the obstacle identifi-

cation surface below the MDA in the visual segment

of an IAP that has a published VDA/TCH. When the

VDA/TCH is not authorized due to an obstacle

penetration that would require a pilot to deviate from

the VDA between MDA and touchdown, the

VDA/TCH will be replaced with the note “Visual

Segment- Obstacles” in the profile view of the IAP

(See FIG 5−4−14). Accordingly, pilots are advised to

carefully review approach procedures to identify

where the optimum stabilized descent to landing can

be initiated. Pilots that follow the previously

published descent angle, provided by the RNAV

system, below the MDA on procedures with this note

may encounter obstacles in the visual segment. Pilots

must visually avoid any obstacles below the MDA.

(a) VDA/TCH data is furnished by FAA on

the official source document for publication on IAP

charts and for coding in the navigation database

unless, as noted previously, replaced by the note

“Visual Segment – Obstacles.”

(b) Commercial chart providers and naviga-

tion systems may publish or calculate a VDA/TCH

even when the FAA does not provide such data. Pilots

are cautioned that they are responsible for obstacle

avoidance in the visual segment regardless of the

presence or absence of a VDA/TCH and associated

navigation system advisory vertical guidance.

2. The threshold crossing height (TCH) used to

compute the descent angle is published with the

VDA. The VDA and TCH information are charted on

the profile view of the IAP following the fix

(FAF/stepdown) used to compute the VDA. If no

PA/APV IAP is established to the same runway, the

VDA will be equal to or higher than the glide path

angle of the VGSI installed on the same runway

provided it is within instrument procedure criteria. A

chart note will indicate if the VGSI is not coincident

with the VDA. Pilots must be aware that the

published VDA is for advisory information only and

not to be considered instrument procedure derived

vertical guidance. The VDA solely offers an aid to

help pilots establish a continuous, stabilized descent

during final approach. 

3. Pilots may use the published angle and

estimated/actual groundspeed to find a target rate of

descent from the rate of descent table published in the

back of the U.S. Terminal Procedures Publication.

This rate of descent can be flown with the Vertical

Velocity Indicator (VVI) in order to use the VDA as

an aid to flying a stabilized descent. No special

equipment is required.

FIG 5−4−14

Example of a Chart Note

3/15/07

7110.65R CHG 2

AIM

2/28/19