AIM 

4/20/23 

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 navigation 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 

4. 

A straight

−

in aligned procedure may be restricted to circling only minimums when an excessive descent 

gradient necessitates. The descent angle between the FAF/stepdown fix and the Circling MDA must not exceed 

the maximum descent angle allowed by TERPS criteria. A published VDA on these procedures does not imply 

that landing straight ahead is recommended or even possible. The descent rate based on the VDA may exceed 

Arrival Procedures

5

−

4

−

22