[ND/GPWC] Cut off altitude around airport missing on terrain display

[BravoMike99]

Aircraft Version

Experimental

Build info

{
    "built": "2023-04-15T13:57:47+00:00",
    "ref": "refs/heads/experimental",
    "sha": "df9b2e907563c9dc1d1020fe3d9b66a4054e7533",
    "actor": "2hwk",
    "event_name": "manual",
    "pretty_release_name": "experimental:df9b2e90",
    "version": "v0.10.0-exp.df9b2e9"
}

Describe the bug

Currently the terrain on ND feature does not simulate the altitude cut off using to the nearest runway elevation during takeoff and landing. This can result in terrain below the destination/departure elevation showing or cluttered terrain pictures at certain airports. Some examples attached: (LIMC, elev 700 feet) (LPPT, elevation around 370ft)

(LPLA, elevation around 160ft)

Expected behavior

The terrain picture of the honeywell GPWS should hide terrain below a calculated cutoff altitude which is calculated depending on the nearest airport elevation. This should result in a less cluttered terrain picture during takeoff and landing.

Steps to reproduce

Turn on terrain on ND at multiple airports (e.g. LPPT, LIMC etc.) and observe the minimum terrain altitude displayed.

References (optional)

Honeywell maintenance component and Honeywell pilots manuals: Mention that terrain with elevation within 400ft of nearest airport elevation should not be displayed/colored black. AMM: The cutoff altitude varies between 200 and 400ft, depending on the airport.

It is also possible to observe the cut off effect on some videos, LPPT here for e.g. despite being an EIS1 frame: https://youtu.be/Vzt7TdbenRs?t=199

Additional info (optional)

Build does not seem to matter. It has been like this for a few versions/probably since the initial terrain implementation.

Discord Username (optional)

Bruno_pt99#5802

[beheh]

/cc @svengcz

[svengcz]

Ok, for the destination should it be working. Seems like a bug. Will take a look.

Do you have a reference for the cut off during departure? Find only something in docs and refs for the destination

[BravoMike99]

Ok, for the destination should it be working. Seems like a bug. Will take a look.

Do you have a reference for the cut off during departure? Find only something in docs and refs for the destination

sorted in PM 😃