Incorrect Terrain Indication on ATC Mode

I’ve discovered an issue regarding the terrain indication on the Approach ATC’s “drag and vector” feature. In 1st picture below, you can see that I’m using the “drag and vector” feature to assign a heading for an aircraft. The info about the terrain, heading and distance from aircraft is displayed when using the feature. As you can see, the information about terrain is showing that there is terrain at 4,700 feet, however it’s not physically visible for the ATC or the aircraft. The second picture is the aircraft’s viewpoint, showing there are no mountains around the area. Notice that the aircraft is at 4,000 feet ASL, and around 3,000 feet AGL, therefore the aircraft should definitely see the mountain in front of it. There are a few points of “random” high elevation around this area.

The two images:

Approach Controller’s point of view:

Aircraft’s point of view:

I’ve been able to reproduce this bug with the following steps:

  1. Select PHOG as an airport to control (Approach Frequency, as Tower and Ground does not have a “drag and vector” feature).
  2. Use the feature to check the terrain elevation by dragging the pink line from the aircraft to the area around waypoints WUNBU, JOLUN and XUSQA. It’s quite a small area, therefore it may take a while to catch it.
  3. Notice how the elevation rapidly increases and decreases in this area.

My equipment is:

  • iPad Pro 12,9’, using iOS 11.4
  • iPhone X, using iOS 11.4

To combat the issue, I tried to clear scenery cache in case the scenery was corrupt. I’ve also pain takingly reinstalled IF, but the issue is still there.

I hope I’ve been as clear as possible and if there are any things I need to clarify or add, please state so in the replies.

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Its hard to tell if there’s really an issue here because your two screenshots are in two completely different spots.

In your first image the aircraft is at the end of the cone and directly south of the field while your second image the aircraft is southeast and within a few miles. It’s probably better to test this when the aircraft is over the water and see if the altitudes show differently.

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Yes, they are in (slightly) different areas. However, if the aircraft is at 4,000 feet, a mountain at 4,700 feet should definitely be in sight (straight ahead-ish), since the visibility was high.

If you’re able, try the below quote next time when you open approach again. If there’s a significant rise in elevation then we may have an issue. This should further prove if there is indeed an issue.

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Will do, I’ll post results later.

Just attempted this with an aircraft overwater, (and quite far away). The issue is still there.

Alright, I’ve just attempted to reproduce this and was unsuccessful. Here I am vectoring an aircraft well and over the big blue salt mass south of Honolulu. Below you’ll find vector distances of 8nm and 65nm respectively. Both indicate 0 feet. I swept the vectoring tool 180 degrees from wing tip to wing tip looking to see if I can get any false indications and was unable to receive any.

IMG_1881

IMG_1882

Oh apologies, I misunderstood what you were trying to say. I thought you asked me to reproduce it while the aircraft is over water and try vector him to the area around PHOG. If you could try vector the aircraft to an area around PHOG, you’ll see spikes in terrain up to 5,000 feet indicated on the “drag and vector” feature. However, this terrain isn’t there - meaning it’s a false reading on the “drag and vector”. It can cause problems when vectoring an aircraft around that area because you’ll need to send the aircraft to 6,000 feet to overcome to “fake mountains” (terrain elevation +1k), which is too high to send them for an approach. Also, I’ve looked at charts for PHOG, and wasn’t able to find any spikes in elevation from ~900 feet ASL to 5,000 feet AGL in the area shown in my two pictures.

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Ok. I’ll look thanks!

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