Hornet AoA during trap question - can anyone with RW experience comment? - ED Forums
 


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Old 08-01-2020, 07:13 AM   #1
Stearmandriver
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Default Hornet AoA during trap question - can anyone with RW experience comment?

Hello,

I'm curious about a behavior the DCS Hornet exhibits during a trap. It seems that every time, just before touchdown, the AoA indexer indication changes from on-speed to fast. This is mirrored by the E bracket in the HUD, and happens even when there is zero stick or throttle input being made.

I'm wondering what we're seeing here? Is this an impact of ground effect on AoA? And what I'm really curious about: does the real plane exhibit this behavior? I don't see it happen when watching cockpit video of real Hornet traps, but of course that could be because the pilots are correcting for it.

It often seems to drive the LSO to comment about a 3pt or nose first lndg, when the landing was definitely at the correct attitude, and an LSO view of the track replay confirms a normal touchdown attitude.

Maybe the two things aren't related, but I'm curious if you see this suddenly-fast AoA indication in the real jet just before touchdown? I've never flown a tactical jet but have flown a few jets with AoA indications... our 73s at work have an AoA indicator in the HUD, and I've never seen it affected by ground affect.

Thanks for any input.
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Old 08-01-2020, 07:34 AM   #2
Emmy
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The island burble causes a patch of “dead air” just before touchdown.

Could that be a cause?
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Old 08-01-2020, 09:24 AM   #3
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The island burble causes a patch of “dead air” just before touchdown.

Could that be a cause?
That's an interesting idea, but I don't think so. My understanding of the burble is that it's the wake of turbulent air flowing over and around the island because of ship motion. So I'd expect to see it when directly "downstream" of the island, based on ship direction of travel. I feel like that would be just before the ramp, and this happens well past that. It's literally less than a second before touchdown, maybe .5 seconds before touchdown. You're in the wires at that point, more next to the island than downwind of it.

Next time I'm in the sim I'll try a carrier style landing on a land runway. I've actually never flown the DCS Hornet to or from land haha. I only recently came to DCS after being a naval aviation simming fan for years in another sim, and it was the release of the supercarrier that brought me here. And I'm really enjoying it, don't get me wrong... the LSO grading kinda bugs me though, and it got me wondering what this AoA reduction is just before touchdown, whether it's real, and if it's related to some of these 3pt grades I'm getting.
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Old 08-01-2020, 09:37 AM   #4
Swiftwin9s
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This is the reverse ground effect that has been so fabled. As you near the ground your nose is sucked downwards creating a fast AOA.

Expect it to be fixed when the FM updates roll around.
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Old 08-01-2020, 10:18 AM   #5
Stearmandriver
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Ok, now that makes sense, thanks! I remember reading about this when I was looking into DCS, but I'd forgotten about it since I'd never (knowingly) experienced it. I've probably never tried to fly level lower than a couple hundred feet though.

So there are FM updates in the pipeline?
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Old 08-01-2020, 10:30 PM   #6
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Quote:
Originally Posted by Stearmandriver View Post
Ok, now that makes sense, thanks! I remember reading about this when I was looking into DCS, but I'd forgotten about it since I'd never (knowingly) experienced it. I've probably never tried to fly level lower than a couple hundred feet though.

So there are FM updates in the pipeline?
Yeah it was an item on the user poll, so expect FM updates. I cant say what timeline we are looking at here though. Could be next week could be in a year.
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Old 08-02-2020, 12:10 AM   #7
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There isn’t any noticeable “ground effect” landing aboard the ship. Granted, all my CVN traps were in the E/F, but the C with its higher approach speeds and smaller wing would be even less effected than the Super.

Ashore I never noticed any ground effect in the A-G airplanes.
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Old 08-02-2020, 12:13 AM   #8
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Quote:
Originally Posted by FightsOn View Post
There isn’t any noticeable “ground effect” landing aboard the ship. Granted, all my CVN traps were in the E/F, but the C with its higher approach speeds and smaller wing would be even less effected than the Super.

Ashore I never noticed any ground effect in the A-G airplanes.
Yeah thats what most of us understand as well. The issue is with DCS unfortunately. Its not a huge thing, but its certainly annoying.
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Old 08-02-2020, 12:46 AM   #9
Stearmandriver
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Quote:
Originally Posted by FightsOn View Post
There isn’t any noticeable “ground effect” landing aboard the ship. Granted, all my CVN traps were in the E/F, but the C with its higher approach speeds and smaller wing would be even less effected than the Super.

Ashore I never noticed any ground effect in the A-G airplanes.
Thanks, that's what I would have expected. It's definitely not a very big deal, but nice to have an explanation.
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Old 08-02-2020, 11:31 AM   #10
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Quote:
Originally Posted by FightsOn View Post
There isn’t any noticeable “ground effect” landing aboard the ship. Granted, all my CVN traps were in the E/F, but the C with its higher approach speeds and smaller wing would be even less effected than the Super.

Ashore I never noticed any ground effect in the A-G airplanes.

IRL, the C tends to fall out of the sky at the ship in the last moments. Most guys (half) jokingly say that no matter where the ball is, they're at MIL for the last 3 seconds.


The E was definitely more forgiving, thanks to the wing as you mentioned.
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