CASE final and drift compensation.

[Fish]

Hi all, 

Ive watched and read a good deal of stuff on the case 1 landing, and the drift compensation is not something which is explained very well. From practice I notice i get the 'you are a little left' most times, but rarely 'you are a little right' 

The reason for this is clear. Because the  landing heading is approx.  the BRC - 10deg, and the boat is generally heading into the wind, the wind is always going to have a component acting on the starboard  side blowing you to port. While the drift C/O HUD symbology compensates for the actual wind, it does not compensate for the 'apparent' wind from the motion of the boat. Basically while the drift co points you to where you should go, by the time you get there, the boat has moved on. So following the HUD symbology will always leave you on the threshold with a higher bearing than the required landing bearing. What seems to be needed is a heading (pointing of the nose), which compensates for the wind drift and the motion of the boat, and to crab to the touchdown, straightening up for the runway line at the last min. 

Would be interested in any comments, specifically how people get the heading to the boat which leaves them on the landing bearing for touchdown. 

 

 

 

 

 

 

 

 

 

 

 

[Nealius]

I was thinking of this the other day. One of my common errors is also being LUL at the start and sometimes in the middle as I’m adjusting my lineup. 

With so many variables like abeam distance, timing of the 180 turn, bank angle, natural wind, and the boat’s movement, I don’t know which is the culprit. I understood bank angle to be no more than 30 degrees, but with 1.2nm abeam distance I find myself overshooting the angled deck with a constant 30 degree bank, so I must have misunderstood the parameters somewhere. Or perhaps my timing of the 180 is off, as I can’t discern the ship’s details like the LSO platform or rundown from 1+nm away without a long zoomed in look that will take my attention off of maintaining pattern altitude. 

[TimRobertsen]

8 hours ago, Nealius said:

with 1.2nm abeam distance I find myself overshooting the angled deck with a constant 30 degree bank

What's your AC weight? Sounds like you are flying very heavy

That is if, by overshooting, you mean you end up right of linup.

[Nealius]

1 minute ago, TimRobertsen said:

What's your AC weight? Sounds like you are flying very heavy

Typically 30~32k lbs. Max trap is 33k if I recall correctly. Occasionally I will trap just below the 33k limit, but I see no real difference in handling between 30k and and high 32k.

[TimRobertsen]

2 hours ago, Nealius said:

Typically 30~32k lbs. Max trap is 33k if I recall correctly. Occasionally I will trap just below the 33k limit, but I see no real difference in handling between 30k and and high 32k.

In my experience, even at max trap weight, the hornet turns really quickly at 30 AOB (below max trap weight it turns even quicker)

These are the numbers I fly by:

Abeam distance, at max trap weight, 0-5 wind:

1.1nm - 30 AOB

1.2nm - 27 AOB

1.3nm - 25 AOB

 

Abeam distance, at max trap weight, 10-20 wind:

1.1nm - 32-33 AOB

1.2nm - 30 AOB

1.3nm - 27 AOB

 

It's very understandable that you end up left of Lineup if you do a 30 AOB with a weight of 30-32k. The hornet simply turns too quickly at such a low weight.

At a weight down around 30k, you might want to try to place the hornet abeam at 1.1nm and do a 27 AOB, or maybe even less (27-25 AOB), depending on the wind conditions of of course.

Strong wind gives you a wider turn-diameter, so you want to tighten the turn, higher AOB, if winds are strong.

Windspeed at 600' is almost double that of the windspeed at sealevel, so for the first portion of the approach turn you can drift unexpectedly close to the BRC.

Needless to say, there are a lot of factors at play.

 

Also: If you fly light weight, at 1.1nm Abeam, you might want to fly about 3-4 seconds past the Rundown-alignment before starting the approach turn, to give yourself a little more room for entering the groove.

Edited November 15, 2021 by TimRobertsen

[Nealius]

44 minutes ago, TimRobertsen said:

Abeam distance, at max trap weight, 10-20 wind:

1.1nm - 32-33 AOB

1.2nm - 30 AOB

1.3nm - 27 AOB

I have 10kts wind in my missions so this makes sense. I'm usually at 1.1nm and I think I'm doing 34~35 AOB, ending up LULX every time. 

[TimRobertsen]

31 minutes ago, Nealius said:

I have 10kts wind in my missions so this makes sense. I'm usually at 1.1nm and I think I'm doing 34~35 AOB, ending up LULX every time. 

Aah, well, being that you usually do recoveries light weight, easing the AOB should put you at a better position at the end of the approach turn.

[Fish]

On 11/14/2021 at 4:34 PM, Fish said:

.................Would be interested in any comments, specifically how people get the heading to the boat which leaves them on the landing bearing for touchdown. ........

Anyone have an answer to this (apart from just eyballing it) ? 

Edited November 17, 2021 by Fish

[Nealius]

7 hours ago, Fish said:

Anyone have an answer to this (apart from just eyballing it) ? 

 

ICLS. 

[Fish]

2 hours ago, Nealius said:

ICLS. 

CASE 1 does not mention ICLS anywhere.

[Nealius]

7 minutes ago, Fish said:

CASE 1 does not mention ICLS anywhere.

Doesn't mean you can't use it. Plenty of real-world Hornet HUD tapes showing ICLS called up during CASE I or II. 

It's obviously not meant to be a primary instrument, since it's supposed to be 100% visual after the turn through the 90 (as I understand it) and therefore is supposed to be eyeballed, but it's a useful "crutch" for rolling out in a good position at the start of the groove. 

Edited November 18, 2021 by Nealius

[Fish]

32 minutes ago, Nealius said:

....... Plenty of real-world Hornet HUD tapes showing ICLS called up during CASE I or II. ........

 

 

That's very interesting. 

[Nealius]

Did some digging to find a couple videos showing that. 

Rhino SHB 

Rhino CASE II (those clouds look way low for CASE II but he's doing the CASE I 180 turn, or so it appears)

Rhino CASE I

Charlie CASE I

[fagulha]

10 hours ago, Fish said:

CASE 1 does not mention ICLS anywhere.

ICLS is a landing tool and is used by naval aviators in CASE I too. From i heard from The Fighter Pilot podcast it´s up for each aviator choice.

[Swift.]

Not very helpful I know, but Ball-Lineup-AOA

If you see one of them drifting, fix it.

In this case Lineup, if you are drifting to the left, you know how to move the jet to the right so just do it. And keep doing it until you are lined up again. Repeat until touchdown

[Nealius]

Best thing to do on line up is anticipate the ships movement, meaning your target will be constantly drifting right. I've been working on this recently because I'm always LUL due to not anticipating the ship's movement. I only use the ICLS for glidslope when coming off the 90, then focus on ball-lineup-AoA in the groove. If you try to use ICLS localizer for lineup in the groove you'll just chase the needle and smack into the island or LSO platform.

Edited November 18, 2021 by Nealius

[draconus]

The shorter time in the groove the less of an issue the drift is.

Now you want math and instruction but after lots of practice you'll just feel and see what to do and where will you end up after 90.

[fagulha]

5 hours ago, Swiftwin9s said:

Not very helpful I know, but Ball-Lineup-AOA

If you see one of them drifting, fix it.

In this case Lineup, if you are drifting to the left, you know how to move the jet to the right so just do it. And keep doing it until you are lined up again. Repeat until touchdown

I´m always doing very small right corrections and anticipating my touchdown point by placing the velocity vector on the crotch when in the groove. it´s a good technique in you opinion/expertise? It works for me and learned it from several sources (reading but from pilot podcasts mainly) but i don´t really know if it´s correct.

Thank you.

[Swift.]

5 hours ago, fagulha said:

I´m always doing very small right corrections and anticipating my touchdown point by placing the velocity vector on the crotch when in the groove. it´s a good technique in you opinion/expertise? It works for me and learned it from several sources (reading but from pilot podcasts mainly) but i don´t really know if it´s correct.

Thank you.

It might help to start out with, but Ball-Lineup-AOA is the scan you need to be doing. Don't factor VV placement into that other than maybe at the very very start as you describe.

[Nealius]

9 hours ago, draconus said:

The shorter time in the groove the less of an issue the drift is

The catch is figuring out when to turn. I tend to turn at 1.1 or 1.2dme and always end up long. I’ve often read to turn at or before the LSO platform, but all I can see is the geometric silhouette of the carrier at one mile. Zoom in to hunt for it, then find myself down at 500ft or climbing to 700 feet because I took my eyes “off the road.”

[draconus]

6 hours ago, Nealius said:

Zoom in to hunt for it, then find myself down at 500ft or climbing to 700 feet because I took my eyes “off the road.”

Keep your "wheel" steady and do a quick glance. Why zoom in? Looking for something particular? Your HSI and TACAN bug is probably enough to tell your position. And it doesn't need to be that precise unless you strive for SHB

Edited November 19, 2021 by draconus

[Nealius]

HSI and TACAN tells me I should be in the right spot (1.1~1.2nm) yet my grove is still in excess of 20 seconds every time. Some anecdotes from real pilots indicate turning abeam the LSO platform, slightly before the LSO platform, or when seeing the rundown depending on carrier speed and natural wind speed, but I can't discern those details on a virtual screen: it's just a mass of pixels.

Edited November 19, 2021 by Nealius

[draconus]

1 hour ago, Nealius said:

Some anecdotes from real pilots indicate turning abeam the LSO platform, slightly before the LSO platform, or when seeing the rundown depending on carrier speed and natural wind speed, but I can't discern those details on a virtual screen: it's just a mass of pixels.

All of that means some radial position wrt carrier - that's what I meant by HSI/TACAN bug. Add/subtract a few degrees to see what works for you - no point in zooming in for ship details.

[fagulha]

12 hours ago, Swiftwin9s said:

It might help to start out with, but Ball-Lineup-AOA is the scan you need to be doing. Don't factor VV placement into that other than maybe at the very very start as you describe.

I shoulded pointed out that my scan is Ball-Lineup and AOA as you mentioned, the procedure i mentioned above is done at the Start. Thank you for your insight.

[TimRobertsen]

Regarding when to start the approach turn: As @draconus says, Tacan-bug is the way to go

No wind: Tacan-bug is aligned with the center of the "E" in "MODE".

20 knots wind: Tacan-bug is aligned with the top of the "M" in "MODE"

Any winds between 0 and 20, you start somewhere between Middle-E and top-M.

It works fairly well, with the added bonus of not having to take your eyes of the instruments.