Meatball and ICLS angle

[Shack]

What is the glidepath angle of the ICLS and the range for the meatball?

[MooneyTail]

I'm assuming if it's true to life then it is 3.5 degrees which will give an effective glideslope of 3 degrees (due to ship's movement), and as for the range of the meatball, it'll be however far you can see it from haha. Realistically you should make out where you are on glideslope at roughly 1 to 3/4 of a mile though.

Again, that's if it's modeled to real life, and I haven't been able to extensively tested it in DCS yet myself.

[Ahmed]

It is indeed 3.5 in the .lua files.

 

Could be interesting to experiment with IFLOLS angle 4.0 degrees for strong winds, but probably not idea to mess with the values until there is an in-game (ME?) option ;)

[Shack]

By range, I meant the glidepath angles that are available for descent angle adjustment. such as 3 - 4 degrees to account for rougher seas? The issue is more of pitching decks due to rough seas that would probably warrant a steeper landing approach?

[Hog_No32]

By range, I meant the glidepath angles that are available for descent angle adjustment. such as 3 - 4 degrees to account for rougher seas? The issue is more of pitching decks due to rough seas that would probably warrant a steeper landing approach?

 

Why would you want a steeper approach when the sea is rough?

[Curly]

Why would you want a steeper approach when the sea is rough?

To ensure adequate hook to ramp clearance

 

Hook to ramp refers to the distance from the tip of the hook to aft section of the carrier runway.

 

 

Safety requirements say it should be no less than 10 feet. If hook to ramp distance is less than 10 feet there is a large risk of inadvertent engagement. Say if the ship heaves, for example. Hook to ramp distance is primarily a function of the distance from the hook touchdown to the ramp.

 

Hook to ramp distance can be adjusted by changing the basic angle of meatball. Lets look an actual carrier recovery bulletin used by LSO's.

 

 

 

 

CV 62 Independence stands out. The first thing to note about her is, that she can't recover aircraft using a 3 degree glide slope because the hook to ramp distance is less than 10 feet. This is because the three wire is located to close to the ramp. Since it’s based on right triangles, we can mathematically prove it.

 

CV 62 Hook touchdown point = 185 feet forward of the ramp

Tan of 3.0 = Hook to Ramp clearance /185 (Hook Touchdown distance from ramp.)

Hook to ramp = 9.69

Thus you can never safely land aircraft via a 3 degree glide slope on the Independence.

 

To use a 3 degree glide slope on any carrier the hook touchdown point needs to be at least 191 feet forward of the ramp. As

Tan 3 = 10.009/191.

 

The Saratoga and the Forrestal are even worse, their touchdown point is only 178 feet from the stern.

 

The main concern with AOA on the approach is Hook to Eye Distance. Hook to Eye, is the distance from the pilots head to end of the arrestor hook. If we didn’t take this distance into account the hook would always land short of the target wire. Hook to Eye varies with each aircraft. Again lets look at a a real Aircraft Recovery Bulletin.

 

 

 

 

As we can see all aircraft have different hook to eye distances. Thus the meatball has to be adjusted for various aircraft types. In order to ensure each aircraft's tail hook lands half way between the 2 and 3 wire, on 4 wire boats.

 

 

So if hook to ramp clearance calls for a 3.5 degree glide slope, The meatball will set to angle of 3.5 and then optical tuchdown point moved forward 16.70 feet if we’re recovering Hornets. So that the hook path lands half way between the 2 and 3 wire.

Edited July 26, 2018 by Curly

[MooneyTail]

For higher wind conditions (think 40+ KTS), the basic angle could be set to 4.0 degrees, but that will still give you an effective glideslope of 3 degrees. You have to remember that unlike a stationary runway, the ship is moving away from you and the slower your closure is, the flatter your glideslope will be.

 

The IFLOLS will be set to a basic angle and then it makes adjustments based on what aircraft is entered into the system and it's H/E value. All of this is done to ultimately give the aircraft's tailhook an acurate 3 degree glideslope to the target (generally between the 2 and 3 wire).

 

If there are rough seas and the lens stabilization can't keep up, or if the dynamic H/E value consistently drops below the safe 10 ft hook to ramp clearance, then the LSOs will rig MOVLAS (Manually Operated Visual Landing Aid System) and manually control the ball and ultimately, the aircraft's glideslope.

[Hog_No32]

Not entirely new to me but interesting reads. Thank you gentlemen.