Flying an ICLS approach

[Hippo]

Regarding number 1

TBH, I wasn't even considering VSI lag, and had assumed it's not modelled in DCS. I assume that the lag effect that is being modelled is engine spool time, which seems to be very long. Does it seem too long to you? I was referring to very minor thrust adjustments when I'm already very close to s+l.

 

Regarding number 2

I get that adjustments will be necessary, but continuously? (calm day)

[G B]

TBH, I wasn't even considering VSI lag, and had assumed it's not modelled in DCS. I assume that the lag effect that is being modelled is engine spool time, which seems to be very long. Does it seem too long to you? I was referring to very minor thrust adjustments when I'm already very close to s+l.

 

 

I get that adjustments will be necessary, but continuously? (calm day)

 

 

When I mentioned lag with a high VSI I wasn't referring to the instrument itself. I was describing that the higher momentum will take longer to overcome.

 

 

For the second one, on a perfectly smooth day, maybe not "continuous" as in every single moment, but continuous as in a regularly occurring and frequent amount. Again, IRL there's no oscillations as you described, but the pilot is managing the straight and level flight. It is just subconscious and easy when trimmed out. edit: It won't oscillate around 0 VSI while its trimmed out. But it's possible through small corrections a very minor PIO may cause what appear to be "oscillations"

Edited April 25, 2020 by G B

[Ramsay]

2. the fpm very slowly oscillates up and down around a central point, rather than settling

 

It seems to be impossible to end up with 0 vv, without constant throttle corrections, no matter how small.

 

This is what I see in the sim, does the real aircraft behave in this way?

 

The behaviour I see in the descent is the same in that I can't maintain a constant rate of descent - I see the same oscillations once I stop moving the throttle. I would expect that the vv would settle to a constant value (on a calm, no turbulence or gusts, day).

 

There is a long discussion thread on the FCS control logic and how accurate it is/isn't.

 

https://forums.eagle.ru/showthread.php?p=3541649#post3541649

 

There's a thought that in Powered Approach mode the FCS should reference pitch, rather than AoA and this causes the oscillations (phugoid) seen in DCS.

 

The FCS discussion is somewhat technical and although I can follow it, I don't have the maths/knowledge to judge which view is correct.

Edited April 25, 2020 by Ramsay

[Flamin_Squirrel]

1. it now takes several (around 3) seconds for this thrust increase to cause a change in fpm (flight path marker) motion / vv.

 

It takes nowhere near that long. You need to make small corrections more often.

[G B]

It takes nowhere near that long. You need to make small corrections more often.

 

This.

[tweet]

Hippo, there is some really good advice people have been offering to you. Some not so much but everyone is trying to help. May I offer you some advice and maybe help you find a way forward?

 

My profile is a very short snapshot of my life flying, 38 years. One of the most rewarding things I've ever done is instructing at USAF UPT and PIT. PIT is the school where UPT IPs are trained. We taught those who would be teachers. I was a flight commander and a flight examiner in that world for six years and have something short of 3000 hours in the Tweet, T-37, most of it instructing. There's little I haven't done to teach pilots. Let's see if I can help you.

 

Human babies learn to roll around on the floor then to sit up then to crawl then to pull themselves up to a standing position and only then do the begin to walk and finally run and jump. Flight training works on exactly that same model - a building block process of the simple leading to the more complex.

There is very little that is more complex than flying an AOA overhead traffic pattern and approach to a freaking moving boat. A pilot uses every single type of maneuver that is possible in a fixed wing airplane in the traffic pattern. The best way to learn is by breaking the complex down into small pieces and practice each until you have the pieces down cold. Only then can you put all of them together to learn the entire evolution.

 

This is going to be really basic. I'm doing it like this because missing an early part and not having it mastered causes problems in more complex maneuvers. Trying to make corrections on the fly is a later skill that you will learn if you are persistent and practice, practice, and practice until you do these things in your sleep.

 

1. Straight and level unaccelerated flight - Practice constant altitude, constant heading, constant airspeed flight. Let's pick 350 KCAS at 800' AGL over the water on a fixed heading. Do this until you can stay within about 20-30' of 800', +/- 5 knots, +/- 2 degrees of heading for several minutes. This is basic and the hardest maneuver a pilot does. Nothing is supposed to change but it does and if you aren't constantly checking all three repeatedly one will wonder. This builds your scan and muscle memory. This is also important because getting to the break at altitude, on airspeed, and on the proper track for initial is the beginning of everything else. Errors here affect the rest of the pattern and approach and you ability to fly them.
   
2. Steep turns - Start with 60 degree level turns, 2 G, at a constant airspeed. You need to be able to maintain +/- 50' and +/- 5 knots for two 360 degree turns consistently. Then do the same for 3 G. You figure out the bank angle. Then 4 G. Move on when you get these two items sorted out.
   
3. During the two previous steps you should be remembering the power settings for each maneuver. Those settings are your starting point when trying to stabilize your airspeed. Later you'll get some ball park figures for different weights and drag indexes/weapon loads. Remember baby steps. You should also get lots of practice trimming for zero stick force and figuring out how much is needed when changing airspeed. Benchmark pitch attitudes and power settings are the basis for the precise flying you'll need for everything but especially to land on the boat. One great technique for discovering starting power settings is to engage ATC and watch what the machine does.
   
4. Do steps 1 and 2 but practice airspeed changes.
   
5. Do steps 1 and 2 but practice constant airspeed and constant rate descents and climbs. Note how much power change it takes to establish then stabilize 200, 500, and 1000 FPM descents and climbs. Do the same for returning to level flight.
   

I'm sorry if you read this far expecting to have solved the issue that caused you to make your post. This is the beginning. You will have everything you need to begin working to solve your problems in the pattern if you work on these diligently and demand precision of yourself. Yes, it's boring if you choose to think that way. Otherwise, you will flail around and may finally find something that more or less works. The choice is yours. Learn to fly well or just accept what you manage to figure out.

 

Last point, walking the throttles. Yes, it is an awesome technique. It's something I taught and used my entire career. I use it in DCS to good effect for AR and around the boat. Over controlling power is a serious challenge to precision flying. It's most common in the traffic pattern, close formation flying, and AR (Air Refueling). Small movements are difficult when you use big arm muscles but using your hand and fingers is much easier. Needing big power changes is a symptom of a poor crosscheck.

 

A pilot cannot ever afford to concentrate on just one parameter like heading, airspeed, or altitude. When you concentrate on one another will always, not may but always, get out of whack. You have to constantly move your eyes from attitude to heading to altitude to airspeed and toss in a peek at the power every few cycles. You need to know what pitch, bank, and power setting will give you the performance you're looking for. Then you have to figure out which control or combination is needed. Fix one, keeping the scan going, then work on another one. The faster you can make the process the easier flying well will come.

 

Contact me when you can do these exercises within the parameters I suggested. I'll tear down the rest of the pattern for you then. It may take a few hours or a few weeks. You'll get out what you put into it. Good luck.

[Deano87]

Flying a carrier approach in the hornet is similar to formation flying or air to air refuelling, if the throttles are stationary = you're doing it wrong.

 

You want small movements, very often. This makes the response time of the engines much less of an issue.

[Theodore42]

Theodore42 on your video I can see what other exp. users saw on my own "wrong" way to do (so now I do it, at least for this point, correctly) :

Your "E" bracket is totally moving up and down during all final approach, instead of being Always perfectly centered with the Velocity vector. That is meaning you are using pitch which is wrong (it would only be correct for small adjustment for Desc.Rate before being on glide slope if you were using ATC approach mode).

 

My e-bracket is all over the place because I'm dealing with 10 feet per second of turbulence. So set the turbulence level to 100 and give that a try and tell me how easily you fly the ball.

:P

I had the FLCS page up so you can see what the control surfaces are doing.

 

Like I said, in my post, some people will be able to cope with one axis, better than i can with 2 and you are apparently proof of that.

 

As for using the throttle levers individually, RL pilots use that technique for landing, and AAR, so i guess you are just special.

 

IMO a newbie would be better off just worrying about 1 throttle axis.

And I am special, thanks for noticing!

:D

 

EDIT from the FUTURE:

@ toutenglisse

YES! I'm so glad you went and did that!

Was it fun?

:)

Edited April 28, 2020 by Theodore42

[toutenglisse]

My e-bracket is all over the place because I'm dealing with 10 feet per second of turbulence. So set the turbulence level to 100 and give that a try and tell me how easily you fly the ball.

:P

I had the FLCS page up so you can see what the control surfaces are doing...

 

Sorry I missed all the context. I tried and no surprise it was horrible. I put max temp (50°c) and max turbulence - but the max was 60*0.1 not 100 (100 went back to 60 when clicking outside the box).

 

EDIT : my units are meters/sec not feet/sec...

 

Edited April 26, 2020 by toutenglisse
in post

[Greyman]

IMO a newbie would be better off just worrying about 1 throttle axis.

:D

 

If said newbie has only one axis on their throttle, I'd have to agree. :)

[CBStu]

Flying an ICLS approach is very difficult. It takes a ton of practice. I started w/ straight-in approaches and can do them pretty well, now that I have done 1000+ of them. The FA-18 never settles to where you don't need to adjust the throttle. This is the way it is so may as well get used to it. Is the throttle response a little slower than IRL? I don't know, maybe it is. Doesn't matter though. This is the way it is. When I decided to get serious about carrier traps I realized the throttle on my VKB stick was too coarse. So I epoxied an extension onto it which helped a little. But finally I stepped up and spent the $250 or so to buy a Thrustmaster Warthog throttle. It is a revelation. Now, instead of having 1.25 inches of throttle movement off to full, I have maybe 5 inches. This is so much better. My summary; carrier traps are really hard to do so they require a lot of study, a lot of practice, and a really good throttle. There is nothing wrong w/ the DCS FA-18 modeling.

[TonyG]

Throttles are constantly in motion. Flying an ICLS is fairly straightforward, but you should be switching to visual (ball) by 3/4 mile anyhow.

 

Lots of anticipation needed because we're missing the seat of the pants feel that you have in RL.

 

 

 

I think a properly flown CASE I approach has more challenge to it than a properly flown CASE III approach in the sim. CASE I is far more dynamic, requiring a lot of config changes in a short period of time. CASE III, you've got a 10nm run in to get things configured and trim sorted out before the descent at 3nm.

[Bunny Clark]

1. it now takes several (around 3) seconds for this thrust increase to cause a change in fpm (flight path marker) motion / vv.

 

2. the fpm very slowly oscillates up and down around a central point, rather than settling

 

It seems to be impossible to end up with 0 vv, without constant throttle corrections, no matter how small.

 

This is what I see in the sim, does the real aircraft behave in this way?

 

I've never flown a Hornet in real life, but my experiences flying real and virtual aircraft, including quite a bit of DCS Hornet have informed me:

 

1. Yes, this is expected. One of the primary disadvantages of jet engines is that they do not respond quickly to throttle input. The Hornet actually has pretty responsive engines, there are jets out there that take as long as 8 seconds for engine RPM to stabilize after a throttle change. This problem tends to be more pronounced at lower power settings as well, making landing even more difficult.

 

2. No aircraft will ever fly perfectly strait and level all on its own without any control input, there are just too many variables. The Hornet seems to fly very stably on its own when in flight configuration because it has an auto trim system that is constantly adjusting the aircraft trim to 1G. When in landing configuration that goes away, as the Hornet switches to an AoA trim system, and you'll start to see little disturbances disrupt aircraft flight path. You will need to constantly fly the aircraft.

 

Overall, you will be making constant power, pitch, and roll adjustments through the entire landing circuit. Do not expect that you'll be able to dial in the perfect amount of power and ride that all the way in, it just doesn't work that way. With jets engines one way to compensate for the lag in throttle response is to use multi-part inputs. Rather than bumping the throttles a tiny bit in the direction you want to correct towards and waiting to see a slow response, push them further than you need to and then bring them right back. This will get you both a faster response and reduce the tenancy for the jet to "float" on lagging throttle inputs.

[Diesel_Thunder]

I've put a lot of practice the past few days doing nothing but touch and goes (boring, but necessary). Learning to fly the AoA bracket with the throttles really paid off, and I stopped fighting the FCS when trying to pitch with the stick when the gears and flaps are down. I'm constantly adjusting the throttles to maintain that glideslope. I've gotten way better doing pattern work over land, and was finally able to get a few carrier traps. There is little margin for error when trying to land on the boat.

 

I only recently picked up the Hornet, and carrier ops is a huge challenge. It has kinda forced me to learn more and become a better pilot. That practice has paid off nicely, not only with the Hornet, but with all of my planes. The Viper is similar in its landing behavior. I had the Hog for quite some time but always landed it poorly (high and fast), and am now able to quickly get it on AoA in landing configuration. And the Mustang is more manageable now too.

 

The Hornet and the Viper both require constant attention to the throttle. The Hog is much more forgiving when it comes to throttle management. Gear, full flaps, and some speed brake, and you can usually find a nice happy spot for the engines, with minor corrections here and there.

 

This video by Lex Talonis really helps put it in perspective, and has some great info:

Edited April 27, 2020 by Diesel_Thunder

[Phantom453]

I just wanted to throw in here on Case III approach landings to seek a bit of advice on flying the ICLS needles in the Hornet.

 

Back in the day when I was constantly flying the the A-10C, I got reasonably good with ILS approaches, to the point where I could put it down on the the threshold every time in the thickest fog possible. So I feel I understand the concepts and steps necessary for an ICLS approach.

 

However, over the last week or so, I've been training on the Hornet doing ICLS approaches. Mostly during the day because I'm out of practice and because the carrier night landing lights are not working ATM. My main issue is being able to follow the needles down for a successful approach with the Hornet. I find that despite my adjustments vertically or horizontally to get on glide slope, there seems to be very little change on the position of my aircraft glide slope marker in relation to the HUD ICLS needles. So much so, that I seem to be chasing to the needles to the point that I'm well outside the correct approach to the carrier (I can see it because I'm practicing during the day time).

Am I doing something wrong with my approach? I'm coming in at 1,200' along the TACAN set to the BRC and then getting on-speed about 8 miles out at 1,200' waiting for the needles. From that point it becomes a mess!

 

 

I'm starting to wonder:

Is it just me out of practice?

Are the ICLS needles working correctly ATM and representing a 3 degree glide slope accurately in line with the final approach for landing? To me the beam seems to be way to wide?

Is it just me out of practice?

Is it th lack of fidelity with the smaller needles on the F/A-18 HUD compared to the A-10C needles?

Is it just me out of practice?

Am I doing something else wrong?

 

I'd really appreciate any advice/ tips on this from anyone who feels they have a sound grip in doing an ICLS approach to the carrier.

[G B]

TACAN BRC is not used during case 3. You use Final Bearing. BRC won’t be aligned with the ICLS.

[Phantom453]

TACAN BRC is not used during case 3. You use Final Bearing. BRC won’t be aligned with the ICLS.

 

Thanks for that.

 

I've just re-watched Matt Wagner and Jabber's Case III vidios again and picked up on that point.

 

Any other pointers? Thanks for your reply. :thumbup:

[CBStu]

Phantom, the ICLS localizer line (the vertical one) shows up quite far away. I haven't specifically checked this but it's some where in the 12 mile range. But the glide slope line (the horizontal one) only shows up at about 6.5 miles out on a straight in approach. Are you flying the included mission in either the Caucuses or Persian Gulf 'Instant Action' list? I fly the PG because the water is a nicer color but the missions seem to be identical. I just flew it to check things. By hitting active pause as soon as it starts and setting up tacan and icls, I see it starts 8.5 miles out at 2000 ft. The localizer shows immediately and staying at 2000 ft the glide slope shows at 6.5. In this mission you start lined up w/ the boat to do a pattern approach. I usually do it straight in so I need to fly significantly to the right to get the localizer centered. I use Banklers for practicing pattern approaches.

Edited April 28, 2020 by CBStu