AFM in laymen's terms...?

Can someone please explain in laymen's terms how AFM affects takeoffs, flight, and landings compared to the original flight modelling.

ie: F-15C new AFM modelling in ver. 1.2.8 vs. ver. 1.2.7 [without AFM].

I've read some of the posts but all that's mention is technical.

Thank you.

More realistic flight.

Try the free Su-25. If the technical stuff doesn't make sense to you, trying it out might be the best course of action to get an understanding.

In very simple terms, the calculations required to simulate the physics of flight are more detailed and robust with the new PFM. The net effect, to get to the point, is a more authentic flight experience. In this way, the aircraft should feel more like the real thing when you're flying it.

It has a vary enjoyable quality when landing and flying as opposed to f***k it.

Can someone please explain in laymen's terms how AFM affects takeoffs, flight, and landings compared to the original flight modelling.

ie: F-15C new AFM modelling in ver. 1.2.8 vs. ver. 1.2.7 [without AFM].

 

I've read some of the posts but all that's mention is technical.

 

Thank you.

Takeoff - The plane has mass while on the runway. With SFM, you could input extreme left/right rudder commands the plane would instantly obey without any secondary effects. AFM creates a more realistic response, the plane doesn't change directions instantly. The weight on the wheels is also modeled which has an effect on traction, stability, and the planes orientation (you can roll the plane over like a top heavy car).

Landing - Similar to take off. The most noticeable difference is the instant of touch down. The SFM model basically turned off the aerodynamics when the plane successfully landed and ignored how the plane actually landed. AFM models all the forces all the time, and reaction forces on landing are considered. You won't magically stick the ground when coming in too hard with AFM, unlike SFM which breaks reality.

In flight, weight balance matters and as a consequence so does trim in roll and yaw. You also feel the weight of the plane in maneuvers, and initial reactions (like how quickly pitch changes with max stick back) are different. Edge of the envelope flying is completely different. Stalls during maneuvers can lead to spins instead of just a scripted loss of altitude.

In my experience there isn't really any point where the difference between AFM and SFM isn't seen.

Takeoff - The plane has mass while on the runway. With SFM, you could input extreme left/right rudder commands the plane would instantly obey without any secondary effects. AFM creates a more realistic response, the plane doesn't change directions instantly. The weight on the wheels is also modeled which has an effect on traction, stability, and the planes orientation (you can roll the plane over like a top heavy car).

 

Landing - Similar to take off. The most noticeable difference is the instant of touch down. The SFM model basically turned off the aerodynamics when the plane successfully landed and ignored how the plane actually landed. AFM models all the forces all the time, and reaction forces on landing are considered. You won't magically stick the ground when coming in too hard with AFM, unlike SFM which breaks reality.

 

In flight, weight balance matters and as a consequence so does trim in roll and yaw. You also feel the weight of the plane in maneuvers, and initial reactions (like how quickly pitch changes with max stick back) are different. Edge of the envelope flying is completely different. Stalls during maneuvers can lead to spins instead of just a scripted loss of altitude.

 

In my experience there isn't really any point where the difference between AFM and SFM isn't seen.

So disabling 'natural head movement' and/or 'head shift movements on/off' does not affect AFM appreciation?

The Mig 29 I take it does not have AFM.

Thank you Exorcet and to all.

Much more twitchy

Will fall over while taxi-ing VERY easily

Flying at high altitude, well, don't make any sudden moves or you'll be violently spinning and spiraling downwards.

Flying at low speed , same thing .

Engines seems to have gotten a boost.

Making sustained turns can get a bit weird (same speed same joystick position same everything, but after a few seconds > spin out of control )

Landing, a lot harder

Wheelbrakes , they don't do much anymore

Air brake at low speeds , well, same thing doesn't do much

Out of the top of my head ^

I've never fallen over while taxing.

Landings are easier for me.

Much more twitchy

 

Will fall over while taxi-ing VERY easily

 

Flying at high altitude, well, don't make any sudden moves or you'll be violently spinning and spiraling downwards.

 

Flying at low speed , same thing .

 

Engines seems to have gotten a boost.

 

Making sustained turns can get a bit weird (same speed same joystick position same everything, but after a few seconds > spin out of control )

 

Landing, a lot harder

 

Wheelbrakes , they don't do much anymore

 

Air brake at low speeds , well, same thing doesn't do much

 

 

Out of the top of my head ^

Yikes!...and pilots find this appealing?

Yikes!...and pilots find this appealing?

That question does not make sense ... ;o)

The question should be, "and pilots find this more realistic behaviour appealing?" and the answer will be most likely be "yes". :D

That question does not make sense ... ;o)

 

The question should be, "and pilots find this more realistic behaviour appealing?" and the answer will be most likely be "yes". :D

And I would agree with you if in fact it is realistic behaviour...that's why I appreciate everyone's feedback.

Based on some opinions it would seem that some feel you are losing more realistic behavior than you are gaining with the first offering of F-15C AFM

Just read this article, interesting:

http://www.belsimtek.com/news/217/

Much more twitchy

 

Will fall over while taxi-ing VERY easily

 

Flying at high altitude, well, don't make any sudden moves or you'll be violently spinning and spiraling downwards.

 

Flying at low speed , same thing .

 

Engines seems to have gotten a boost.

 

Making sustained turns can get a bit weird (same speed same joystick position same everything, but after a few seconds > spin out of control )

 

Landing, a lot harder

 

Wheelbrakes , they don't do much anymore

 

Air brake at low speeds , well, same thing doesn't do much

 

 

Out of the top of my head ^

Very accurate layman's description :thumbup:

I like the dynamic response of the AFM, but the sensitivity needs to be just a little more forgiving.

I'm also finding that engine shutdowns occur more often, (not stalls but complete engine shutdowns) especially during rigorous combat and aerobatic maneuvers.

Bottom-line: Practice up on your in-flight engine recovery routines and spin recovery. Because with the new F-15C AFM, you'll be using that skill frequently.

Quote:

Originally Posted by Maximus_Lazarus

Much more twitchy

Will fall over while taxi-ing VERY easily

Flying at high altitude, well, don't make any sudden moves or you'll be violently spinning and spiraling downwards.

Flying at low speed , same thing .

Engines seems to have gotten a boost.

Making sustained turns can get a bit weird (same speed same joystick position same everything, but after a few seconds > spin out of control )

Landing, a lot harder

Wheelbrakes , they don't do much anymore

Air brake at low speeds , well, same thing doesn't do much

Out of the top of my head ^

Very accurate layman's description

I like the dynamic response of the AFM, but the sensitivity needs to be just a little more forgiving.

I'm also finding that engine shutdowns occur more often, (not stalls but complete engine shutdowns) especially during rigorous combat and aerobatic maneuvers.

Bottom-line: Practice up on your in-flight engine recovery routines and spin recovery. Because with the new F-15C AFM, you'll be using that skill frequently.

From what you posted sounds like the new F-15C AFM needs a lot of adjusting before it can be called realistic

It's a lot more realistic than the SFM that used to be there in 127-. Sure it's still in beta so tweaks are to be expected but the main thing about AFM/PFM - dynamically calculated behaviour is there. The aircraft just "feels alive" as opposed to the static modeling of the SFM that we used to have. It's actually pretty amazing - the new flight model IS a huge improvement over the old one, no question about that.

If you fall over while taxing then you are going to fast and or turning to sharp...

It's all good, except instantaneous spinning... just watch f15 videos in youtube.. in DCS you can't pull a little without starting spinning around, dammit. Also you can pull down like crazy. Something is definitely still wrong there :P

From what you posted sounds like the new F-15C AFM needs a lot of adjusting before it can be called realistic

I think Maximus' post was exaggerated. I've never even come close to falling over while taxiing. You would have to deliberately try to fall over to do it. At normal taxi speed, the F-15 is rock stable.

The F-15 does seem to be a little unstable with some hard maneuvers, but it's nothing you can't prevent after flying on the limit a few times to adjust. It's much better than scripted SFM stalls in any case.

Wheelbrakes and airbrake do plenty. They just not reverse rockets like they were with SFM.

Thank you all for your feedback!