[PFM] F-15C 1G stall characteristics. Harder to fly = more realistic?

[LJQCN101]

I've been testing the F-15C PFM for a period of time, got some really strange feeling in terms of pitch short period mode, dutch roll mode, inertia-coupling, departure/spin characteristics, etc.. So I wanna start with some simple flight characteristics such as 1G stall, and compare it to the description in the real life manual.

 

(Reference manual: T.O. 1F-15A-1)

 

Here's the video link :http://v.youku.com/v_show/id_XNzUzMTc5MzA4

 

As one can see, the AOA buffet is modelled quite well. Wing rock and yaw oscillation are not observable. And the worst part, I can't pull the aircraft above 38 units AOA, let alone to stabilize at 45 units. The aircraft just went roll departure everytime when reaching 35 units AOA, which reveals a poor departure resistance.

 

Here's a departure/spin susceptibility summary of a real life F-15. If it were me to fill in the blanks for DCS F-15C, I won't give any words similar to "Resistant".

 

So what is called "Resistant" then?

 

In December 1979, the NASA Langley Research Center conducted a study on stall/post-stall characteristics of a real-time simulated fighter. During the test, the control system is modified to decrease the susceptibility to departures while not degrading maneuverbility and control response. There're Basic Control System, which has least anti-departure ability; Control System B, and Control System C.

 

Finally in Control System C, with full lateral stick input applied at 0.6Mach and an altitude of 9144m, followed by a full nose-up pitch command, the control system effectively handled the aircraft during the whole 11-sec-test so that there're no pitch/roll departure occured compared to the Basic Control System.

 

And that is called "Resistant". With such departure susceptibility as in DCS F-15C, I wonder if it represents the real one, will it even be approved to put into production.

[panther494th]

Hi been interested in the f15 for years and have met guys that know and seen them dog fight for real over my house . i know you get guys that say learn to fly it but.

The f15 is a stable platform it fly in air and on ground real life. so the physics' are to sensitive in game .if they want to make the f15c diffrent put some fire control on it.

so please fix .

[theropod]

there is nothing to do except wait for those problems corrected when it is out of beta.

[Sabredog]

I'm disappointed that Belsimtek have left the F-15 flight model in such an unfinished state for this long. No wing rock, incorrect departure AoA and a tendancy to yaw into crosswinds are just a few of the problems. These issues really should have been addressed in a patch by now.I am worried that with Belsimtek not finishing other modules to what I consider to be a complete standard, these issues will persist and be ignored. The Sabre may be the last module I buy from Belsimtek if they don't add EGT modelling to the Huey and finish the F-15 flight model.

[theropod]

I'm disappointed that Belsimtek have left the F-15 flight model in such an unfinished state for this long. No wing rock, incorrect departure AoA and a tendancy to yaw into crosswinds are just a few of the problems. These issues really should have been addressed in a patch by now.I am worried that with Belsimtek not finishing other modules to what I consider to be a complete standard, these issues will persist and be ignored. The Sabre may be the last module I buy from Belsimtek if they don't add EGT modelling to the Huey and finish the F-15 flight model.

 

then ED may handle this PFM improvement not Belsimtek because this is Eagle Dynamics product.

[Davis0079]

to the best of my knowledge, although they "helped" do some things, the Flaming Cliffs F-15c is not Belsimteks responsibility...otherwise it would be in their threads....

 

 

...but yes...the F-15 flight model is still being tweaked...constructive criticism and links to good documentation is always appreciated....

Edited August 11, 2014 by Davis0079

[Sabredog]

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

 

The flight model is Belsimtek's work and it's up to then to finish it.

[theropod]

belsimtek seems busy with their beta products and upcoming products.

 

please ED takeover F-15 improvement!

[blkspade]

Its funny that someone else has noticed this. I was just looking into info about the F-15's handling a few days ago and came across a rather lengthy document of a report on the eagle's wing rock behavior. It clearly missing in the PFM, and I'm guessing the spin is a very early attempt at implementing it. For now it at least helps to have a little curve in the pitch and some dead zone in the roll just to cancel out the little incidental lateral stick while pulling.

[Exorcet]

belsimtek seems busy with their beta products and upcoming products.

 

please ED takeover F-15 improvement!

I think the FM is doing pretty well. As far as I know it's still in beta. They were busy before increasing aircraft stability, and it was noticeably improved. Some more things might need tweaking, but as it is the plane flies pretty well and is fairly convincing. The biggest issue for now is probably the lack of wing rock, but I'd say that worrying about that bit being left out is a bit premature at the current time.

 

Also, let's remember that there's going to be some error between the sim and reality.

[blue 22]

from the article I read its a AFM not a PFM it its going to be set in flaming cliffs only alone mods have PFM the clickable cockpit and things mention above for example a-10c,ka-50, huey and the newer models are PFM.

 

if it is a DCS f-15c then the PFM must have the clickable pit as well.. just sayin.

[blkspade]

from the article I read its a AFM not a PFM it its going to be set in flaming cliffs only alone mods have PFM the clickable cockpit and things mention above for example a-10c,ka-50, huey and the newer models are PFM.

 

if it is a DCS f-15c then the PFM must have the clickable pit as well.. just sayin.

 

The FM in both of those stands for Flight Model, which has basically nothing to do with the cockpit.

[archer86]

from the article I read its a AFM not a PFM it its going to be set in flaming cliffs only alone mods have PFM the clickable cockpit and things mention above for example a-10c,ka-50, huey and the newer models are PFM.

 

if it is a DCS f-15c then the PFM must have the clickable pit as well.. just sayin.

 

http://forums.eagle.ru/showthread.php?t=122801

 

here,you can read more certain explanation.

[blue 22]

ok I read.. and I have been corrected sorry. I just want another pit to click, shutting up now

[SDsc0rch]

subscribing to this thread...

[LJQCN101]

I think the FM is doing pretty well. As far as I know it's still in beta. They were busy before increasing aircraft stability, and it was noticeably improved. Some more things might need tweaking, but as it is the plane flies pretty well and is fairly convincing. The biggest issue for now is probably the lack of wing rock, but I'd say that worrying about that bit being left out is a bit premature at the current time. Also, let's remember that there's going to be some error between the sim and reality.

 

Totally agreed. It seems to me that the lack of a specific flight characteristic such as wing rock is a less concerning issue than what already exists. May be I'm too sensitive about handling quality and stability issues.

 

For example duiring my test on pitch short period mode and dutch roll mode of the aircraft, I observed an abmormally high dampening momentum in both pitch and yaw axis no matter CAS is on or off. But that's easy to fix I think, and hopefully we'll see a pretty satisfying PFM at last. :thumbup:

[Bolt-1]

. if it is a DCS f-15c then the PFM must have the clickable pit as well.. just sayin.

 

If you notice with the appropriate key board commands some of the switches, knobs, and dials move in the pit.

although not directly clickable in the pit with the mouse