fenix flight dynamics

[ha5mvo 241]

So I hopped onto the Fenix bandwagon.

While the system simulation is quite impressive - on par with the FS Labs from initial impression, I keep wondering how accurate are the flight dynamics.

On initial climb for instance, I keep getting high pitch command with about 4000 f/m ROC for a GW of 66 tons. Is that realistic?? 

Before I get into a tedious series of pitch/power experiments, did anyone check it thus far?

Also, and this is something subjective that I can't back up with figures, but the FBW feels a bit "unstable". Removing the pressure from the stick will cause make the plane bounce back a little as if it needed a little bit of trim.

 

anyone with any input on this?

[Bobsk8 12,584]

3 minutes ago, ha5mvo said:

So I hopped onto the Fenix bandwagon.

While the system simulation is quite impressive - on par with the FS Labs from initial impression, I keep wondering how accurate are the flight dynamics.

On initial climb for instance, I keep getting high pitch command with about 4000 f/m ROC for a GW of 66 tons. Is that realistic?? 

Before I get into a tedious series of pitch/power experiments, did anyone check it thus far?

Also, and this is something subjective that I can't back up with figures, but the FBW feels a bit "unstable". Removing the pressure from the stick will cause make the plane bounce back a little as if it needed a little bit of trim.

 

anyone with any input on this?

A few Airbus Airline Pilots have commented that the Fenix  flight model is very realistic. There are hours and hours of Youtube Videos that Airline A 320 Pilots of made, and this is a frequent comment that they make. 

Edited June 2, 2022 by Bobsk8

[ha5mvo 241]

1 minute ago, Bobsk8 said:

A few Airbus Airline Pilots have commented that the Fenix  flight model is very realistic. There are hours and hours of Youtube Videos that Airline A 320 Pilots of made, and this is a frequent comment that they make. 

Impressions and "feeling" are subjective. I'm more interested in figures. I'd be surprised if I'm told that 4000 feet per minute is realistic for anything other than an empty plane...

[rick celik 1,243]

I’m sure they are talking about figures too when it’s coming from real airline pilots…who see the fpm in-front of them everyday. 

[Bobsk8 12,584]

4 minutes ago, Ridvan Celik said:

I’m sure they are talking about figures too when it’s coming from real airline pilots…who see the fpm in-front of them everyday. 

It amazes me that a few simmers, many of them who couldn't get a C 152 off the ground, tell us how they feel they  know more than an  Airline Pilot with an ATP rating , about the way a particular aircraft should handle.  

[Silicus 850]

Fenix said that they are building their own engine model, as there are limits to the current (MSFS) one. Right now it is about 6% off.

Also the CEO variant takes longer to go from take off law to climb law then the NEO, meaning it takes requires more time before the fly-by-wire system kicks in. Just some info.... 

[MrBitstFlyer 3,837]

23 minutes ago, ha5mvo said:

Impressions and "feeling" are subjective.

From simmers maybe, but from real world airline pilots that fly the real thing and get drilled in multi million pound simulators?

[sd_flyer 6,034]

29 minutes ago, ha5mvo said:

Impressions and "feeling" are subjective. I'm more interested in figures. I'd be surprised if I'm told that 4000 feet per minute is realistic for anything other than an empty plane...

Since bus drivers "feeling" not satisfying your interests why not A320 flight manual dig in performance charts and figure out the numbers ?

 

[MattNischan 3,778]

12 minutes ago, MrBitstFlyer said:

but from real world airline pilots that fly the real thing and get drilled in multi million pound simulators?

Very much so. Pretty much every aircraft dev will tell you that they will receive downright opposing suggestions from two different pilots all the time (who, generally don't at all have exact figures), and that often pilots "absorb" (for lack of a better term) a lot of flight model differences because they're used to, well, actually flying a plane, which is a much more feel and muscle memory sort of exercise than a test pilot type of situation where exact telemetry is also important.

Generally if the pilots are in a majority agreement you know you at least hit the feel enough so that it's in that muscle memory ballpark, but even still you can be off from book figures by a decent amount. Compounding that is that book figures are themselves not hugely precise: it's what a few planes did on average on a best-possible-average type day with humans at the stick. So often you have to really divine an alternate reality that compromises between all these different inputs.

On top of all that the million pound simulators are using table lookup physics which are derived from, you guessed it, the book figures, and they effectively have zero non-normal envelope data. So that adds another layer of inexactness. But it's good enough for training purposes (because again, good pilots "absorb" these differences, and the procedures are really what is being trained in these sims).

Edited June 2, 2022 by MattNischan

[ha5mvo 241]

3 minutes ago, sd_flyer said:

Since bus drivers "feeling" not satisfying your interests why not A320 flight manual dig in performance charts and figure out the numbers ?

 

for sure! just thought someone might have actually bothered doing it already...

[sd_flyer 6,034]

1 minute ago, MattNischan said:

 

Generally if the pilots are in a majority agreement you know you at least hit the feel enough so that it's in that muscle memory ballpark, but even still you can be off from book figures by a decent amount. Compounding that is that book figures are themselves not hugely precise: it's what a few planes did on average on a best-possible-average type day with humans at the stick. So often you have to really divine an alternate reality that compromises between all these different inputs.

I kind disagree! I were to test sim airplane in now way I could rely on muscle memory from real counterpart but rather on pitch attitude power setting and execrated airplane behavior . 

[sd_flyer 6,034]

3 minutes ago, ha5mvo said:

for sure! just thought someone might have actually bothered doing it already...

In this case I would rely on review of real bus drivers. I'm pretty suite something like that would immediately caught their eye. There are several of them I've seen on youtube

[ha5mvo 241]

Muscle memory is absolutely inapplicable on a desktop simulator, not unless you have a genuine airbus stick or a Boeing yoke. Even than, a "feeling" is not something you can carry over from real life experience to the sim. I KNOW that from my own GA experience and I have no reason to believe its any different for  bigger planes.  Otherwise the only  relatively reliable parameter is to compare the models behavior to the published figures.

[omarsmak30 4,067]

1 hour ago, ha5mvo said:

Impressions and "feeling" are subjective.

But you are on your desktop, what do you feel? 🤔

[RichieFly 728]

RE: The climb rate.

For what it's worth, I've heard one of the airbus pilot steamers comment that the climb performance is a little higher than real life for a given weight and temperature combination.

For me, it's really great...the aircraft.