A2A's new 172 - torque not modelled?

[Greg Hollen 27]

Reading through several posts on A2A's support forums, it appears that their new 172 does not currently model any torque or gyro effect during takeoff and climbout.      Apparently, A2A were not happy with FSX's core flight dynamics in this regard, so they decided to simply abandon the FSX limited physics altogether (by purposely and unrealistically limiting torque effect in the 172's FDE), and instead plan to model torque and gyro effect with Accusim at some later point in the future.      As it stands now, however, takeoffs and climbouts in the A2A 172 can be performed without any rudder input at all.     Yikes much?      This is a pretty glaring flight physics omission, especially when modeling a premium priced trainer aircraft!

 

Frankly, the default FSX Cessnas are more realistic is this regard and I'm really scratching my head as to why A2A would release their 172 aircraft so 'underdeveloped'.      I can understand A2A wanting to model flight physics in a much more accurate way than the  FSX platform itself will allow, but to simply release an aircraft without torque and gyro effects at all is a little incomprehensible to me, especially given A2A's past accomplishments.   

 

Perhaps the A2A 172 is being targeted at a more enthusiast type of crowd, rather than more hardcore simmers with real-world flight experience, but I gotta admit that I just don't get it.    

 

 

[ryanbatc 12,857]

I'm not sure if there is really so much that people would notice...  Larry from these forums had a pretty good writeup about his thoughts and experiences (I can't seem to find his post it's probably burried in the A2A release thread).  I flew a c172 once and it was a N version.  I got my ppl asel in the warrior and don't remember too much right rudder on takeoff...

[Ponk 51]

My 172 is parked up in the hanger. I can't live with these flight dynamics. My pitch control is unbelievably sensitive and I can't fix it. The aircraft just doesn't fly as I know and expect it too. I commented on a2a and there are others with concerns.

 

I don't buy Carenado since years as I like to install, fly...and know it flys correct and feels right (the pmdg and realair way).

 

Looking at ways to get my money back on this product, if that's possible with a2a?

[Q_flyer 766]

 My pitch control is unbelievably sensitive and I can't fix it.

 

Changing this;-

 

[flight_tuning]

elevator_effectiveness=2

 

to this.....

 

[flight_tuning]

elevator_effectiveness=1

 

...made a huge improvement to the twitchy pitchy elevator for me.

 

Give it a go.

[Pict 15]

A real c172 (did my ppl and ir in a 172n as well) doesn't have that much torque on takeoff or climbout from my experience - most times i'm just resting my right foot on the rudder pedal without much pressure to keep her coordinated (i always made sure the small metal manual tab on the rudder had some left curve in it on my preflight so that was probably why).

 

 

The default 172 doesn't have much torque/p-factor even with the sliders all to the right - but FSX's native fdm harks back to the fs5.0 days at it's most basic (when a fast processor was 66mhz) so like its predecessors, it doesn't model torque/p-factor/prop gyro effects perfectly or rather it only models them at a very basic level.

 

 

To me the A2A's doing the smart thing by not modelling it in the basic fdm, as this will probably allow their Accusim addon to model these effects properly without having to waste processor cycles cancelling out the effects first, before modelling them itself.

 

 

--Xavier

[ryanbatc 12,857]

Yes the way you wrote that "rest my right foot on the pedal" is how I remember the Warrior.  I'm no expert on the C172 but that's just my experience in the warrior (160hp).

[LAdamson 240]

My comments from the other A2A thread...

 

 

------To give an example of required right rudder..... I was once flying a Cessna 172 (180HP) from the right seat, for three touch and goes for currency. On the second takeoff, my mind seemed to think I was flying left seat, and I pulled back the throttle, as I would the yoke in the left hand to rotate. With engine power at idle, the plane swung quickly to the right, as I was already applying right rudder to stay on the centerline. It happened so fast, that I dang near ran over the right side runway lights. What it shows, is that we're definitely using a fair amount of right rudder......even on those little Cessna 172s. For comparison, my Van's RV6 with the same 180 HP engine, took quite a bit more right rudder, with a heavier feel. It would push the left wheel down like crazy on a touch and go, with high power/low airspeed, but it didn't want to roll left with takeoff airspeed, either.----

 

 

Personally, I do have to have a sense of needing right rudder pressure on the roll and initial climb. It's one of those things, I first notice about any flight model, that requires it in real life. Even these little Cessnas and Pipers will all head to the left side runway lights, if you don't compensate. I had "use of rudder" pounded into my head, early in my flight training. It's stuck with me.

[ryanbatc 12,857]

Maybe I misread your post. Blah I've got no idea how the real one operates.

[Pict 15]

The amount of right rudder needed in the real 172 (at least in the 172n and 172p) seemed to vary depending on whether the metal manual trim tab on the rudder was adjusted or not.

 

My instructor loved to bend it towards the right to force me to use more right rudder (was "simulating" a higher performance aircraft as i was continuing onwards to the malibu and mu-2).

 

One of the 172s at the flight i did remember having to stomp on the right rudder as it has a rudder balance issue..buuut it was the easiest 172 to spin so it was my favourite (the others seemed too docile in stalls/spin).

[Scott - A2A 164]

Greg,

 

I’m going to assume you are a first-time Accu-Sim customer so let me try to explain our development philosophy.  Accu-Sim is our own, growing flight simulation tech / engine that we interfaced with FSX (we turn off areas of FSX and turn them over to Accu-Sim).  This allows us a great deal of freedom and capability, since it’s all our home grown technology.

 

After five years of development Accu-Sim now simulates the combustion engine in it’s entirely, the prop, and all systems (this is why we can "hot swap" a prop in flight and see not just a graphical change, but a change in performance).  However, FSX’s FM is quite good (and efficient).  So rather than a massive and complete replacement, the Accu-Sim plane runs a hybrid FM with Accu-Sim handling specific areas.

 

Take the C172 up and stall it in many different ways.  Try it with no power, nose level, nose high, etc.  Add power, try it in a bank, etc.  Notice how the nose responds to the throttle, and how and when the ailerons lose their effectiveness.   Much of what you see is true to the Cessna 172 and is being handled in Accu-Sim, not FSX.

 

However, the torque and slipstreaming in FSX just does not deliver the results we see in the real 172.  So we reduced it just to the level that it was not interfering so much.  But you still do need to use the rudders to fly properly.  Take the plane up in a 60kt ias climb and keep pulling back, using ailerons to keep the wings level.  You will see plenty of yaw that requires rudder to counter.  On my system, I also use some right rudder on takeoff and on standard climbs, more so in steeper climbs.

 

Moving forward, we do have new physics effects in development including new torque and slipstreaming effects.  When these are ready, they will come out in the form of one of our Accu-Sim Core Updates, currently at v.1.5.2 and can be seen here:

http://www.a2asimulations.com/forum/viewtopic.php?f=23&t=32774

 

Scott.

[ryanbatc 12,857]

Thanks Scott.

 

What I really liked so far is how the rudder effectiveness changes (quite dramatically) with airspeed.  I did a lot of xwind landings with and without flaps and at different speeds, and takeoffs with xwind and it performed really well... very cool.

[nudata 10]

It will only become better - THANKS :rolleyes:

[spilok 1,136]

Changing this;-

 

[flight_tuning]

elevator_effectiveness=2

 

to this.....

 

[flight_tuning]

elevator_effectiveness=1

 

...made a huge improvement to the twitchy pitchy elevator for me.

 

Give it a go.

Thanks G-400 Flyer,

 

This has REALLY cured the "twitchiness" of this plane.  Great fix.

 

Stan

[bluemanrom2 1]

Moving forward, we do have new physics effects in development including new torque and slipstreaming effects.  When these are ready, they will come out in the form of one of our Accu-Sim Core Updates, currently at v.1.5.2 and can be seen here:

http://www.a2asimulations.com/forum/viewtopic.php?f=23&t=32774

 

Scott.

 

Will the c172 benefit too ?

[Lewis B 14]

In the future yes it will be updated along with the CORE aircraft. One thing we have recently found is that the controller sensitivity has a massive impact on the percieved flight model. If you are running at 100% sensitivity you have a very short time between input and full deflection. This could explain why some are finding it so sensitive as they have a sensitve setting for controllers that might not really need it.

 

Additional Scott's done some tests in the real deal that we will be showing later