Thursday, January 3, 2013

T-45C Goshawk updated to version 2.32


I am sorry to release an update so soon, but the latest Goshawk version (2.31) had some issue in the new flight model that needed to be addressed, specifically the stabilizers and trim authority were not strong enough to maintain the proper landing speed and attitude without huge movement of the control stick.
Aside, I was notified that the roll rate was signficantly slower than the real deal, and so I improved the roll rate too (which is now in the area of 170° - 180° /sec as per NATOPs value). Changes are as follows.


VERSION 2.32
- Roll rate increased and now much closer to the NATOPs value
- Increased stabilizer and stabilizer trim authority


Latest version 2.32 can be downloaded from the side bar, while files at avsim and flightsim are being uploaded as I write.
Since the only thing that is changed is the aicraft configuration file, you may want to dowload that file only by using the link below.

DOWNLOAD aircraft configuration file only by clicking HERE

Hopefully there will not be any further change or update in the near future. Sorry for the incovenience!

19 comments:

Anonymous said...

Dino great job on this T45 I learned how to land with this aircrft, it is great, onething I found in the aircraft.cfg that has been there from befor is this

[fuel]
LeftMain = -0.0, 0.0, 1.50, 219, 213.5 ; Fuselage Bag Tank //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
RightMain = -0.0, 0.0, -1.0, 219.0 213.5, ;Integral Wing Tank //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)

I beleive it should be

[fuel]
LeftMain = -0.0, 0.0, 1.50, 213.5 , 8.0 ; Fuselage Bag Tank //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)
RightMain = -0.0, 0.0, -1.0, 213.5 , 8.0 ;Integral Wing Tank //Longitudinal (feet), Lateral (feet), Vertical (feet), Usable(gallons), Unusable (gallons)

regards Jorge

Dino Cattaneo said...

Thanks Jeorge

I believe you are right, although it seems to me that within the simulator the available fuel quantity seems OK... so this is not a show-stopper issue and will keep it for a further update.

Brandon said...

Unfortunately, it seems this FDE update causes some problems. The pitch trim is indeed better, but the roll stability is poor. At most speeds below 350 kts, a full stick roll deflection causes the plane to depart controlled flight, due to a yaw moment. Its like there's some sort of adverse yaw thing going on. This happens regardless of weight, thrust, or realism settings. It can be partially controlled with rudder input during the roll, but the T-45 shouldnt need such rudder input for a coordinated aileron roll.

ScimmiaSpaziale said...

In Italy we have a saying: "Squadra che vince non si cambia" (Roughly: you shall not change a winning team). That is to say I'd have probably done a better job by not changing anything.

Very few people complained about the original T-45C flight model, and I have tried to follow the suggestions of a tiny minority. I also should have done much more testing myself. In this case, for example I have focused too much in following the maximum NATOPs values in this part:

11.2.1.1 Cruise Configuration. Roll control is good throughout most of the flight envelope and aileron forces are independent of airspeed. The aircraft responds quickly to roll initiation. Typically maximum roll rates are 160 to 170 degrees/
second and are obtained from 350 to 400 KIAS below 0.85 Mach, however, roll rates up to 270 degrees/second can be experienced with large lateral inputs at 0.82 to 0.84 Mach.

Other relevant sections are:

11.3.2.2 Roll Performance. At Mach numbers up to 0.9, aircraft response to both small and full lateral inputs in 1g flight is crisp and predictable.
Roll rates of up to 180 degrees per second can be achieved between 0.7 to 0.9Mach. During loaded rolls, the aircraft exhibits a tendency to unload, losing up to 2g’s at higher entry load factors. During loaded rolls at high subsonic Mach numbers
(greater than 0.8Mach), roll response can be unpredictable. Loaded aileron rolls in the low
transonic region (0.8 to 0.9 Mach) can produce large roll rates in excess of 260 degrees per second due to reduced roll damping at AOA near
stall.

Severe roll departures should happen only in these conditions:

11.6.5.3 Coupled Roll Departure. It has been predicted analytically that lateral stick or coordinated lateral stick and rudder pedal with full
forward stick held through more than 180 degrees of bank angle change could result in a coupled roll with roll rates in excess of 500degrees/second. Due to the severe nature of this predicted departure mode, it has not been flight tested and, therefore, its existence has not been verified. Roll rates this high would be damaging to the wing structure of the aircraft.

Another big defect, IMHO, is that now full "pull" deflection of the stick may cause the a/c to overstress too easily.

I am sorry for the poor quality of the recent releases, although I still believe this FDE is a step in the right direction.

ScimmiaSpaziale said...

Other relevant sections:

11.6.2 Lateral Stick Rolls. During lateral stick rolls above buffet onset, the aircraft rolls in the
direction of the applied lateral stick. However,an abrupt pitchup due to inertial coupling, or mild roll oscillations may be experienced during the roll. During maneuvers near full aft stick, a large amount of sideslip is usually present as the
lateral stick is neutralized following bank angle changes near 180 degrees. This sideslip generally results in an additional uncommanded roll in the direction of the original roll command or as much as 180 degrees due to strong lateral stability.
However, depending on control input timing,the aircraft could experience no additional roll or a slight nosedown motion or unload. If controls are neutralized, all rates will return to zero following the uncommanded roll.
Peak roll rate increases with increasing Mach number. Roll rates in excess of 250 degrees/second may be encountered in the 0.8 Mach
number region when using large lateral inputs.
The magnitude and frequency of the roll rate oscillations also increase with increasing Mach number. If aggravated controls are maintained,
the roll oscillations can diverge and couple the aircraft into a pitchdown departure as described
in paragraph 11.6.5.1. Rolls below 8 units AOA are generally free from the oscillations experienced at high AOA; however, the aircraft may experience a forward stick departure characterized by a rapid buildup in sideslip, as described in paragraph 11.6.5.2.

11.6.3 Coordinated Lateral Stick And Pedal Rolls. Rolling with coordinated lateral stick and rudder will always produce a faster roll rate than when rolling with lateral stick alone or rudder alone. However, at high speeds, the additional increase in roll rate due to the rudder is very small due to the small rudder deflection angles
which can be generated. Maneuver dynamics associated with aggravated control inputs at AOA below 8 units are degraded from those at AOA above 8 units. During flight test, full input 180 degree coordinated rolls at less than 8 units AOA did not result in departure, however, the
rudder did tend to lock out during some maneuvers. This rudder lock out tendency is a strong indication of impending departure. Full coordinated
input rolls held through more than 180 degrees of bank angle change at less than 8 units AOA may result in a violent pitchdown departure as described in paragraph 11.6.5.1. Neither symmetric nor asymmetric store loadings have a significant effect on coordinated maneuver characteristics.

Dino Cattaneo said...

Ok...

After several test flights, provided that my joystick settings are OK, here is what I found (+ indicates a good thin IMHO, - a defect):

+ Roll rate is generally much closer to the Natops than any of the previous FDEs. Actually, it seems quite (+/-10°/sec)and roll response is crisp
+ Carrier operations behavious seems OK
+ Full Forward+side stick deflection may result in a (controllable) departure as it should be
- Non-coordinated rolls of more than 180° show a tendency to departure (which should not be there)
- Coordinated rolls of more than 180° seems more stable, but roll rate is slower.

All in all, it is far from being a perfect flight model, IMHO, but it seems more accurate than the original FDEs and I do not think there is the need of a urgent fix.

Frank said...

Hello,
we started our flusinews.de Freeware Award 2012 in december 2012 and are proud to announce the winners. Our readers had some time to vote, and one of your Add-Ons became "Best Freeware 2012" in one of our categories, congratulations!

You can find out more about it here: http://www.flusinews.de/rubriken/specials/der-flusinews-de-freeware-award-2012/flusinews-de-freeware-award-2012-die-verleihung/

It is in german, but I think you'll understand the most important part with using google translate or so.

And you can of course share the award-image on your website, facebook etc.

Matt Mitchell said...

I have reverted back to the previous major revision model, As this latest updates, Is a step in the right direction as far as roll speed, but any major moves in the stick causes complete loss of flight model and AC begins to flip and roll uncontrollably from any hard nose pull up or a simple barrell roll, regardless of speed.

Dino Cattaneo said...

@Frank

Thanks a lot, I am honored!

@Matt

Thanks for your feedback. You may want to keep all the other, non FDE-related files (i.e. all except for the .air and Aircraft.cfg files) as there are minor fixes here and there.
As for your comment, I have been unable to replicate that to the extent you claim (maybe my joystick settings). I experience instabilities on the yaw and picth axis after any full travel, uncoordinated stick movements at speeds below 300 knots. Roll instability is can be great indeed, if bank angle is above 180° degrees.
With coordinated maneuvers the problem seem less evident, although the roll rate is decreased (which differs from the real thing, afaik).

Gentle maneuvering, however, does not show much problems - and coordinated maneuvers at proper entry speed seem to work fine on my system...

SPLIT-S 180 kts
AILERON ROLL 300kts
BARREL-ROLL 350kts
WINGOVER 300
LOOP 380kts
IMMELMANN 380kts
CUBAN-8 380kts

Anyway, my apologies if the perceived quality is poor.
Since basic maneuvering and carrier operations seem OK, IMHO...and since I do not have much time, I will keep the T-45C as is for the moment.

Improvements, suggestions and feedback (and even harsh criticism, as long as it is constructive!) is really welcome!

Brandon said...

Dino,

I did some more poking around in the .cfg file and I think I may have solved the roll instability problem. It seems the MOI's may have been set too high.

empty_weight= 9304.000
empty_weight_roll_MOI= 5000.000
empty_weight_pitch_MOI= 14000.000 //38000
empty_weight_yaw_MOI= 7000.000 //12000
empty_weight_coupled_MOI= 0000.000
max_gross_weight= 13500.000
CG_forward_limit= 0.000
CG_aft_limit= 1.000

[flight_tuning]
cruise_lift_scalar = 1.0
parasite_drag_scalar = 1.0
induced_drag_scalar = 1.0
elevator_effectiveness = 1.2
aileron_effectiveness = 1.9
rudder_effectiveness = 1.0
pitch_stability = 1.0
roll_stability = 1.0
yaw_stability = 1.0
elevator_trim_effectiveness = 1.5
aileron_trim_effectiveness = 1.0
rudder_trim_effectiveness = 1.0

I'm friends with a new Navy pilot who just did carrier quals in the T45C, and he spent about 15 minutes with these settings. He said it should be crisp to respond to control inputs in both pitch and roll, and the rudder control is somewhat lacking, and said your plane felt just about right with these settings.

These changes dont seem to adversely effect anything, but more testing should probably be done.

Hope this helps,

Dino Cattaneo said...

Thanks Brandon

There are also other readers fo this blog who had flight time in the real T-45C... I will gather their feedback, too.

At the moment I do not feel the need of an immediate fix, nor I have the time for that... I'll gather some more feedback and change requests, and evaluate some further additions - and then release an update probably in February.

Anonymous said...

Hola:
Gracias por el trabajo, pero de ser un avion super estable; a entrar casi siempre a velocidades bajas para aterrizar cabezeando e inseguro.

Supongo se solucionara, porque lo que leo es que varios usuarios tienen problemas tambien.

Saludos, Jesus

Dino Cattaneo said...

Hi Jesus,

I am sorry but my Spanish is pretty poor, so I am not sure I grasp you problem.

As far as I can tell, version 2.32 landing behaviour (especially for carrier operations) should be OK - which does not apply to 2.31 (which had horizontal control surfaces issues).

Anyway, improvements to FM are being carefully evaluated along with other improvements.

Anonymous said...

PS...

Brandon's fix seems to have solved the roll/departure problem. Nice job Brandon!

Terry

Ian Mowdy said...

What is the button for the intake covers because shift+e+4 opens the ladder so what is the other command?

Varun Krishnaswami said...

Hey man your F-35 is absolutely amazing, I would like to ask you could you add those kind of effects like the vapor on the wings during high G turns on the F-14 the same way you added on the F-35??

Dino Cattaneo said...

@Ian
Engine covers are not implemented in the F-35 v2.00 series (although they were present in the 1.00).

@Varun
Thanks for the appreciation. The new F-14 will have those effects.

Varun Krishnaswami said...

Amazing Dino, I would love to see that in action, also can i contact you more often on Google+ as I too am looking forward to making beautiful planes for FSX and wish to learn from you!! I would love to be a part of your projects, I have already added you in my circles on G+, can I add you on Facebook too??

rsgunner said...

Dino

Any chance on the next upgrade of the T-45C an AOA indexer be added to the screen that displays the HUD only.

The T-45C is my default aircraft. It keeps getting better.

Russ