yes Is the Flight Model going to be updated?

[Razor18]

7 hours ago, Skysurfer said:

What I wrote above, negative static stability in roll in the landing config. 

 

Basically every aircraft in a turn needs a bit of counter-aileron to be applied to keep the bank from increasing. Reason is, the airflow around the "inside" wing is slower, than the airflow around the outside wing, resulting in different lift above the left and right wing. Some fly by wire systems counter it by themselves without the pilot holding the a stick a bit to the outside of the turn, I don't know if the F-18C Lot 20's FBW is supposed to do it...

Edited February 7, 2021 by Razor18

[Skysurfer]

4 hours ago, Razor18 said:

 

Basically every aircraft in a turn needs a bit of counter-aileron to be applied to keep the bank from increasing. Reason is, the airflow around the "inside" wing is slower, than the airflow around the outside wing, resulting in different lift above the left and right wing. Some fly by wire systems counter it by themselves without the pilot holding the a stick a bit to the outside of the turn, I don't know if the F-18C Lot 20's FBW is supposed to do it...

 

 

No. This is very much not true. Especially once FBW comes into play. 

[Razor18]

Please be a bit more specific, which part is "very much not true"? I mentioned indeed that some FBW systems CAN solve it for you (I dunno if that of the F-18C does it), but the lift difference is indeed there in a turn.

 

Aileron - wikipedia

 

"With ailerons in the neutral position, the wing on the outside of the turn develops more lift than the opposite wing due to the variation in airspeed across the wing span, which tends to cause the aircraft to continue to roll. Once the desired angle of bank (degree of rotation about the longitudinal axis) has been obtained, the pilot uses opposite aileron to prevent the angle of bank from increasing due to this variation in lift across the wing span. This minor opposite use of the control must be maintained throughout the turn."

 

Ask anyone, who flies in RL too.

Edited February 7, 2021 by Razor18

[maxTRX]

I can't say for sure that our Hornet follows the 'numbers' since I haven't studied and tested every part of the flight envelope but there are 3 or 4 issues related to FCS that I know for sure do not occur in RL:

In PA:  ballooning on flaps down  

           extreme pitch up after lift off, doing touch and go's

In UA:  lack of yaw dampening at light weight after a quick roll (no wing loading). Most of us have experienced these perpetual oscillations...

 

Other then that, I'm oblivious to any other quirks and bugs. I'm sure there are some, possibly related to weight/drag or engine performance.

Well, I guess we'll be seeing changes sooner or later.

 

Generally... it's a kickass jet.

[Skysurfer]

On 2/7/2021 at 2:35 PM, Razor18 said:

Ask anyone, who flies in RL too.

 

 

I do. Also the fact that every real Hornet driver I spoke to stated the same. Commercial airplanes usually tend to exhibit positive static stability in pitch and roll. And the aileron itself has no effect on that, it's the general config, sweep and wing geometry + local AOA. It makes no sense to program a FBW law to exhibit these unwanted behaviours in the first place. 

[Stearmandriver]

7 hours ago, Skysurfer said:

 

Also the fact that every real Hornet driver I spoke to stated the same. 

The Hornet drivers stated the same... what? That the Hornet actually has an overbank tendency? 

[Skysurfer]

4 hours ago, Stearmandriver said:

The Hornet drivers stated the same... what? That the Hornet actually has an overbank tendency? 

No, that it in fact is pretty neutral and holds said AOB. Read the previous conversation. 

Edited February 9, 2021 by Skysurfer

[Stearmandriver]

8 hours ago, Skysurfer said:

No, that it in fact is pretty neutral and holds said AOB. Read the previous conversation. 

 

I did, that's why I asked.  You seemed to be claiming that overbanking tendency is not a real thing, which is what confused me.  Every jet I've flown has exhibited overbanking tendency beyond about 25 degrees AoB.  Positive stability in roll applies at smaller bank angles, but it seems inevitable that at some bank angle, the speed disparity between the inner and outer wing in a turn will create enough lift differential to overcome the degrees of positive stability. 

 

It makes sense that fly by wire systems would correct for this - the Airbus does, for instance - so it makes sense that the Hornet wouldn't exhibit this behavior (which was the original point, the DCS Hornet does).  But it is indeed a real thing. 

[LaFleur]

I've noticed that when the F-18 is loaded with one Centerline Fuel Tank, two AIM120Cs on the cheeks, 4 AIM120Cs on the inner pylons, Removed outter pylons, and 2 AIM9Xs on the wing tips, which is a symmetrical load, it keeps banking to the left and needs to be trimmed. Anyone else experience the same? Of course I've checked that my stick in centered and the two engines have the same thrust. This only happens to this particular configuration.

[maxTRX]

14 hours ago, LaFleur said:

I've noticed that when the F-18 is loaded with one Centerline Fuel Tank, two AIM120Cs on the cheeks, 4 AIM120Cs on the inner pylons, Removed outter pylons, and 2 AIM9Xs on the wing tips, which is a symmetrical load, it keeps banking to the left and needs to be trimmed. Anyone else experience the same? Of course I've checked that my stick in centered and the two engines have the same thrust. This only happens to this particular configuration.

 

Yes, I've seen this before. I did a quick test of the outboard pylons.

With no pylons at all, the jet rolls very slowly to the right.  Even with one pylon loaded on left outboard station... it still rolls right.

With only one pylon on the right outboard, the jet rolls to left correctly.

 

I hope I didn't mix up the direction of roll... I'll double check.

[wilbur81]

16 hours ago, LaFleur said:

I've noticed that when the F-18 is loaded with one Centerline Fuel Tank, two AIM120Cs on the cheeks, 4 AIM120Cs on the inner pylons, Removed outter pylons, and 2 AIM9Xs on the wing tips, which is a symmetrical load, it keeps banking to the left and needs to be trimmed. Anyone else experience the same? Of course I've checked that my stick in centered and the two engines have the same thrust. This only happens to this particular configuration.

 Yes, I've noticed the same. It was introduced (apparently?) in one of the two latest O.B. updates. One of us will probably need to provide a track. It will also happen if the two inner pylons have single 120s vs. the double racks... but it may simply be related to the outer pylons being removed altogether.

[maxTRX]

10 minutes ago, wilbur81 said:

 Yes, I've noticed the same. It was introduced (apparently?) in one of the two latest O.B. updates. One of us will probably need to provide a track. It will also happen if the two inner pylons have single 120s vs. the double racks... but it may simply be related to the outer pylons being removed altogether.

 

I think it's more like re-introduced or has never been addressed.  I remember the outboard pylon issue being reported about a year or more ago.

Edited February 11, 2021 by Gripes323

[frumpy]

On 2/8/2021 at 4:05 PM, Gripes323 said:

           extreme pitch up after lift off, doing touch and go's

 

A friend pointed me on doing a no-flap takeoff: It's tough to keep the attitude below 10°, as it easily goes to 15-20°. With flaps its like a walk in the park, set 7° and everything goes fine.

[maxTRX]

6 hours ago, frumpy said:

 

A friend pointed me on doing a no-flap takeoff: It's tough to keep the attitude below 10°, as it easily goes to 15-20°. With flaps its like a walk in the park, set 7° and everything goes fine.

 

Taking off with auto flaps is a different story.

I'm referring to coming in for a touch and go with AOA trim set and flaps full (or half) or bolterring on a carrier. When any 2 wheels hit the deck, the FCS resets the logic and in case you decide to go airborne again the proper pitch up is captured. It will not try to maintain your landing AOA even if you leave your flaps and gear down requiring the stick all the way forward.

With increasing airspeed the flaps will adjust and transition into UA mode even if you leave the gear down (and overspeed)... Of course there's no reason to do that, hehe.

Staying in the pattern w/o raising gear and flaps should be effortless from what I gather. No need to pull the throttles to idle and shove the stick forward to prevent going into a loop.

Probably around 150 knots when turning back to downwind, check/trim for AOA, it shouldn't be far off and head for 180.  That's my understanding anyway

[Svend_Dellepude]

19 hours ago, Gripes323 said:

 

Yes, I've seen this before. I did a quick test of the outboard pylons.

With no pylons at all, the jet rolls very slowly to the right.  Even with one pylon loaded on left outboard station... it still rolls right.

With only one pylon on the right outboard, the jet rolls to left correctly.

 

I hope I didn't mix up the direction of roll... I'll double check.

 

Probably still this issue.

 

 

 

[Bravo One]

just find some excuse to make it faster, thx

[wilbur81]

Good grief!! Do Swiss F/A-18C's have a modified FCS like the Finnish ones? This demo is incredible... the Hornet's performance here looks VICIOUS!

 

Edited March 25, 2021 by wilbur81

[Skysurfer]

21 hours ago, wilbur81 said:

Good grief!! Do Swiss F/A-18C's have a modified FCS like the Finnish ones? This demo is incredible... the Hornet's performance here looks VICIOUS!

 

 

 

Correct, 9G airframe and no real AOA limit.

[LaFleur]

On 3/25/2021 at 4:03 AM, wilbur81 said:

Good grief!! Do Swiss F/A-18C's have a modified FCS like the Finnish ones? This demo is incredible... the Hornet's performance here looks VICIOUS!

 

 

Damn... I want that FCS.....