Pitch up / trim up after flaps usage

[_e10]

Hi,

 

I am not sure if this is a bug or a problem on my end.

Since the last OB update from yesterday I cant fly the hornet anymore because it is pitching up for no reason.

 

Steps to reproduce:

- Instant action -> Caucasus cold and dark

- BAT on

- APU on

- Right engine

- Left engine

- FCS reset

- T/O trim

- [Rctrl] + [Enter] to bring up controls indicator.

- Notice everyting is centered like it should be.

- Set flaps to half

- Notice the cross (which indicates the flaps position I guess) on the controls indicator moves a bit downward.

- Set flaps to up

 

=> Cross does not come up.

FCS page and F2 view shows flaps are at 0%.

When I takeoff the plane pitches up even if I go full stick forward...

 

Already deleted my control layouts but this did not help.

I can reproduce this 100%. Track is attached.

 

Its not only this mission. Same when I try the new mini campaign.

 

I am not posting this to the bug forum because it seems there is nobody else with this problem... Otherwise @mods feel free to push this

 

 

Any ideas? :huh:

pitchuptrk.trk

[JUICE-AWG]

T/O Trim is 12 Degrees of input so that might be what's pushing you up on a runway takeoff. Carrier T/O is hands off until airborne and normally pushes you up. T/O Flaps are normally HALF position and if you have HOTAS Trim settings, make sure you don't have a runaway TRIM situation where your aft trim (Pull Back) is stuck on the controller. BTW, normal TRIM settings in a fighter are HAT Down = Nose Up and DCS F/A-18C has this described in the controls correctly.

 

 

 

Question: Do you have some Deadzone and Curves on your main AXIS Commands? I use 3 DZ and 20 for CURVE on Pitch and Roll, and I use 8 DZ on Rudder with 20 on CURVE...add some DZ and Curve and see if that helps.

 

 

Good Luck!

[Diemos]

Remember also; The Flaps Up position in the Hornet sets the flaps to automatic. They adjust themselves continually during flight to maintain the desired attitude/trim. The pilot's input is really telling the computer, "This is the attitude I want."

 

Since you're on the ground, it probably assumes your next action will be to takeoff, so it retains the half down position until it detects the need to move...

 

Maybe?

[pistolpete01]

Huge Pitch Up When Setting Full Flaps

 

I'm not sure if my thrust is too much or my speed is too high, about 200-250 IAS, but during the upwind leg on carrier case 1 landing, I get a huge pitch up in the aircraft as soon as I set full flaps and I end up gaining about 1,000 ft. before stabilizing the E bracket with the VV. I've tried looking on youtube for some tips but I'm still struggling.

 

I guess just keep practicing.....?

[Flamin_Squirrel]

Short answer: You shouldn't be lowering flaps on the upwind leg, you should be doing it during the break.

 

Longer answer: Carrier landing is tricky. Practice is good, but learning the correct techniques is just as important. It will take a little time, but it's worth it if you want to land well.

 

Have you seen Jabbers video on case 1? It's is very good and should hopefully answer all your questions:

 

[_e10]

Hi,

 

 

no curves or anything else on any axis. As said, controls indicator shows everything is centered.

 

 

Yeah TO trim 12 degree is fine but when I am airborne I cant prevent the plane from doing loopings even with stick full forward.

 

 

Controls indicator shows still everyting as centered EXCEPT the flaps cross which is still lowered from the center but the flaps are in the up/auto position, F2 view and FCS page confirm this.

[strikers_blade]

Hi,

 

I am not sure if this is a bug or a problem on my end.

Since the last OB update from yesterday I cant fly the hornet anymore because it is pitching up for no reason.

 

Steps to reproduce:

- Instant action -> Caucasus cold and dark

- BAT on

- APU on

- Right engine

- Left engine

- FCS reset

- T/O trim

- [Rctrl] + [Enter] to bring up controls indicator.

- Notice everyting is centered like it should be.

- Set flaps to half

- Notice the cross (which indicates the flaps position I guess) on the controls indicator moves a bit downward.

- Set flaps to up

 

=> Cross does not come up.

FCS page and F2 view shows flaps are at 0%.

When I takeoff the plane pitches up even if I go full stick forward...

 

Already deleted my control layouts but this did not help.

I can reproduce this 100%. Track is attached.

 

Its not only this mission. Same when I try the new mini campaign.

 

I am not posting this to the bug forum because it seems there is nobody else with this problem... Otherwise @mods feel free to push this

 

 

Any ideas? :huh:

 

Can you make the track longer? unless I did something wrong, I can only see your startup sequence. Could you include when you are actually experiencing the problem mid-air ?

beside the wheel brake being on, we can't see much more for now.

[JUICE-AWG]

I missed it maybe, what flight controller do you use and I had un-commanded flight control input problems when I put my cellular phone too close to the Joystick Cables...clear the area of any unneeded electronics if applicable.

 

 

Oh, and try this...start cold start, use Auto Start Sequence (Left WIN Key and HOME) and let the jet start itself. I notice that often when I manual start, I mess up the FCS and have control issues often under manual start.

[webweaver40]

Great step by step Trev, thank you!

You're trying go to full flaps too fast. If you're going to configure the aircraft and fly the pattern in a step-wise fashion, try this:

 

1. Upwind at 350 KIAS, 800 ft, idle throttle, fly out to 1.5 nm TACAN DME
    
   
2. 3.5 G break, gear at 250 KIAS while turning and decelerating and maintaining 800 feet.
    
   
3. Roll out on to reciprocal of carrier heading, maintain idle, begin descent to 600 feet
    
   
4. Flaps to mid below 200 KIAS, let the airplane settle for a moment
    
   
5. full flaps at 150 KIAS
    
   
6. Trim up to E bracket as required
    
   
7. Catch descent at 600 feet with power addition.
   

 

That will prevent the pitch up and ballooning effect of adding too much drag and lift at too high an airspeed.

 

Sent from my SM-G965U using Tapatalk

[_e10]

I made a short video to show what I mean.

Sorry, no youtube (No account ;)).

 

https://streamable.com/1y0lz

 

 

Please note the cross which appears below the center on the controls indicatior window after I set flaps to half.

 

 

Edit: Track file attached.

trk1.trk

Edited September 27, 2018 by _e10

[Flamin_Squirrel]

Except he's wrong.

 

You're trying go to full flaps too fast. If you're going to configure the aircraft and fly the pattern in a step-wise fashion, try this:

 

1. Upwind at 350 KIAS, 800 ft, idle throttle, fly out to 1.5 nm TACAN DME
    
   
2. 3.5 G break, gear at 250 KIAS while turning and decelerating and maintaining 800 feet.
    
   
3. Roll out on to reciprocal of carrier heading, maintain idle, begin descent to 600 feet
    
   
4. Flaps to mid below 200 KIAS, let the airplane settle for a moment
    
   
5. full flaps at 150 KIAS
    
   
6. Trim up to E bracket as required
    
   
7. Catch descent at 600 feet with power addition.
   

 

That will prevent the pitch up and ballooning effect of adding too much drag and lift at too high an airspeed.

 

Not correct. Flaps and gear come down together once below 250kts.

[Svsmokey]

Except he's wrong.

 

 

 

Not correct. Flaps and gear come down together once below 250kts.

 

I would love to fly the hornet IRL , in which case I would definitely fly by the NATOPS . However , I can only fly the one I have in DCS , and I also have a large pitch-up moment with full flaps . I , for one , am going to try the suggested profile , and thank the poster for the suggestion . Not meaning any disrespect .

[Svsmokey]

OP . Any chance the speedbrake is partially deployed ?

[Flamin_Squirrel]

That's totally understandable, and everyone should fly the way they want to.

 

I generally think it's better to use the correct procedure to do something first, even if it's a bit harder to start with, then work on technique to make everything come together. For example, in this case the reason I think the NATOPS procedure will help you is because if you drop flaps while still pulling hard in the break, the added pitch from the flaps makes so much less of a difference than if you're straight and level. My opinion of course. Good luck :joystick:

[Svsmokey]

My thinking is that IRL , you can feel the stick force decreasing as you add corrective trim . Absent FF , we don't have that ability in any simulator .

[bbrz]

I don't understand the problem. The flaps start extending below 245kts and while there is a nose up moment, it doesn't take a lot of forward stick to counter the nose up moment.

At 33000lbs with the flaps in auto the AoA at 245kts is ~4.5deg. Extending the flaps to full decreases the AoA by around 3deg. That's not exactly a lot.

Since you know when the flaps are extending it's no problem to counter the pitch up and the ballooning. You are flying the F/A-18, not the other way round.

 

If you wait with full flaps until 150kts, AoA increases above 7deg with half flaps in the meantime and I don't see any reason why you are getting that slow intentionally.

 

In the end the workload is way lower when you simply get the gear and flaps out just below 250kts and control pitch and AoA, instead of doing all this in three steps with rather large pitch and AoA changes in between.

[Svsmokey]

Agreed . I have been using 1/2 flaps in the break , and full on entering downwind and it does help . Still , i find it difficult to trim "hands free" onspeed and AOA well before the aft turn absent FF . I don't yet know if Trev's suggestion will work , but it is worth trying .

[Flamin_Squirrel]

The stick in the (real) Hornet has springs. All the feedback in the Hornet controls is achieved through the fly by wire (which of course is replicated in the DCS version) so a FF stick is no real advantage here.

[Svsmokey]

Good point . However whether the feedback is generated by computer or by the air flowing over the control surfaces is irrelevant to the pilot , as long as he gets that feedback . Or are you saying that in landing mode the pilot receives no stick force feedback of any variety ? Never having flown a real hornet , i can not definitively say , but both light aircraft i have flown certainly do , and that feedback is essential .

[Flamin_Squirrel]

Good point . However whether the feedback is generated by computer or by the air flowing over the control surfaces is irrelevant to the pilot...

 

Yes, but it does mean that all the feedback can be generated by software on our PC as it is in the real plane, so a force feedback stick no longer provides any real advantage ( for the hornet anyway ).

[Svsmokey]

Let me try another tack . In any system wherein the pilot is responsible for trim , including the hornet in landing mode (presumably) , the pilot is interested in trimming to neutral stick pressure for the AOA he or she desires . Doing so without actual stick feedback will result in a trial-and-error cycle wherein he applies trim , relaxes the stick , and adjusts trim again to achieve his goal . This will result in upsets of AOA , with the result of inconsistent altitude and speed . Contrast this with the IRL method wherein you hold stick pressure for AOA , and apply trim until that pressure is neutralised . Voila ! No changes of altitude or speed .

[pistolpete01]

OP . Any chance the speedbrake is partially deployed ?

 

 

Nope..speedbrakes not deployed. Thanks everyone for the suggestions, will definitely try going to half first then full flaps below 150

[JUICE-AWG]

Great step by step Trev, thank you!

 

Sent from my SM-G965U using Tapatalk

 

 

Right on the money with those steps!

[majapahit]

I don't fly F18 in RL but with the F18 DCS (which seems pretty close to RL according to the real pilots and when I scrutinised RL YT landings)

 

I remind myself that this F18 is heavily predisposed by throttle control, with massive thrust after a distinct and somewhat bewildering spool-up and falling from the air like a brick the instant you’re below ‘on speed’ in the landing groove.

 

So, you bank, you add throttle, you level, you yank the throttle for an instant while monitoring the expected ‘on speed’ bottom, you’re in the landing groove, you monitor your speed continuously so to yank the throttle but then again easing out near ‘on speed’ for to keep you from the catastrophic bottoming below ‘drop like a brick’ speed.

 

You add flaps you yank the throttle and ease with the stick. You enter a steep bank and loose elevation a little, you push the throttle and do all the necessary corrections with the stick, your flaps come out halfway and then full during an halfway and "over speed" break (the short ones), you cut your high throttle for an instant and focus on the expected and estimated ‘on speed’ for that type of bank in that type of turn.

 

This takes a while, for to recognize all the different ‘modes’ possible (from infinite speed/configuration possibilities).

 

I thought I had a lot of problems with this ‘ballooning’ of the F18 when entering in the wake of the Stennis some of the times but not all of the times,

 

but you can avoid this (at least in the DCS F18 ) by throttle anticipation,

 

by being somewhere exactly “around” ‘on speed’ and keep yanking that throttle up and down,

 

whilst staying in the (and appropriate divergences of) your landing groove (don’t just follow the needles, that’s a bad idea, follow the deck around the needles in particular in high winds and the deck bouncing up and down, which you can see, and you're really aiming to set yourself up for the #3 wire, trap configuration, the exception are these 'perfect' F18 pilots who have perfect control but that's why these guys earn the big bucks :) )

 

and whilst constantly monitoring your speed ribbon read out, to know where exactly you’re at, in the F18 power/lift/’drop like a brick’ curve, you throttle up too long you balloon out from the groove because of the power spooling effect and then you're just too late (and something DCS weird happens perhaps).

 

That’s what I do

 

(these last weeks, my Oculus Rift had arrived and I can actually see what I’m doing though as if looking through the bottom of 3D milk bottles).

Edited September 27, 2018 by majapahit

[bbrz]

... the pilot is interested in trimming to neutral stick pressure for the AOA he or she desires . Doing so without actual stick feedback will result in a trial-and-error cycle wherein he applies trim , relaxes the stick , and adjusts trim again to achieve his goal . This will result in upsets of AOA , with the result of inconsistent altitude and speed.

That's a wrong assumption. Neither in an F-16 or A320 the stick provides any feedback and it's no problem to e.g. counter the strong ballooning in an A320 when deployed the flaps.

 

Again, as the pilot you (should) now exactly when your airplane is doing what, so there's no reason why the the airplane shouldn't exactly do what you want without trail and error.

 

As majapahit mentioned above; anticipation is the key.

Edited September 28, 2018 by bbrz