[NO BUG]take off auto flaps - f18 - pitch up?

here is a auto flaps carrier take off

How did you come to the conclusion he's in AUTO flaps in that video?

How did you come to the conclusion he's in AUTO flaps in that video?

Looks to me, that the leading edge is not down at take off, which it would be if flaps were set. But notice as his wheels leave the deck the leading edge drops engaging flaps to increase lift till his speed increased and the leading edge raised up again.

Looks to me, that the leading edge is not down at take off, which it would be if flaps were set. But notice as his wheels leave the deck the leading edge drops engaging flaps to increase lift till his speed increased and the leading edge raised up again.

Your analysis is incorrect. The ailerons are obviously deflected down creating a gap at the trailing edge of the wing were the aileron meets the launch rail.

About 30 seconds into the video the aileron is flush with the wingtip indicating the flaps are raised.

Your analysis is incorrect. The ailerons are obviously deflected down creating a gap at the trailing edge of the wing were the aileron meets the launch rail.

 

About 30 seconds into the video the aileron is flush with the wingtip indicating the flaps are raised.

what does the leading edge do just as he leaves the deck?

any way, got a new one for ya. Did some testing.

Load a mission that starts you in the air, say free flight, or a one on one dog fight,

then land with auto flaps, you can now take off with auto flaps, no pitch up.

Land and take off all day with auto flaps, no pitch up.

Now land once with flaps, if you take off with auto flaps now, you will pitch up.

If that’s the case I’m thinking it has to do with pitch trim settings.

Flaps are down for TO in that vid.

The LEF track with the TEF relitively. The LEF track up after the launch because he brings the TEF up.

Any take off/landing without flaps is extremely "non standard". I find it hard to believe that pilot is flaps auto for that TO at the boat. The pilot would have an amazing litany of crap to answer for if anything whent wrong when he was OFP.

what does the leading edge do just as he leaves the deck?

They Move...Which is exactly what they are supposed to do. If you refer to pg I-2-55 in the book that shall not be mentioned...you'll find a detailed explanation of Flap Operation. It states in part:

With Flaps "HALF" Selected, Below 250 knots, leading edge flaps are scheduled as a function of AOA. Trailing edge flaps / aileron droop are scheduled as a function of airspeedto a maximum of 30° at approach airspeeds.

So Yes...with Flaps HALF selected, the Leading Edge Flaps will move independently just like they do in the video while the trailing edge flaps remain fixed at 30° until 250 knots or the Flaps Switch is moved to Auto. But that's not the important part...The important part is this little tidbit...

With Flaps "AUTO" selected With weight off wheels, leading and trailing edge flaps are scheduled as a function of AOA. With WOW, leading and trailing edge flaps and aileron droop are set to 0°.

Since the leading edge flaps are obviously down prior to the cat shot...the Flaps are obviously not in AUTO,

The -000 is your friend.

They Move...Which is exactly what they are supposed to do. If you refer to pg I-2-55 in the book that shall not be mentioned...you'll find a detailed explanation of Flap Operation. It states in part:

 

 

 

So Yes...with Flaps HALF selected, the Leading Edge Flaps will move independently just like they do in the video while the trailing edge flaps remain fixed at 30° until 250 knots or the Flaps Switch is moved to Auto. But that's not the important part...The important part is this little tidbit...

 

 

 

Since the leading edge flaps are obviously down prior to the cat shot...the Flaps are obviously not in AUTO,

 

The -000 is your friend.

Ok so whatever, so that vid is not auto flaps. We are barking up wrong tree here. Who cares.

Fact is DCS flaps seem bugged.

new tests show

no pitch up problem if you start mission with cold start on ground

no pitch up problem if you start mission hot in air

pitch up problem if you start hot on ground

Well crap, looks like the cold start does not count. It only works because it fails to synchronize cockpit controls with hotas controls at mission start like the settings say due to auto start cycling flaps to half.

So although my HOTAS WARTHOG was set to auto flaps, the jet was set to half flaps.

TO checks for the hornet included checking the FCS page to ensuring all control surfaces where at the deg intended.

I.e. :

"(All previous stuff)........... Surfaces are , 12, 30, 30 ,30 and 12(16,etc) stabs up, seat armed, takeoff checks complete "

Something like that.

Point being, check the surface before you take the jet flying. Switch position was not "trusted" 100%.

Hope this helps :)

Ok so whatever, so that vid is not auto flaps. We are barking up wrong tree here. Who cares.

 

Fact is DCS flaps seem bugged.

new tests show

no pitch up problem if you start mission with cold start on ground

no pitch up problem if you start mission hot in air

pitch up problem if you start hot on ground

You forgot “no problem if FLAPS switch is set properly for takeoff” as directed.

Ok so whatever, so that vid is not auto flaps. We are barking up wrong tree here. Who cares.

 

Fact is DCS flaps seem bugged.

new tests show

no pitch up problem if you start mission with cold start on ground

no pitch up problem if you start mission hot in air

pitch up problem if you start hot on ground

What is your trim setting, in each of these cases? I think the reason it pitches up is because your setting TO trim with AUTO. That demo pilot said he used only +3 on stabs. Way below TO trim, see lex’s last post.

I’ll bet anything thats the problem.

Apparently there are demonstrations teams that takeoff with Flaps in Auto. The Blues don't.

LoL dude, Do like 5 mins of research before you open your mouth. Blue 5 takes off for the dirty roll with Flaps AUTO.

As can be seen here

and here:

and here:

aaaand here:

Honestly Sierra, we get it. You're triggered by the fact that people want to fly the aircraft in a way that you don't agree with. I don't think any of us are unsure of your position lol. So why keep going on about it. You're not getting the point, WE ALL know that the SOP is Flaps HALF for takeoff. But we are trying to figure out what causes the jet to pitch up in the way it does when you do a Flaps Auto takeoff. What scenarios does it happen, is it trim related etc etc etc. And if at the end of the day its realistic.

I'm gonna say what we have is realistic, because every single one of those TOs the pilot had a pretty significant pitch moment, but the difference is they all used very little positive stab trim. Nowhere close to +12 and they had much more control.

So if we come back to DCS; people are hot starting or auto starting AND setting TO trim (or more likely its set for them by the game.) Then they attempt an AUTO flaps TO and they experience an extreme pitch moment. Seems reasonable to me. If you don't set TO trim or just use a little positive stab trim and keep the jet light, you'll still experience high pitching just like the demo teams, but it's MUCH more manageable, and in line with those videos.

*Edit just tested in game, and my suspicions are correct the pitch up is definitely associated with trim setting, however once airborne it is very hard to trim the FCS back to 1G and that is because the trim rate is so low, and that IS a confirmed bug. So don't use crazy high pitch trim when attempting this because It'll take forever to get back to 1G Or just use the correct settings per the guidelines. :)

...Then they attempt an AUTO flaps TO and they experience an extreme pitch moment. Seems reasonable to me. If you don't set TO trim or just use a little positive stab trim and keep the jet light, you'll still experience high pitching just like the demo teams, but it's MUCH more manageable, and in line with those videos.

Taking off with auto flaps with the trim at +12 or 0 always results in a strong pitch up. Less severe with 0.

The problem is that you need to keep trimming for at least 1min to get back to 1G because trim is presently way too slow (too slow trim confirmed by ED)

I'm gonna say what we have is realistic, because every single one of those TOs the pilot had a pretty significant pitch moment, but the difference is they all used very little positive stab trim. Nowhere close to +12 and they had much more control.

 

So if we come back to DCS; people are hot starting or auto starting AND setting TO trim (or more likely its set for them by the game.) Then they attempt an AUTO flaps TO and they experience an extreme pitch moment. Seems reasonable to me. If you don't set TO trim or just use a little positive stab trim and keep the jet light, you'll still experience high pitching just like the demo teams, but it's MUCH more manageable, and in line with those videos.

That is a possibility. I shall ask my Swiss contact about this and see what he says, the issue with the sim is that even if you use a lot less trim it will still pitch up forever. It’s not so much the initial pitch up on rotation that is the issue. I can totally see how that can be influenced by trim setting. That’s only natural. But I still don’t see why the jet wouldn’t eventually return to trimming for 1G once airborne, instead it flies around at 3+G hands off, and can only really be reset by cycling the flaps. It’s almost like whatever takeoff trim is there doesn’t get cancelled by the sim If you get airborn in Auto.

Interestingly if I land in Auto and come to a full stop, and then get airborne again in auto the jet behaves exactly as one would expect, trimming for 1G once airborne.

But I still don’t see why the jet wouldn’t eventually return to trimming for 1G once airborne, instead it flies around at 3+G hands off, and can only really be reset by cycling the flaps. It’s almost like whatever takeoff trim is there doesn’t get cancelled by the sim If you get airborn in Auto.

 

Interestingly if I land in Auto and come to a full stop, and then get airborne again in auto the jet behaves exactly as one would expect, trimming for 1G once airborne.

I can see it, because if your trimming in AUTO your changing the bias from 1G to whatever you set it too, so if it's +3 or whatever the system thinks you want 3G at neutral stick. Even though your setting that on the ground; because your in AUTO the FCS thinks it's airborne and those settings are retained after WOW goes off. It doesn't know what you want, only what you tell it.

So if you trim while in AUTO on the ground the position indicators won't move at all but the computer is still registering trim input for AUTO mode. So once your airborne those settings immediately take effect, which wouldn't be a huge problem IRL because you could just trim it back real quick, but because of the slow rate in DCS it seems like your stuck pitching, but in reality it just takes forever to manually trim back to 1G because of the DCS bug. So long in fact that you might assume it's not working at all, I took off with +3 and it took about a minute of forward trim to get back to 1G at level :D

As too coming to a full stop, I would guess some sort of reset is triggered, but that's also interesting.

So if you trim while in AUTO on the ground the position indicators won't move at all but the computer is still registering trim input for AUTO mode.

That's wrong. You can trim from the standard 12° to e.g. 0°....but it takes 120sec...

LoL dude, Do like 5 mins of research before you open your mouth. Blue 5 takes off for the dirty roll with Flaps AUTO.

I’ll be completely honest I didn’t do any MORE than 5 minutes of research because the statement was made “The Blue Angels do it” and in less than five minutes I found a video showing that was bunk. Oh look! It appears 1/2 of 6 Blue Angels do in fact take off with flaps up. My bad. Please tell me you are not really going to build your entire case on that? You understand the Blue Angels fly aircraft with a special OFP right? They’re not “off the shelf” Hornets. You understand all of their maneuvers are specifically authorized right?

So OK... my bad 2 F-18s take off with flaps up. That’s not proof they all can or should.

Honestly Sierra, we get it. You're triggered by the fact that people want to fly the aircraft in a way that you don't agree with.

Triggered? Nobody is triggered. I am honestly trying to help. This isn’t about “you” flying the airplane in a way I don’t agree with. It’s about you operating the aircraft in a way that violates established procedures / guidlines and then complaining about the results. I could just sit back and let you guys flail around doing it wrong till the cows come home if that’s what you’d prefer.

It’s really not complicated. Doing an Auto flap takeoff is what causes the jet to pitchup. If you select Half Flaps per the NATOPS checklist there is no pitchup on takeoff. Problem solved

But have at it guys. I’llleave now you folks to joust at your windmills.

It’s really not complicated. Doing an Auto flap takeoff is what causes the jet to pitchup.

Nope. It's not that easy. If you read the above posts you will see that there's big difference in pitch up with the flaps in auto, depending when and under which conditions you are trying to do that and this shouldn't be the case.

You forgot “no problem if FLAPS switch is set properly for takeoff” as directed.

Dude, that's not the point. It should mimic what the real jet would do in the same conditions. If you land with gear up, what happens, if you get to close flying in formation and get into the turbulence of another jet, how does it react. If you pull straight up and cut the throttle, and come to a stop does it fall backwards, or roll on its back or go into a spin?. If you come in to slow to land does the jet stall, at what speed?

If you were only able to do what the manual suggests it would be very boring. And you would never know the jets limits. No flying upside down, no knife edge, no flat spins, no high alpha attempts to hover a jet like a heli.

If in fact the real jet behaves with a violent pitch up when you take off with flaps in auto, i am OK with it. That's what i would want it to do. But i would put money on the fact that this is not how it would behave. I am pretty dam sure it would resist taking off, you would need to pull back on the stick to get it up or you would over speed on runway and blow a tire or something. Once you pulled back the auto flap system would react surely, by applying some flaps to react to the low speed and high AoA but once you got your speed up around 250 (my opinion) is they would then retract and trim the jet to 1G as they are programmed too. If the real f18 doesn't return to 1G trimmed flight like its programmed to in every other flight condition then i would say the real jet has a bug and it should be fixed. At least i would be happy ED got it right, just like HeatBlur programmed in many of the problems the f14 had, its awesome to know the same qurkes the real jet had are programmed into the Sim.

What you get out of being the devils advocate and resisting my attempt to question if ED got this right or not is beyond me.

If in fact the real jet behaves with a violent pitch up when you take off with flaps in auto, i am OK with it. That's what i would want it to do. But i would put money on the fact that this is not how it would behave. I am pretty dam sure it would resist taking off, you would need to pull back on the stick to get it up or you would over speed on runway and blow a tire or something.

Do you try these things before you post? That's exactly what happens if you e.g. trim to +3 with the flaps in auto. At ~230kts the tires blow and she will definitely not rotate on her own.

What is your trim setting, in each of these cases? I think the reason it pitches up is because your setting TO trim with AUTO. That demo pilot said he used only +3 on stabs. Way below TO trim, see lex’s last post.

 

I’ll bet anything thats the problem.

I don't think trim has anything to do with it.

I have tried trimming on ground say 10 secs of nose down trim, take off with flaps half and nothing, flys level, 1g. i have trimmed it in air so that it pitches up violently, then landed and took off only to have it fly level at 1g again. Once you take off, auto flaps seems to reset trims and flys the plane at 1g, so whats the deal when you take of while in auto flaps.

Do you try these things before you post? That's exactly what happens if you e.g. trim to +3 with the flaps in auto. At ~230kts the tires blow and she will definitely not rotate on her own.

Do i test before i post, hmmmm, really. lol. Are you playing the same game dude? don't touch a thing, no trim adjustments, no T/O trim, just full after burner. it will take off by itself no blown tires and a speed of about 200.