Take Off Trim: sim vs. Chuck's guide

[itarrow]

Hey there, I'm finding that if I take off from Stennis using Chuck's Guide recommended trim based on weight (ie 19 at about 47.000), my front undercarriage get always stuck out, while if I use the "in-game" setting of 12 I have no problems (same weight of 47K).

 

Which is the correct setting for trim at take off ? Am I doing something wrong ?

[Deano87]

There is something weird going on with Cat launches at the moment, other people are reporting blacking out at high aircraft weights and broken undercarriage as well. So I think its just something that is WIP. for the moment just use whatever works.

 

https://forums.eagle.ru/showthread.php?t=225219

[Fonz_408]

I'm using 16 for carrier ops with no problem in current beta

[itarrow]

Ah yes, I am also always blacking out on take off.

 

Will use the “suggested” trim instead of the one in Chuck’s guide while waiting for a solution.

 

Blacking out while taking off is not really a nice experience, even in a sim ...

[Deano87]

Ah yes, I am also always blacking out on take off.

 

Will use the “suggested” trim instead of the one in Chuck’s guide while waiting for a solution.

 

Blacking out while taking off is not really a nice experience, even in a sim ...

 

Agreed lol.

 

The blacking out is not actually because of the acceleration of the catapult its because of excessive nose bouncing during the cat shot which is causing very high instantaneous G-loadings for the pilot. This is also whats breaking the nose gear, its getting smashed into the deck a few times during the launch hehe.

[Raz_Specter]

I am also using 16 but have experienced a cupped or blackouts for 1/2 a second be its recoverable

[Banzaiib]

do you turn obogs on before the right engine starts? I hit the switch before the right engine is fully spooled, and never black out... just throwing that out there.

[Condor_USAF]

Agreed lol.

 

The blacking out is not actually because of the acceleration of the catapult its because of excessive nose bouncing during the cat shot which is causing very high instantaneous G-loadings for the pilot. This is also whats breaking the nose gear, its getting smashed into the deck a few times during the launch hehe.

 

Wow, crazy that DCS has modeled realism to this extent.

[shagrat]

Just to clarify: the correct procedure per se is to trim as per Chuck's guide (basically what is listed in the NATOPS manual of the F/A-18).

At the moment the cat start seems to be bugged, so you need to adapt and use any setting that works.

[sk000tch]

Wow, crazy that DCS has modeled realism to this extent.

 

Hmm kinda leaning the opposite way on this one...

 

Current g’s are known, most of the modern aircraft display it on hud. Those that don’t I’d imagine the FM knows.

 

So talking about modeling pilot effects, impacts like collisions and whatnot with extremely high (de)celleration are different, but in flight it’s sustained g’s that induce blackout. In short bursts very high positive g loads are violent and take some getting used to but don’t cause blackout. My aerobatic flight time is limited (spendy hobby), so I never became particularly skilled, but 8-10gs for say, 5 seconds or so to pull through a vertical dive is fun. Fighter planes have the speed and thrust to sustain long 5-6g turns and thus can induce black/grey-out, but it’s the time at g that causes it (I think around 15-20s is the magic number but not sure). That’s how it should be modeled, hard bouncing your nose gear should be like hitting a big speedo bump too fast, you might break something expensive but not going to black out.

 

Damage model should model individual system failure (e.g. AAA hits to wing causing flat tire in a-10 is a good example). DCS could actually improve quite a bit here relative to other sims. So I’ve got no problem with something wonky in the beta causing unrealistic loads on landing gear and failures, that’s what beta is for. But it shouldn’t trigger blackout.

[shagrat]

Hmm kinda leaning the opposite way on this one...

 

Current g’s are known, most of the modern aircraft display it on hud. Those that don’t I’d imagine the FM knows.

 

So talking about modeling pilot effects, impacts like collisions and whatnot with extremely high (de)celleration are different, but in flight it’s sustained g’s that induce blackout. In short bursts very high positive g loads are violent and take some getting used to but don’t cause blackout. My aerobatic flight time is limited (spendy hobby), so I never became particularly skilled, but 8-10gs for say, 5 seconds or so to pull through a vertical dive is fun. Fighter planes have the speed and thrust to sustain long 5-6g turns and thus can induce black/grey-out, but it’s the time at g that causes it (I think around 15-20s is the magic number but not sure). That’s how it should be modeled, hard bouncing your nose gear should be like hitting a big speedo bump too fast, you might break something expensive but not going to black out.

 

Damage model should model individual system failure (e.g. AAA hits to wing causing flat tire in a-10 is a good example). DCS could actually improve quite a bit here relative to other sims. So I’ve got no problem with something wonky in the beta causing unrealistic loads on landing gear and failures, that’s what beta is for. But it shouldn’t trigger blackout.

it should not be wonky, either. That is why it is a beta. Obviously the whole calculation has some weird inputs, that cause a cascade of strange effects.

The blackout may not even be triggered by the "spontaneious G", but by any other chain of inputs that trigger "Black Out effect = ON".

So let's wait for the next patch notes and what happens after they fixed it.

[macedk]

There is something weird going on with Cat launches at the moment, other people are reporting blacking out at high aircraft weights and broken undercarriage as well. So I think its just something that is WIP. for the moment just use whatever works.

 

https://forums.eagle.ru/showthread.php?t=225219

 

Thank you :)

 

 

Exactly what happened to me :)

[Los]

You can also just take off perfectly fine without applying any trim, so there's that too...

[Flamin_Squirrel]

You can also just take off perfectly fine without applying any trim, so there's that too...

 

Not really. It makes a difference to how much you sink off the bow.

[Condor_USAF]

Hmm kinda leaning the opposite way on this one...

 

Current g’s are known, most of the modern aircraft display it on hud. Those that don’t I’d imagine the FM knows.

 

So talking about modeling pilot effects, impacts like collisions and whatnot with extremely high (de)celleration are different, but in flight it’s sustained g’s that induce blackout. In short bursts very high positive g loads are violent and take some getting used to but don’t cause blackout. My aerobatic flight time is limited (spendy hobby), so I never became particularly skilled, but 8-10gs for say, 5 seconds or so to pull through a vertical dive is fun. Fighter planes have the speed and thrust to sustain long 5-6g turns and thus can induce black/grey-out, but it’s the time at g that causes it (I think around 15-20s is the magic number but not sure). That’s how it should be modeled, hard bouncing your nose gear should be like hitting a big speedo bump too fast, you might break something expensive but not going to black out.

 

Damage model should model individual system failure (e.g. AAA hits to wing causing flat tire in a-10 is a good example). DCS could actually improve quite a bit here relative to other sims. So I’ve got no problem with something wonky in the beta causing unrealistic loads on landing gear and failures, that’s what beta is for. But it shouldn’t trigger blackout.

 

I want to agree with you on this, and certainly there are no reports of pilots even approaching anything remotely close to a blackout on launches. But what we don't know is how many g's the DCS model is simulating during these heavy launches. Maybe it's (erroneously) simulating something stupid large like 40g instantaneous impulse force, which wouldn't happen in real life but IF it did, that can cause a brief blackout.

 

So looks like DCS physics model is still very detailed, just needs to be reconfigured to more realistic tolerances.