Is there anyway that the g-limiter override can be left permanantly on. I understand (please correct me if I'm wrong) it isn't a toggle switch but needs to bo constantly pressed in order to get the expanded flight envelope.

Thanks TIM

Whoa, partner... the G-Limit Override does not 'expand the flight envelope.' The only thing that would do that is changing the laws of aerodynamics and physics.

The G-Limit Override allows you to TEMPORARILY operate your aircraft in a part of the flight envelope that is normally prevented by the G-Limit function of your flight computer. This is for the safety of your aircraft.

Operating beyond the G-Limit is a good way to overstress your airframe, leading to potential aircraft damage... annoying little things like the wings falling off and stuff.

G-Limit Override capability is provided for the circumstance in which you are willing to trade the potential for aircraft damage to prevent garanteed aircraft damage, such as from bullet holes.

Also, once you have engaged G-Limit Override once, it's rather unlikely you will have a need to do it again. You are probably in a turning fight, and have scrubbed so much speed in the Over-G turn that you wouldn't be able to exceed max G again for quite some time, even if you wanted to.

So, no, there is no way to lock the G-Limit Override engaged, because there is no reason or value in doing that in the real nor the simulated aircraft. You CAN, however, re-engage G-Limit Override as many times as you want. You get the Master Caution only the first time, because the G-Limit Override warning remains on your BIT page after the first instance.

"...this is for your safety as well as for the safety of your aircraft."

Mmmmmmhhhhh...maybe!

Agreed I should have been more specific. Obviously the G-Limiter button doesn't morph the aircraft into a new design. The aircraft has an absolute flight envelope inside of which are set various operational flight envelopes. I meant to say gain access to more of the operational envelope.

My understanding is that as modeled the envelope is restricted to 7.5G and expands to 9G with the overide; abit like the CAT1-2 button in Falcon AF. Now assuming your not going to be turning and burning with a full bomb load (in which case you deserve to get shot down) I'd like the 9G envelope please. However I do understand that (if experiences BFMing in FalconAF are to be believed) you're not going to be pulling 9G for long if you want to keep at best sustained turn rate. But still, I suspect (all other things being equal) if you gave a group of fighter jocks the choice between BFMing a 7.5G limited F18 and a 9G limited one there wouldn't be many takers for the former. But I could be wrong.

As far as wrecking the plane is concerned; well aren't the Swiss / Australians ? Canadians not G-limited in the way modelled in the game. Are they wrecking their planes. Are the USAF wrecking their F16's or perhaps that's a stronger plane than the F18 (given that that's navalised.)I don't know I could be wrong.

My gut feeling is give me 9G accessible and I'll promise to be real gentle with bombs hung underneath (as I should be anyway).

TIM

The F/A-18 flight computer continually re-calculates the G-Limit based upon several flight characteristics, such as current weight and altitude, and displays it on your HUD.

Unless I am way off base, the G-Limit Override is just what it says: overrides the G-Limitter. You can pull as much G as you can find as long as it is engaged.


How about this: you have a choice between two Toyota Corallas, one with seatbelts and a speedometer that goes up to 90 MPH, the other with no seatbelts and a speedometer that goes up to 160 MPH. Which one do you pick?

One of them has safety equipment installed, one does not. But the overall performance of the vehicles is pretty much the same. The second one is "160 MPH accessible", but unless you drive it off a cliff, you're not likely to see that speed. And if you do, it will probably be only once.

Same as the F/A-18. Even if you remove the safety equipment, you're unlikely to be able to exceed the calculated max G for more than a moment at a time. It's those pesky laws of physics again.


The Canadians, Australians, Swiss, and Jamaicans don't use a G-Limitter? Interesting, I guess. All I know is that the fine folks at McDonnell Douglas (US) who are smarter than the both of us put together and who built the aircraft, designed it with a G-Limitter for use in the US Navy for US pilots to protect both the pilot and the aircraft. (Perhaps US pilots and aircraft are more valuable.)

I did a little rearch and discovered that the Japanese A6Ms flown by kamikaze pilots did not have a G-Limitter, either. And those guys were some good pilots.

Maybe it is I, and the aircraft engineers who designed and built the F/A-18E Super Hornet, who are wrong.

The G-limit override moves the maximum available G from 7.5G to 10G (not 9).

We have been told on this forum that real pilots only use the G-limit override when they feel they would die without its use.

If you have a programmable joystick, you can program a joystick button to hold down the override keystroke the first time you press the joystick button, and release the keystroke the next time you press the joystick button.

If you have a Cougar or CH HOTAS. it's best to reprogram the g-limit override keystroke from "Y" to a joystick button in-game, then program your HOTAS to hold that DirectX button down. I don't think you can do this with other programmable controllers.

F-16 have a similar G-limiting system in their flight computers as well as far as I know, they both use fly-by-wire systems that were developed at the same time. As far as being stronger, the Navy purposely makes their airframes and landing gear stronger to handle the rigors of landing on a flight deck, etc so as far as that theory goes, the F-18 is stronger than the F-16. And yes, the Airforce is wrecking their planes (F-15's comes to mind). There was also an Airfoce pilot over-G'd his F-16 doing a min. radius turn at an airshow I watched a few years back and cracked the spine doing 9 G's.

I'm not trying to tell you what you can/should or can't/shouldn't do in the simulator, by all means over-stress to your hearts content, there aren't going to be any "real" consequences but in real life it's a little different. You would be grounded if you made a habit of over-stress. It creates a HUGE mess for the maintainers tearing everything appart for NDI inspections, etc.

As far as the Toyotas go... I want the one with the safety features AND the Speedo that reads upto 160mph, but then I'm just greedy. Why wouldn't you want to know what speed you were at above 90? Here in the UK you'll get points (and they don't mean prizes!) around 90,... over 100 and you'll need to dig out the bicycle or bus pass. The speedo thing makes me laugh. Can you remember as kids racing upto parked hot cars (sporty not stolen) and oohhing and aarrrhing at how high the speedo read; the innocence of youth!

I agree with you. The fine folks at McD or Boeing or whoever it is who designs/ builds the things are way smarter than us. But then I suspect if the price is right they will build you what you want..within those pesky Laws of Physics. So say one guy wants the jet limited to 7.5G with a little button that allows it to go higher (do the real pilots have to hold it down?) so as to reduce long-term airframe stress...no problem mate. And if another guy says nnaarrhhh forget the button we'll just take the "full encholada"...well your money your call. Didn't some of the A/B models have stress problems around the Tail roots? Mind you I think I'd have more than stress around the tail roots if someone was regularly slamming me onto a deck at 150 knots.

Know to repeat I'm not suggesting I want to go hair arse tearing around pulling 9G all the time or that it is even good BFM sense to be perpetually on the limiter ..but every now and then! I reckon a badass Mig29 headon trying to leadturn me counts as "one of those situations where I might feel I was going to die without it".

Interesting thoughts on the G-limiter. One that continually varies the max allowable G dependant on weight (varying with fuel and ordanance usage)sounds neat compared with one fixed at 7.5G. I suspect the real version is the latter but I can't see why the former couldn't be devised. Anybody know The Truth....I understand it's out there ....somewhere.

I suspect my Flightstick pro isn't high tech enough to implement your suggestion but I'll give it a try.Thanks anyway. Alternatively I'll get a specially designed paperweight to stand on the Y key.

TIM

That would be a nice piece of logic added to the campaign. IF you use the limiter on the mission you can't use that airframe for the next 2 missions or something (while it is ostensibly inspected).. That would be a good penalty for using it unless it really was necessary...

BeachAV8R

A much better piece of logic would be to make the Y switch a proper TOGGLE switch. That way ..if you wanted... you could pretend to be an Australian/ Swiss/ Canadian pilot on secondment to the carrier group.

Don't you guys find that impacting R77's and R73's REALLY REALLY overstress the airframe!

I suppose you can console yourself as you float down into enemy territory with the knowledge that.. should you make it back to the carrier at leaast the maintainers won't have to do an NDI inspection.

TIM

Well..perhaps it is exactly those cyclic operations that you refer to..(catapult shots, carrier landings) and the pace and rate of operations that the U.S. typically operates at that requires the G-limitation. Fatigue is cumulative...

And to throw it back at you...I guess when your strike package has 6 planes instead of 8 because two airplanes are back getting NDI inspections you can just assume you didn't need those 2 additional airframes to complete the mission..

BeachAV8R

See, here's where your discussion gets silly.

You're trying to imply that the only way to evade missiles is to have G-Limit Override locked on all the time.

It's for just such a circumstance that the pinky trigger on my stick is mapped to G-Limit Override. Rather than placing a paperweight on the Y key, the Override is always immediately avialable on an as needed basis.

I don't have to explain to the crew chief each time I trap why 'G Limit Override' is locked into my BIT page. I use it when I need it.

Apologises for the sillyness..I just felt I was being dragged down a path; "annoying little things like wings falling off" "guaranteed damage such as from bullet holes" "Toyotas speedos" "Kamkikaze pilots" "Perhaps US aircraft and pilots are more valuable"(I suppose they are to the US.)..etc etc.I suppose I should rise above such stuff but what the hell.. a bit of cut and thrust, friendly banter, never hurt anyone.

Back on topic;

Anyone know how the real G limiter works? Is it a straight cut-off at 7.5 or variable as has been suggested. The latter sounds like a great idea (abit like Airbus's protected flight envelopes).

Do the real pilots have to keep the button depressed or is it a toggle?

Is there anyway that it can be made a toggle in the game?

When would YOU switch off the G limiter? My vote goes for anytime I'm in a threat enviroment and don't have CAT-ll(or is it lll) stores on the wings?

Do F16 pilots routinely fly around with the CAT switch on II irrespective of loadout and only switch to I when under attack?

When Navy pilots are practising BFM do they have the G limiter switched on?

Is 9G OVER STRESSING an F18? Okay you can argue that any G is stressing the plane and will at varying rates degrade the structure; but surely the era in which this jet was designed in required 9G performance in Air Combat and the consequent absolute margins to allow the plane to be regularly taken there as part of reccurent training.

Actually does anybody know how freqently the airframes of jets like the F15 to 18 can be taken to 9G. I assume the g profile is monitored and recorded. Is it just a cumulative period of time or is the rate important i.e. only so many times per month ?

TIM

PS-- I promise not to be silly. Let's face it we're all in the same family..lovers of this great simulation!!

Completely agree..

I don't really know anything about the G-limiter, its design, functionality, or rationale behind why some aircraft of the same type have one and others don't. I'm guessing it is a pretty complex issue. It could be, as mentioned before, the pace and frequency of cyclic operations that U.S. planes are subjected to...or it could be a general limitation to not only save wear & tear on the airframe, but on delicate (somewhat) avionics and weapons systems. I suppose the logic is that it isn't only the airframe that suffers during high-G maneuvers, but also the rest of the avionics, systems, and ordnance.

It would be interesting to hear an engineer or maintainer discuss the factual reasons for the implementation of the limiter. It could also be a mix of fatigue issues along with actual dissemination of flown BFM maneuvers that show that 7.5G gives you a better long term survivability than being able to pull 9G more frequently. It would be a statistical analysis perhaps. For instance, the Airbus uses software limits to constrain the performance of their aircraft with the logic that such constraints will result in more likelihood of remaining with the "normal" envelope of flight and requiring less "abnormal" pilot inputs to keep things safe. They would weigh that against the ability to take an aircraft up to the structural limits and performance and assess which is safer. I can see why pilots would want total control of their aircraft, but it has been my experience that most pilots probably aren't as good as they think they are (myself included). There are certainly those that are the exception to that rule.

So maybe (and this is just a theory) the 7.5 G is designed to keep that 90th percentile of normal pilots to fly to their maximum ability..which might hurt those 10% that can fly beyond it..but in the big scheme of things it just comes down to overall benefits.

I don't know..this is just theory and speculation on my part. As I said, I'm sure there are tons of variables that go into it.

Good discussion and I'll be interested to learn more.

BeachAV8R

One other thing that might bear consideration..is that a pilot in combat is likely pretty excitable. Pulling off a bomb run or something they might, in their heightened state of adrenaline, pull more than what they would normally do under the circumstances. Survival instinct in combat, and competitive pressure in training, probably serve to push the airplanes up to and past their limitations. Putting in a buffer against those limits might be a way of tempering the aircraft against a super-ambitious pilot..who is otherwise distracted while having his "fangs out".. (?)

Using Control Manager, indeed it is On another note, I don't think I've ever pressed the G-Limit override button.

Well, here's some info on flight control systems. Not all necessarily G-limit related but it should answer some questions.

Like Beach was saying, much of the controls are to keep the aircraft within the "envelolpe". The way fly-by-wire works is, the pilot provides the input (i.e. pulling back on the stick), the computer then measures that input and "decides" if the aircraft can do what the pilot is asking. The computer then sends outputs to the various control surfaces to make the plane do what it "thinks" you want it to do while staying within relative parameters. Prior to this type of control system (F-14's for example) pilots would often overstress the airframe just like Beach mentioned. They get in Indian country, the adrenaline is pumping, they pull too hard coming off target and snap 9+ G's on the jet when it wasn't really necessary for them to do so. Fly-by-wire limits the amount of deflection on the control surfaces regardless of how hard you pull on the stick so you don't overstress the airframe. This also keeps the pilots from knocking themselves out due to G-lock. Overstress doesn't always occur at a specific number of G's either, it's more determined on how quickly the acceleration is enduced on the airframe. If you do a gradual pull to 9 G's, while it is definetly still possible to overstress (and you'd probably pass out), you are less likely to damage the airframe than if you "snap" them on really fast.

As far as real G-limiters, for the F/A-18, it is set at 7.5G's but it is possible to snap more than 7.5 for a moment or 2 with the G-limitter still on. The concept of varying G load limits was discussed already in this thread by Hedgehog. If your aircraft is in a certain configuration, there is going to be a limited amount of G's you can put on the jet based on the laws of physics. If you're flying at high Alpha and only doing 90kts it is impossible to pull 9G's in that configuration. If your wings are loaded with ordinance and fuel, your weight (Mass times the force of gravity) will limit the number of G's you can pull. Here's an analogy: Try throwing a baseball as far as you can and see how far it will go. Now grab a shot put that is the same diameter as the baseball and throw it as far as you can. The baseball will go a lot farther because it is lighter in weight. Your amount of stregnth (force) on both the ball and the shotput were the same, as was the aerodynamic shape. A slow moving aircraft produces less lift, which means the force of weight is greater. Same with the loaded jet full of ordinance and fuel, it's heavier. A faster moving aircraft (assuming straight and level flight) produces more lift which reduces the force of weight. Obviously an empty aircraft weighs less than a loaded one, the lighter aircraft can pull more G's. When the Blue Angels fly, the solo pilots start off pulling around 7.5G's but end up pulling 8+ sometimes toward the end of the show when the aircraft has less fuel. They do this without using G-limit override at all so like I mentioned above, it's possible to exceed the 7.5G-limit in real life but the jet won't maintain that unless you override it. The excessive G's will stay on for a moment and the computer (G-limiter) will adjust the control surfaces to lessen the pull and bleed off the extra acceleration back to the limit.

Clear as mud?? I hope my "textbook" gave you at least a few of the answers you were looking for!

I'll tell you what, Tim. I'm not a real pilot, I'm a sim pilot. I don't have any answers for you about how the G Limiter works (or doesn't work) in a real F/A-18. But I can tell you how it works in the sim.

Regardless of what "The Book" says, in the sim, your flight computer continuously recalculates your max allowed G. And, as it turns out, engaging G Limit Override increases the G Limit to a new, higher value. It is not simply a flat 7.5 G to 9 or 10 G.

I just loaded my jet with a big pile of stores for all the good little girls and boys, jumped in, whipped the reindeer and went for a spin.

As soon as the wheels were in the well, the FC informed me on the HUD that I wouldn't be pulling any more than 6.4 G. I went full blower, cranked up to nearly 500 kias, and commenced to yanking. Not amazingly, I could not pull more than 6.4 G, even if I leaned hard left in my computer chair.

Suddenly, a Lithuanian F/A-18 went screaming by, its pilot yelling, "Ich habe nicht Gee Limitischment!" So I put on some smash and cranked her over again, squeezing my pinky trigger this time to engage G Limit Override. The Master Caution illuminated, and now the G Limit in my HUD was displayed as 8.6. I was easily able to exceed the previous 6.4 limit, although with all the stores and fuel I had onboard, 8.6 was not going to happen.

Quick review:

G Limit: 6.4
G Limit Override engaged: 8.6

As I flew around, burned some fuel and pickled off some stores, those numbers continued to change.

I'm not trying to justify the function of the G Limit Override by contrasting it to the F-16 CAT switch or the heated seat switch in my wife's Honda CRV. I'm just telling you how it works in the sim.

Not quite. An object's weight does not change as a function of velocity. The weight of an object is, as you say, its mass multiplied by the acceleration due to gravity. A slower moving object does produce less lift, which means the sum of the forces acting in the vertical direction is more negative for a slower object (assuming positive = up).

You must have heard the story incorrectly...

The F-16's standard acceleration limits is 9g , load depending.. in the configuration flown at airshows it is pretty light and 9g is WELL within limits..

Additionally the FLCS really never allows an over-g in the Viper. The F-15 and the F-18 (I don't know about the F-18E, it is probably like the F-16 since it is newer tech) Can be overstressed as they have primarily a manual flight control system with a fly by wire secondary

That's what I was implying Joe, the sum of forces is a greater "downward force" which is exactly what weight is. The mass always remains the same, the effective downward force is reduced as lift increases. That's what I meant to say.