Forum: F-16 Armament & Stores

Last edited by Gums on Mar 08, 2009 - 05:35 PM; edited 1 time in total

Salute

Listen to John-boy.

The "category" change had to do with we old dinosaurs that believed we could move the stick anywhere at any gee and any AoA and the FLCS would keep us outta trouble. Many of us did not like the idea of a "limiter", but we soon came to love it.

Then we started to carry more and more heavy stuff on the wings.

Rolling at high gee was bad for the structure.

Rolling at high AoA could defeat the FLCS logic and control laws.

So we implemented the Cat III and added the Cat II [self-control limit, not FLCS-contolled].

The big drop tanks were rated nine gees. But that was symmetrical, not rolling.

The Cat III didn't limit gee, as you could pull nine gees in symmetrical maneuvers until fifteen degrees AoA. The lower AoA limit and roll rate limit were nice for training, as the IP could use the switch and give the "gomer" a chance to exploit the full Cat I capability. We IP's would have to fight a high-speed fight, but could NOT do the "bat turn" or hassle at max AoA when getting slow.

later,

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Elite 1K Joined: May 26, 2005 - 08:39 PM Posts: 1496

Quote:

If you turn away from the store while taxiing, you want to slow down a lot or you'll lift the main gear on the inside.

I bet that was a brown-streak moment for the first pilot who found THAT out!

Quote:

Naturally, you can depend on competitors showing the competition is the worst possible light. The F-16 was not designed to carry the AIM-7, but it was scabbed on before the AMRAAM was ready. Seems pretty obvious to me that when you expend one weapon from a small airplane, it will be affected more than when the weapon is expended from a significantly larger airplane. DUH! (That's directed at Boeing/MAC, not skicountry)

Thanks John for the informative answer.

You are absolutely correct about the competition slighting its rivals. I dutifully sat through the procession of charts and diagrams stone faced so as not to give the game away (either way).

The Hornet was obviously at a distinct advantage in this particular comparison because it carried its AIM-7s conformally on the body rather than way out there on the wing. Obviously in that configuration firing one off didn't make much of a difference handling wise.

And yes, in exchange for some of its wonder-boy low speed handling, the Hornet got hammered on range, acceleration, etc. by just about everybody.

Ski

johnwill wrote:

Can you tell me if the F-18 unit provided an automatic variable limiter or just an indication of a variable limit?

Sorry for the late reply.

It's variable since the Max allowed G is displayed at the lower left HUD and it limits your max G to that value, and when you have less fuel/less AG stores, the value increases. You also have a G override switch and tune the max G up 1/3 (e.g. 10 from 7.5) when in emergencies.

Also the flight control of F-18 auto trimms the aircraft instead of manual trim on F-16. Shocked

A big increase in quality flight control!

Oh well that's a decade of technology gap I guess...?

Apologize for the slight OT.

skwabie,

Thanks for the info, don't sweat the OT.

One of the difficulties in using fuel load or store load to control the automatic g-limiter is the need to maintain redundancy. All flight control sensors (accelerometers, airspeed, ailtitude, etc) are supposed to have at least triple redundancy to assure double failure-safe operation. So MAC either came up with triple redundant fuel quantity and store load, or waived the requirement. I suspect they waived the requirement since g-limit doesn't really control the airplane. The worst that could happen would be an over-g condition.

johnwill wrote:

You could for example, have different g limits for every gross weight, every speed, every altitude, every store download, every roll rate, etc. The g limit would constantly be changing and no pilot could keep up with it.

John this is a very good point. This is exactly how the F-15's Overload Warning System works. An F-15 pilot could roll inverted from medium altitude and pull 6g, now going vertically downwards. He could then pull out at 6g and low altitude, but the plane having accelerated would mean he has over-g'd the aircraft.

Obi

skwabie wrote:

Also the flight control of F-18 auto trimms the aircraft instead of manual trim on F-16. Shocked

A big increase in quality flight control!

Hi skwabie

Both the F-16 and f-18 have autotrim in pitch.

There are some differences in the same config vs. Cat I/III which is dependant on the block of F-16. 'Hal' will give you what you need as long as you select the correct Cat switch position. Heavy/light is not always the answer - it can be dependant on the item limits such as MXU-648 travel pods...limited to Cat III even though its only 400+ lbs fully loaded.

ender wrote:

Hi

I have a question with AGM-88 Cat configuration.
If 2 HARMs are loaded, it's allowed to fly in CAT I mode or it's mandatory to select CAT III mode?

Understand HARM isn't considered as a heavy weapon but I not sure.

Thanks!!

Carrying 2 AGM-88's are a CAT III loading in even a pretty clean config with just tip missiles. It can only be CAT I after both missiles have separated from the aircraft.

~ViperDude

Obi_Offiah wrote:

skwabie wrote:

Also the flight control of F-18 auto trimms the aircraft instead of manual trim on F-16. Shocked

A big increase in quality flight control!

Hi skwabie

Both the F-16 and f-18 have autotrim in pitch.

Indeed, corrected Confused

I also came to know that the F-16 doesn't auto trim in roll though, which can be a bit PITA sometimes. Does the F-18 have this feature? Coz I've seen some ridiculous loadout on it, like wing tank on one station and a GBU-12 on the opposing station.

Forum: F-16 Armament & Stores

AGM-88 in Cat I/III mode