Super Hornet G Limit question

[deyv]

...in F-18 super hornet in [Flight Control] section is MaxG line...my question is...does it limit for the airplane??...because if it is I think it should be 9 or even 12g(!!) for super hornet instead of 7,5...I lost my wing during high speed maneuvers in WoI (!!!):P...of course I had heavy loadout but it still shouldn't happen....I read that navy gives usually "safe info" and on the air shows you can see that pilots takes 9g in super bugs during maneuvers... what is your knowledge about that guys??

[+MigBuster]

[flight control] determines more to do with how the AI handles the jet (I think)

 

 

The airframe is given a rating - this doesn't mean a jet is completely limited to this - although going over this rating for a length of time will damage the airframe it seems.

 

Did the pilot say this was a sustained 9G turn for any length of time? - also i'm not really sure you can tell a jet is pulling 9G by just looking at it.

 

no idea what the F-18E/F models are rated to - pretty sure the FA-18A/C models were 7.5 - 8G according to a test pilot we have on here.

[+column5]

That parameter only limits G for the AI. But the Supa Honet only has a 7.5 to 8 G capability in real life. Same with the Classic Hornet--only the Swiss aircraft are certified to 9 G.

[deyv]

of course I didn't just look on it... :):) and he took 9g for about 2 maybe 3 seconds. Inside was chief test pilot of boeing super hornet program Ricardo Traven...also f-18 was loaded (6 aim-120 and 2 aim-9). I found info about upgrade f-18 from 7,5 to 9 g for swiss

[deyv]

...but as said column5 it's swiss "just" hornet :P:P...anyway thanks for info :)

[+Typhoid]

"I lost my wing during high speed maneuvers in WoI (!!!):P...of course I had heavy loadout but it still shouldn't happen....I read that navy gives usually "safe info" and on the air shows you can see that pilots takes 9g in super bugs during maneuvers... what is your knowledge about that guys??"

 

mixing real life and sim here. the sim is accurate in putting that max g load on. However, in real life the aircrew also has to consider what he might be carrying. Your comment on the heavy loadout is the key and actually validates the sim.

 

The NATOPS, or Dash-1 for the pale blue suit gents, will have a table with a graph that equates load and max g. In other words, you will have a different max g based on what you are hanging on the stations. I would venture to guess that you have not seen in any airshow, any aircraft loaded to the gills pulling 7-9 g's. At least more than once...........

[+Fubar512]

Once upon a time, aircraft had a 1.3-1.5 X stress margin. For example, Randy Cunningham pushed his F-4 so hard during a dogfight, that he broke a flap hinge.

 

He later admitted to hitting 11.5 instaneous Gs during a hard pull, on an aircraft that was "officially" stressed for 7.5 G (sustained).

 

I suspect that if one were to try that sort of stunt today (pushing max sustained G +.5, if the FBW system were to allow it), your bird would fold up like a cheap camera.

[+column5]

Another point to consider is that higher G does not automatically mean tighter turn radius.

[+Fubar512]

Another point to consider is that higher G does not automatically mean tighter turn radius.

 

If the G-level were to be attained at the same IAS, say, 400 knots, then a 6 G turn at 90 degrees angle of bank would be tighter than a 3 G turn at the same angle-of-bank, but not by a 100% margin.

[+Syrinx]

Do modern aircraft that use FBW technology have different settings for g-loads etc.

 

I mean, in peacetime you might not want to pull 9g or 6-7g sustained for any number of reasons.

 

In war, you probably would if you had to.

 

Is there a "war" setting for want of a better word (simplistic generalization I know) that would enable the FBW computer to add more flexibility and give more freedom to a pilot ?

 

Allow him\her to push the envelope right to the edge instead of within safe limits ?

[deyv]

I think that FBW technology doesn't actually control g limits... it won't let airplane go out of control...

[Guest 531_Ghost]

Once upon a time, aircraft had a 1.3-1.5 X stress margin. For example, Randy Cunningham pushed his F-4 so hard during a dogfight, that he broke a flap hinge.

 

He later admitted to hitting 11.5 instaneous Gs during a hard pull, on an aircraft that was "officially" stressed for 7.5 G (sustained).

 

Those were the days. The most I ever recorded from the G meter on the aircraft (F4N) was 9 Gs. That bird was in the hangar a while after that.

[+Fubar512]

I think that FBW technology doesn't actually control g limits... it won't let airplane go out of control...

 

Actually, it does.

[+MigBuster]

Do modern aircraft that use FBW technology have different settings for g-loads etc.

 

I mean, in peacetime you might not want to pull 9g or 6-7g sustained for any number of reasons.

 

In war, you probably would if you had to.

 

Is there a "war" setting for want of a better word (simplistic generalization I know) that would enable the FBW computer to add more flexibility and give more freedom to a pilot ?

 

Allow him\her to push the envelope right to the edge instead of within safe limits ?

 

 

Well if Falcon is as accurate as they say then the F-16 has a little CAT switch that dampens the handling (makes it sluggish ) of the A/C thus making it much harder to get above Gs that would damage it.

 

For example if carrying any stores other than missiles on the wings you set the switch to catIII - and you will get a continuous warning until you do - so this is defo a way of limiting what you can actually pull (if accurate)

 

Then when you have dropped your bombs (or at an acceptable weight ) then you will be warned to switch back to cat1 - which gives you full dogfight responsibility and agility

[+column5]

If the G-level were to be attained at the same IAS

 

That's what I was getting at. Speed is also a factor in how tight your 7.5 g turn will be.

[MAKO69]

The F-18 Supers are limited by the flight computer not sure what it is and how long it will sustain the G load. It wont let the pilot hurt the aircraft, the f-22 has the same govener to limit stress on the airframe and prolong the life of the plane.

[Caesar]

I used to have the Super Bug NATOPS, but I have no idea what happened to it. If I remember the info correctly, the Super Bug has a 7.5g symmetric limit. As everyone has already mentioned, combat loadouts change limits, and then there's rolling limits which are different than symmetric limits, usually a bit lower.

 

EDIT: Also as said, in combat, the gloves come off; if you need 8g to survive on a plane rated for 6.5 (and its available at airspeed/altitude/etc), you're going to load 8g on the plane or go down with it in flames.

Edited August 8, 2008 by Caesar

[+drdoyo]

When I was with the Indiana Air Guard and during our first ORI (Operational Readiness Inspection) in the F-16C we had a pilot over G his aircraft. The F-16 was over limit for it's loadout by 1 G. We spent the next 2 days replacing stripped nutplates and sheared rivets on the bottom of the wings in the stress areas. Aircraft can be pushed beyond their loading limits and still come home, but it doesn't mean by any length that there was no damage done.

Edited August 9, 2008 by drdoyo

[Caesar]

Good point, the plane might come back, but it might also need days of work. I recall that "Hoser" Satrapa put 12G on a Tomcat to evade a guns-kill and the plane didn't have a scratch on/in it, while a nugget (unnamed by the airframer) loaded around 9.9G and the plane was grounded with some of the internals twisted and parts pulled out of place. That later case might not have even been a combat hop, come to think of it!