Stores G and CAT limits

[NikolaiVChr]

So Mover and Gonky (Real F16/Hornet driver) made some interesting comments about G limits.

Empty drop tanks: 8.5G (With 2 droptanks attached not beyond 8.5G) Bombs: 5.5G Tanks when not empty: 6.5G TGP: 7.33G ECM Pod: ? G

He also listed these as the aircraft limits:

F-16 9.5G F/A-18 8.0G Mirage 9.5 F-14 8G F-15 9.5G SU-27 9.5G MiG-29 9.5G A-10 7.33G F-5 7.5G MiG-21 9G F-86 7.5G MiG-15 6G JF-17 8.5G Harrier 8.5G Viggen 7.5G All Props 8.5G

*G limits for all aircraft consist of the main aircraft G limit and a .5 buffer.

So, after reading Movers posts on Eagle forums, and watching parts of Gonky video about this some times, it has become clear to me that except for CAT III limits, this is limits not imposed by the aircraft but the pilot simply taking care not to exceed it.

So from F-16 forums:

johnwill wrote:

The limit with full 370s is 6.5g. Considering that all g limits have a 150% design factor, 7g would not cause any structural failure. Plus the only time you have full 370s is just as you drop off of a tanker. The only 4g limits I ever saw were for 600 gallon tanks with fuel and for gear down. Cat 3 was SUPPOSED to be used with external store loadings with 5.5g or 6.5g, but those were supposed to be pilot-observed limits. The pilot who sadly couldn't pull out prior to impact was not inhibited by a lower Cat 3 g limiter, but could have been done in by the Cat 3 AoA limiter if he was at a too low airspeed. Categories 1, 2, and 3 were developed for various sets of external store loadings. Cat 1 was essentially air to air without underwing tanks, Cat 2 was air to air with underwing tanks, and Cat 3 was air to ground (and ferry with three tanks).

the g indication system on the F-16 is a mess, to be kind. Since g limit is a structural concern, the g should be measured at the center of gravity. For some reason known only to them, the flight control guys put it 13 feet forward of the cg and above the roll axis. Result - the g reading is affected by pitch acceleration and roll rate. You and I would call that an error. But the pilot doesn't see that g reading on the HUD. It contains its own accelerometer and that's what the pilot sees. Of course it is also affected by pitch acceleration and roll rate, so more errors.

The primitive YF-16 had a variable g limiter, which accounted for reduced load at other than .95/10k. It's limit varied from 7.33 to 9, depending on speed and altitude.

For the initial F-16 stores list, only the SUU-20 (7.3g) and AGM-65 (6.5g) were rated above 5.5g.

basher54321 wrote:

Most A-G stores have a 5.5g (symmetric) limit, but the AGM-65 is 6.5g.

Also the reason almost all AG weapons is 5.5 is so that pilots can remember the number somebody wrote. If every weapon had a separate number would be many numbers to remember. And that also hints at that these G limits is pilot imposed, not control system imposed.

So on the JA37 I had a little dialog you could enable that would show you the current G limit that you are supposed to adhere to. Maybe we should consider something like that for the F-16 also.

And all our stores needs to adhere to the CAT scheme if you haven't done that already @JMaverick16 When I initially set the CAT limits on the stores, it was guesstimates if they were I, II or III.

So: CAT I: A/A and center tank CAT II: Wing tanks CAT III: A/G [and 3 tanks, but our CAT system don't support that right now]

Open question: CAT for fuselage pods (probably CAT I) and CAT for ECM Pod (probably CAT I).

[JMaverick16]

I guess you pulled those out from the Fight For Honor tread hehe. Quick answer, I did add CAT selection for newer stores and they should be close to actual. Although I can ask around as well. IIRC ECMs are CAT II min or so. Will read better once I'm out of uni.

[NikolaiVChr]

Suggestion1: Pop up info every time soft G-limit is changed so the pilot know what not to exceed. Suggestion2: In the payload dialog, list G-limit for every option.

[NikolaiVChr]

CAT values for stores now fixed. Still need G-limit info to pilot.

[JMaverick16]

Still need G-limit info to pilot.

Which info?

[NikolaiVChr]

Read the suggestion comment..

[JMaverick16]

I'd go for one, otherwise presets as they are would get cluttered much more.

[NikolaiVChr]

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