This will be a separate suggestion, currently we only implement single plane maneuverability, so there will be a bug report to revert this and a suggestion to implement dual plane maneuverability.
It will only affect the I-Hawk while F90 keeps its 20G, correct?
Literally says originally the wings were 14G’s single plane, and then extended to 20G’s single plane creating “loads that were significantly than those originally designed for”
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That does make some sense.
From what I understand from this, originally I-Hawk’s wings were designed for the same G limit as basic Hawk, but then during development, they changed the “threat g level” from 3 g to 6 g and consequently, changed the missile guidance and increased the missile G and AoA limits to meet the new requirements:
The problem however, is with this part:
From what I understand from this, the autopilot uses single plane maneuvering as long as there is no need to use max pull, and switches to dual plane when it needs max pull.
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Then there is this part, suggesting limiting “commanded G” to 12, “which is what the structure was designed to accommodate”
And we know that the 12/14G value is the single plane design limit of the wings.
Meaning the missile autopilot actually pulls its (20g) “commanded g” in single plane.
Though, another interpretation for this could be that the missile autopilot actually is not capable of dual plane maneuvering @MiG_23M @David_Bowie :
Because the autopilot is not capable of dual plane maneuvering, it cannot equally distribute the load on both pairs of wings. So:
1- “When pitch and yaw are limited” (e.g. The autopilot is trying to pull 5G in one axis and 10G in another axis), the forces are not “being distributed equally on both sets of wings”.
1- Only when the autopilot is trying to pull max G in both axes (i.e. “When pitch and yaw are not limited”, i.e. When the autopilot is trying to pull 20G in pitch and 20G in yaw), the forces are “being distributed equally on both sets of wings”
This is also more consistent with the rest of the document, highlighted here and here.
You are not understanding what is being said. The missile achieves 20G in single or dual plane. It does not need to use dual plane to achieve 20G. My point is that in real life, it maneuvers most of the time in dual plane so as to maintain roll control at higher angles of attack. The proof is just further evidence that tail control missiles launched in “X” configuration primarily use dual plane.
They said a 30% load factor was applied to that, which is ~18.2G
Yet, still it states quite clearly that the autopilot will pull in single plane up to 20G.
As shown.
@sudo_su1 Settle down on this one, I got it.
Thats my point?? I dont know why people are saying its only in dual plane pull.
The point being made is that if the Sedjil maneuvers in combined plane, and has the maximum maneuverability given to it - the Phoenix likely uses similar guidance and should also be given its’ maximum load limit. It was further evidence that the Phoenix has more than 17G’s maneuvering limits seeing as it was designed with higher wing load limits and deflection angles than the Sedjil.
According to the same document, 20g capability was not integrated into the I-Hawk until 1974, they even tried to reduce manoeuvrability to 12g in 1973.
To the contrary
The document clearly states that the increased 20g and 22 deg AoA limits which were chosen in 1969 due to change in requirements, were the “current I-Hawk” specs at the time of the writing of this report in 1973.
In fact, the whole reason for the very existence of this document is that the 20G 22 deg limits caused some breakups / failures in service. (Which is not relevant to WT as it does not model reliability)
As a result, the Ad Hoc group was consulted to independently investigate the matter and come up with potential causes and solutions.
And limiting the missile to 12G and 15 deg (which are the limits of the Basic HAWK) was only one of the many suggested (temporary) “potential fixes”:
Which is not clear if (this particular fix, limiting the missile to 12G and 15 deg AoA) was even implemented …
A follow on 1974 report makes it clear that the suggested final fix is the incorporation of ERCL (Elevon Rate Command Limiter) with 20G and 26 deg AoA limits.
Which means that the the main reason for the breakups was actually loss of roll control, rather than the 20G pull on the wings, but also noting that the “elevon hinge moment” might possibly be the main cause, “if there is a single cause”:
All in all, the missile went into production and was in service with 20G and 22 deg limits for a few years.
Even if the limits were later temporarily lowered to 12g and 15 deg to increase missile’s reliability and lower the chance of breakup that’s not relevant for WT.
AFAIK, the G limit for F-14 was lowered later in its service to extend the life of the operational airframes as well … That has no relevance in WT …
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It kinda is relevant to WT, since the missile did not work properly when pulling said 20g single plane…
As WT only models single plane maneuverability, the Sedgil should be dropped to 12g single plane, as that was the determined g loading the missile could functionally pull without structural failure.
The missile should be limited to what was determined to be functional irl.
And btw, saying it was “in service” with 20g does not mean it could pull 20g. It means the guidance computer could try to pull 20g, not that the missile could pull 20g. From the documents it seems rather clear that the missile could not pull the full 20g the guidance computer might try to pull, which is why the guidance computer was eventually revised down to 12g.
The limits were increased in 1969 during the development process. (And seems like the missile went into production the same year)
The missile was declared operational in 1971/1972
This report is from 1973
The missile was completely functional with the 20g and 22 deg limits.
It was just later determined that the missile had some reliability problems.
No missile has 100% reliability IRL.
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You’re misunderstanding the whole case.
The missile structurally could not sustain the full commanded 20g’s. What the guidance computer would try to pull is irrelevant, the missile could not do it. It was reduced to prevent it from even trying.
Just because the guidance controller tries to do something, does not mean the missile structure CAN do said thing.
This excerpt you posted literally stated that all missiles that failed had the same issue: they tried to pull too hard and broke up.
No
The missile could sustain 20G
That’s why only a fraction of the launches resulted in loss of control and breakup.
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The fraction of the missiles that failed were all the missiles that had the common element of “terminal high g maneuver”
ie: they pulled to hard and could NOT sustain it
It isnt optimal to always pull max g’s, the missiles that did not fail clearly did not attempt to pull the full 20g single plane.
Your own sources prove clear as day the I-HAWK cannot pull 20G single plane. It is structuraly incapable of doing so
Where does it say that
That’s just on the list of many “potential fixes” suggested by the Ad Hoc group which was consulted to investigate the matter.
BTW, as I explained here, it does not seem like Sedjil was modified as per the suggestions of the Ad Hoc group, as the 1974 follow on report says that the “gapped wing configuration” has solved the elevon hinge moment potential cause of the problem, but Sedjil does not have gapped win configuration:
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You’re right, “potential” reduction to 12g.
Doesnt change the fact that regardless of what change was eventually implemented, the Sedjil is in structural configuration of the I-HAWK that has a guidance computer with a 20g limit, but a structural limit that is very clearly below said level. The missile CANT pull 20g, but it could try (and fail).
Which means more so than anything that the Sedjil CANNOT pull 20g, as no fix for the high g loss of control/breakup was implemented lmao
At the end of the day, its up to gaijin to decide if they will choose to model the missiles max g limits based on the guidance computers theoretical attempted limits, or the missiles very real structural and aerodynamic limits. I’m curious to hear what the decision on that point will be @David_Bowie