Roll trimming
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Guys, i have what is probably a stupid question for someone that’s been flying falcon 4 since 2000 but here goes…
As we all know, when on asymmetric load-out the jet experiences a rolling moment and we counteract it with trimming. However, why isn’t that something the FLCS does automatically? Since the FLCS applies pitch trimming to balance the jet’s instability (by design), am i under the wrong impression thinking this could also be applied to rolling? I’d appreciate an answer from our gurus here! -
@master-yoda said in Roll trimming:
Guys, i have what is probably a stupid question for someone that’s been flying falcon 4 since 2000 but here goes…
As we all know, when on asymmetric load-out the jet experiences a rolling moment and we counteract it with trimming. However, why isn’t that something the FLCS does automatically? Since the FLCS applies pitch trimming to balance the jet’s instability (by design), am i under the wrong impression thinking this could also be applied to rolling? I’d appreciate an answer from our gurus here!No it does not trim in Roll
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@master-yoda I think this a pretty valid question. Being a Falcon simmer for as long as yourself, my personal very unprofessional take on this is that what the FLCS does is much more complicated and vital to the jet. It is not just adjusting trim in pitch, it also utilizes the rudder to keep the jet stable etc… Whereas the pitch/roll trim adjustment is something that can easily be commanded by pilot input depending on the given loadout, KIAS etc. However annoying that may be. If we go down this route, perhaps the FLCS should take off/land/AAR on its own (which may happen in not so distant future with the newer fighter jets. I read somewhere F-35B pretty much auto-lands in VTOL mode).
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There is a little switch that says “ATT HOLD”.
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Press A
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@mav-jp I didn’t ask weather it roll trims, i know it doesnt! I also never implied that lockmart should add such a feature!! I merely asked weather its possible in theory for the FLCS to roll stabilize, much like it pitch stabilizes.
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@master-yoda i think Mav meant that we have no idea if it could, hence —> LM
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This post is deleted! -
@master-yoda said in Roll trimming:
@mav-jp I didn’t ask weather it roll trims, i know it doesnt! I also never implied that lockmart should add such a feature!! I merely asked weather its possible in theory for the FLCS to roll stabilize, much like it pitch stabilizes.
The feature does already exist in a different way … Set ATT HOLD (Attitude hold. It provides the same services and allow to work hands off the stick).
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@airtex2019 said in Roll trimming:
There is a little switch that says “ATT HOLD”.
Does “ATT HOLD” attempt to achieve “zero roll-rate” or does it attempt to achieve a desired bank angle?
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@master-yoda said in Roll trimming:
am i under the wrong impression thinking this could also be applied to rolling?
Maybe an interesting way to pose the question – do more modern jets do this? (Hornet? Raptor? etc)
Or is there something fundamentally problematic about it… eg. wanting pilot to have more direct authority over those control surfaces, during landing?
Maybe it was a sense of risk-aversion, or limitations of the technology of the time… eg. not wanting to base fbw controls off instruments that are gyroscopic?
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@airtex2019 said in Roll trimming:
@airtex2019 said in Roll trimming:
There is a little switch that says “ATT HOLD”.
Does “ATT HOLD” attempt to achieve “zero roll-rate” or does it attempt to achieve a desired bank angle?
I don’t know … maybe it is written in the book.
Anyway …
There is no roll auto trim on F-16.
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@airtex2019 said in Roll trimming:
@airtex2019 said in Roll trimming:
There is a little switch that says “ATT HOLD”.
Does “ATT HOLD” attempt to achieve “zero roll-rate” or does it attempt to achieve a desired bank angle?
The feedback loop is on Roll Rate
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@airtex2019 said in Roll trimming:
@master-yoda said in Roll trimming:
am i under the wrong impression thinking this could also be applied to rolling?
Maybe an interesting way to pose the question – do more modern jets do this? (Hornet? Raptor? etc)
Or is there something fundamentally problematic about it… eg. wanting pilot to have more direct authority over those control surfaces, during landing?
Maybe it was a sense of risk-aversion, or limitations of the technology of the time… eg. not wanting to base fbw controls off instruments that are gyroscopic?
Hi, Airtex, The RL Hornet does. For example, it’s fairly common to see drop tanks on 5 and 7, to help TGP masking. The jet’s FLCS software can handle that. The BMS Hornet does not, at least not totally. It seemed the BMS Hornet was easier to trim out then the Viper, though I haven’t tried this in 4.35.
BTW, trying this in the BMS Hornet usually lead to a TRP FUEL caution when the tanks emptied.