If FAR part 135 doesn't require alternates then could somebody please explain 135.219, 135.221, and 135.223
Okey-dokey. 135.219 does not speak to alternates; it simply stipulates that you may not depart under IFR unless the destination at ETA will be at or above IFR landing minimums.
135.221 does not require an alternate, but only stipulates that one cannot designate an alternate under Part 135 unless the weather will be at or above minimums at ETA.
135.223 does not require an alternate. It stipulates the conditions under which an airport may be designated as an alternate.
The inference provided by 135.223(a)(2) suggests that an alternate is required. However, relief is provided by 135.223(b) which stipulates that an alternate is not required provided that certain meteorological conditions exist. Only when those conditions exist is an alternate required, and this is not specific to part 135.
But, seeing as you asked, an alternate IS required by 135.217, for takeoff, under specific conditions named therein.
... However, stating an alternate during a briefing would be considered "filed" as the FSS is a part of the ATC system and everything is officially recorded.
Absolutely incorrect. Who told you that? Filing is what it is. Simply making a statement to ATC is NOT filing. If you file, you file flight plan, or ammend the plan. Quipping that you're goign to use an airport as an alterate is NOT filing that airport as an alternate.
Bear in mind that regardless of what is filed as an alternate in your flight plan, you are under NO obligation to use that airport for an "alternate."
I don't think the alternate even appears on the controllers flight strip so my only concern is the lawyers.
You are correct, as previously stated here that the filed alternate does not appear to the controller. You are incorrect in thinking that making a statement to a FSS briefer cures any legal woes you believe you might have in filing an alternate. T'aint so.
They can do it, but they have to call the data center at the ARTCC where the flt plan is stored. If they're busy don't expect them to offer to do that. So really the only way to add an alternate is to either file a new flt plan, or tell ATC in the air.
A briefer will always do this if you ask. Don't wait for someone to volunteer. The briefer is not a mind reader, and isn't going to change, modify, or interfere in your flight plan. That's not their place, and they won't do it. You want a change made to your flight plan, call FSS and request that the change be made. Not a problem.
Telling ATC in the air won't change the filed plan, as ATC doesn't have access to the full flight plan. You're spinning your wheels, there. Further, that information isn't going to get passed down the line, nor will it be used to modify your filed flight plan.
Don't attempt to file a new flight plan. You'll cause all sorts of problems, not the least of which is confusion between the old and the new. If your'e going to do that, cancel out the old one by a positive request, but you should still anticipate that you may have problems with more than one plan entered. Don't file a new one. Modify the one that's in the system. It's easy. One phone call takes care of it.
The same thing applies if you're filed but want to move your departure time. An example of that might be a lifegaurd flight waiting for a patient, or a corporate pilot waiting for a passenger...no telling for sure when they'll show up. An hour later you find that you need to bump your departure time back two more hours. Simply call FSS, and advise. A moment of waiting, and FSS will confirm for you that the change has been made. It's easy, it works, and the FSS specialist will not refuse to help you. Nor does the specialist have that option.