When filing a VFR Flight Plan, where/how do you include intent to use a Class B transition?

Question

When intending to use a VFR transition route through Class B airspace, do you put the intended route on the flight plan, the alternate route (if you don't get clearance for some reason), or both?

Which fields does the information go in? e.g. Does the intended route go in route of flight and the alternate in "Other Information" or vice versa?

Example:

I am planning to fly from KHAF to KAPC. Ideally, I'd like to fly using the Bay Shore Transition, as marked on the SFO TAC:

KHAF VPSCS VPOYS VPSBT KAPC

If I'm not cleared into the Class B, I'd instead fly

KHAF SAU KAPC (staying outside the Class B)

How would I file this plan?

Where does one request a VFR transition route through class B? deals with the ATC, not the filing.

Here is the form I will be using:

Answer 1

Since VFR flight plans are only used for SAR, and your route would only matter if you aren’t talking to ATC, I would file the route you intend to take if ATC denies you the B transition—or refuses to talk to you entirely.

If they do talk to you and grant the transition, then there will be a clear record of your actual path, and nobody will bother to look at (that part of) the route in your VFR flight plan. Or any other portion of your route where you have Flight Following, for that matter.

Note that, for calculating ETE and required fuel, Murphy’s Law says you should use whichever route is longest.

If you’ll be getting a WX briefing, mention the possible diversion to ensure your briefer checks that area too, but realistically, you won’t get in if there’s anything there serious enough to matter.

Answer 2

In answer to your specific question, as I understand you are asking, I would just put in the intended route (e.g., Bay Shore Transition) in the "route of flight" section and the route outside of class B airspace in the "Other Information" section.(annotating it as another potential route you might fly).

But keep in mind, for a VFR flight, Air Traffic Controllers do not get the information from the flight plan you file with FSS (Flight Service Station). The route of flight and other information on the VFR flight plan is primarily for search and rescue purposes should that be necessary. That is if you open, but fail to close your VFR flight plan, the information filed (on your VFR flight plan) will aid in any subsequent search and rescue operation.

Check out Aeronautical information Manual AIM 5-1-4 for some extra guidance.

So, when in contact with ATC (prior to entering the Class B airspace, of course) advise them of your intentions and request. Remember, these controllers do not know what you filed on your VFR flight plan (unless you fail to close it and a search is initiated, then controllers/facilities along your planned route of flight might be queried whether or not they provided service to you).