Can you use sudden charge with Fledgling Flight?

[Oni Shogun]

This has come up with a GM in PFS who is saying you cannot. I think you can via how the rules are written.

[NorrKnekten]

You cannot, for several reasons.

Sudden charge can only be used with speeds that you currently have, These means basic Climb, Burrow, Swim and Fly actions and nothing more, we know these are the referenced ones due to capitalisation of their names.

Fledling Flight only gives you a flyspeed for that action, After the action is complete you no longer have a fly speed, And you cannot perform any other non-triggered action while also doing another action.

[Finoan]

Agreed. To repeat/rephrase and add citations:

Sudden Charge is usable with Fly if you have a Fly speed when you use the action. A Strix with Fledgling Flight doesn't have a Fly speed normally (unless they are getting it from something else). So they would be unable to use Sudden Charge with the Fly speed that they generally don't have.

Also, the Subordinate Actions rule prevents replacing either of the Stride actions in Sudden Charge with a Fledgling Flight action.