I know my manager is flailing and/or drowning when:

Too busy all the time

S/he starts contradicting herself day to day.

There is all talk and no action.

She doesn’t have the time to check in and ask how to help; or she has too much time and keeps changing the story of what’s important.

The asking is replaced with telling.

They end the conversation with acknowledging open issues.

I am afraid of bringing him news because I know he will not like it.

They don’t follow-up on action items we identified (team, 1:1, or hallway meeting).

They stop asking questions.

Her messages and manner become inconsistent.

They stop coming out of their office.

Staff members start getting thrown under the bus.

His calendar is full of weekly project meetings with no time blocked for 1:1s or other work.

They have a new opinion after every meeting they attend.

Every new thing becomes the highest priority.

Communication becomes limited to terse tactical directives.

He asks me questions that indicate he doesn’t know what I do.

Becomes insecure and creates conspiracies.

They don’t ask about what team members are trying to learn/get better at.

(Sourced via the fine humans on Twitter.)