Maintain (altitude) until established

[B767Driver]

"I'll have to dig for an FAA reference"

The IFR PTS allows for no more than a full scale deflection on a LOC or ILS. That's why I teach "case break" is legal, on a Localizer, to descend. I've never heard half scale before.

I looked into this one...and it's a local FAA interpretation. Evidently, the local FAA office did not like the "case break" interpretation of the final approach course...and defined it further for my company. Undoubtedly, there is more history surrounding the issue than that...I don't what it is. However, it is an ops specs limitation for my company.

Using 10 degrees or "needle alive" is a common interpretation and I'm not aware of it being an issue otherwise.