Hopefully someone can give a more informed comment. For me, it's the seats directly in-line with the first turbine, and a few seats back.

edit: Well, I hope we are beyond boohoo LLM based info now. Here is Fable 5 High's explanation, and I loosely verified it. I post this to save many watts of energy due to others asking the same thing.

Simplified:

> I'd like to avoid seats in the rotor burst zone: the rows roughly in line with the plane of the engine's fan and turbine disks, plus a few rows fore and aft of that.

More details:

> The term you're looking for is the rotor burst zone — sometimes called the uncontained engine rotor failure (UERF) debris zone. That's the phrase an aerospace engineer or pilot would immediately recognize.

> Here's the physics behind it: the fan, compressor, and turbine disks in a jet engine spin at enormous speeds (turbine disks can exceed 10,000 RPM). If a disk or blade lets go and the containment case can't hold it, the fragments fly out tangentially — meaning they travel in the plane of rotation of that disk, perpendicular to the engine's axis. They don't spray forward or backward much; they carve out a relatively narrow band.

> FAA guidance (Advisory Circular 20-128A, which designers use to minimize hazards from these events) models the debris path as the plane of each rotor stage plus roughly ±15 degrees fore and aft of it. Since an engine has multiple rotor stages spread along its length, the combined hazard band along the fuselage is a few rows wide, centered roughly abeam the engines.