[Candor7]

G-LOCK?

Is that Ground Lock or G-Lock in terms of the number of negative Gs being generated on say pulling out of a loop?

You're talking mechanical malfunction or pilot error?

[buccaneer81]

The plane was coming down on a vertical loop, she said.

G-Lock in terms of the number of negative Gs being generated on say pulling out of a loop?

Fairly common during aerobatic maneuvers. He could have just been too low for the loop.