"By September 10, search crews had found eight previously uncharted crash sites,[54][55] some of which are decades old,[56] but none related to Fossett's disappearance."
To be clear though: I was talking commercial operations which generally operate above the radar plane. I'm not even sure how/if Fosset's plane would appear on radar as he had no ADS and he didn't file a flight plan which means he was in class G or possibly E airspace on a VFR mission (very low altitude).
Wow.