Originally Posted by
Bagheera S
In 1982 a Hawk at Bedford was undertaking wake turbulence research when it experienced an uncommanded and very low roll;- 20ft. The pilot went out just fractional within the seat survival envelope, while the observer decided to stay in. The aircraft landed upside down and slid 1200ft down the runway. As the structure deformed and was worn away, the observer head was progressively held against the runway. The wreck came to a holt just as the Asphalt was wearing through the fabric next to the chaps scalp.
https://aviation-safety.net/wikibase/55500
They were not "undertaking wake turbulence research", I think that was a new task afterwards as it had not been a recognised issue beforehand. The observer (a navigator, initials BM) did not "decide to stay in" - he had a large camera on his lap and so could not eject. In fact, however, he was effectively uninjured whilst the ejected pilot suffered serious injuries as I recall, as he went out sideways.