OK. Some more information. I did find the thread but I had to use different search criteria. This looks like a bug in the search function.

Go to the 'Jets' forum and type 'wildcat' into the search box at the bottom of the page. You will get no hits. Then type in 'ducted fan fuel' and you will get plenty of hits, one of which is the thread I was looking for with 'Wildcat' in the subject line.

So why does the single word 'wildcat' find nothing where there is a thread with 'wildcat' in the subject?