I joined a FB group that apparently has a lot of Australian members. Some of them have casually mentioned that ‘this airplane was grounded by the ban on wooden-wing aircraft’. Not being Australian, I’d never heard of it.
When did Australia ban wooden-wing aircraft? Why?
Maybe this is your answer: http://www.airwaysmuseum.com/Grounding%20of%20glued%20aircraft%206os.htm
They are certainly not banned as a whole.
The specific post that prompted the question is this [emphasis mine]:
Wood structure was banned in the US for commercial aircraft shortly after the death of Knute Rockne in the crash of a Fokker Trimotor, attributed to failure of the wooden wing spar.
BIG nitpik here. The Ford Trimotor had an all metal structure. The airplane that killed Knute Rockne in 1931 was a Fokker F-10 Trimotor, which did have wooden wings. evidently water leaked into the structure and dissolved some of the glue that held the spars together. Not a good thing.
SORRY - I misread the post about Knute Rockne just above. The poster was exactly right - it was a Fokker. Teach me to jump the gun!
If I had known how to delete my post during the edit phase I would have done so, But couldn’t find any was to get rid of it.
You can’t delete, but you can edit it. Delete all of the text in the post, and then type ‘nm.’ or something. 
They were not actually banned in the US at that time, but made economically onerous by inspection requirements, since the wings of a/c of that time hadn’t been designed with internal structural inspections in mind. You’d have to strip and replace the wing’s fabric or wood skin each time to inspect the internal structure. And the public lost confidence in wood winged airliners, another huge factor in their virtual disappearance as airliners without an actual ban.
Many wooden winged combat planes were built up to and during WWII. The British Mosquito is probably the most famous, of almost all wood construction including fuselage. But many early WWII Soviet fighters had wooden wing structures, though they later transitioned to composite wood/aluminum wings (later Yak-7’s and early Yak-9’s for example) and eventually all metal (like the Yak-9P which made up most of the North Korean fighter force at the start of the Korean War). Most combat a/c of most combatants in WWII had basically aluminum wing structures though.
Mooney was a major general aviation maker in the US which built some wooden winged planes till the 60’s. Since then new wood winged planes are generally kit type or from small specialized producers. As the thread originally refers to, the Avro Anson was being used as a small passenger plane when grounded (wood winged versions) in Australia in the 60’s. But plenty of smaller and vintage wood wing planes remain in general aviation use all over the world including Australia.
Not to mention Bellanca.
Back in the late 50’s to early 60’s I knew several guys who had AT-50 Cessna Bamboo bombers like the original Sky King airplane of early TV. Any who, they said that the wing spar was so overbuilt they could have up to one half inch of dry rot on the bottom of the spar & it was still airworthy. (No cite)
Also, last I checked, there has never been a mandatory AD on a Bellanca wing spar.