Originally Posted by
DaveUnwin
Seconded Pobjoy. I've flown a few Pawnees (its one of my favourite types) and that aroma was always there. Great aircraft though. I wrote about someone crashing my favourite PA-25 in 'Requiem for a Pawnee'.
Not sure the exact chemical, but the Pawnee glider tug I flew years ago hadn't sprayed in decades, had the hopper removed, and still had a very strong, very distinct chemical smell.... that was a great little airplane.
Of note to this unfortunate accident, there are a number of structural ADs for the Pawnee... the main spar cluster being one of them. The one I flew had severe corrosion discovered in an aft fuselage cluster after I'd already flown it for a season...required a bunch of structure to be cut out and new structure welded in.
The structure of ag planes in particular gets exposed to some very nasty, very corrosive chemicals..... and some of the more complex bits offer places for chemicals to collect and start to cause issues.... The newer ag planes, like modern Air Tractors have done a lot to address this, with very easily removable fuselage panels and extremely good corrosion proofing and sealing of structural stuff.