Originally Posted by
First_Principal
Indeed, see here from 'our' C-47; drip trays were always put in place directly after flight, followed by a board to protect the tyres when the tray filled up, then handy rags when it all cascaded down the boards... all quite normal:
From this it's possible to see that if the underside of the Stearman hadn't been wiped down recently a bit of oil may not have attracted much attention (disclaimer: conversational comment only, I've never flown a Stearman, nor am I familiar with this operation, who may religiously clean their a/c after each flight!):
Photo taken the day before the incident, of the subject aircraft landing at our local airport, Bournemouth after display.
Note clean underside.
As a respected and long established air display operator, flying in front of crowds of people every year, it’s in their best interests to present their aircraft in as clean condition as possible.