On Monday, July 25, 2016 at 11:24:11 AM UTC+8, wrote:
I just bought mosquito 303 and there is an 6x8 inch Inspection hole behind main gear is that factory.

Yes that is Glasflugel standard, all the Mozzy's and Hornet's have the hatch, it is access to the rudder circuit bellcrank and stops, amongst other things

Chris Runeckles