Every Airstream model has its own set of airflow characteristics. In my Classic 28, the flame never blows out, but the box cooled poorly because of poor airflow over the fins in the back until I fixed it with a fan and shroud on the fins.
Some folks cut down fiberglass air conditioning filters to use as wind brakes inside the refrigerator rear compartment. In a previous Airstream, I bought a thin metal filter intended for an air conditioner. I cut it down to fit inside the finned door, restrained by two bent metal rods. When on the road, I put it in the door. It cured the flame outs. When parked, I removed it to allow full airflow.
The recent Dometic recall installed a shield that should help prevent flame blowouts.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10