I'm not so sure they were 'dangerously close' to stall speed. While I can't find specifications for the N2Y biplanes hosted by the Macon, keep in mind that the

I'm not so sure they were 'dangerously close' to stall speed. While I can't find specifications for the N2Y biplanes hosted by the Macon, keep in mind that the N2Y is a two-seat inter-war biplane trainer with a 115 hp engine--it was not a fighter or pursuit plane. Additionally, it would have been designed to use the short, unpaved runways characteristic of pre-WWII airfields. All these factors point to low stall speeds. So if we wanted to estimate the stall speed based on comparable aircraft, we'd be looking for a 100-ish hp, two-seat trainer. Aircraft of that description typically have a stall speed in the 35 to 45 knot range. The source of all truth (Wikipedia) lists the cruising speed of the Macon as 55 knots / 63 mph with a max speed of 75 knots / 86 mph (altitudes not given). The Macon's cruising speed would be right around the recommended approach speed for aircraft like these, and it could have certainly accelerated to higher speeds to perform heavier-than-air aircraft operations.