01/31/2011. Remarks by Johan Visschedijk: "Of the 114 Model 12s produced three were temporarily fitted with a non-retractable tricycle landing gear.

The first was c/n 1253 that became an XJO-3 with the USN (BuNo. 1267), and it was briefly tested in August 1939 aboard the USS Lexington to evaluate the compatibility of this type of landing gear with carrier operations.

The second was c/n 1266, that became a C-40B with the USAAC (s/n 38-582), after completion of its special tests it was brought to C-40A standard.

The third was c/n 1272 (NX18964), which later was delivered to the Tennessee Valley Authority, refitted with a conventional retractable landing gear."