1938 - The Texas Air Force replaces the Consolidated O-3 with the Piper O-5 in Army Observer Squadrons.
The Piper was much different from earlier observer aircraft. They weren't armed (previous aircraft had a machine gun on a ring mount for the observer) and were much smaller. They were cheaper, too and less expensive to operate. The observer had a decent view from the rear seat without having to hang over the side of the aircraft. Sitting in the enclosed cockpit reduced fatigue from wind buffet.
The Army was very pleased with the O-5, and it would remain in service much longer than expected. The airframe would even be adapted for aerial medical evacuation during WWII.
Observer Squadrons were known to paint their supported Army unit's insignia on their aircraft for low-level recognition. Shown on this example is the 1st Division's patch, just behind the national insignia. It was also incorporated into the 11th's official squadron insignia.