The Second World War was an epic period in American history. American military organizers were able to successfully transition from a relatively small, under-equipped, peacetime professional force to perhaps the most powerful military force in the world in the space of approximately four years. They did this with a primarily civilian army and a fabulous combination of industrial ingenuity, flexibility, and entrepreneurship. One of the best examples of this ingenuity was displayed in the development and use of small liaison aircraft.

Piper L-4 on takeoff sketchThe liaison aircraft had their origin in the light plane industry developed in the United States. All but one of the major "L-bird" designs were based on civilian models currently available on the market. The United States unique form of government and understanding of personal rights, responsibilities, and freedom had led to the development of aviation as a tool not only for military purposes, but for the average citizen. After World War I and the advancement of aircraft technology, increasingly larger numbers of individuals used aircraft for their personal enjoyment, transportation, and business opportunities.

Although aircraft had been used from their earliest origins for battlefield observation, reconnaissance, and other military purposes (including some artillery observation in World War I via two-way wireless telegraph), their utility had been somewhat limited by the types of communication equipment available. During the mid to late 1930s various Army officers and units experimented with the possibility of using small aircraft currently available on the market in order to improve the accuracy and efficiency of their artillery.

In 1938 a competition for Observation aircraft resulted in three winning aircraft including the first of the L-birds - the Stinson O-49/L-1. In total, 352 L-1s were built by the time production ceased.

1938 also saw the beginning of the Civilian Pilot Training Program in which a number of future L-bird pilots, as well as others were first introduced to aviation. A number of the future L-bird aircraft including the Aeronca, Piper, and Taylorcraft civilian models were used in this program.

During the 1930s Piper Cubs and similar aircraft had been used by some artillery outfits as they experimented with observation aircraft and during the 1940-41 War Maneuvers representative aircraft from Piper, Taylorcraft, and Aeronca were officially tested. As a result of their successful use, Lbirds earned their place in the Army. Observation squadrons had long been a part of the Army Air Force, but often times their usefulness was limited by the operational restrictions and lack of timely communications between the squadrons and the ground units who would most benefit from their work.

Beginning in early 1942 the first of the civilian L-birds entered service and training started for new Liaison Squadrons that would serve in the various theaters of warfare. Older Observation squadrons also formed the nucleus of a number of the first Liaison Squadrons. In addition, a number of enlisted men and officers were trained in the liaison role at Ft. Sill in Oklahoma and many of these men went on to serve with various Army units attached to the front-line units.

Liaison aircraft served in a variety of roles including, but not limited to: Artillery observation, reconnaissance, aerial photography, medical evacuation, search and rescue, primary flight training, pilot proficiency, supply, mail runs, and more. Some enterprising pilots even went to the point of arming their aircraft with bazookas and other small weapons for attacking enemy troops and vehicles.

The liaison pilots and their aircraft performed their job well throughout the war. Perhaps the effectiveness of one aspect of the Lbirds' role can best be measured from the following quote:

"Allied artillery merits the highest praise. It is adaptable and is skilled at concentrated precision fire delivered by large formations. Observation by spotting aircraft and forward observers is incessant and complete... The artillery of some armies may be noted for massing fires, and that of others for precision firing. It remains a unique ability of American artillery to deliver massed fires with the greatest precision in space and time."

- A captured German intelligence bulletin.
Quote from Patton's Third Army at War by "George Forty"

The information in this article is by no means exhaustive. Sources of information include Box Seat Over Hell by Hardy Cannon and Bill Stratton, The Fighting Grasshoppers by Kenneth Wakefield, emails with James Gray of SOPA, and other  research by the author.