Hot air balloon sea level, and humidity of the air surrounding. On a warm day, a balloon cannot lift as much as on a cool day, because the temperature required for launch will exceed the maximum sustainable for nylon envelope fabric. Also, in the lower atmosphere, the lift provided by a hot air balloon decreases about 3% for each 1,000 meters (1% per 1,000 ft) of altitude gained. Standard hot air balloons are known as Montgolfier balloons and rely solely on the buoyancy of hot air provided by the burner and contained by the envelope. This style of balloon was developed by the
Organization of the Air Service of the American Expeditionary Force "observation wings" were created to coordinate the reconnaissance activities of the five corps air services. The basic units of the air service were the squadron for powered aircraft and the company for balloons. 45 squadrons (38 of which conducted combat operations) of aircraft and 17 companies of balloons served at the front. The 20 pursuit and seven bombardment squadrons were authorized 25 aircraft (including spares) and 18 crews each by the "Field Service Regulations", while the 18 observation squadrons were each authorized 24 planes and 18 crews. Balloon companies were equipped with one balloon and approximately six observers each. The