On 7 August, the 135th Aero Squadron flew its first mission of the war.
The first sortie was quite an affair with Brigadier General Benjamin Foulois, then Chief of the Air Service, Zone of Advance, leading the formation of squadron aircraft.
A motion picture operator was present to record the event.
 Motion pictures were taken of the 18 American planes lined up in front of the hangars.
The sortie, however did not cross the line into enemy territory, for the planes flew only as far as Nancy.
After about an hour, all planes returned to Amanty without any problems.
For the next week or so the squadron performed subsequent missions, with no enemy aircraft being engaged, although German Anti-Aircraft Artillery hitting the planes with shrapnel.

The first combat with enemy aircraft took place on 16 August during a photographic mission across the lines.
While the observer was taking photographs, the plane was attacked by a German aircraft.
In the combat that ensued, the pilot was wounded three times in the leg and the aircraft fuel line was severed by a bullet causing the engine to stall.
It was only the skillful piloting of the wounded pilot who managed to make an un-powered glide back across the lines.
For his actions, the pilot was awarded a Distinguished Service Cross, he was taken to a hospital but re-joined the squadron later.

Initially the 135th was assigned to monitor and photograph the sector from Bouconville to Pont-à-Mousson.
Just before the Battle of Saint-Mihiel attack on 12 September, the squadron was reassigned to the front of the 89th Division as well as the IV Corps Artillery, providing adjustments to the artillery as required.
On the day of the attack, rain was falling and the clouds were unusually low.
However operations commenced with 2d Lieutenant Bowyer as pilot and 1st Lieutenant Johnson as the observer.
Due to the aircraft having to fly very low, and though the American artillery barrage, one shell struck their aircraft.
The plane was instantly demolished in the air, killing both men.
Subsequently, both officers were recommended for the Distinguished Service Medal.

Numerous sorties and combats occurred throughout the month of September, with the squadron being shifted from one division to another, providing the commanders operational intelligence and reconnaissance photography.
On 30 September, the squadron, along with the IV Corps Observation Group, moved to Croix de Metz Aerodrome, near Toul.

From Toul, mission of the most perilous nature were undertaken under difficult circumstances; however, the pilots and observers of the squadron continued to provide excellent results.
Besides the work of observation and photography, the 135th made a number of bombing missions, carrying twenty pound bombs which were dropped on objectives in enemy territory.
On 26 October 1918 a 135th Squadron DH-4 {observar John F. Curry} was shot down by anti-aircraft fire; Curry and his pilot escaped capture.
On 3 November, the squadron flew in formation on a bombing mission over Chambley and bombed enemy targets in the town.;
the same day the plane carrying Observer Curry-along with a 168th Aero Squadron aeroplane- brought down a German observation balloon.

By the time of the Armistice on 11 November, the squadron made 1,016 sorties and lost five officers in combat; two pilots and three observers.
The squadron was also credited with the destruction of eight enemy aircraft in combat.
On 7 August, the 135th Aero Squadron flew its first mission of the war. The first sortie was quite an affair with Brigadier General Benjamin Foulois, then Chief of the Air Service, Zone of Advance, leading the formation of squadron aircraft. A motion picture operator was present to record the event.  Motion pictures were taken of the 18 American planes lined up in front of the hangars. The sortie, however did not cross the line into enemy territory, for the planes flew only as far as Nancy. After about an hour, all planes returned to Amanty without any problems. For the next week or so the squadron performed subsequent missions, with no enemy aircraft being engaged, although German Anti-Aircraft Artillery hitting the planes with shrapnel.
The first combat with enemy aircraft took place on 16 August during a photographic mission across the lines. While the observer was taking photographs, the plane was attacked by a German aircraft. In the combat that ensued, the pilot was wounded three times in the leg and the aircraft fuel line was severed by a bullet causing the engine to stall. It was only the skillful piloting of the wounded pilot who managed to make an un-powered glide back across the lines. For his actions, the pilot was awarded a Distinguished Service Cross, he was taken to a hospital but re-joined the squadron later.
Initially the 135th was assigned to monitor and photograph the sector from Bouconville to Pont-à-Mousson. Just before the Battle of Saint-Mihiel attack on 12 September, the squadron was reassigned to the front of the 89th Division as well as the IV Corps Artillery, providing adjustments to the artillery as required. On the day of the attack, rain was falling and the clouds were unusually low. However operations commenced with 2d Lieutenant Bowyer as pilot and 1st Lieutenant Johnson as the observer. Due to the aircraft having to fly very low, and though the American artillery barrage, one shell struck their aircraft. The plane was instantly demolished in the air, killing both men. Subsequently, both officers were recommended for the Distinguished Service Medal.
Numerous sorties and combats occurred throughout the month of September, with the squadron being shifted from one division to another, providing the commanders operational intelligence and reconnaissance photography. On 30 September, the squadron, along with the IV Corps Observation Group, moved to Croix de Metz Aerodrome, near Toul.
From Toul, mission of the most perilous nature were undertaken under difficult circumstances; however, the pilots and observers of the squadron continued to provide excellent results. Besides the work of observation and photography, the 135th made a number of bombing missions, carrying twenty pound bombs which were dropped on objectives in enemy territory. On 26 October 1918 a 135th Squadron DH-4 {observar John F. Curry} was shot down by anti-aircraft fire; Curry and his pilot escaped capture. On 3 November, the squadron flew in formation on a bombing mission over Chambley and bombed enemy targets in the town.; the same day the plane carrying Observer Curry-along with a 168th Aero Squadron aeroplane- brought down a German observation balloon.
By the time of the Armistice on 11 November, the squadron made 1,016 sorties and lost five officers in combat; two pilots and three observers. The squadron was also credited with the destruction of eight enemy aircraft in combat.
135th Aero Squadron