Following the relative quiet of St. Pol, the Escadrille saw intense action at Senard. Its primary mission was to fly patrols and escort allied bombers which were supporting the Verdun offensive.
The weather was perfect for flying and the squadron was flying three sorties a day and enduring German bombing raids at night. In all, the squadron fought 150 air battles over a six-week period.
The high activity took a heavy toll on the group. Douglas MacMonagle and Courtney Campbell were killed in action. Harold Willis was downed and taken prisoner of war, and Stephen Bigelow was seriously wounded and forced to leave the squadron. Willis Haviland and Thomas Hewitt also left the squadron.
At the end of September, the squadron was sent back to Chaudun where it had served during June and July. Its mission was to support the Malmaison offensive.
Lt. Thaw took command of the squadron when Captain Thenault took ill.
The offensive was launched on 10 October and on that
day, Lufbery downed six German aircraft, a squadron record.
During this time, Masson, Didier, Lovell, and Johnson left the squadron. The two lion mascots Whiskey and Soda were sent to a Paris zoo where they lived out their days.
James Hall returned to the group, and Christopher Ford joined it. Ford would be the last American volunteer.
In the summer of 1917, an invitation to join the American unit was sent to these airmen. However, bureaucratic confusion in the French War Ministry, and subsequent mismanagement by American officials seriously delayed the process. Around Christmas, the members of the Escadrille were formally discharged from French service, but their commissions in the American service had not arrived.
On 7 January 1918, the Americans
entered American service and Lufbery was commissioned a major and made
commander of the American 95th Pursuit Squadron. Bill Thaw also was
made a major and given command of the 103 Pursuit Squadron.
On 18 February 1918, the Lafayette Escadrille was formally withdrawn from the French order of battle.
The pilots of the Escadrille went on to serve in various capacities in the American air service.
During its 22 months of duty with the Service Aeronautique, the Lafayette Escadrille could claim 39 confirmed, official victories because of the strict rules required to claim a victory. According to unofficial reports, the number of victories was at least twice as great. Nine pilots lost their lives; six were killed in combat, one was shot down by anti-aircraft fire and two died in flying accidents.