The U.S. Air
Service in World War
Ed. Maurer Maurer
The 12th Aero Squadron in the Baccarat Sector.
During the first week of June the 12th Aero Squadron received
notice that orders would shortly issue for its movement overland
to Vathemenil, in the Baccarat sector, to the southeast of
Luneville. Accordingly, an advance party of several officers and
a considerable detachment of men were sent forward to prepare
the airdrome and buildings for the arrival of the squadron. The
fact that the location assigned for the airdrome possessed
little else than some newly erected hangars necessitated a great
amount of labor by this advance party in the preparation of the
landing field, offices, and quarters for both enlisted and
commissioned personnel. A construction squadron had not been
available for this work; the utilization of squadron officers
and men in the advance party and in addition the necessity for
utilizing a large proportion of the squadron in this work after
its arrival interfered with active operations for a period of
four days. However, the tactical situation in that sector at the
time was not such that this delay could result seriously, the
observation work during this time being carried out by the
French squadron which the 12th was to relieve. On the other
hand, much benefit was derived by the squadron in its earnest
and strenuous endeavors to complete the airdrome installation
necessary to the conduct of active operations over the front; a
unit spirit of teamwork was developed which proved invaluable in
the months to come.
During its first week in this sector, the squadron gave up its
equipment of A. R. airplanes and received 18 Salmson two-seater
observation airplanes equipped with the radial Salmson engine of
260 horsepower. This airplane proved most satisfactory in every
respect; no observation airplane used upon the western front up
to the conclusion of the armistice gave greater all-around
The Tactical Situation.
The Baccarat sector was a typical "stabilized" or "quiet" sector.
The enemy was strongly entrenched in positions which had been in
existence for many months. Barbed-wire entanglements and
machine-gun strong points reinforced the lines of trench work.
To the rear he was supported by the usual complement of field
and heavy artillery.
In the air his forces were considerably more numerous than was
the case in the Toul sector. A rather active observation service
was supplemented by a pursuit force which carried out daily
patrols of the sector. The latter, although not equipped with
the latest types of enemy pursuit airplanes, was active and
aggressive. Bombardment squadrons operated on practically all
clear nights against various posts of command in the sector,
allied airdromes, and the towns and villages adjoining the lines.
Farther to the rear the enemy had a considerable amount of
pursuit aviation which devoted its energies to the attack of
allied day bombardment squadrons which were then carrying out
long-distance raids into Germany throughout that area.
The sector of the 42d Division, United States Army, to which the
12th Squadron was assigned, extended approximately from
Badenviller to Blamont, some 12 kilometers. As in the Toul
sector, the positions of the infantry were strongly organized by
means of trench systems, barbed-wire entanglements, and
machine-gun emplacements. The infantry was reinforced by the
divisional artillery which consisted of two regiments of field
and one regiment of heavy artillery. The division operated under
the command of the 6th Corps of the 8th French Army. The command
of all aviation forces in the Baccarat sector operating for the
6th Corps, 8th French Army, was vested in the "commandant of the
sector aeronautique," whose headquarters were located at
Luneville. This officer corresponds to the present corps chief
of Air Service in the American Air Service.
In addition to the 12th Aero Squadron, the aviation forces of
the sector consisted for the most part of observation squadrons
operating in conjunction with the divisions to the right and
left of the 42d Division, United States Army. These squadrons
carried out observation work for their divisions of the same
nature as that to be performed for the 42d Division, United
States Army. In addition, there operated one observation
squadron which did the work of the Army corps. There was no
regularly assigned pursuit aviation patrolling that section of
the front. As a consequence the observation airplanes there
operating had to rely solely upon their own armament as a means
of defense against hostile aircraft.
Mission of the 12th Aero Squadron.
The mission devolving upon the 12th Aero Squadron in this sector
1. Reconnaissance and surveillance of the enemy.
2. Adjustment of artillery fire.
3. Cooperation with the infantry should a situation arise
requiring the dispatch of an infantry-contact patrol to locate
the position of the front lines.
4. Training with the infantry and artillery.
(a) Terrain exercises for practice in marking out the front
(b) Panel exercises, e.g., simulated adjustments of artillery
5. Coordination and completion of training of flying and ground
personnel under actual war conditions.
Plans Made to Fulfill Mission.
To operate as an individual squadron all that was required in
addition to the organization of the squadron, as described under
that heading in the chapter on the operations in the Toul sector,
was to place in active operation the squadron radio equipment,
to install a photographic section, and to assign for duty at the
squadron a branch intelligence officer. Under the direction of
the squadron commander, the work over the lines was to be
distributed by the operations officer and assistant operations
officer according to a roster of the flying personnel,
exceptions to be made occasionally in cases where certain pilots
and observers were particularly well qualified to carry out some
special mission. In general, the routine operations of the
squadron were carried out in accordance with the methods
prescribed in the Toul sector.
Post Security and Defense.
The defense of the airdrome was organized along the same lines
as those described in the chapter on the Toul sector. Carefully
prepared plans for the defense and, if necessary, the withdrawal
of the squadron in case of hostile attack were received from the
commandant of the secteur aeronautique, 6th Corps, 8th French
Army. These plans were given careful study and all necessary
steps were taken to carry them into execution in case the need
Communication and Liaison.
1. Interior communications.-Telephone lines were constructed
connecting the various offices, barracks, and hangars.
2. Telephonic- Long-distance telephone lines to tactical posts
of command in the division and Higher Air Service headquarters
were maintained through regional switchboards.
3. Radio.-The squadron radio section insured, in this stabilized
sector, the sending and receipt of radio messages between all
points in the divisional area. In addition, it made possible the
receipt and record of all messages sent by the squadron airplane
in their work over the front.
4. Airplane.-(a) Radio, from the airplane to the ground.
(b) Visual signals, from airplane to ground, e.g., rockets.
(c) Dropped written messages, from airplane to ground.
(d) Visual signals, ground to airplane, e.g., rockets, bengal
flares, signal panels.
5. Motor-cycle dispatch service.
6. Personal.-Frequent visits by the commanding officer, pilots,
and observers of the squadron to the posts of command of the
In the actual fulfillment of the missions assigned to the pilots
and observers of the squadron in this sector the same general
methods were pursued as those described as being the routine
methods for the execution of the various types of missions
carried out by corps observation units in the chapter on
operations in the Toul sector. For the most part, the missions
performed were confined to those of artillery adjustment and
visual and photographic reconnaissance. On only one occasion
were infantry contact patrols attempted. That occurred during a
raid the enemy carried out against the American troops at the
time of the relief of the 42d Division by the 77th Division,
United States Army.l The raid took place during the night, and
on the following morning the 12th Aero Squadron was requested to
locate the friendly front line. In attempting to carry out the
request, the observer in the first airplane dispatched returned
with a serious wound caused by antiaircraft artillery fire. The
second observer, when the infantry failed repeatedly to respond
to his signals calling upon them to mark out the first line by
means of panels or bengal flares, flew so low that he was able
to distinguish the uniforms of such men as exposed themselves to
view, and was thus able to give a rough idea as to the position
of the friendly infantry. Unfortunately, he was wounded by
machine-gun fire from the ground before he had fully satisfied
himself as to the location of our first-line troops. The third
airplane dispatched encountered no better fortune than the first
two in receiving a response from the infantry, but he was
finally able to report briefly upon the position of the latter
by means of observations made at extremely low altitude.
For the most part, aside from the visual reconnaissance missions
performed at dawn and twilight of each day, and a certain number
of photographic missions requested by the division and the
commandant of the secteur aeronautique, practically all of the
work undertaken was that solicited by the squadron commander and
the observers. It being realized that the plan of operations in
this sector was one of training, every effort was made to
arrange and perform as many adjustments of artillery as were
possible. The only limitation placed upon this type of work was
that which resulted from a shortage of artillery ammunition, the
artillery regiments being allotted only a fixed amount for their
per diem allowance.
Great stress was laid upon the matter of exercises. Under the
direction of the squadron commander, and with the advice of the
commandant of the regional secteur aeronautique and that of a
captain observer from one of the nearby French observation
squadrons, a large number of exercises was carried out with the
infantry and the artillery. The infantry exercises took the form
of training the infantry in the proper use of their panels and
bengal flares marking out the line at the call of the aerial
observer. These exercises, for the most part, took place with
reserve battalions in the second or third lines. With the
artillery, exercises were arranged frequently for the practice
of a method for rapid adjustment of specially designated
batteries against fugitive targets located by the observer in
the enemy lines and reported to the battery by means of dropped
written messages. This method of adjustment was designed
especially for use in a war of movement. It had been adopted by
the French observation squadrons of that sector after a long and
thorough study of enemy and allied methods in the major
operations of the preceding spring. The "shoots" were conducted
over the actual lines; the targets were chosen by the observer
after taking the air. Usually they were points in enemy
territory assumed to be fugitive targets. Too much value can not
be given to the results of this form of exercise to both the
artillery and the observers of the squadron. Considerable
success marked the efforts of both the artillery and the
observers, and the experience gained later proved of value to
Considerable advance was made on the part of the observers of
the squadron in gaining a knowledge of the importance of close
personal liaison with the officers of the divisional artillery
and infantry posts of command. Various incidents arose which
taught the observers that few of the American troops entering
the lines for the first time would have even a working knowledge
of the elements which are so necessary to bring about some
measure of success in the cooperation of the observation air
service with the divisional ground troops. It was brought most
forcibly home to all the squadron observers that great and
prolonged effort would be necessary on their part to fit the
ground troops to properly fulfill their part in working with the
Air Service during the execution of artillery fire adjustments
or infantry contact patrols. Questions connected with the
execution of artillery fire adjustments were mainly those of
proper operation of the artillery radio stations and the
functioning of the crews assigned to them for the operation of
panel strips used to signal the airplane observer. As regards
the infantry, the main difficulties may be briefly stated to
(a) To insure the proper supply and distribution to the
first-line infantry of infantry signal panels and bengal flares.
(b) To instruct the individual infantryman in their proper use.
(c) To train the individual infantryman to respond by signal to
the requests of the airplane observer for the marking out of the
line as automatically and readily as a soldier responds to fire
During the three weeks operations by the 12th Aero Squadron in
the Baccarat sector much valuable advice and aid were given by
the corps observation air service commander-the commandant
secteur aeronautique, 6th Corps, 8th French Army-and by the
experienced observer whom he placed at the disposal of the
As the result of attacks from hostile pursuit forces during the
execution of the missions assigned to them, considerable
experience was gained by some three or four tours of pilots and
observers of the squadron in aerial combat.
In the main the actual operations conducted by the 12th Aero
Squadron in the Baccarat sector were only a continuation and
development of those carried out previously in the Toul sector.
The conduct of visual and photographic reconnaissance missions,
prearranged artillery fire adjustments, and infantry contact
patrols was similar in every way to that of like operations in
the Toul sector. In a few instances visual reconnaissance
missions were dispatched under orders from the secteur
aeronautique of the 6th French Corps to procure certain specific
information in well-defined areas of the enemy positions, but on
the whole reconnaissance missions covered the entire divisional
sector under standing orders to observe and report upon all
forms of enemy activity. In the course of the squadron's stay in
the Baccarat sector it was learned that a general visual
reconnaissance of the sector produced very little in the way of
valuable results except when performed at dawn or just before
darkness; reconnaissance missions performed during the daytime
scarcely ever realized success sufficient to justify their
dispatch and execution. This fact is easy of comprehension when
it is remembered that the sector had long been stabilized and
that no active operations were in course. Enemy and friendly
activity was almost entirely confined to the hours of darkness.
Undoubtedly the most valuable lessons of the period at Baccarat
were those learned concerning the scope of personal liaison in
preparation of successful cooperation between the squadron and
the divisional ground troops. In addition, the experience
derived in the execution of the exercises with the artillery,
which had as their purpose the rapid adjustment of fire of
specially designated batteries upon fugitive targets in a war of
movement, although not of great extent, was sufficient to
acquaint the observers of the squadron with the general
principles of this form of aerial work and to impress them with
the importance of developing it in the future.
From the point of view of the squadron alone it had undoubtedly
proved of great value for the unit to be thrown entirely upon
its own resources during the period of its operations in this
sector. A considerable training was acquired by the officers of
the squadron while it thus operated as an isolated Air Service
unit, which they would not have received operating as one
squadron in a group during the same length of time. As a
tactical matter, this fact proved of great value during the
American Air Service operations on the Marne, for at that time
the need immediately arose for a much larger number of observers
trained in the principles of liaison with ground troops and the
conduct of group and squadron operations than had been necessary
or were available at any previous time.