The original report`s layout have been preserved as much as possible - i.e. the inaccurate reference to the manufacturer as 'Messerschmidt'.
Some French expressions, and names of organisation and ranks were also kept for the sake of easier
reference without hindered by clumsy attempts to translate them into English.

The author begs the dear Reader to overlook the possible errors and welcomes any and all corrections and suggestions, especially concerning spelling or translation mistakes. Email at

Special thanks must be expressed to JV69_BADA for his translation.
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Original French papers in PDF format.

French terms and their English equivalents in the report.

Centre d'Experiences
Ariennes Militaires
Military Aeronautics
Experience Center
Centre d`Essais du Matériel Aériennes Militaires
Test Center of Military
Aviation Material
Général Inspecteur et Commandant
Supérieur de l`Aviation de Chasse
General Inspector and
Commander-in-Chief of Fighters
Général Commandant en Chef
des Forces Aériennes
General Commander and
Head of the Air Force
Escadrilles d'Expérimentation Experiemental/Evalutation Squadron


R E P O R T   O N
M E S S E R S C H M I D T   1 0 9   A E R O P L A N E

I  -  G O A L

    By the letter n°462-3-IS/EMG from 23 January 1940 relating to
the live trials with the Dewoitine 520, Général
Commandant en Chef des Forces Aériennes asked for a specific
study of this plane in combat against the Messerschmitt 109.
    On the other hand, the Général Inspecteur et Commandant
Supérieur de l`Aviation de Chasse, in his letter n°937/IC
from 25 March 1940, of which a copy has been sent to the Centre
d'Experiences Ariennes Militaires, asked for trials to be done by the
Centre d'Experiences Ariennes Militaires, for comparison of the respective
qualities of the Me 109 and the current French fighters
Dewoitine 520 and the Bloch 152 modified on the following points:

                                     (low altitude
                      ( - level      (the engine`s ra-
- the performance in  (   speed at   (ted altitude.
                      (              (High Altitude.
                      ( - climbing speed.
                      ( - diving speed.

- maneuvrability at different altitudes.

Centre d'Experiences Ariennes Militaires has established
an experimentation program, of which the details shall be given

- 2 -

below. Advantage was taken of the
availability of the Messerschmitt 109
to study combat between this airplane and the modern French reconnaisance
and observation planes Bloch 174 and Potez 63-11 and to check the conclusions
arrived from the results of defense trials of the multiseat planes (Cf. Report
of the
Centre d'Experiences Ariennes Militaires n°367/S of 18 April 1940).
        The Messerschmidt 109 with a Daimler Benz DB 601 engine held at the
Centre d`Essais du Matériel Aériennes Militaires has been delivered at the
end of March to the
Centre d'Experiences Ariennes Militaires. A Munerelle type
oxygene mask and a Debrie 35mm gun camera were installed into the Messerschmidt
(see photos).

        The trials took place between the 1st and the 21 April.
Delayed in Briey by the atmospheric conditions, it has been executed most
of the time in Marignane with the help of the Escadrilles d'Expérimentation.

II - P R O G R A M M E

        The programme proposed by the Military Aeronautics
Experience Center, inspired by the "Directive for Modern
Material Practical Experimentation" (Note n°220/S
from 26 February 1940) inculded for the comparison between
fighter airplanes studies the following points:


        This Study has for goals the search for the optimal use
of the performance and the flight qualities already highlighted
by the
Centre d'Experiences Ariennes Militaires

- 3 -


                                ( - level Speed
        - Messerschmidt 109     ( - climb Speed

                                ( -
maneuvrability, in particular
        - French airplanes      (   on high angles and
                                (   on at high speed.

                Conclusions on the aim stability, while the
airplane is in climb, in turn, in descent.
        To avoid the combat trials degenerating into the chaos of
individual mélée from which no conlcusions could be drawn, the
combat has been split in different phases where the attacks and the
possible means of defense has been studied separatly.

        The following scenarios has been considered:

a) Plane attacked by surprise (both adversaries playing
                               both roles).

        - Best break (evasive) maneuvre
        - Possibility to break the combat and eventually
          trying to take the advantage back.

b) Plane not surpised by adversary

        - Best maneuvre to have the advantage
        - Opportunity of accepting a turn fight or to avoiding it.
        - Possibility of breaking off the fight after having engaged.

        With the goal of limiting the number of engagments (combats)
and to take account of the incertitude on the Me109 delivered by the
Centre d`Essais du Matériel Aériennes especially concerning the engine`s
funcionality at high altitudes (1), the different scenario`s

(1)See report of the
Centre d`Essais du Matériel Aérien
   n°291-S/SD of 30 March 1940.

- 4 -

has been studied at altitudes next to the rated altitude of studied planes (+/- 5.000 m.)
        We can allow ourselves to admit, that the respective
maneuvrability of the airplanes
stays almost the same at 8000m as at 5000m.


        This comparison should permit to complement the
results obtained by the
Centre d`Essais du Matériel Aérien
in it`s performance measurements. The goal was to determine
differences in level and climb speeds in case these could not
have been determined by combat excercises.

III - O R G A N I S A T I O N   O F   T H E   T R I A L S

SEANCE PROGRAMME (for example Messerschmidt against
                  Dewoitine 520).

I  - Simultaneous climb to 8.000 - Times for climb
     checked at 1.500 and 5.000m - Simultaneous level flight at 800,
     5.000 and 8.000 meters.

II - Combat engagement
at around rated altitudes.
     (between 5.000 and 6.000 m.)

   A/ Airplane Suprised

        The engaging airplane take an atlitude advantage of
minimum 500 meters, dive and take place in the rear sector
of the attacked airplane. The latter starts his evasive defense
maneuvre when the attacker is about 300 meters behind him.

a) Messerschmidt Surprised - Dewoitine D520 attacking

    1/ Evading maneuvre by optimum climb,

- 5 -

    2/ Evading by Turn Fight (continuous
       hard turn)
         The attacked airplane tries to get advantage

    3/ Evading by prolonged dive.

b)  Dewoitine 520 Surprised - Messerschmidt attacking

    2/ Same maneuvres as above (1)

Or 6 Engagements for each considered case.

    B/ Airplane not Surpised

   Engaging in combat at the moment the two planes
   pass each other in opposite way at the same altitude.

    1) Best maneuvre to take advantage.
    2) Once advantage is taken, one gets back to one of the
cases studied in the previous paragraph.
        The engagement, started in turn fight, has been
repeated twice, once to the right, once to the left side.

      The number of engagements is thus 8:
       - 6 for the first case considered.
       - 2 for the second case considered.

        For the combat against multiseat observation and recconaissance planes
the programme was as the following:

    1) Defense of the multiseat airplane by it`s speed

        a/ the fighter being about 800 m. behind at the same


(1) We added to this programme, for the Dewoitine 520, the evasive maneuvre
of suddenly throttling back and sliding.

- 6 -

altitude, the multiplace airplane evading on full power in a straight

    b/ the fighter having an altitude advantage of 500 m.,
the multiseat airplane evades in a shallow dive and the fighter
attempts to keep with it.

2) Multiseat airplane defense by

        The fighter having an altitude advantage of between 500 and
1000 m.

    a/ Defense by a hard 180° descent turn
    b/ Defense by climbing spiral,

4 engagements per séance.

IV - V A L U E S   T O   B E   A T T R I B U T E D   T O   T H E  E X P E R I M E N T S.

        We can't give full credits for the results obtained with a single plane
of type Messerschmidt 109; fuel
mixture in particular used to be inperfect at
high altitutes and problems with the fuel circulation were perceived in tests
above 6. 000 meters. We elimineted from the test pr
ogram written here above
everything that should have been done above this altitude with the sole goal
of eliminating a false perception resulting from using a plane with lower than
normal performance. But we can allow ourselves to use the results obtained up to
6000m, as the working of the airplane and the engine seemed to be perfectly normal
until this altitude.

- 7 -

        As it concerns the
maneuvrability, we should take note that
the testing was done by a pilot that could have been inconvenieced by
some particularities of the airplane (small cocpit and inverted throttle);
but after some hours of flying he seemed master the craft; the performances
annonced by the CEMA were actually matched.

- 8 -

V - R E S U L T S

            I) Messerschmidt Vs D. 520 (I)

A - Performances

    a) Level flight at low alt (600 m.)
               Speeds were found similiar speed;
Test done
on the Messerschmidt with the radiator flaps fully
open. Closing the flaps should give a light advantage ( 20 - 30 kmh)

    b) Climb to 5.500 m.  PG
                The climb speed of the Messerschmidt
is slightly superior. It has a quality that favorize it:
the engine`s cooling is satisfactory, on the other hand the D.520
had to throttle back due to the increasing temperature of the
coolant agent (once at 4500m and once at 3000)
                The climb of the 109 to 5.000 m took apprx. 6' 20".

    c) Level flight at 5.500
               Speeds showed a slight superiority
for the Messerschmidt 109.

    A/ Messerschmidt surprized

a) Break (Evade) into left spiral

    D520 taken from the 3 first modified to that type.

- 9 -

             The D520 could get a firing solution for several
seconds, but the Messerschmidt could escape taking advantage of
his superiority in climb speed.

        b) Escape in a continous turn
             The 109 escaped slowly.

        c) Escape by a dive
             Speed reached by the 109 as per the speed indicator :
The 520 follows in the dive. (We should note of the fact that the
airspeed indicator speedometer of the Messerschidt is generous in
comparison with the french speedometers)(I)
             After each long lasting dive, there has been a systematic
incident with the D.520, which gear came out in the ressource, not
being able to get locked again. There also have been an incident with
the micro-pomp that made the Flaps not working.

    B/ D.520 surprized
a) Break (Evade) into a right climb spiral.
     Advantage to the 109 that retain his fire solution in this maneuvre.

b) Defense by throttling back and sliding
     If this maneuvre is done at he precise moment the 109 open fire, it's very

(I) The coefficient of the (pitot?) antenne position for the Messerschmidt is inferior to I.

- 10 -

effective whatever the kind of plane used. The
Messerschmidt 109, because of it`s great speed build in
the dive, is not able to break (evade). It`s break can take
him far enough to allows the D520 to take the advantage back.

        c) Defense by a dive
               The Messerschidt 109 follows easily the D.520
in it`s dive. D.520, in the high speeds reached stays more
maneuvrable in the dive.

                c/ Combat without suprise (Altitude 4500 to 6000m.)
  ^     ---
  |     D520
  |      |   
a) D.520 arrives on the right of the 109
Me 109   v
         Turning combat into the right.
 ---               No decision for a long time;
The adversaries try to take advantage for a short period.
         Suddenly the D.520 stalls several times to the left, executing    
         1/2 or 3/4 roll with full throttle; the Messerschmidt also seems
         wanting to stall but his auto-rotation movement is slowed down by
         the opening of the wing slats giving strong movements on the stick.
                   After those stalls, rapidly recovered, the D.520 loose the
         distance and the combat finishes with a advantage for the 109  who can get a good              firing solution without ever been in the gunsight of the D.520.


- 11 -

              b) D.520 arrives comes on the left side of the Messerschmidt 109
                 Turning combat into the left.
                 First part of the combat is equal. Each
adversary tend to take the advantage one after the other for quite a long time.
        Maneuvres became closer, the D.520 stalls sudddenly on the left.
        instead of gainig control of the stall, the pilot ended with a
        heavy inversion on the limits of the plane. The Messerschmidt,
        due to the strong
        stick reactions, couldn't follow and loosed the D.520 from his
        view for a few moments. In continuation of his inversion, the
        D.520 can place itself in the rear sector of the Messerschmidt,
        and getting rather fast a firing solution even if the 109 making
        evasive maneuvres. Conclusion : Advantage to the D.520 that could
        fire with excellent conditions at the end of the fight and without the 109 having the         D520 even once in his gunsight.


            A - Performance

                 - Level flight Speed slightly higher for the
        Messerschmidt on the tested altitudes.

                 - Climb speed is greatly superior for the
        Messerscmidt, which
allows it to obtain


- 12 -

a certain advantage. The evolutions on extended climb are to be avoided
for the Dewoitine 520.

            It has seemed that the Dewoitine 520 should get the advantage
in combat on "manual" and slightly lowering the pitch.
This point should be systematicely checked by a group equipped with D520.

            - Dive speed : the two planes seemes to have the
same speeds.


         B - Maneuvrability in combat

           - The D.520, in close combat evolutions (maneuvres) seems to
stall more than the Messerschmidt 109, holding on the air by his wing-slats.
The stall of the D520 is very brutal and start always to the left; it is indeed
serious in the combat
to the right, the Dewoitine 520 pilot making almost a full
roll; as result, the combat should ALWAYS be started to the left, at least if
the choice of the turn direction is possible.
           -After the turn-combat trials, resulting in all tests with a brutal
stall of the D.520, even if the stall is easy to control, resulting in a loss of
control of the plane even for a few moments, results in loosing of sight on the
adversary. It's dangerous, especially at this moment when the 109 seems to have
advantage, to regain control after a stall-roll and to try to get back into
turn-combat. It's better to transform the stall-roll into an inversion to the
limits as far as

- 13 -

possible, the Me109 due to his high speed is only able to follow but with a
serious delay. The stall used that way becomes a break(evasive) maneuvre, that
allows the D520 in some situations to take the advantage back swiftly.

            - Except for the stall-roll fact, we can say the 2 planes have the same maneuvrability. The simulated combats were rather long before one plane or the other
could take advantage on the other. In any case, the D.520 should be considered as more maneuvrable because of the less heavy reactions on the stick and especially on the
pitch on high speeds; the Messerschmidt pilot had to frequently use the pitch trim-wheel;
this is a hard and annoying maneuvre because of the place of the trim-wheel.
Au contraire, the D.520 pilot can leave his trim on a middle position or at least use
it to smaller proportions, an advantage for the D520 when high speed
maneuvres or
dives followed by "candles" (maneuvre straight up towards the sky)

            - Nothing particular to say about the aiming-stability for any of those
planes. This stability is satisfactory except when the plane has the tendency to stall, especially in turning

            What particulary concerns the state of the combat material, the
Messerschmidt seems actually


- 14 -

to be in a very good state (see Annex).
            Au contreire, the D.520 had insufficient cooling in the climbl; also
there have been system failures for the undercarriage and micro-pumps.

        2) MESSERSCHMIDT 109 VS BLOCH 152 (I)

A - Performances

    a) Level flight at low altitude       (During those levels flights
                                          (on a distance of 15Kms, the Messerschmidt get
    b)   "      "   at 5500
meters        (a slight advantage (Messerschmidt :
                                          (radiator flaps open,

    c) Climb Speed

             Sensibly great advantage to the Messerscmidt
             During simultaneous climbs to 5.500,
the differnece between the two planes was several hundred meters.

             In combat, the climb speed is an excellent advantage
for the Messerscmidt, that allows him, when he wants, to take some
advance in a spiral climb and put himself out of range of the Bloch.


    a) Messerschmidt Suprised

       I) Break into a spiral climb left or right.

            The Messerschmidt can escape rapidly.



(I) [Text missing]

[The rest of the report is missing.]

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