OF ME.109G-2 (TROP).
1. An Me.109G
captured in the Western Desert was allotted
to No. 209 Group for performance tests.
The tests were laid down in H.Q.,
S.54515/OPS dated November 29th 1942 and addressed to A.H.Q., Egypt.
The aeroplane was maintained by a
party drawn from a Squadron in the Group, and assistance was given by
Levant, particularly the Meteorological Section, and by No.4
Enemy aircraft section H.Q., M.E. gave much information
and assistance, Flight Lieut. MacBean, 87246, was attached and wrote
descriptive part of this report. He has a remarkable knowledge
of enemy aircraft.
Preliminary tests were chosen
to get an outline of the performance and were completed quickly
and an interim report was sent in as required by H.Q., M.E. letter. The
remaining tests were completed by 29th January
The new engine (D.B.605) is
little better than the old
one (D.B.601) in the 109F, the main improvement being an increase in
height. The fine performance is due largely to the size of the
aeroplane. It is
remarkably small and light considering the size of the engine.
The cockpit is simple. A number
of technical controls
such as regulation of oxygen flow, adjustment of coolant radiator and
radiator flaps and airscrew pitch control have been made automatic and
attention from the pilot. The pilot is then able to give more
attention to fighting tactics, teamwork, navigation and practical
The shortcomings of the
aeroplane are, the weakness of the ailerons at high
diving speeds, the weakness of the undercarriage, the
stiffness of the tail trimming gear at high speeds, and
skittishness during landing and take off.
The small size of the 109G
remains a prime
reason for its good
performance. It is recommended that British aeroplanes should be
designed to be
small, but that skittishness on the ground should be prevented by
British cockpits should be
freed of auxiliary technical controls which need the attention of
the pilot, and the regulation of oxygen flow, adjustment of coolant and
radiator flaps and airscrew pitch should be controlled by reliable
It is recommended that a small
enemy aircraft test flight should be formed in the Middle East
so that performance figures are made available to Air Ministry. The
required are suggested as one engineer pilot, one admin. officer, on
pilot, two fitters, two riggers, an electrician, signals and armourer.
DESCRIPTION OF AIRCRAFT
The Messerschmitt 109G-2 is a
development of the Me.109F-4, from which
it is indistinguishable in the
air. The main difference lies in the engine, that in the Me.109F-4
D.B.601 E, while the Me.109G-2 has a D.B.605 A. There are also several
detail modifications but the airframe remains substantially the same.
Span 32' 7", Length
29' 9": Wing area
173 sq. ft: All up weight (as fighter without wing guns) 6820 lbs.
(approx) Wing loading 39.4 lbs. per
sq. ft. (approx).
cylinder inverted 'V' liquid cooled in line, with
direct fuel injection. This
motor appears identical to the D.B. 601
E except for modified
cylinder head blocks
Below are given performance figures for a D.B.
601 E and D.B. 605 A tested respectively in October 1941 and July
figures are obtained from German engine history sheets and the
significance of the two horse
power readings given is not
known but may
indicate some correction for air temperature or atmospheric
Tested October 1941.
DB. 605A. Tested July 1942.
|Take off (5 mins).
Climb and Combat (30 mins).
|Take off (5 mins).
Climb and Combat (30 mins).
propeller is a
V.D.M.9 - 12087. Three bladed metal constant-speed with electric pitch
hand controlled or automatic. Diam. 9' 10" Max. blade width 11
13. The technical
features which affect the operation of the aeroplane are
those for the 109F and are briefly recapitulated here for convenience.
is a small aeroplane with a big engine and this largely gets its high
performance. The cockpit is correspondingly small. The supercharger
is driven through a hydraulic clutch in the same way as the D.B.601.
the effect of a multi-speed drive without attention from the pilot. The
is also automatically limited.
14. The airscrew
control can be selected for hand setting or
for automatic. The hand control is a rocking switch on the throttle
automatic, the airscrew governor is operated by the throttle lever to
give the appropriate revs at all throttle openings, and there
is no control for the pilot. The effect on range and engine life from
having the best combination of boost and rev must be good and the pilot
same time is relieved from attending to the pitch control lever.
15. The airscrew is
electrically operated, and the
handbook warns against overspeeding if a dive is started suddenly, so
that the pitch change is presumably slow like our electric airscrews.
16. The flaps of both
the oil and
coolant radiators are thermostatically controlled. The operating
fluid is engine oil for the oil radiators, and hydraulic system oil for
coolant radiators' flaps. Control of the coolant radiator flaps by the
possible but normally he will set it to automatic. The flap operation
mechanical, by a wheel and the undercarriage retraction is hydraulic
without emergency hand pump.
17. The fuselage is
designed to be as small as possible to give the
maximum performance, and consequently the cockpit is
rather cramped for anyone over 6 feet tall. The controls
are laid out so that all ordinary ancillary controls are worked by the
hand, the right side of the cockpit having only switch buttons. This
combined with the automatic setting of airscrew pitch and of coolant
water and oil, simplifies the task of the pilot.
18. Details of
the controls, which
are similar to those on some allied aircraft, are given in
the German handbook of which a translation is held in
the Enemy Aircraft Section, H.Q., M.E. A photo of the
cockpit, consisting of three photos put together, is Figure 6. The
pedals are level with the seat so that the pilot is in a good position
resist acceleration; all ancillary controls are
convenient to reach and to use.
19. Owing to the
the top of the front cowling is narrow and the view forward on
each side is reasonably good. The instruments supplied
Artificial horizon and turn indicator
air speed indicator
mechanical position indicator.
warning light (20
minutes to go).
20. The hood is small
and has no
curved surfaces. The thick perspex panels are flat and allow a
good view through them. A sliding panel on top and each side allows a
view in bad conditions. The hood is jettisoned by a red lever on the
21. This is almost
identical to the Me.109F-4 and
consists of one flat and one curved 10 m.m. plate protecting the back
of the pilot's head. Three plates, the upper one 8 m.m. and the
lower 24 m.m. [Note: This must be
two 4 m.m. thick plates as noted elsewhere
protect the pilot's back. A 63 m.m. bullet proof glass
shield set at approx. 60° is mounted 13 m.m. behind the 8 m.m.
windshield. A dural bulkhead consisting of 30 layers of 0.8 m.m. sheet
together is fitted to the lower 2/3 of the fuselage cross section. The
tank is 'L' shaped and is situated behind and below the pilot. It is of
flexible rubber construction enclosed in a plywood box for support and
of inner and outer layers of hard black rubber and a centre layer of
sealing rubber. The capacity is 85 gallons. The oil tank is of
light alloy, ring shaped, fits round the airscrew reduction gear, and
holds 8 1/2 gallons. The
coolant header tanks are also of unprotected light alloy and are
on either side of the crankcase. Occasionally fuel tanks made of
light alloy have been found on Me.109'Es and F's and once on a G. [Note: This was an occasinal trait of
lightened high altitude fighters.
22. The standard
German fighter R/T set, FUG VII a, is fitted
as on the Me.109F. For further details reports are available through
Aircraft Section, H.Q., M.E.
23. The standard
Draeger Unit as on Me.109F is fitted,
the supply being drawn from 3 light alloy bottles of normal type
mounted on the
bulkhead behind the fuel tank. The oxygen-air mixture is regulated by a
barometric capsule up to 33,000 feet, above which height pure oxygen is
delivered, the rate of flow being controlled all the time by the
breathing, though a hand operated button is
to give a sudden extra supply if desired at any time.
The layout is the same as the
Me.109F and consists of a Patin Master compass fitted in the
rear fuselage behind the laminated dural bulkhead which
repeats electrically to a slave compass on the instrument
This is identical to the Me.109F which has been fully
reported previously, and consists of 2 x M.G. 17, 7.92 m.m. machine
mounted over the engine firing through the airscrew disc, and 1
M.G. 151, 20 m.m. cannon mounted on the rear of the engine and firing
through propeller hub. 200 rounds may be carried for the cannon and 500
for each machine gun. M.G. 17 are cocked and fired by compressed air,
electrically controlled. The M.G. 151 is cocked and fired
electrically. Wiring is also provided for the installation of two more
M.G. 151, 20 m.m. cannon, one under each wing, just outboard of the
These guns have, however, only once been found fitted.
Of the two M.G. 17's is
mechanical by flexible push rods enclosed in tubes operated by cams
driven from the accessory drive at the
rear of the engine.
As the axes of the M.G. 17's
are only 14" apart and these are only 17" above the axis of the M.G.
it would appear that harmonisation is scarcely neccessary. At 50 yards
there was no
apparent converging of the trajectories of the M.G. 17's but it was not
possible to check the trajectory of the M.G. 151 which
had moreover been removed and replaced by another gun making any
28. Stop Butt
Since the M.G. 151 and M.G. 17 have been fully tested and reported on
by Woolwich and
rates of fire and velocities ascertained, it is not considered
carry out further trials. Reports are available through H.Q., M.E.
is simple and could be carried out by four men in under ten minutes.
Operations consist of removing empty belts and cases from cannon and
two quickly detachable trays under fuselage. Lifting both sides of
cowling (three quick release fittings on each side). Replacing old M.G.
with new and fitting belts (the M.Gs. are very accessible).
Removing cannon breach cover in cockpit (three quick release fittings)
fitting new belt (magazine in port wing accessible via two quick
release covers). Feeding belt through guide and inserting in breach.
breach. Replacing cover. Lowering and securing engine cowlings. Gun
could be carried out if necessary during or in between any of these
The guns are quickly
removable for maintenance and this
should provide no difficulties. Both guns and cannon are very simple in
operation being recoil and having a minimum
of working parts.
Provision is made in the
electrical circuit for a cine-camera but these are not fitted as a rule
only two aircraft have windows in the port wing, just outboard of the
wheel recesses, been found
for this purpose.
32. Sights and
Revi C/12/D reflector sight is fitted
(as in the 109F). This is a simple sight having no range computing
device. It is provided with a glare
shield and dimming control, and an
emergency ring and bead sight attached to the right hand side.
33. The elevators
harden up at
high speeds and retrimming is necessary, which is difficult
as the trim wheel hardens up and becomes almost
sold in a dive. Some force is needed on the stick at
high speeds, but accelerations as great as the pilot can stand can be
34. The ailerons are
satisfactory up to a moderate dive, and
after that were used charily owing to the warning in the handbook of
weakness. Comparative combat trials are needed to complete this section
of the report.
aeroplane tends to swing to the left towards the end
of the take off and firm right rudder is needed. The take off is very
good so that the throttle can be opened slowly and it is then easier. A
pilot in still air will take 350 yards.
Stalling speed is 102 m.p.h. indicated flaps and wheels down, and 112
m.p.h. with flaps and wheels
up. With flaps and wheels up, the ailerons control becomes distinctly
at about 140 m.p.h. when the slots open.
37. The trim is
effective and not
too sensitive. At high diving speeds it becomes almost solid.
38. Approach should
be made at 120
The aeroplane is rather skittish and
the pilot concentrated
on keeping straight and did not look at the A.S.I. in the cockpit
to see speed at touch down.
the known stalling speed, the speed at touchdown can
be deduced as 105 to 110 m.p.h.
minimum landing run to be expected in still air with a normal pilot
is 550 yards.
and speed readings are tabulated on
subsequent pages. Results are also plotted as Fig. 1. Speed Fig. 2.
climb Fig. 3. Rate of climb — Different speeds Fig. 4. Rated Height
Time to Height. All tests were done at maximum engine power. (Germans
have cancelled maximum emergency power, apparently owing to
dive and shallow dive are very fast. Controls
become heavy but large deflections are still possible at 350 m.p.h.
N.B. The handbook warns against rough movement of aileron controls
and particularly during recovery, as likely to cause a crash.
Limit speed 467 m.p.h.
The petrol consumptions are tabulated on subsequent page.
Duration must vary greatly with operational conditions and the time
spent in dog fighting; the duration to be expected normally is
complete standard German
set of instruments was not fitted. Instruments flying is judged
to be normal and straightforward.
and exhaust shielding are similar to the
engine was always started by hand. It often
started at the first attempt and always started (when in our hands) at
second or third attempt. An experienced crew can probably count on a
good weather conditions at the first attempt.
48. A small
separate tank is
provided for the priming pump which can be filled with specially
volatile starting fuel for starting in bad weather conditions.
BUXTON Gp. C. (?)
ME. 109 G - 2 (TROP).
FIRST TEST FLIGHT. 0905 -
0955B HOURS 29th
1. The Me. 109
G. was made
serviceable by 451 Squadron Detachment.
The aeroplane had been restored to standard good
condition except that the oil radiator flap was locked open as
received, as the functioning of the
thermostatic control was apparently bad; no oil thermometer was
available; there was a splinter hole and score mark in one airscrew
Close examination of the airscrew blade is therefore made between
During take off, there is a marked swing to the
left which occurs towards the end of the run as full power is given.
Acceleration is quick and take off
run fairly short.
After take off, climb was
started, partial climbs being made at each height; full speed level
made mostly on the way down. The figures are tabulated
in Appendix "A" and the air temperatures for compiling true speeds
are tabulated in Appendix "B".
The air filter was cut out at about 8000 feet and
was put in again after all tests had been done, before coming in to
The propeller pitch control was left in automatic
throughout, and the figures of boost and revs given in Appendix "A" are
therefore those set by the automatic mechanism.
The radiator flaps were left in automatic and
kept the temperature at 80°C most of the time in the easy
conditions of cruising
used between test runs. The maximum temperature seen was 100°.
The altimeter readings were not exact as the
needle was swinging.
15000 to 20000 feet in the climb, the engine
hesitated and petrol pressure was seen to be low. This immediately rose
on the electric pump, and the engine then ran normally.
engine has some rough
periods, but usually, and particularly at high r.p.m.,
to the high rate of climb, it is necessary
to allow a margin of up to 3000 feet to settle down into a steady
climb; thus for
timing a climb from 15000 to 17000 feet it is desirable to pull up to
climbing speed (e.g.
150) at 12000 feet. In full speed level flights, speed is picked up
control is steady and it is easy to maintain
accurate speed with reasonable care.
almost 45 minutes flying, the red fuel
shortage (15 minutes to go) warning light showed. Owing to the fuel
swishing about, the light shows intermittently and is an
15. In the
approach to landing, torque can be
distinctly felt and so the engine should be opened up slowly when
SECOND TEST FLIGHT. 1415 -
1530B HOURS. 30th DECEMBER 1942.
series of 1000 feet timed climbs were done at
various heights. Owing to the high rate of climb, and to the fact that
sensitive altimeter needle was swinging over a considerable arc, the
not likely to be accurate, and therefore climbs at certain heights were
repeated for a height difference of 2,000 feet so that any error in
have less effect.
The cooling flaps on the radiator are
automatically controlled and they open as the engine temperature rises.
They are big enough to cause considerable drag when wide open.
will cause more drag on a long continuous climb and so decrease the
performance. To test this point, a long battle climb will be made.
Tests are being continued in cloudy weather as the
effects of the up currents and bumps are not thought to be so important
some preliminary figures.
THIRD TEST FLIGHT. 0920 -
HOURS 31st DECEMBER
On the third tests, repetitions were made of
climbs and level speeds which seemed necessary to fill gaps in the
performance curves plotted from the previous two test flights. A test
made to find the rated altitude at 1.3 at: boost and corresponding revs
automatic (i.g. interconnected) airscrew control.
During the climb from 30070 to 32000 feet, the
cooling flaps were seen to be wide open, owing apparently to a sticky
They were adjusted to normal position by using the manual control but
of climb obtained must have been somewhat reduced by this.
variation was noticed in the airscrew r.p.m.
presumably due to the automatic control functioning slightly
rated height of the engine was found by doing
a steady climb at 200 mph. indicated and noting the boost pressure at
thousand feet. The automatic boost control keeps the boost constant
height, and it decreases above. By plotting a graph of boost against
the line of the decreasing boost can be drawn and this meets the
1.3 boost at 21300 feet which is taken as the rated height as
governed r.p.m. (2750).
speed was tested at
23,200 feet (true) which gave 262 m.p.h.
indicated equal to 378 m.p.h. computed.
ME.109 G - 2.
FOURTH TEST. 1505 - 1615B
original good maintenance crew under Sergeant
Osborne left with their squadron, and a new crew has taken over.
Dill-Franzen of No. 7 S.A.A.F. came to change the airscrew. The new
in normal adjustment and appears to give the same results.
take off, the engine was opened up nearly
to full power, and firm right rudder was needed to stop swing to left.
is tabulated. Landing was made in reasonable tail down attitude, nearly
and brakes were initially applied to stop swing, and then both brakes
on firmly. Landing run is tabulated.
were then made (at 5,000
feet) on stalling. Stall was read first with flaps and wheels
with flaps and wheels fully down. The figures show that 120 m.p.h. (195
is the minimum safe speed of approach, and only gentle
turns should be made below 150 m.p.h. (240 km/hr).
climbs from 4,000 to 6,000 feet were then
made to find best climbing speed. Radiator flaps were set with the top
flap level with the wing flap
(control on "RUNE"). An inexplicable quick climb at 160 m.p.h. was
repeated and a more normal time was got. Air intake filter was in use.
climbs were then made from 19,000 to
21,000 feet (Altimeter). First 140 m.p.h. climb was probably slow as
engine hesitated owing to
low fuel pressure which was raised by switching on electrical fuel
repetition was also slow as boost fell during climb owing possibly to
slight stickiness of automatic boost mechanism. A similar slight fall
of boost pressure happened at the 160 m.p.h. climb, but not on the
two others, on one of which r.p.m. was
slightly high. The intake filter was of course out for this test. The
flaps were in "automatic" and were controlling satisfactorily, the
temperature being low and the opening small. The opening did not vary
than about an inch during this series of climbs.
engine was rather rough at times at low
power, but still is reasonably smooth at full power.
Office, A.H.Q. Levant was asked if any currents could
occur which might account for the irregular results at 5,000 feet.
They state that an up current occurred locally between
surface and 9,000 feet with a maximum of 400 feet
per minute at 6,000 feet.
TEST OF ME.109G-2
(TROP) 1 HOUR 10
17th JANUARY 1943
Approx. 270 yards.
m.p.h. 47° to take off direction.
18.5° C. Millibars sea level
1014. Height 130 feet.
Approx. 430 yards.
three point attitude on touching and brakes used firmly.
12 m.p.h. 20° to landing direction.
18.5° C. 1014 Millibars sea level. Height 130 feet.
With flaps and wheels up. Port
aileron control is lost
m.p.h. indicated. Nose
at 110 m.p.h. indicated.
With flaps and wheels
Ailerons duff at 112
Nose drops at 102 m.p.h.
196 yards approximately.
15 m.p.h. dead ahead.
17 degrees C. 1011 Millibars
sea level. Height 130 feet.
440 yards approx.
15 m.p.h. dead ahead.
17 degrees C. 1011 Millibars
sea level. Height 130 feet.
FIFTH & SIXTH TESTS.
run and landing run were measured.
climbs were made at 27,000 feet, which is the greatest height
at which Met. Temperatures were available.
speed test was also made at 27,000 feet.
level speed test was made at 16,500 feet first with radiator flaps open
and then with them closed. Speeds are plotted on
the speed curve to show their effect.
sixth test, which was to be a climb to height had to be stopped
before any readings were got, because the hood jettisoned itself.
ME.109, G-2 (TROP).
SEVENTH AND EIGHTH TESTS.
0935 - 1030B HOURS 29th JANUARY 1943
to height was made to conclude the
programme of partial climbs.
climb was made at full throttle with the
airscrew in automatic.
stop watch was
quickly after taking off
and operating undercarriage retracting button, i.e. about three
quarters of the
length of the runway. Subsequent readings were made by looking at the
watch. The aerodrome is at
130 feet and the altimeter was set to 130 feet (1015 Millibars) before
twenty-five thousand feet the coolant temperature was seen
to be low and the radiator flaps were wide open. This must have
temporarily reduced the rate of climb. The automatic thermostat must
stuck, and the radiator flaps were set by hand to a small opening.
keep the (unknown) oil temperature
down, the climb was made at 170 m.p.h. up to 25,000 feet and reduced to
m.p.h. from 25,000 to 35,000 feet.
oil pressure was
steady throughout, one division above minimum.
made with wheels and flaps up and wheels and flaps down.
120 m.p.h. the aircraft began to lose height. The nose did not fall
appreciably and there was no
tendency to drop a wing and there was
still aileron control.
Just below 105 m.p.h. the aircraft began to lose height but again it
showed no vices and aileron control was maintained.
slight and quick vibration was noticed
when just approaching the stall. Several bursts of motor were given
the stall but it was always possible to check any tendency to swing.
[Reproduction of large tables that
would be included in the end of the report, showing
meterological, calibration, misc. small details about these test, ie. see
from 20. to 30., which are generally just repeating the same Figures 1-5, just in tabulated from has been left out
from this reproduction
as they contain little useful information. They may be added to this
report later on.