Messerschmitt AG.
Performance Measurment Me 109 G
with DB 605 A and DB 601 E.
 Test Report
109 19 L 42
 Date 19.9.42
 Copy   3
 Dept. Flight Testing

Reason:Following a comparison of sea level speeds with DB 605A and DB 601 E in the same airframe, a performance comparison was also conducted with both engines at altitude.

1.)Climb and full throttle levels with DB 605 A and the corresponding production VDM adjustable propeller.
2.)Climb and full throttle levels with DB 601 E and the corresponding production VDM adjustable propeller.
3.)Measurement of coolant temperature in high-speed flight.
Measurement with dynamic pressure recorder and Junkers Log.

Results: Speed with DB 601 E at sea levelVo   =   319 mph
Speed with DB 605 A at sea level Vo   =   315 mph
Speed with DB 601 E at FTH = 19,685 ft.v      =   386 mph
Speed with DB 605 A at FTH = 20,013 ft.v      =   389 mph
Service ceiling at 98 ft/min with DB 601 EH     =   40,354 ft.
Service ceiling at 98 ft/min with DB 605 AH     =   41,339 ft.

The values stated above are measured at Climb and Combat power and are converted to normal day and correct setting of the supercharger regulator.
The influence of the radiator flap position on temperature and speed can be seen on page 9. The coolant temperatures of both measured engines are similar, i.e. any large heat removal of the DB 605 is balanced by higher air and water speed.

Aircraft:Me 109 G-1Werk Nr. 14026Registration BD + GU
Engine:DB 601 EWerk Nr.777Hours of operation 46 h 48‘
DB 605 A Werk Nr.76098Hours of operation 30 h 45’

Propeller:For Me 109 F with DB 601 E
3-fl.VDM-adjustable propeller 9-1210.31
Werk Nr. 12.10544 D = 3 m
For Me 109 G-1 with DB 605 A
3-fl.VDM-adjustable propeller 9-12087.31
Werk Nr. 13.14470 D = 3 m

Links Schwermetallkühler, Rechts Leichtmetallkühler
F 750 C ALT 750 B
Oil cooler:
Schwermetallkühler Gerätenummer 9-6150 A W.Nr. F 100780

Type & day
of the flight,
Stoppflug13.7.42BaurDB 605
Steigflug u. Geschw.
in großer Höhe
Geschw. i.kl. Höhe8.8.42"601
des Kühlers
Steigflug; Geschw.
in großer Höhe
Geschw. i.kl.Höhe u.
Des Kühlers
Log-Eichung mit gr. Fahrt19.8.42"605
Log-Eichung mit kl. Fahrt20.8.42"605

Condition of the
Conforms to production 109 G-1 with some modifications: Enlarged vertical stabilizer and automatic flettner. Slat set up not standard. Radiator indicators, wing thermometers; starting from 1.8 42 Doppelloggabel.
1. Condition
109 G-1 fuselage with DB 601 E engine.
2 Ventilation scoops for spark plug ventilation 40 mm wide and 28 mm high (Mtt execution). Intake scoops not thickened.
Generator ventilation scoop on the right.
2. Condition
109 G-1 fuselage with DB 605 A engine.
4 Ventilation scoops for spark plug ventilation 70 mm wide and 30 mm high (Rechliner execution).
Thickened intake scoops.
Compressor ventilation scoop on the left.

Climb and speed at altitude (full throttle levels) were flown with climb and combat power
with DB 601 E: n = 2500 rpm and p = 1,3 ata boost pressure.
with DB 605 A: n = 2600 rpm and p = 1,3 ata         "
During climb with both engines Va = 162 mph.
The oil cooler was thermostatically controlled during all flights; the radiator was manually adjusted during high-speed flight, thermostatically controlled during climb.
The measurement of the test flights was accomplished with trip (Fahrt- ), height, boost and blower pressure recorder as well as the full throttle stages also with Junkers log. Additionally the pilot read off: outside- water temperature, radiator flap position , engine rpms, Log-drehzahlen (Doppellog) and time.

Results:See   Page 1
         Page 5Climb performance with DB 601 E
         Page 6     "             "          with DB 605 A
         Page 7Speed vrs. Alt. with DB 601 E
         Page 8       "           "       "   DB 605 A
         Page 9Influence of radiator flap position on
temperature and speed
         Page 10Radiator position during climb

The addition of 3 km/h is already added to the speeds shown on page 1, which is to correct for the speed loss from the radiator flap position indicator.
With the speed calculation from trip recorder the thermodynamic Stauerhöhung was considered. This should be considered in the comparison with earlier measurements. Without this correction the speed at full throttle height would appear approximately 7 mph greater. The plotted data points are average values from Log and dynamic pressure measurements. The agreement of the two Logs, as compared to calculated Vw lie within +/- 3 km/h on average. The respective radiator flap opening and the water temperature converted to standard temperature are the written data points.
The speeds measured in 1.Stoppflug with DB 601 E (V.B. 109 14 L 42) were increased 6 mph with additional measurements. The reason could not be ascertained.
Augsburg, den 19.9.42

Leistungsmessung Me 109 G mit DB 605 A und DB 601 E.

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