Messerschmitt AG.
Influence of the engine cowling
shape on the speed of the ME 109 G
 Test Report
109 06 L 43
 Date 22.4.43
 Dept. Flight Testing

Reason:The mounting of 2 MG 131 in the fuselage over the engine necessitates the attachment of double bumps (see Abb.), due to space considerations, as the standard production cowling of the Me 109 G with DB 605. For reduction of the additional drag caused by these bumps, an enlarged, smoothly faired engine cowling was made.
 Flight tests were made to determine the influence of 3 different cowling styles on the level speed of the Me 109 G.
Test flights using combat power were conducted with each of the cowling designs; the speeds obtained were converted to sea level and normal temperature.

Results:1.Standard production 109 G – engine cowling: Vno = 306 mph (492 km/h)
 2.Standard production 109 G – engine cowling with double
bumps for MG 131: Vno = 300 mph (483 km/h)
 3.Enlarged, faired engine cowling Vno = 304 mph (489 km/h)

Aircraft:109 G – 6 Trop. Werk.Nr. 16476      SL + EM
Propeller:3-fl VDM – 9-12087a Verstellschraube Werk Nr. 312.8306
Weight:Ready for take-off ~ 6834 lbs (3100 kg)
of Aircraft:
Production 109 G with tropical equipment (sand filter at the intake), single-wire antenna, under-wing armament, outside air thermometer on the left wing, radiator flap indicator, main-wheel covers with indicator, non retractable tail wheel, normal camouflage finish, 2 ETC 50 under the fuselage arranged one behind the other.
Date of
Test flights:
20.4 u. 22.4.43
Pilot:Schmid, Lukas
of the Test:
Test flight with combat power n=2600 U/min; p=1,3 ata radiator flaps completely closed. No weapons were installed in the fuselage during the test fights
    Messerschmitt AG. Flugerprobung.     Gruppe:  Leistungen       Bearbeiter:   Wanner

Zusammenstellung aller Leistungmessungen umgerechnet auf Grundausführung from 14.1.44 gives 309 mph (498 km/h) at sea level after corrections and adjustment to condition of basic model Me 109 G.
Einfluss der Form der Motorhaube auf die Geschwindigkeit der Me 109 G

WWII Aircraft Performance   Me 109 G Flight Tests