Messerschmitt AG.
Drag of 160 liter external tank,
without fairing, beneath the fuselage.
 Test Report
109 15 L 43
 Date 15.8.43
 Copy 3
 Dept. Flight Testing

Reason:FS.RLM Nr. 01238 from 30.7.43
 Since the 300 liter tanks are generally not utilized, Colonel Galland suggests drag should be decreased by using a smaller tank.
Test flights with three different conditions.
Results: The following values are not converted, since air conditions did not change during the test.

      ConditionV mph V/mph
      smooth machine 327 0
      Mounting bracket without tank 324 - 3  
      Mounting Bracket with 160 l-Tank 308 -19

 B = 729 mm Hg, t = + 14 °, y = 1,179 kg/m3,
 p4 = 1,30 ata, p2 = 1,72 ata.
 Tests with an un-faired 300 liter external tank on a Me 109 E/3 (vgl Test Report from 30.7.40) resulted, after conversion to an Me 109 G, in a speed loss of 31 km/h. This calculation is still confirmed by a test. A decrease in size of the tank thus brought no speed gain. A fairing is in the works. A significant improvement is anticipated from this measure.
Aircraft:Me 109-G/5           CN + WF
W. Nr. 15562
Engine: DB 605 A               W.Nr. 37648
Propeller:3-fl. VDM adjustable propeller D = 3,0 m
Blattbaumuster 9 – 12087
Condition of
Standard production 109 G with smooth camouflage finish, single-wire antenna, tail wheel out, radiator flaps closed.
 Augsburg, den 16.8.43
    Messerschmitt AG. Flugerprobung.     Gruppe:  Leistungen       Bearbeiter:   Wegener

Speed was 314 mph (506 km/h ) at sea level after corrections and adjustment to condition of basic model Me 109 G. Zusammenstellung aller Leistungmessungen umgerechnet auf Grundausführung from 14.1.44
Widerstand des unverkleideten 160 l Außenbehälters unter dem Rumpf.

WWII Aircraft Performance   Me 109 G Flight Tests