Kurfürst - Mtt. AG. Datenblatt, Me 109 G

English version
German version

Notes

    This calculated performance sheet was prepeared just a month before the operational introduction of the Bf 109G, by when serial production was already under way. The calculations were acceped as the official performance specifications for the Bf 109G-1 subtype, as these very figures were repeated as reference values in a report on the ERLA factory's speed measurements on 13 serial production aircraft (along with the +/- 3% tolerance limits, ie. a minimum 640, maximum 680 km/h being the borders for acceptance by BAL).

     Appearantly the calculated dataset proved rather accurate - the avarage of the ERLA values obtained on production airframes was 652 km/h (the accepted airfames results ranged from 632 to 664 km/h, the three rejected airframes below the minimum tolerance not included), and three production airframes exceeding the reference specification; however the avarage the rated altitudes measured (ranging 6450m to 6950m) was lower, 6700m, probably as a result of the greater variance in thermal effiency than expected originally.
    It should be noted that the ERLA values were obtained with 120 mm wide radiator flap opening, about three times of the usual standard Schnellflugstellung (which was 40mm), resulting in higher drag and must have reduced the obtained speed results slightly.

    Trials at E-Stelle Rechlin on a Bf 109G-1 - the results were later becoming the official specifications for the type in a Kennblatt issued on 8 March 1943 - resulted in 650 kph at 6400m; the tested aircraft appearantly had a fixed tailwheel resulting 12 km/h speed loss, which needs to be taken account.

    Soviet performance trials at the NII VVS with a captured Bf 109G-2, Werknummer 14 513 are in remarkably good agreement with the Messerschmitt datasheet below : 666 kph was achieved at 7000m altitude. This aircraft's tailwheel was semi-retractable and thus the results are directly comparable to the Messerschmitt datasheet below.

    Similiar factory trials as Erla's were performed at the W.N.F. and Messerschmitt Regensburg factories underlined Rechlin's (and thus Erla's as well) values.

For graphical comparison of these trials, please follow this link.

All aformentioned trials were done at Steig- und Kampfleistungs, ie. 1,3ata boost and 2600 rpm.
This limitation was in force until October 1943, when the full rating, 1,42ata boost and 2600 rpm was cleared for operational use for the DB 605A-1.

Given the great similiarity it can be also applied to the similiar G-2, G-3 and G-4 subtype, from which the G-1 only differed in the presence of pressurized cocpit and/or the radio set.

Introduction to the datasheet

Condition of the Aircraft:

Airframe: similiar to Me 109 F
additional scoops for spark plugs and compressor.

Engine: 103° Coolant temperature at engine exit point,
and corresponding to an overpressure of 0,75 atü
radiator: omission at the radiator duct exit .

Conditions for the performance values :

All values refer to Normaltag (Standard Day).

Level Flight: varying radiator flap position over the
whole altitude range (resulting from operation with 103°
and 0,75 atü)

Climb: From 0 m up to FTH radiator flaps half open [ ca. 220mm ]
(as per previous coolant test flights it appears somewhat insuffi-
cent, but until the completition of coolant test flights with the
Me 109 G this can be kept safely).

From FTH to the ceiling in order to simplify the calculation,
continous progressive transition of the radiator flap position:
closing from half-open to Schnellflugstellung [ 40 mm open ].
(In reality, depending upon engine, the Schnellflugstellung is
already achieved by ca. 2500-3000 m above the FTH.)

Flight duration: The substractions for warming up etc. as per
the Rechlin guidelines were taken into account. The consumption
corresponds to the values in the engine datasheets - tolerance.
(this means that the additional 15% presented added to the
operational datesheets is not was not used!)

Introduction to the IV/43/42 datasheet.

Augsburg, on the 21^st May 1942. Bu/F/Gtr. [signed]

D a t a s h e e t Me 109 G 1 model. calculated values.
					IV/43/42
Engine (reduction gear) DB 605 (9-605-2008) Startleistung (PS/revs/min) Engine output at Sea Level " at alt. with ram (PS/m/revs/min)			PS " "	1:1,685 1475/2800 1310/2600 1230/7000/2600	blocked at present Steig-u.Kampflstg
Propellor			m	3 Ø 3 blades.
Wingspan Lenght Height Wing area			m " " m²	9,97 8,94 2,45 16,10
Armament 2 MG 17 2 x 500 rounds 1 MG 151 1 x 500 rounds
Equipped Weight Crew ( .... Mann) Ammunition (2 MG 17 /1 MG 151 .... Schuß) Fuel Lubricant Bombs Flying weight			kg " " " " " "	2546 100 73 296 27 -- 3042
Maximum level speed (Ga*) Steig-u.Kampleistung	N(PS)	H(km)
	1230	VH 7,0 km	km/h " " " "	660
	1270 1350 1350 1260 860	0 2 4 6 10	km/h " " " "	535 583 624 647 638
Cruising speed and range (at max.continous output, at middle weight 2780	N(PS)	gbr(gr/PSh)
	1090	225	0 2 4 6	600 km/h
Endurance at 6 km with economy continous.			h	1,1'
Service ceiling at Ga* Service ceiling at Gmittel Service middle ceiling w. 1 engine Ga*			km " "	12,2
Climb time at Ga* H = 1 km 2 4 6 8			min " " " "	0,9 1,8 3,6 5,7 8,5
Landing speed at weight = 2740 kg (w/o.Bombs, with fuel for 2/3 h V_m Flight mit max. cont. output. Wingloading			km/h kg/m²	140 180
corresponds to Rechlin guidelines from 26 August 1939
Augsburg, on the 17^th May 1942 Pa/../... [signed]

* Presumably the G_a abbreviation stands for Gewicht, Abflug, ie. Weight at Take off.