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IL-2 Sturmovik: Me 109 Weapons
By Len "Viking1" Hjalmarson

Article Type: Preview / History
Article Date: June 05, 2001

IL-2 Sturmovik was originally conceived about three years ago. At the time the plan was to simulate a selection of Soviet Russian aircraft and develop a mud moving simulation with the IL-2 Sturmovik as the centerpiece.

But . . . the times they are a changin!

The design gradually expanded, and now we need to consider a new “unofficial” title for this sim. Here are the contenders:

  • Air War: Eastern Front
  • Red Star: Black Cross – Eastern Front Air War
  • WWII Fighters: Allies and Axis in the East
  • Allies and Axis: WWII Eastern Front
The point is that IL-2 is no longer merely a mud moving sim, and no longer limited to Russian aircraft. The current list of flyable Axis aircraft is as follows:
  • Bf 106F-2
  • Bf 109G-2
  • Bf 109G-6
  • Bf 109G-6 (late)
Note: Strictly speaking, the Bf prefix is correct when referring to 109's but the Bf and Me prefix is and was used interchangeably with 109's. For more info on this debate, see the Feedback Forum for this article.

Maddox Games also hope to add the G-6/AS in time for release. This model used the DB-605ASM equipped with MW-50 boost system. No one has ever modeled this system correctly in a PC simulation.

Axis aircraft to follow (free add-on) shortly after release are the Fw190A-4 and possibly the Fw190A-8. Eventually the Fw190D-9 will also be released.

Me109s just off the runway.

The Me 109 – History of the Type

The aircraft designed by Willy Messerschmitt and Walter Rethel was completed by a factory force of fifty-two, and would go on to break all German or American production records. Between 1935 and 1945, some 40,000 would be produced, twice the number of the Spitfire and the Fw 190

109s forming up in IL-2

The first operation model of the 109 left the factory at Regensberg in February, 1937. Test pilots continued to complain about the visibility from the 109 compared to the Heinkel 112, with its spacious cockpit and wide track landing gear. But the 109 could fly rings around the Heinkel. The 109 was quick and maneuverable, as well as stable. By the end of 1936 the competition was over and Messerschmitt had won.

The first 109s were armed with three light 7.9mm machine guns: one mounted between the cylinder banks of the engine, with two in the upper decking of the cowl. Tests were also conducted with a 2Omm cannon positioned to fire through the propeller boss.

Meanwhile, the 730 hp Jumo engine was being fitted with a variable pitch propeller, a two-stage supercharger, direct fuel injection and automatic boost control. These additions would have worked well in the 109, but raw horsepower won out for the early models. Daimler-Benz's DB 600A delivered 960 hp and in June, 1937, one of these engines was placed in the tenth pre-production prototype.

Cockpit View showing IL-2



Me109 with Yak falling away

The Bf 109B was powered by the Jumo, as was the C model. The D model introduced the Daimler-Benz 600A engine, and when Daimler-Benz developed the DB 601 with direct fuel injection and supercharging, the new and improved version was reserved for the 109.

When the German Air Force invaded France in May, 1940, the Luftwaffe had approximately one thousand Me 109s available for service in ten fighter wings. After the campaign, 75 lbs. of armor plate was added to the aircraft's seat and canopy and the engine-mounted 2Omm cannon was discarded in favor of two wing-mounted weapons, for the new E model. The problem of limited range was addressed with the inclusion of a 75 gallon drop tank.

109 F-2 with 250kg bomb.



109 G-6 with Mk 108 30mm cannons

Three months prior to the invasion of Russia in June, 1941, the Luftwaffe introduced the much improved Me l09F, which equipped two interceptor wings based on the Channel Coast.

When Operation Barbarossa was launched, the Luftwaffe employed 300 F model and 140 E model Me109s.

The Me 109F was a cleanup version, re-moving many of the protrusions and drag producing indentations found in the original design. The oil intake scoop was streamlined, the under wing radiators flattened and the angular shape of the cowling rounded. Turbulent air collecting on the lower wing was smoothed out by directing it through the upper portion of the inboard flaps. The wing was reduced in span, and the tips were rounded. The rudder area was also reduced slightly and the horizontal tail braces removed.

Figure 1. Comparative Horsepower of 109s

Figure 1 shows comparative horsepower of three 109 models. The figures for E and F are averaged, and the figure of 1,475 is for the G-2 with DB605A-1 (later models developed up to 1,800 HP for takeoff).

A new version of Daimler-Benz engine was installed for the F model, the DB 601E, generating 1,350 hp for takeoff. The wing-mounted Swiss Oerlikon 2Omm cannon of the E were discarded and their firepower was replaced by a single Mauser cannon of 15mm, later increased to 2Omm for the F-4, firing through the propeller hub. The new Mauser was rapid firing and had a high muzzle velocity, considered by many to be the finest aerial cannon of the war.

Me109 F-2 in IL-2

The 109-F model could turn in two thirds the space required by an E. The initial climb rate increased by 300 ft. per minute and overall maneuverability was improved. After the war many German aces recalled the F as the best performing and sweetest flying 109 ever.

Adolf Galland loved the 109, but complained that the F model was underarmed, with only one cannon and two light machine guns.
This represented an incomprehensible regression compared with the E series, whose production had stopped in the previous year. The latter had two 20mm cannon mounted in the wings and two normal machine guns. The one cannon of the new F model was modern, had a quicker rate of fire, a better trajectory, and what is more was centrally mounted over the engine and fired through the hub of the propeller.

Nevertheless there were conflicting opinions as to whether the new armament should be regarded as a step forward or a step backward. Moelders shared Udet's opinion that one centrally mounted cannon was better than two in the wings. I regarded one cannon as absolutely inadequate, particularly as I considered machine guns outdated for aerial combat, merely senseless fireworks. One could hardly impress an enemy fighter with them any more, to say nothing of multiengined bombers.

Naturally I recognized the advantages of centrally mounted weapons. But if the armament consisted of one cannon only, then I preferred two decentral cannons, especially when I thought of the gradually declining standard in skill and training of the majority of our new pilots. Not every pilot was as good a sharpshooter as Udet or Moelders.

Adolf Galland, The First and the Last



Eventually he won the battle for more armament and more fighters, and in late summer, 1941, a new proto-type was developed, designated the 109 G (or Gustav).

Me109 G-6 in IL-2. Notice the large fairings.

The G models were powered by a further improved DB 605A engine developing 1,475 hp.for takeoff. Nitrous oxide boost provided additional power for short periods. With boost on the 109G reached a top speed of 406 mph. at 28,000 ft. Normal top speed without boost was 360 mph.

Figure 2. Comparative Weight of Me109s

While the horsepower of the Daimler-Benz engines kept increasing, so did the weight of the Me 109. In fact, while the output of the engine in the G-2 was 1,475 hp, it had almost the same power to weight ratio as the E-4 at 0.24 to 1.

With a pair of 13mm cowl machine guns replacing the original 7.9mm weapons, plus the additional weight of the engine, special equipment, armor plate and more ammunition, the 109 had increased by 2,000 lbs. in weight. This resulted in the G model weighing forty percent more than the E. Since the l3mm machine guns in the cowling had larger breech blocks, fairings were added to enclose them. The addition of air filters and supercharger intakes added additional bulges to the clean lines of the G, until the original cleanup work that produced the F model was a distant memory.
I always felt confident flying the Me-109, even down to the armament. In the FW-190 you had four guns, and much more hitting power, against the three guns of the 109. Nevertheless, I did not like the outboard guns of the FW-190 because the high G-forces caused jamming and mechanical troubles. I preferred three guns in the center of the aircraft, right along the longitudinal axis. This mean you had to aim very carefully, but when you did, our excellent ammunition got the job done. It had high explosive power, and when you hit an enemy aircraft that was "good night."

Gunther Rall, in Fighter Aces of the Luftwaffe,
Constable and Toliver, 1977.




Armament Evolution

Armament changes over the course of development of the 109 types were significant. Six different guns were used: two machine gun types and four cannon types. Four different mounting locations were employed: on top of the engine cowling, just behind the engine, with the gun firing through the propeller hub, within the wings, and under the wings.

The six variety of guns employed were these:
  • 7.92 mm Rheinmetall-Borsig MG 17
  • 13 mm Rheinmetall-Borsig MG 131
  • 20 mm Ikaria MG-FF (the Swiss Oerlikon)
  • 15 mm Mauser MG 151
  • 20 mm Mauser MG 151/20 (used M-Geschoss explosive shells)
  • 30 mm Rheinmetall-Borsig Mk 108
Let's compare the armament changes over six types of the 109: the E4, F2, F4, G2 and G6 early and G6 late.

E-4:
  • 2x20mm in the wings (60 rounds)
    • rate 600 rpm, muzzle 1840 fps
    • round weight 4.82 oz (115 gr)
  • 2x7.92 mm cowling mounted (1000 rounds each)
    • muzzle velocity 2475 fps
F-2:
  • 15mm in the nose (200 rds)
    • rate 650 rpm, muzzle 2500 fps
  • 2x7.92mm cowling mounted (500 rounds each)


Mk 108 30mm with technician.

F-4:
  • 20mm in the nose (150 rds)
    • rate 650 rpm, muzzle 2250 fps
    • explosive round 115 gr.
  • 2x7.92mm cowling mounted (500 rounds each)
G-2:
  • 15mm in the nose (200 rounds)
    • rate 650 rpm, muzzle 2450 fps
    • round weight 92 gr.
  • 2x7.9mm cowling mounted (500 rounds each)
G-6:
  • 20mm in the nose (150 rds)
    • rate 650 rpm, muzzle 2250 fps (115 gr), muzzle 2600 fps (92 gr)
  • 2x13mm cowling mounted (300 rounds each.) ˇV 62 caliber
    • rate 900 rpm, muzzle 2400 fps
  • 2 wing mounted 20mm
G-6AS with Mk 108:
  • 30mm in the nose (60 rds)
    • rate 650 rpm, muzzle 1600 fps
  • 2x13mm cowling mounted (300 rounds each.) ˇV 62 caliber
    • rate 900 rpm, muzzle 2400 fps
  • 2 wing mounted 20mm
    • rate 650 rpm, muzzle 2250 fps (115 gr), muzzle 2600 fps (92 gr)


From 7.92mm to 13mm

As you scan the changes in weaponry listed above, note in particular the caliber and muzzle velocity of the weapons. The penetrating power of a lighter round moving at higher speed can be equal to a heavier round moving more slowly.

On the other hand, a rapid fire weapon puts more lead in the air in a shorter time, and therefore also in a smaller radius of fire. Naturally, this information can be computed in terms of lethality.

Lethality Ratings

Consider for a moment that a 20mm cannon with a rate of fire of 650 rounds per minute and a bullet weight of 5 ounces is capable of placing 44 pounds of lead in the air in 15 seconds. Compare this to a 7.92 mm machine gun, which even with double the rate of fire will only place 6 pounds of lead in the air in the same period of time.

The other consideration in aircraft armament arrived with the development of the MG 151/20. This 20mm cannon used an explosive shell, multiplying its destructive effects greatly, and introducing the pilot to the additional risks of shrapnel.

MG151/15 15mm cannon.

The other evolution of aircraft armament for the Luftwaffe arrived when it became obvious that a 7.9 mm round was not substantial enough against aircraft. The Luftwaffe soon adopted the MG 131 13mm. The belt-fed weapon had a muzzle velocity of 2,400 feet per second, with a 900 rpm rate of fire, a bit less than the 7.92mm MG 81.

The MG 131s bullet was approximately 62 caliber. Compare this to the bullet from a Soviet 12.7mm heavy machine gun at about 58 caliber. Compared to the standard .303 British round, they were much more powerful, but not so when compared to the American 50 caliber weapon. The muzzle velocity of the standard American 50 caliber weapon was 2,800 feet per second, and most US fighters mounted six (the P-47 mounted eight).

When the Me109 first appeared it was armed with engine and wing-mounted Ikaria Oerlikon MG-FF 20mm cannon. Fed by a drum magazine, it had a relatively slow, 600 rpm rate of fire. It was soon replaced by the more powerful Mauser MG 151.

Mk 108 30mm cannon

The first few F series carried the MG-FF, but this was quickly replaced by the new MG 151, 15 mm. Soon afterwards, the MG 151 was overbored and replaced by the MG 151/20. The larger caliber permitted the use of the explosive M-Geschoss shells. The 115 gram shell gave a muzzle velocity of 2,250 feet per second, and the 92 gram shell gave 2,600 fps.

Some K series were built with the MK 108 30mm cannon instead, and some G-series were retrofitted with the Mk 108 as the U4 modification. In IL-2 the player will be able to choose the short nose-mounted MK-108. This version had a slow rate of fire (650 rpm) and a muzzle velocity of 1,600 fps, but If you prefer to fight from 100m or less this is a superb cannon. The shell weighed 312 grams (11 oz), almost triple the weight of the larger 20mm shell.

MG17 installation in Me109

The Mk 108 allowed the 109 to achieve greater destructive power against bombers, but the low muzzle velocity made it a poor dogfighting weapon. The Mk 108 was used for under-wing mounts on various G models and some Fs. Some Luftwaffe aces, like Galland, loved the extra firepower. Others preferred to keep their wings clean.

Some versions of the G-6 were equipped with a hub firing version of the 30mm Mk 108. The weight of each round was 11 oz. The Mk108 was also used by the Me 262 and late model Me 109K.

Sources:



  • Publications:

    • Airpower. Volume 25, No.3. May, 1995.
    • Gunston, Bill. Fighting Aircraft of World War II, Salamander Books, 1988.
    • Shaw, Robert. Fighter Combat. Naval Institute Press, 1985.
    • Toliver,R. and Constable, T. Fighter Aces of the Luftwaffe. Aero Publishers, 1977.


  • Web Sites:


Thanks to Butch2k and Autogun for their answers to questions.

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