New to 109K-4, a few questions

I've enjoyed dozens of hours learning the P-51D Mustang as my first DCS aircraft. Now I'm transitioning to the 109K-4 and have some questions. I've searched all 20 pages of topics for this forum and didn't see answers, apologies if these nuggets were buried somewhere deep in a thread and I missed them.

K-4 HISTORICAL QUESTIONS

1. What is the "circle with bubbles" in the lower right of the armored windshield? I know there's a windshield heater (D100 circuit breaker), but this doesn't look hooked up to any wiring.

2. Was there something about the Kurfurst design that made it much more effective at high speeds than the earlier Gustavs? In steep dives beyond 700 kph, K-4s pitch response definitely feels more sluggish than the Mustang, but not rooted in "cement" as pilot reports described in earlier 109s. I've heard of Flettner (sp?) tabs, were these improving the K-4s high-speed control?

3. How was the Revi gunsight used - both eyes open? One eye closed? I'm using Vive in VR, and it's very distracting trying to target enemies through that small reflector image. I'm used to the Mustang's brilliant K-14 which seems much closer to a modern HUD, easy to keep both eyes open. The Revi is so small can only view through one eye at a time, but when I close the other eye I'm losing depth perception.

4. Why was the 109 canopy required to be closed before engine start? Seems like propwash for idling engine wouldn't have been powerful enough to rip off a well constructed brace, and the advantages for the pilot to be able to look out and and around the nose (as I regularly do when taxiing the Mustang) would have been worth even strengthening the attachment points if needed. Am I missing some larger reason why 109s never taxiied with open canopies?

5. Why was the K-4 pressurized if the pilot also has an oxygen system? I've been reading that the Gustav introduced the pressurized cockpit (not all variants had this), but the K-4 definitely was pressurized. Did the pilots fly without O2 masks and only used them as backups if pressurization failed?

DCS SPECIFIC

6. Were the 13mm MG 131s really this powerful in real life? If so, what made them so much more effective than the AN/M2 in the Mustang? I've just worked through the Aerial Gunnery training mission several times, and I've repeatedly shot down the Mustangs with short bursts from the two 13mm cowling MGs. It's been a real surprise, since I have many hours in the Mustang tracking enemies and firing burst after burst, having to wear them down over time. I came into the K-4 expecting those cowling MGs to be mostly useful for ranging, and having to rely on the MK 108 to finish the robust American aircraft.

(BTW - I know the damage model is going to be revised for WWII aircraft, but I would have expected the problem to be all smaller caliber weapons. Are the American AN/M2 0.50cals just particularly undermodeled in DCS?)

7. Landing Training Mission - how do you trigger the instructions after the initial turn North and the pattern description? I consistently follow directions and turn N, cross the river and then just cruise on and on. No further instructions. I check F10 and the airfield I'm apparently supposed to land at is way off to the SE. I turn and fly there manually, but never get any further voiceovers. Is there a trick to this mission to get the training script to fire at the airfield? I found the Mustang Landing Training to be particularly valuable in learning that aircraft.

Thanks for any responses - love learning more about historical aircraft this way. Hoping others might also enjoy having these questions answered.

Ill leave the rest for someone else but 4.

@ 2:46 or so

1. there was capsule against humidity, i think

2.Flettner tabs on ailerons were planed, but never used in mas production

5. K-4 were not pressurized, if Bf model was pressurized it got add number 1,3,5...

3. While by no means an expert, judging by the sights in German planes being offset to the right of the centerline, I would assume they were meant to be used with both eyes open, but only looking through them with one eye, the same way reflex sights on modern rifles are being used today.

I agree it is somewhat of a hassle for people whose left eyes are dominant. I know the first couple of rounds during gunnery training I always spend trying to switch my eye dominance around - if I don't, all my rounds will actually pass my chosen targets to the left.

4. I would assume it has something to do with either noise or exhaust entering the cockpit.

6. The MG131 did in fact have access to HEI ammunition. I don't know offhand what the ammunition mix is for it ingame, and I know the ammo choice for the P-51's M2s has been...controversial, but pound for pound, the German 13mm was among the best HMGs of the war and certainly better than the Browning.

Note I said pound for pound, not gun for gun. One M2 is certainly superior to one MG131.

1. I believe its a fitting place for the (very rarely used) telescopic sight on 109s.

2. The K-4s controls are I believe to be the same as the Gustav's etc. Even the DCS model is closely built from Soviet and German control graphs of F-2 and 109G. It is, and was not as bad as portrayed by some games. Pretty hefty stickforce, giving you the bucket in cement feeling yes (which you can't perceive in the sim), but the plane remained maneuverable.

Now, for the K-4 there were some control upgrades planned (ailerons with Flettners, these were more often seen on G series), and change of elevator gearing for the elevator for lighter forces. I believe it wasn't serialized by the war's end, since they stopped developing the K in around February 1945 and concentrated on jets, while the chief designer wanted to have both modifications 'in' together, to maintain control harmony I suppose.

3. The Revi is similar to a Red Dot or similar reflector sight. In real life you use it with both eyes open, it doesn't matter which, your brain puts together the picture and you perceive it as if the crosshair would hover in space. Its completely natural.

I suppose the offset was done to keep the sight picture parallel to one dominant eye's line of vision, and hence eliminate aiming problems from conflict between how the two eyes would see it.

In the game however, I guess VR just can't handle it very well. Haven't tried VR myself, but I would believe the good solution in this case would be if the Revi would be an overlay seen only by the right eye.

4. Earlier boxy canopies had a sliding side panel, the Erla style late canopy did not have this. In any case, there is a pretty hefty weight on the canopy in a form of a large slab of armor and armored glass, I guess nobody wants to be slammed on the head if the plane bumps during taxying...

5, The K-4 wasn't pressurized, and all aircraft had oxygene system. At 8000 meter there is not much oxygene outside, so just relying on one tiny cocpits worth of oxygene on a 5 hour cruise is probably not a good idea.

6. The MG 131 wasn't particularly powerful, it was a very compact gun with sufficient power to punch through armor and that's just about it. The M2 is a more potent gun ballistics wise , originating in ground based HMG that was supposed to take on things like bunkers and thinly armored early tanks in trench warfare etc. Bottomline though - both guns make cc 13 mm tiny holes in laughably thin aluminium sheets. Both bullets have laughable amounts of content in the relatively tiny bullets. Both guns are powerful enough to break anything in an aircraft. So guess it just comes down to rate of fire and better concentration of hits from the fuselage mounted MG 131s. Wing mounted guns have shotgun accuracy and the M2 is not an exception.

Re. 4 - remember that the mechanic, who cranked up the starter, has to run and jump off the wing - obviously towards trailing edge rather than towards the prop. Would be kind of difficult to do with the damn opened canopy exactly in the way (watch some Youtube vids with restored 109s being hand-cranked to see what I mean).

Awesome set of answers. Thanks to everyone who responded so quickly. As you can see from my post count, I'm new to the DCS community, and the helpfulness and knowledge in this community is impressive.

1. Gotcha. I know Adolf Galland would install rifle telescopic sights in his 109s, didn't know that was available as a general option. The alternate explanation that it's a capsule for humidity is an interesting idea. The Mustang has a defroster to blow hot air against the windshield, but maybe the 109 needed something additional to the windshield heating element.

2. That makes sense that it's more of a subjective perception than a genuine limitation. The 109K still seems reasonably maneuverable except at the very highest speeds. I've also heard that the reports of "stick rooted in cement" often came from Allied pilots who were used to lighter stick forces, but it wasn't an issue for German pilots who were used to it.

3. Yup, learning how to keep both eyes open and it's getting more comfortable in VR, but still feels like looking through a straw compared to the Mustang. The K-4 seems to operate more like a sniper rifle, being lethal straight ahead but much harder to use for deflection shooting like the Mustang.

4. Great points about the mechanic needing to jump off backwards and the risk of having that heavy armored glass come crashing down on one's head. Also props to DefaultFace for sharing that video. Very cool to see the inertial starter wound up with resulting engine start.

5. Aha, I knew the Gustavs were pressurized in odd numbers, didn't realize same held for Kurfurst.

6. I've heard that the MG131 had a theoretically faster ROF than the AN/M2, but it needed to be synchronized through the propeller, which dropped the actual rate of fire. I'm still surprised at the way Mustangs just come apart under the MG131s while the AN/M2 seem to be relatively ineffective against the 109/190, but as you say, there's the convergence effect to deal with when using American fighters.

As for the Landing Training mission, I've now landed the 109K five times in a row without mishap by practicing on my own. I then started the Challenge Campaign last night and even managed to get the 109 down on the first try during the Challenge Campaign's crosswind landing (#5?). That was almost certainly luck, but I think I can proceed without needing that specific training mission.

One more question for the group here:

Is the overheating (or lack thereof) historically accurate? I just finished the Challenge Campaign mission where you need to climb from 1000 to 6000m in minutes, and I was astonished at the ability of the Kurfurst to just power uphill under full MW 50-boosted power without temperature rising. I'm so used to the P-51D, where heat management of the Merlin is a major part of successful flying. Did the 109K have superior cooling systems or some other engineering solution which allowed it to operate at full power at moderately low airspeeds (270 kph) without having Merlin's problems?

I've just been impressed at how much more "carefree" the 109K is to fly compared to the P-51D, once you get it off the ground. Much harder to stall, no problems with engine overheating... wow.

Also, I'm reading that the K-4 was optimized for high altitude fighter-to-fighter combat. But wasn't the Fw 190D-9 also being optimized for fighter-to-fighter combat? In late 1944 as the Reich is being flattened by strategic bombers, was the Luftwaffe betting on the Me-262 as their sole anti-bomber design?

109 Production Numbers

Here's a simple Excel pie chart I put together for myself to visually "get" the relative numbers of each type of 109 produced.

To me the HE charge of the MG131 is over performing because of the current DM that counts each shell as if it does the same amount of damage with every hit on one main big part, such as back of the feuselage, it does higher damage than AP, so HP of the section drops quicker.

With current DM it just a DPS race and higher DMG per shot + higher ROF give the MG131 an edge. Add the fact that the shotgun pattern makes .50s hit the overall plane and not one part makes them even weaker.

Regarding the M2 vs MG131:

Currently in DCS, it seems to me that HE shells do much more damage vs aircraft than AP ones.

MG131's bullets are a bit more cannon shell-like, and they have some HE content in their somewhat bigger interior volume.

Brownings in F-86 and P-51 are underperforming in DCS, at least against aircraft. Only a concentrated burst of a decent length hitting a weak spot seem to do anything of significance. Due to mentioned shotgun pattern, even this is rather difficult to achieve, especially on targets that aren't inclined to cooperate.

Ah, that makes sense and matches what I've seen in-game. The MG 131 seems to have a HE effect, often ripping off tails and wings with a short burst while the AN/M2s seem to have to wear down an enemy over time. It makes air combat more dangerous for the P-51 since you have to settle in and track an enemy for a length of time, peppering them until they go down. The K-4 seems to be able to come in and with a single burst knock a plane down and keep going...

This is a good read: http://www.jg-51.com/topsecret/gunnery.pdf

AM - thanks for the JG51 Gunnery PDF. Some good stuff in there, and the screenshots of those old flight sims bring back memories. My first flight sim was Microsoft Flight Simulator on the original 1984 Mac.

#1 is probably a valve that controls cockpit pressurization. At low altitudes it stays open and at higher altitudes spring (or something else) would close the valve and then outside air will be pumped into the cockpit to pressurize it. Not sure if DCS K4 is pressurized or not (and even if it is, if developers actually implemented the visual part of it) so I don't know if it works. This is very similar to how modern oxygen masks work.

AM - thanks for the JG51 Gunnery PDF. Some good stuff in there, and the screenshots of those old flight sims bring back memories. My first flight sim was Microsoft Flight Simulator on the original 1984 Mac.

Glad you enjoyed it! :thumbup: