pvanroy

I strongly doubt Wołowski's ID of W.Nr. 413598 as a supposed Erla-built G-14/U4, for the following reasons: - As already mentioned by rafju, the rear wall of the cockpit of 413598 appears to be missing the rectangular protruding battery cover. This strongly suggests it is a G-6. (The head armor and Morane mast could conceivably have been removed by the British after capture, and the larger oil tank is normally associated with the DB 605 D engine, although some late-production G-14/AS machines also had it) - Its W.Nr. falls in a known block for Erla-built G-6 aircraft - Erla is not known to have built any /U4 machines The /U4 modification was designed by WNF and entailed more than simply swapping out the 20 mm MG 151/20 gun with a 30 mm MK 108. The introduction of the MK 108 required a number of considerable design changes, including a completely re-engineered ammo bin, new linkages for the rudder pedals, a revised control stick, the re-introduction of compressed air bottles and pneumatic lines and the addition of a pneumatic outlet on the right side just behind the exhaust, as shown in D.B Andrus’ post (the MG 151/20 was electrically cocked, whereas the MK 108 was pneumatically cocked). The G-6/U4 and G-10/U4 were constructed by WNF at its Wiener Neustadt plant, and at its Diana subsidiary in Tišnov (Tischnowitz). The G-14/U4 was built by WNF in Wiener Neustadt, but not by its Diana subsidiary, which continued producing the G-6/U4 until switching to the G-10/U4 in late November 1944. In addition, a production line for the G-14/U4 was also set up in Kőbánya (a district of Budapest) with the intention to produce aircraft for both the Luftwaffe and the MKHL; however, the new production line was bombed out by the USAAF after only a few aircraft had been completed (29 I think, need to check). So, for all practical purposes, production of the G-14/U4 was a WNF affair.

That canopy indeed looks like a major improvement over the original, which was a two-piece affair that tapered towards the rear. Still, if that's the only thing they changed, it's the proverbial lipstick on a pig. While some later 21st Century offerings sit in the uncanny valley between a toy and a model, this one firmly falls on the toy side.

Honestly, I wouldn't recommend this one. It's indeed a kit version of one of 21st Century Toys very first offerings from some 20 years ago. Describing it as 'crude' is charitable. Detail is mostly absent, the panel lines put Matchbox' trenches to shame, and most importantly: it has severe shape issues. The nose is too heavy and wrong in shape, the canopy only bears a passing resemblance to the real thing (it tapers towards the rear...), the shape of the rear fuselage is off... Some of the later 21st Century Toys offerings have potential as a good basis for a stunning model (the Me 262 comes to mind, but it would still require a lot of work), but not this one. HpH does a 1/18 scale Bf 109 E-4, but that will set you back 475 EUR... : HpH 1/18 Messerschmitt Bf 109 E-4

Ok, my final intervention in this thread, I too think it really has run its course. First, the 25 mm statement was NOT made by me, it was made by Gazzas, and I just quoted him. Second, I didn't 'create a scaffolding of outrage' - I've constantly said it was an extremely minor issues, and by everything I have seen, the kit looks exceptional. Signing off now.

1. I’m not an expert, and I never claimed to be. I just happen to have fairly extensive documentation on the Bf 109, including a large part of technical manuals. 2. There may indeed be differences between parts produced, and their original design drawings, which indeed quite often got modified afterwards, with notes identifying changes scribbled by hand on them. However, that’s of no relevance here, as the document I provided is an official, RLM-issued repair manual, not an engineering/design document. This technical manual sets out the exact mandatory procedures, techniques, materials and tolerances that needed to be followed when making repairs. Whenever changes were made, an updated edition of these manuals was issued. 3. I’m not trying to ‘expose’ anyone. You asked me twice to provide an official technical document that specified dimensions for the gap, and I did just that. When you didn’t like what the official documentation you asked for showed, you were the one who – bizarrely – started arguing against it. 4. This discussion came about because you kept insisting that the wide gaps shown by Black 6 are normal and within specification, which has now unequivocally been demonstrated is not the case. This is also supported by all the other images of other aircraft, both in this thread and elsewhere, which consistently show a much tighter fit of the flanges than shown by Black 6. So, no matter how you look at it, in this respect, Black 6 is a bit of an outlier. 5. As a corollary of this, the flange as depicted by the ZM kit is slightly overscale. I totally understand the technical reasons for this, and have repeatedly stated that it is absolutely not a big issue. The problem arose when you kept insisting that the rendition of the flange in the ZM kit was spot on, while, in fact, it is slightly overscale. Given the absolute triviality of the matter, and the molding-technical justifications for it, I really don’t understand why it is so difficult to simply admit this. 6. The official technical documentation specifying the permissible gap sizes and a load of photographs are now all available in this thread. Anyone who cares about this arcane matter can now look at all this information and make up their mind about the issue themselves. 7. I'm taking a break from this, this is getting tedious. For god's sake, it's a tiny flange on a plastic scale model!

Mr Brinzan, you clearly don’t understand the technical document I posted. The drawing with the +/- 2 mm tolerance you refer to is clearly indicated as pertaining to the ‘Querruder und Klappe’, i.e. ailerons and flaps, so it has absolutely no bearing on the current discussion. The next drawing, which is germane to this discussion, is identified as pertaining to the ‘Leitwerk’, or tail. Here are the minimum and maximum dimensions of the gaps noted, these are the permissible ranges for the gaps, not tolerances on these ranges (as an aside, does it make sense to specify maximum and minimum tolerances for the size of a gap?). Since you don’t seem to understand technical documents, I’ve added the preceding page III 09 from the repair manual, which explicitly states: “The maximum and minimum dimensions for these gaps, which have to be maintained when replacing parts, are to be found in drawings and tables 45a through d.” Link to the original here (relevant parts highlighted): D. (Luft) T.2109/Rep. page III 09-10 The drawing/table relevant to the tail is 45d, with no specified minimum, and a maximum allowed width of 1.5 mm for the distance between the fin and stabilizer. I hope this clarifies things, and you are now able to understand the purpose and meaning of the drawings and table I shared earlier. Please, Mr Brinzan, for your own sake, stop arguing with original Messerschmitt technical documentation that was formally approved and issued by the RLM. You’re really not doing yourself or your credibility any favors.

So, I just realized that I actually have a PDF of the 1942 edition of D. (Luft) T.2109/Rep. saved on my computer right here. I don’t want to have another turn on this merry-go-round, but since Mr Brinzan earlier twice expressed great interest in seeing an original Messerschmitt document specifying tolerances for the gap between the fin and stabilizer, with some trepidation, I’m posting the relevant information here. D. (Luft) T.2109/Rep. is the general repair manual I for the Bf 109, and at the time of publication, was valid for all series up to the G. An introductory remark specifies that for items specific to the G, further documents will be issued later, but that all general repair guidelines and provided examples are equally applicable to the G as they are to earlier series. So, while the diagram specifying the tolerances for the gap between fin and stabilizer shows an earlier braced tailplane, these tolerances are equally applicable to the F and the G series (also note that the earlier A-E series too had a very narrow flange of upturned skinning at the base of the stabilizer). Now, as to the tolerances for the gap, D. (Luft) T.2109/Rep. (p. III 10 of Chapter III) provides no minimum value, which is logical, considering that the smaller the gap is, the better, as long as the tailplane can move unimpeded for trimming. The maximum permissible value is given as 1.5 mm. For those of you who would like to see a scan of the original, I have uploaded an extract of the relevant pages here (tolerances highlighted): D. (Luft) T.2109/Rep. page III 10 This, of course, means that the measured width of up to 10 mm for the gap on Black 6, as reported by Mr Brinzan, is approximately 6.7 times greater than the maximum value permitted according to original wartime Messerschmitt documents. The reason why such an out-of-tolerance gap was permitted on Black 6 likely has to do with the fact that, during its airshow days, it was a display warbird, being operated under very strict flight and performance limitations. The flanges are neither structural nor flight-critical elements, and, within certain performance limits, you could likely fly the aircraft safely without them even fitted, just like you could in principle fly e.g., without spinner, undercarriage covers or even cowling (in fact, the He 280 V2 flew without engine cowlings, and the Bf 109 J / HA-1.109-JL prototype had the side panels of the cowling removed on its test flights). However, doing so will rob you of a lot of performance, and force the aircraft to be operated under restrictions. The whole point of all these fittings was to limit drag as much as possible, and on an operational airframe the performance penalty incurred as a result of lax tolerances would be entirely unacceptable (training airframes may have been treated in a more relaxed manner). Hence, the strict wartime tolerances dictated by Messerschmitt. On the other hand, during its display days, Black 6 was not an operational fighter aircraft anymore, but a very severely restricted piece of flying heritage. Hence, adhering to strict tolerances for drag-reducing fittings like the tailplane flanges was much less of a concern, and the restoration crew likely decided to use the old, somewhat beaten-up and out-of-spec flanges instead of newly manufactured parts out of considerations of authenticity. Most sheet metal used in skinning on the Bf 109 had a thickness of 0.75 mm. If we add this to the maximum allowable gap of 1.5 mm, we get a maximal permissible distance between the fin and the outer surface of the flange of 2.25 mm. For the ZM kit, this means that the depiction of the flange (circa 9.6 mm in scale, as reported by Mr Brinzan) is approximately 4.3 times overscale for a wartime operational aircraft. I want to stress again that this is an absolutely minor issue, that can easily be rectified for anyone inclined to do so. And from the photos of the kit tailplane posted by Mr Brinzan, it seems clear that even without correction, the end result will look more than acceptable. So, I really hope no-one is going freak out over this tiny glitch, and we can just leave it here!!!

I can see them without problem. Maybe some setting on your computer?

Mr Brinzan, many thanks for posting these pictures of the ZM tailplane! These indeed are very enlightening, and I agree that a distance of the flange of less than 10 mm on either side of the fin is within realistic limits for a real, flyable aircraft, and certainly as good as anyone could ever want in a model. It just would have been good if you had simply posted these images and measurements when the issue first was raised, as it would have avoided several pages of needless drama. I really don’t think anyone in this thread intended to attack your work, or you personally. People just brought up what they honestly perceived as a genuine issue – i.e., a supposed gap of 25 mm, which, if true, clearly would have been excessive. As the designer of the kit, you are the person who is best placed to comment on this issue. You have now quite conclusively demonstrated that that the depiction of the gap in fact is within reasonable limits, and I really believe that this is all anyone was hoping to get out of this discussion. Personally, I feel this matter is now settled. Thanks again for taking the time to do these measurements and for posting these instructive images!

The “25 mm” refers to an earlier post in this thread by Gazzas, where he shows a close-up of the assembled tail of the ZM kit and states that the distance of the flange works out to circa 25 mm in scale. I don’t have the kit yet myself (my local retailer is still awaiting stock and I didn’t pre-order from ZM directly), so I can’t confirm the exact measurement of 25 mm, but comparing the assembled tail to both photographs, and actual airframes I saw myself in the past, I’m afraid the flange does indeed appear a bit overscale on the model. Please, understand that I’m not trying to dish this model – to the contrary. Everything I’ve seen so far leaves absolutely no doubt in my mind that it is an amazing effort, the very best Bf 109 on the market by a very wide margin. As a Bf 109 fanatic for over 35 years, I can see myself getting multiple copies of this kit. It’s just a matter that even this model is not perfect, as no model ever has been or ever will be. There are a couple of very minor issues, which overall do not detract from a brilliant effort at all. I can understand that having your work critically discussed like this is sensitive, especially as some people in the past have tried to inflate the minor deficiencies of the kit. This is not my intention. I was just hoping for an objective and honest discussion about the many merits and few shortcomings of the very best Bf 109 kit ever made, so that anyone wanting to address these minor niggles is aware of them. That’s all.

1. First, a simple request. As Gazzas has shown, in the ZM kit, the distance between the outer surface of the flange and the fin is at least 25 mm in scale. Can anyone show any evidence, either photographic or documentary, that corroborates a gap of circa 25 mm between the fin and the flange in any variant of the Bf 109 F/G/K as is depicted in the ZM kit? 2. I am currently travelling, so I don’t have access to most of my references, but I should normally be back to access them in 7-10 days, so I can check then if my memory of a specified width of 1 mm for the gap is correct or not. As I clearly indicated in my previous message, I am NOT definitely claiming that Messerschmitt specified a gap of 1 mm, I’m just working from memory, which may be incorrect. In any case, Mr Brinzan posted several images from the Handbuch and the Ersatzteillisten, but you’re unlikely to find the tolerances for the flange specified there. The Handbuch is a general technical description and operations manual, outlining protocols and procedures, and these manuals will generally only specify critical ranges and tolerances for e.g. deflections of control surfaces, etc. The Ersatzteilliste is simply an illustrated spare parts list with numbers for the individual parts and subassemblies, so that units and workshops could order required replacements, and does not normally provide any tolerances. The tolerances for parts in an assembly will be indicated on the relevant engineering drawings, and may also be listed in the repair and maintenance manuals. Therefore, the tolerance for the flange *MAY* be specified somewhere in D(Luft)T 2109/Reparaturanleitung from 1942, so you could have a look there. Again, I said *MAY* - I can’t check this at the moment, so don’t misquote me as saying it definitely is! 3. I also EXPLICITLY stated that the gap likely could be quite a bit larger than 1 mm on a used airframe, but Mr Brinzan for some reason cut this statement when quoting my earlier post. However, the flange is intended to reduce drag, first by covering the rectangular gap in the fin through which the stabilizer is mounted, and second by smoothing the abrupt transition between the horizontal stabilizer and the vertical fin. So, there is an incentive to keep the gap as small as practically possible, because the wider it gets, and the further out the flange sits, it starts moving from the low-speed laminar boundary layer close to the fin into high-speed air, where the flange would start to generate turbulence and hence drag – i.e., the opposite of what it’s supposed to do. Moreover, if the flange moves out too far from the fin, it also loses its efficiency as an aerodynamic cover for the gap in the fin surrounding the stabilizer. This is an issue of particular significance for an operational aircraft, where performance is of the utmost importance. As it stands, none of the images posted in this thread, nor any I have ever seen elsewhere, nor any preserved examples I have seen, including Black 6, show a gap of the order of 25 mm as depicted by the ZM kit. Indeed, Mr Brinzan himself, in this very thread, has stated in his opening post that the gap between the flange and the fin in Black 6 is of the order of 7-10 mm, so significantly less than the 25 mm of the ZM kit. Hence, again, the simple question: does anyone have any evidence for a gap as large as 25 mm, as shown by the ZM kit? 4. This thread is getting increasingly bizarre. From all I can tell, it seems no-one previously brought up the root of the stabilizers in ZM’s Bf 109 G kit. Mr Brinzan started this topic himself – yet, when he is confronted with the fact that, judging from available evidence, the flange on the ZM kit appears a bit overscale, he immediately becomes defensive. Rather than candidly addressing this minor deficiency of an otherwise stellar kit, it seems Mr Brinzan unfortunately keeps reverting to straw man arguments while avoiding the actual issue – begging the question why he drew attention to this topic in the first place. Again: this is NOT about whether there is a gap between the fin and the flange – there obviously has to be, and NO-ONE is disputing that. Neither is anyone claiming that the gap cannot possibly be bigger than 1 mm – it very well can be, within limits. The issue at hand is that, while there obviously is a small gap between the fin and the flange, a distance of 25 mm as shown by the ZM kit appears exaggerated, based on the available evidence. If this is not the case, then please show evidence of an actual Bf 109 F/G/K with the flange sitting as far out as depicted by the kit – so far, all images and measurements that have been posted, including of Black 6, seem to confirm that the gap between the fin and flange was considerably smaller than suggested by the ZM model. Again, I think this is a minor issue which can be fully corrected with some work, so it’s nothing to get worked up about!

Yes, the Me 262 also had a variable incidence tailplane for trim in pitch, but it was operated by an electro motor. In addition, the elevators had inset trim tabs, but these were de-activated on most aircraft. The Bf 108 also had a manually actuated variable incidence tailplane. This solution for trim in pitch is common on German single-engine aircraft of the era - you can find the same mechanism also on e.g. the Ju 87 and Fw 190.

Indeed, Black 6 was NOT restored to flying condition after its 1997 crash; the team behind the restoration only repaired the aircraft for static display, re-using as many original parts as possible. This probably also explains the somewhat beaten-up look of the fairings on the stabilizers and the root of the fin - so not the best example to illustrate normal tolerances for the fitting of these fairings. In the words of Russ Snadden himself: "Damage was confined, in the main, to the rear fuselage and the vertical tail, but the propeller and its spinner were destroyed and the cockpit canopy damaged. We removed every component from the fuselage before setting about cutting out the damaged areas. A new section of rear fuselage was grafted in using a jig and an original, but reskinned, fin fitted and the rudder rebuilt using as much original material as possible. While these repairs were being effected, the team cleaned up all internal equipment and repainted where necessary. I might add that this work was not required by contract. Simultaneously our engine 'bods' partially stripped the engine for inspection as required by the Air Accident Investigation Branch as part of its thorough investigation. Nothing was found which could have contributed to the events during that last flight. The Daimler-Benz was assembled and inhibited, after which the exhaust ports and supercharger intake were sealed. The original VDM propeller, which we had held in reserve, was assembled and fitted together with a replacement spinner supplied by a good friend in Germany. Our final task at Duxford was to repaint the aeroplane, a task with which we were very familiar."

Of course, there is a small gap between the flange on the stabilizers and the vertical fin. The flange is screwed onto the stabilizers, and hence needs to be able to move freely to adjust the trim in pitch, so by necessity there needs to be a small gap between the flange and the fin. I don't think anyone is disputing that, or the fact that, as a consequence, the flange sits proud of the fin. Rather, the issue is that in the ZM kit, the depiction of the flange is a tad heavy handed, and its distance from the fin is a bit overscale. In reality, the flange sits a couple of mm proud of the fin, as the numerous images in this thread show - I should check, but IIRC Messerschmitt technical documentation specifies a gap of 1 mm; add to that 0.75 mm for the thickness of the sheet metal, and you arrive at 1.75 mm distance for the outer surface of the flange from the fin. Factoring in wear, and the fact that out-of-wind tolerances needn't be as tight, the real distance on a used airframe may be somewhat bigger. So, let's double this number and round it up, and you arrive at a realistic distance that maybe can go up to 4 mm (and an aircraft would still be safely flyable with a larger gap, but as the gap gets bigger, the flange will start to generate drag, which is undesirable, at least for an operational aircraft where performance is paramount). As Gazzas previously has shown, on the ZM kit, the flange sits around 25 mm in scale proud of the fin, which is clearly excessive; I at least have never seen any actual airframes, or photographs, documenting a 25 mm gap. That being said, personally, I don't think this is a big issue, as it seems fairly straightforward to rectify. In addition, even taking into account this and a couple of other minor shortcomings, the ZM kit still is without any doubt the most accurate and detailed Bf 109 of any type in any scale ever produced, and will likely stay so for a long time. So, yes, the depiction of the flange on the new ZM kit is a bit overscale, but that's no reason to blow the whole matter out of proportion

It's planned to be an entirely new kit. According to the announcement by Arma Models, they intend to use cast resin, injection molding, 3D-printed resin, photo-etch and cast metal, depending on which material/technique is best suited for each part to reproduce the maximum of detail accurately. All that sounds extremely expensive, but Arma Models are promising an affordable price. How they intend to that is unclear at the moment! Apparently, they are also being supported by Kamov in the design of the kit. So, it all sounds great, but of course it still needs to happen in the real world... Arma Models is almost exclusively focused on the domestic Russian market, so finding a distributor outside of Russia will probably prove challenging. Ordering it directly from Arma Models or possibly some specialist Russian model store will likely be the most reliable way to get the model - if it actually does get made, as it's currently only in the design stage. Arma Hobby is Polish, and does mainly 1/72 and some 1/48 scale aircraft models. They are highly unlikely to release any modern Russian aircraft. Arma Models on the other hand is a Russian producer predominantly focusing on kits, conversions and detail sets for modern Russian aircraft and military vehicles.

Arma Models just announced that they are going to release detailed multi-media models of the Kamov Ka-52 in 1/72 and 1/48, supposedly at an affordable price. However, they note that they can easily re-scale their designs, and have a poll going for releases in other scales, including 1/35 and 1/32. According to one of their replies in the comments section, the number of votes for 1/35 makes it likely they'll also release the Ka-52 in this scale in the future. Link here: Arma Models Ka-52

Cessna XMC

Well, it seems we're in agreement then. Thanks for pointing out that early and late styles of linkages were not interchangeable - I had always assumed they were. I think part of the redesign had to do with saving light alloys - a good deal of the changes made to the K-4 centered around replacing light alloys with either steel or wooden parts - e.g. even the wing fillets on many K-4s were laminated wood, as was the seat bucket. In the case of the ammo can, I think the redesign might also have been at least in part related to an effort to make the MK 108 more reliable: this gun was prone to breaking its belts, especially under load, and this problem was never really entirely resolved. If memory serves me well, I seem to recollect that the MK 108 feed in the Me 262 also underwent some redesign for the same reason (but don't quote me on this). It would make sense for WNF to have used up its existing supplies of old housings/linkages before standardizing on the new design, so it's probably not unexpected to find examples of both the old setup and the revised K-4 arrangement among the G-10/U4, especially in the early production blocks. I do hope ZM or another manufacturer will do a K-4. However, if ZM do one, that will involve some significant retooling, well beyond the MK 108 arrangements!

Yes, all machines equipped with MW 50 would all have had the pressure gauge on the left side of the cockpit just below the sill.

This is a bit of a conundrum. The same part numbers obviously implies that they are the same part. Comparing the K-4 linkages to those of the G-10/U4, they indeed appear identical. However, comparing these to earlier G-/U4 linkages, those to me seem to be different. In this respect, it is important to note that Arsenal 45 explicitly lists the linkages as applicable to the G-10/U4 and K-4 – also implying the earlier G-6/U4 and G-14/U4 were different. Vogt (2012, p. 152 and p. 293-294) further explicitly states that the rudder linkages of the K-4 were different from those of the G-/U4, and were redesigned to save raw materials in their production (K-4 linkages were mainly constructed from sheet steel). Finally, discussing his work on the design of the K-4, Bölkow also mentions that the rudder linkages were entirely redesigned (in Schmoll 2017, p. 172). So, it seems to me that the rudder linkages of the G-6/U4 and G-14/U4 were different from those of the K-4. The reason for the redesign apparently was materials savings. Since production of the G-10/U4 at WNF ran in parallel to K-4 production at Mtt Regensburg and Erla, it seems reasonable that the G-10/U4 would have standardized on the same linkages as the K-4. I’m not at all claiming that this is definitely what happened, but it seems a plausible explanation. References: Schmoll, P. 2017. Me 109. Produktion und Einsatz. Regenstauf, MZ-Buchverlag. 311 pp. Vogt, H.H. 2012. Messerschmitt Bf 109 – Einsatzmaschinen – Das Nachschlagwerk. Zweibrücken, VDM Heinz Nickel. 384 pp.

That’s a very good question, and I certainly do not claim to have the answer. However, the MK 108 had a tendency to break its belts, so maybe the redesign of the ammo can was undertaken with the intention to lower stresses on the belt? Or maybe it was just an attempt to somehow simplify construction? Incidentally, you can ask the same question about the rudder pedal linkage in the cockpit: why was this redesigned in the K with respect to the G-/U4? Regardless of the reasons, it’s a fact that the K-series was designed by WNF, just like the G-/U4 had been previously. Hence, any MK 108-related changes in the K must have had a valid technical reason, as WNF was responsible for both the design of the G-/U4 and the K. In addition, the head of the design office at WNF responsible for the design of the K (Ludwig Bölkow) came from the design office at Augsburg, and had the production office and ten engineers from Regensburg assigned to assist him. So, there was clear coordination between WNF and Mtt during the development of the K.

I think most commercial CA debonders nowadays use propylene carbonate, because it is non-toxic and has only limited potential for irritation. Undiluted acetone obviously attacks polystyrene, but in principle it should be safe to use on PUR. That said, I agree it's not really a leap of faith you'd want to take on an expensive and rare kit! So, maybe test on a casting block first to be safe?

I don't quite agree with this. First, you're incorrect to state that the K-4 was a Mtt creation, and that design teams at Mtt and WNF did not talk to each other. In fact, WNF was responsible for the development of the new K-series, the redesign being led by Ludwig Bölkow, who at the time was head of the design office in Wiener Neustadt (having come from the design office at Mtt Augsburg). The production office at Mtt Regensburg and ten engineers were subordinated to Bölkow for the task. WNF converted a G airframe into a K prototype late in 1943, and likely built at least one K-2 airframe in 1944 (possibly W.Nr. 600 056). So, while in the end the K-4 was only produced by Mtt Regensburg and Erla Leipzig (limited number of K-4/R6), the primary design of the K-series was done by WNF. So, your explanation for the differences between the G-/U4 and the K-series associated with the MK 108 cannot be down to a lack of communication between Mtt and WNF. Rather, I think there are genuine practical considerations at play. Placing the bottles in the unused ammo tray for the MG 151 brings them even closer to the CoG, and makes them also more easily accessible than when placed under the MW 50 tank. I suspect the reason that this was not done earlier on the G-/U4 may simply be because it would have required too much redesign and/or retooling to relocate the pneumatic lines on an aircraft type that was already in production. It shouldn't be forgotten that, while externally very similar to late AS and D-engined G-series aircraft, the K-series was in fact a major redesign, partially intended to rationalize and simplify production.

Quite a few organic solvents will attack cyanoacrylate. Acetone normally works for softening cured CA, and nitromethane works even better. There are quite a few CA debonders commercially available, some gelified to prevent the debonder from running off and to make it less volatile. Freezing works be breaking the CA polymer bonds, but since synthetic resins are also polymerized, there is in principle some risk that freezing may also make the resin brittle.

You are referring to the old 1997 edition, not the new 2019 one - in the revised 2019 release, these pages cover most of the appendix, the bibliography, and the index. The information present on the development and use of the B-3 on p. 281 - 295 in the old 1997 edition is also contained integrally in the new 2019 edition, but has been split up over two chapters: Chapter 7: New Weapons, new variants for the development, and Chapter 18: Rumania Changes sides for the operational part. While the text has been re-written somewhat in the new edition, there is no really new information compared to the old edition. Chapter 19: What will 1945 Bring? from the revised 2019 mentions strength returns of 1 January 1945 showing seven B-3s present with 13.(Pz.)/SG 9 at Schippenbeil, and the capture of three disabled B-3s from that unit by the Soviets at Schippenbeil on 22 January 1945, together with three photographs of one of the machines (W.Nr 160252, the only known photos of an operational B-3 ). This information is an addition to the 2019 revision, but apart from that, there is no further further coverage of the operational use of the B-3 compared to the 1997 original.