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Everything posted by pvanroy

  1. 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!
  2. 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.
  3. 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.
  4. 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.
  5. 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?
  6. 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.
  7. 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.
  8. 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.
  9. If you're looking for the ultimate reference on the Bf 108, this is it: Schneider Bf 108 book It's not cheap, but absolutely worth the money if you're really interested in the fine details of the type. It also covers post-war production and operators. The book has a section on exports, where among others, the aircraft of the U.S. mission in Berlin are discussed. Summarizing, the first aircraft was Bf 108 B-1 W.Nr 836 and it was purchased by the U.S. Navy. The machine was first flown by Fritz Wendel in Augsburg on 08 January 1937, and was transferred on 30 March 1937 from Augsburg to Rangsdorf. It was probably transported to the U.S.A. in 1940, and was examined in detail by Fairchild in Hagerstown, MD. This machine was scrapped some time after the end of the war, and the wreckage was buried under the runway extension in Hagerstown. This aircraft was painted light grey all-over, with black U.S. Navy titles on the fuselage and BuNo 0724 in black on the tail. It had a Schwarz wooden fixed pitch propeller. At least two photographs exist of this machine, which are reproduced in the book. In March 1939, the U.S. mission received a second aircraft, Bf 108 B-1 W.Nr 2004, which was purchased by the U.S. Army. In Army service, it received the official designation of XC-44, and the Serial No 39-718. The aircraft was used as the personal transport of the military attaché. Reportedly, Charles Lindberg flew this aircraft personally during one of his visits to Berlin. The aircraft was impounded by the RLM on 15 November 1941. At the time the machine had accumulated 76 flying hours. It was delivered to the Luftwaffe, and its ultimate fate is unknown. No photographs are known to exist of this aircraft, but according to accounts, it was painted yellow all-over, and had the pre-war U.S. national markings on the vertical tail and under the wings. This was one of the first airframes to be equipped with the new Messerschmitt P7 constant speed propeller, used in conjunction with the Argus As 10 E engine.
  10. Strictly regarding the operational use of the B-3, there isn't really much new in the revised edition. What is of interest are the addition of the three photographs of W.Nr 162052, and the revelation that the heavily retouched image of a supposedly operational B-3 in flight was actually a creation of Gert Heumann, based on the mirrored photograph of a standard B-2. While there is obviously quite a significant overlap between the 1997 and 2019 books, the new edition is significantly reworked, and although I do have the original 1997 book, I don't at all regret buying the new edition.
  11. The VDM website only lists four volumes for sale.
  12. For the Hs 129 B-3, it's going to be difficult to do more than one decal option that is historically supported. Only around 20 production aircraft were built, and just one of those (W.Nr 162052) is documented in three photographs after its capture by the Soviets at Tonndorf on 22 January 1945. However, in the photographs, the aircraft is very heavily covered with snow, making it impossible to see any markings. The only other photographically documented option is W.Nr. 140494, Stkz. DO+XG, which was a test aircraft converted from a B-2. These are the markings shown in the built model, and are pretty much the only option that is not speculative. Another B-2 test machine associated with B-3 development that is recorded photographically is W.Nr 141258. However, this aircraft did not have a real BK 7.5, but carried a wooden mock-up of the gun and its fairing for aerodynamic testing.
  13. Well, if you want to go into details, from the instructions it also seems the fuel cut-off lever, cold start handle, stores emergency jettison handle (or handles for WNF/Diana machines, which had them on both sides of the cockpit) may be missing. However, even if that's the case, these things can all be scratched quite easily. It may not be perfect, but it certainly is the best 109 G cockpit out of the box by far!
  14. All Israeli machines had landing gears with the original negative camber. The neutral camber was tested on S-199 numbers 2, 44 and 65, and was introduced on the Avia production line from aircraft 112 onwards - so after the last Israeli machines were delivered (112 made its first flight on 30 June 1948). As far as I can tell, no S/CS-199 ever used the larger 190 X 660 mm wheels, all aircraft from the start seem to have had the narrower 160 X 660 mm wheels. In fact, it seems that this is probably also the case for the S/CS-99 (post-war produced WNF/Diana-standard G-10/U4, with some changes). I have no date for when the rounded wheel wells were introduced, but I think it is fair to assume this also happened after the delivery of the final Israeli machines - so in my opinion, all Israeli aircraft likely had the typical angular G wells.
  15. Well, you should be able to use the Eduard rack, and the Hasegawa rack without modification for the F-1/-2/-3/-4, and the G-1/-2/-3/-4. In other words, you can use the available ETC 500 IX/b racks from Eduard and Hasegawa without change for any F, and for the early G versions that had MG 17 guns. If you want to do G-5/-6/-8/-14/-10 or K-4 with an ETC 500 IX/b rack, you will have to add the chutes at the front. So, in other words, if the aircraft is armed with MG 131 guns over the engine, you need to modify the rack. Hope this helps!
  16. The rack you arrowed is the ETC 500 IX/b for a single 250 kg bomb. The other rack is in the lower left corner - this is the cover for 4 individually mounted ETC 50 VII d racks, each of which could carry a 50 kg bomb. The reason why the ETC 500 IX/b on the sprue looks different to the ones in the photographs was already explained by Radu and me - it has to do with the ejection ports for the MG 131 casings. In aircraft with MG 17 guns mounted over the engine (i.e. all Bf 109s up to and including the G-4), the spent casings were collected on board, and there were no ejection chutes. These aircraft used the rack you arrowed (it can be seen in the second photograph Radu posted, which shows an E-1/B or E-8). With the introduction of the MG 131 over the engine in the G-5/G-6, the spent casings were no longer kept on board, but ejected through two chutes on the bottom of the aircraft. When the rack you arrowed was mounted, the cover of the ETC 500 IX/b rack partially overlapped the ejection chutes. To solve this problem, a chute or channel or whatever you want to call it was added to either side of the cover at the front, which connected to the ejection chutes on the belly of the aircraft and guided the spent casings out to either side of the rack. This is what you see in the first and the last picture Radu posted, and it is the reason why the rack covers used on the G-5/G-6 onwards were wider at the front. It has to be stressed that the ETC 500 IX/b rack itself remained the same for all aircraft from E-K - it was only the cover that was modified to accommodate the ejected spent casings from the G-5/G-6 onwards.
  17. Indeed, as I noted, later versions had some modification to the cover to accommodate the ejected casings - but it would not seem too difficult to modify the the ETC 500 IX/b cover provided in the Eduard set to make it suitable for the G-5/G-6 onwards. In any case, the Eduard rack can be used without modification for any variant up to and including the G-4.
  18. The Bf 109 E-K all used the same bomb racks - the ETC 500 IX/b which could take a 250 kg bomb; 4 ETC 50 VII d racks which each could take a 50 kg bomb; and, up to the G-14, a special dispenser for 24 SD 2 butterfly bomblets. However, use of the SD 2 rack was rare after the E, as there were problems with release of the bomblets; the SD 2 rack was subsequently replaced by cluster bombs containing the bomblets as submunitions, and it was outright discontinued on the G-10 and K. The only difference between the E and later versions is that in some cases, the front of the aerodynamic cover for the ETC 500 IX/b rack was slightly modified to prevent spent casings from the machine guns over the engine from colliding with the cover. Eduard has a bomb set for the 109 E which with little or no modification can also be used for later versions: Eduard bomb set AML also includes the 4 x ETC 50 VII d carrier in their Israeli S-199 conversion, but if you mail them they might be willing to sell it separately: S-199 conversion with ETC 50 VII d That is an ETC rack for a 300 l drop tank, not a bomb rack.
  19. No. But there is a full-scale model on display at Planes of Fame: He 100 Planes of Fame FSM
  20. I see. Apologies for the misunderstanding!
  21. No snake for the V1 - the snake was painted on the V4 (armed fighter prototype) for propaganda photos. The V1 was first left unpainted, with puttied seams and rivets, and covered in highly polished clear varnish. After the record attempt, the aircraft was painted in highly polished RAL 5008 Graublau (the Messerschmitt company color, also used on e.g. civilian Bf 108) - NOT RLM 24 as you often see quoted.
  22. The Kamov Ka-50 and Ka-52 have a Zvezda K-37 crew ejection system, but it is not really an ejection seat. The crew members are attached via a lanyard to an extraction rocket which pulls them out of the cockpit. The seats themselves are not ejected, they are fixed in the cockpit and are designed to be shock absorbing in case of a crash landing. The ejection sequence is as follows: 1. Rotor blades are blown off with explosive charges; 2. Canopy is blown off; 3. Seat belts are cut; 4. extraction rocket fires and pulls crew member free of the aircraft. The system itself works very reliably, and is certified for speeds between 0 - 350 km/h and 0 - 5000 m altitude. The only downside is that the ejection sequence takes 2 - 3 seconds, which is an eternity when flying NOE.
  23. Actually, it is a bit more complicated than that. It all depends on the thermal conductivity of the coating. Most paints are indeed insulators, but if the coating has a conductivity similar to or higher than the metal, there is obviously no insulating effect. Anodization and other specialized coatings do indeed have greater conductivity than most metals, so in that case there is no issue with heat transfer at all. If the coating also has a high emissivity in the IR spectrum, such a coating would indeed improve the rate of radiative heat flow, providing a radiative cooling advantage. This advantage increases exponentially with temperature, so there would certainly be a benefit for a radiator. However, aircraft radiators generate their cooling effect predominantly through convection; the contribution of cooling through radiation is normally quite small. Still, I could see it being useful for keeping an engine from overheating while idling on the ground or taxiing, when convection is limited. Also, in high-power applications where even the most minimal advantage may make the difference between winning or losing (like in combat aircraft and race machines), even a small gain in radiative cooling efficiency might be worth the trouble. It would potentially also make more sense in a car, where the radiator is less exposed, and which may spend considerable time idling or moving at slow speed in city traffic - which are all factors significantly limiting convective airflow through the radiator (hence the addition of a fan).
  24. Actually, there is a resin model by AMC of the Chelomey 16X in 1/32 scale, although that kit provides the later camera nose. It's quite a nice kit, but the nose is solid resin, so you need to drill out the camera window and make a suitable transparent cover. Unfortunately, photographs of the later camera nose are very thin on the ground...
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