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Aardvark

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Aardvark last won the day on September 22 2019

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About Aardvark

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  • Birthday September 30

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    Jet fighter in 72 scale

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  1. "All what You want"!(c) Now everyone who wants to talk about Cold War aerodynamics can do it in a separate topic! B.R. Serge
  2. Hi, all! Since this topic expressed an interest in further discussion of problems with the first versions of the MiG-23, an automatic translation from Russian is published: "Another unpleasant feature was the unstable operation of the side air intakes during glide flights, when one of them was obscured by the fuselage. The disruption of the normal air flow was manifested by a hum, which was clearly audible in the cockpit and warned of the danger of stalling the flow in the input devices. The MiG-23 did not tolerate slipping in flight with the wing folded down, responding to lateral movement with energetic roll development. Such properties of the aircraft required a more thorough study of the characteristics of track and lateral stability. The change in sweep was accompanied by a significant effect on the roll and yaw behavior of the aircraft: when the wing was released with its large span, the machine responded to the leg only by sliding, however, with the wing retracted, the moment of inertia of the aircraft "squeezing the wing" decreased so much that it literally fell into a roll. The reasons for the decrease in lateral stability were the features of the aerodynamics of the machine in combination with control with a differential stabilizer instead of the usual ailerons. In addition to reducing the lateral moment of inertia with the wing folded by about half, countering the roll as the sweep increased was made difficult by the fact that the damping qualities of a fully retracted wing with a small span deteriorated by an order of magnitude. In theory, these features were predictable, but their practical consideration caused many problems. In flight, the aircraft reacted to the ground at elevated angles of attack with side swing and energetic roll. Likewise, sliding led to a stall on the wing, which was especially evident at high flight speeds. Due to the fact that when shifting the wing and performing energetic maneuvers, it was troublesome for the pilot to monitor the change in lateral stability, piloting with aerobatics on the MiG-23 for the first time on domestic aircraft was prescribed to be performed only with the Automatic System Control ( next on text – ASC) turned on in the "stabilization" mode. Moreover: with the suspension of the ventral drop-tank , the reserves of track and lateral stability were so reduced that the flight had to be performed exclusively with the ACS turned on, and in case of its failure and the presence of suspensions, it was allowed to land only by dropping the outboard tank. Aerobatics with a large sweep In flight MiG-23 mod. 1969, with mock-ups of K-23 missiles under the wing, it was prescribed to perform "smoothly and in a coordinated manner, without slipping, avoiding sharp deviations of the rudder, when maneuvering, do not rely only on the sensations on the handle and signs in the behavior of the aircraft, but control it by instruments" (however , the same instructions about "competent and accurate piloting" were contained in the manuals for other aircraft). The presence of other features did not cause significant problems. So, the alarming displacement of the center of gravity, focus and shoulder of balancing forces during wing shifting was easily parried by the handle. With an increase in sweep up to 50oza due to the wing retreat, a small diving moment arose, compensated by taking the handle towards itself by only 30 mm. With a further increase in sweep to 72 °, on the contrary, a weak pitching moment arose, which was eliminated by pushing the handle away from itself by about 15 mm. The change in longitudinal balancing took place quite smoothly, since the full wing transfer took about 18 seconds (a little less when retracting the wing, which was helped by the incoming air flow during the backward stroke). Removal of the rebalancing characteristic of the aircraft, which manifested itself with any change in the flight mode, was ensured by trimming using the trim effect mechanism, the slider button of which was located on the control handle next to the thumb and was controlled by the pilot in response to the occurrence of pressing or pulling forces on the handle. The "game" with the trim button accompanied the entire flight of the MiG-23, accompanying practically any change in flight control and conditions, whether it be a wing shift, a change in speed or a change in altitude. The pilot did this completely reflexively, habitually restoring the balance of the aircraft in the same way as was done when the landing gear and flaps were extended and retracted or when the engine speed increased. This control feature of the MiG-23 accompanied his entire career, making it possible to distinguish the pilots flying on it by the always worn thumb of the uniform leather glove of his right hand. The same skill required constant monitoring of the slide indicator, the movable "ball" of which should be kept as close to the center as possible. The identified shortcomings of technology were corrected by making changes to the design. Among them was the weak survivability of plastic seals in bay." "A significant disadvantage of the MiG-23 was the insufficiency of normal overloads in the angle of attack, revealed during the tests, caused by the early stall of the flow on the wing. In turn, the use of increased angles of attack was a consequence of the interest in improving the maneuverability of the aircraft, associated with the need for a close air combat fighter. As already mentioned, these requests arose already during the tests of the aircraft, forcing significant changes to the design of the machine. Major General Engineer A. P. Ovsyannikov from the Air Force High Command noted the essence of the issue: “The experience of fighting in Vietnam and the Middle East demanded the use of the MiG-23 interceptor fighter in close maneuverable air combat, which made it necessary to draw attention to the relevant characteristics of the aircraft. " If the unsatisfactory strength and the associated limitations on overloads could be overcome by strengthening the existing structure, then this disadvantage required aerodynamic improvements with a deeper intervention. In piloting, the "twenty-third" feature manifested itself as an early occurrence of aerodynamic shaking of the aircraft, which arises when maneuvering with access to increased angles of attack. The shaking was due to the beginning of a violation of the normal flow around the wing, preceding the stall of the flow and the fall of the wing bearing properties with all the ensuing consequences - thereby stalling and the development of a spin. For the pilot, the occurrence of shaking served as a reliable warning signal of the proximity of a dangerous regime, useful and perceived completely reflexively and also eliminated. However, in the MiG-23, with the maneuverable sweep of the wing, the shaking began long before the really dangerous "stall" angles of attack. As noted during the tests, "in the flight configuration, the aircraft in the process of braking experiences a noticeable shaking at the angles of attack, much less critical." But the pilot could not “change himself” in his usual sensations and reacted to the occurrence of shaking by forever returning the plane to a safe mode in a learned way. It turned out that the "alarm" that the shaking served was false, taking away from the pilot a part of the range of flight angles of attack, at which the aircraft fully retained its aerobatic capabilities, and also taking away a couple of units of the used overload and maneuverability. A seemingly ordinary detail in the aerobatic characteristics of the aircraft attracted the attention of the test management group. The question was reported to PS Kutakhov. The commander-in-chief, himself a former fighter, gave it a fundamental sound, demanding that the industry immediately eliminate the deficiency. The reason was the unsatisfactory characteristics of the wing profile, where the early stall began. It was also found that the wing profile has a concomitant critical M number that is too small, resulting in unsatisfactory flight characteristics, including a small boosted ceiling. The situation was aggravated by the fact that the fighter had already gone to the troops. When mastering the MiG-23, it did not cause any special problems, it looked accessible to pilots, but then, when the permissible modes were expanded and the transition to aerobatics, it began to "show temper", showing features of a very risky nature. Design Bureau test pilot V. Ye. Menitsky characterized the aircraft's features as follows: “All these nuances made the aircraft very difficult to fly, although it was very simple to master. In flight schools, they mastered it even better than the MiG-21. I flew both planes, and the MiG-23 immediately seemed easier to me. However, from the point of view of energetic maneuvering and modern requirements for air combat, this machine, of course, did not meet the standards of an aerobatic machine. " Not without bickering in search of the culprits of the mistakes. The leading specialist of TsAGI GS Byushgens, who was the author of the aerodynamic solutions of the MiG-23 wing, indignantly pointed out deviations from "pure" aerodynamics manifested by its design, without skimping on the designers and technologists, whose activities "distorted and spoiled "the original perfection of the design. The opinion was also expressed that the reason for the unidentified features of the behavior of the MiG-23 at the purging stage was that the corkscrew models presented by TsAGI did not have one small detail - the Peony antenna below under the nose, which affected the flow, and she de provoked a violation of the flow and stall. Since the stall, as a rule, took place on the left wing, they began to look for the reasons for this pattern, drawing attention to one more detail - the termination of the emergency LDPE protruding from the starboard side with a sufficiently sized pylon located near the building horizontal of the aircraft. At the angles of attack, it caused a local stall of the flow, which resulted in track and lateral imbalance, followed by a stall just to the left. The LDPE was moved higher, to the canopy of the canopy, where it was closer to the plane of symmetry of the aircraft, eliminating the negative effect. This change was introduced already on the MiG-23S and MiG-23 of the 1969 model. However, this measure did not bring a radical improvement in the stall characteristics, and the tendency to shift to the left bank at critical modes remained. At the same time, the headlights, previously located along the sides in the area of the nose pillar, were removed from the bow. The release of headlights during takeoff and landing was accompanied by a tangible disturbance of the flow, which was directed straight into the inlet devices of the engines. The headlights were moved back, placing them at the bottom of the air intakes behind their cut. Complete alteration of the wing was a deliberately unrealistic undertaking, meaning not only the scrapping of the entire technology in production, but also the need for a colossal amount of new aerodynamic research, purges and experiments with an uncertain result ahead of time. It was necessary to find a way to solve the problem "cheap and cheerful". To eliminate the defect, it was proposed as the most affordable measure to change the wing tip, having reasoned that a breakdown begins with it and, therefore, all the troubles. Now the speed profile of the SR-16M acquired a rounded toe instead of the previous sharp one, which prevented early stalling of the flow from the leading edge with an increase in the angle of attack and created a suction force at subsonic speeds, reducing drag." I think that publishing excerpts from this good book will not do any harm to the authors, but only contribute to the translation of their book into English and publication in the West. But if the authors consider that their rights have been violated, I will undoubtedly delete this text. In addition, I hope this publication will stimulate model manufacturers to create the earliest modifications of the MiG-23, which no one is making now. B.R. Serge P.S. If some parts in automatic translation are incomprehensible or incorrect, write, I will correct or explain. P.P.S. The "Cold War" section seemed to me more appropriate than "Real Aviation" because the first MiG-23 models have long ceased to be "real aviation"
  3. "From the Polish test pilot Andrzej Ablamovich at the Paris Air Show in Le Bourget in 1976 for his very strange appearance and the howl of a jet engine he received the unofficial nickname "Belphegor" after the demon Belphegor." Thus, this is an unofficial name, in fact a nickname, as B-26 - "widowmaker", etc. B.R. Serge
  4. In most cases, I illustrated my messages with a photo from airwar.ru. Everything worked great and " copy the DIRECT link from wherever it is (Photobucket, Flickr, you name it), and you paste it into your posting window. Press either enter, or space, and SPANG! The forum software will automatically convert it to a photo." everything worked like that. But today it's not work....no photo just a link. I used second way - "Down at the bottom right of your posting window, there is a button called Insert Other Media e.t.c." DIRECT link was pink or reddish background and again no result. What is the problem? For me this is not principle, but for those who read my some posting, the link instead of the photo I think creates certain inconvenience. B.R. Serge
  5. How was this plane painted in reality? And what is the equivalent of this paint in the world of model enamels / acrylics? B.R. Serge P.S. Article build analogue model with resin cockpit, short SBC-4 cowling and engine and decals: http://scalemodels.ru/articles/12560-Heller-1-72-SBC-4-Helldiver---poslednijj-biplan-firmy-Curtiss.html WIP topic: http://scalemodels.ru/modules/forum/viewtopic.php?t=67825&highlight=
  6. Which Hawk? And Airfix their two modifications, each in different versions .... how much will it be the same if someone does T.Mk.1 and someone does Mk.100? It's visually different Hawk! In principle, I have Hawk Mk.100 from Airfix in first edition in 72nd scale. I was going to sell it because I needed it for the conversion to Mk.200, but I also have Mk.T.1 and Mk.100 from Italeri. The volume of improvements is practically equal both with Italeri and Airfix separately and in a combination of Italeri + Airfix + NeOmega. Therefore no sense started unbuilt Airfix when early started Italeri. But I am ready to join this GB with the Hawk Mk.100 from Airfix OOB if the Hawk is chosen. Also I am ready to join this GB with the next model from Airfix: - Harrier GR7/GR 9 (probably OOB) - BAC Lightning F.Mk.6 (Not OOB!!! if allowed by the rules) - Swift F.R.5 (conversion in F.Mk.4 if allowed by the rules) if they are will be chosen. B.R. Serge
  7. Mention of this aircraft is banned by the World League of Insect Pests, due to the fact that this aircraft is a weapon of mass lethal psychological destruction for them, as they say: "Better toxic pesticides than seeing this!" Therefore, immediately correct your messages, otherwise the BM will be imposed an insane fine and accusations of genocide Insect Pests! Do you understand what will be done to You when Insect Pests are the majority in the government and the UN? Common! "You don't understand, this is different!" https://en.m.wikipedia.org/wiki/You_don't_understand,_this_is_different! ...as and this too... By the way, competitor Mirage ...and first Mirage: B.R. Serge
  8. @Gorby then only Lugansk maybe get lost in ordinary mines among miners, sorry Donetsk I don’t offer because of Denis Bandsaw Pushilin here. But I will visit you in Lugansk when the borders are opened! This is nothing against my ring card from local Sauron Bank! B.R. Serge
  9. After that, @Gorby I think, now You need to go escape to North Korea, because there the representatives of the Sicilian office @Bandsaw Steve will won't find You! Of course You will have to really do a plastic surgery of the face so as not to differ from others, but You can become the founder of the North Korean branch of BM! Everything on which there is a "PS" marking - polystyrene, where there is a "PP" marking - polypropylene is not suitable. Because polypropylene is not glued with model glue. Not all, only Gold & Platinum! B.R. Serge
  10. Idea interesting but for me personally, probably not realizable, unless it turns out to be a kit lying in my house. B.w.Does this concept imply OOB or a complete minced meat with the participation of the entire aftermarket to which hands can reach? B.R. Serge P.S. In reality this making in Moscow, many modelers gather, including from other cities of Russia, they are given the same Zvezda models (I remember Yak-3) and they make it during the weekend.
  11. I have photocopy some Czech catalog, presumably the mid-70s, there is Heller Ilyushin DB-3F and Tupolev SB in 72nd scale ... what is it, I don't know ... B.R. Serge
  12. Therefore, best models, it's little known aircraft for which there is practically nothing! But according to the law of meanness, when you finish the model of this plane, complete and exhaustive information that you were missing is sure to appear! B.R. Serge P.S. In any case Tu-16 from Trumpeter more look as Tu-16 than B-52 or F-35! Also was 1/72 Tu-16 short-run from Red Wings: http://lonestars.web.fc2.com/INBOX/Tu-16K.htm
  13. Most of them are from the original technical manual. In addition, there is an original take-off video for crews. B.R. Serge
  14. All have on this link: if something is not there, then on the website the link has a feedback from the author, who is an active pilot of civil aviation and understands English. You will not find more information on the Internet anywhere at the moment. B.R. Serge
  15. Carefully look at the ear! Amazing! B.R. Serge
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