Airplanes with wrinkles. Is it worth the worry?


The same photo from The Aviationist magazine. In addition to the dented fuselage - sparks from the engine due to a foreign object


For almost all of its stories aircraft face a characteristic phenomenon in the form of sheathing deformation. Under certain circumstances, a flat external surface undergoes warpage and is covered with “wrinkles” that spoil the appearance. However in modern aviation this is not a problem - such deformations are taken into account during design, and in some cases are provided initially.

External manifestations


Due to various factors, the problem of local deformation of the skin was first encountered in the early stages of aviation development, when aircraft were built of wood and covered with canvas. The introduction of new materials and the improvement of the design made it possible to get rid of wrinkles on the surface, but did not completely exclude their appearance.

The era of all-metal aircraft brought new advantages, but did not save the equipment from the shortcomings. Even modern aircraft models sometimes have characteristic wavy plating sections. The skin is deformed between the power elements, because of which the surface of the airframe takes on a specific form.


Another B-52 with more pronounced wrinkles. Wikimedia Commons Photos

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The topic of warping the skin of the aircraft recently raised again the foreign aviation press. The reason for this was a curious photo of the American strategic bomber Boeing B-52H Stratofortress. It was clearly visible on it that in the area between the cockpit and the wing, the left side of the fuselage is seriously deformed and forms a wavy surface. The boundaries of such a deformation passed along the force elements.

It should be noted that this is not the only photo of the B-52 with similar deformations. Numerous photographs of other planes or helicopters with such a skin condition are known. They often annoy the public, but experts remain calm.

Causes of the phenomenon


In the days of wooden structures and linen sheathing, “wrinkles” were mainly associated with the imperfection of materials and lack of experience in the construction of equipment, as well as with a low production culture. All these factors, including in various combinations, could lead to the formation of small or large wrinkles on linen sheathing.


Passenger Boeing 747 with deformation of the fuselage behind the wing. Photo Airliners.net

A sloppy installation of flexible sheathing led to asymmetric stretching with subsequent deformation. The wooden power set, under the influence of external factors, could slightly change its size and shape, which affected the skin. During the flight, the power set took over the load and also deformed - with a known effect on the shape of the canvas.

In the case of mixed or all-metal structures, the last factor is preserved - the deformation of the airframe under the influence of various loads in flight and in the parking lot. Other warping conditions have been largely eliminated.

Consider the processes of deformation of the skin on the example of the aircraft B-52H, which has become the protagonist of recent publications. In his photograph, it is clearly visible that at the level of the cab sides, the skin protrudes outward along the cells of the grid formed by the frame. Behind this section, closer to the wing, there are several similar "cells" with diagonal wrinkles. Other areas of cladding, including in the immediate vicinity of the warped, they look straight and do not attract attention.

Glider B-52H is built according to the semi-monocoque scheme. Its basis is a strong power set; part of the load is covered by the casing. Moreover, the metal sheets of the casing have a thickness of not more than a few millimeters, which determines their tensile and compression strength and allows to reduce the mass. The design of the airframe is made elastic and responds to loads by some deformations within the established norm. The bulk of the load falls on the frame, but the casing does not remain without work.


Boeing 757 with similar manifestations. The ellipse marks the warpage zone. Wikimedia Commons Photos

In the parking lot, the nose of the airframe rests on the front landing gear and loads are distributed optimally. After refueling and suspension of the ammunition load, the mass of the aircraft increases, and after takeoff it is distributed differently - all the weight is transferred to the wing by means of power dialing and working skin. Performing various maneuvers can lead to a change in the direction and value of the load on specific sections of the frame and casing.

The long-term effect of tensile loads that occurs during the long-term operation of an aircraft can lead to deformation of individual sections of the skin. The consequence of this is the warping of the outer surface with a specific appearance. However, despite the damage to the exterior, the deformed plating sections can retain the required strength and are suitable for further operation.

Continued operation and maintenance of loads lead to further deformations, and the part still has to be changed. However, such processes take a lot of time, during which the plane can get into the photographer’s lens and disturb the public.

Ways to combat the phenomenon


You can prevent warping at the stage of development and construction of the airframe, and for this you can use several basic ideas. First of all, a careful calculation of the structural strength is necessary, taking into account all the loads in the parking lot and in flight. The right choice of materials and details of the parts allows you to make the structure strong enough and rigid without risk of damage to the skin.


The Russian Tu-160 may also have a deformation of the skin - in this case, in the front of the center section. Photo by the Ministry of Defense of the Russian Federation / mil.ru

It is easy to see that on the B-52H “wrinkles” appear only in certain areas where there are large loads, and power elements are quite rare. Thus, the more frequent placement of the frame parts and the fastening of the casing to them allows you to otherwise distribute the load and exclude visible deformations.

Wrinkles are characteristic of flexible metal sheathing. Modern composite materials are more rigid, which is why they do not deform under similar loads. However, composites are more complex and more expensive than sheet sheathing. In addition, their application does not always meet the requirements of the project.

It should be noted that the warping of the skin is not always a problem that needs to be addressed. Such a phenomenon can be initially incorporated into the design to provide the desired ratio of strength, weight and flight performance.

No cause for concern


The behavior of the skin during the different phases of the flight and in operation is taken into account already at the stage of project development. Also determined are the service life and requirements for the cladding panels, compliance with which allows their continued use.


The tail of the Tu-95MS. Sheathing fastening seams are close enough to prevent wrinkles. Wikimedia Commons Photos

Using the example of B-52H bombers with record-breaking age, it can be seen that the “wrinkles” on the skin do not interfere with the operation of the equipment and are not a serious problem. Sheathing elements can be replaced with new ones, but the need for this does not arise too often. As a result, many planes continue to fly with wavy casing, which does not prevent them from performing their tasks.

Similar features of the airframe are observed in many other planes and helicopters of different classes, including in civil engineering. In all cases, deformation and warping alone do not become a cause for concern. Repair is carried out if there are appropriate technical prerequisites, while the appearance is usually sacrificed.

Thus, the recently published photo, which caused a lot of noise, shows only one of the curious features of modern aviation. Designers are well aware of it and take the necessary measures if they are needed. And there are no reasons for panic, even if the “wrinkled” plane looks strange and unusual.
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  1. Aerodrome 22 November 2019 05: 38 New
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    Yes, these "wrinkles" are nonsense, we have half a city of such cars. yes
    1. Uncle lee 22 November 2019 05: 55 New
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      Whatever wrinkles were visible, the airplanes were made corrugated.
      1. andrewkor 22 November 2019 06: 34 New
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        It seems to me that wrinkles eat up the economic efficiency of the aircraft, and this is very important for passenger sides. I think so.
        1. Aerodrome 22 November 2019 06: 50 New
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          Quote: andrewkor
          It seems to me that wrinkles eat up the economic efficiency of the aircraft, and this is very important for passenger sides. I think so.

          but maybe the opposite? in a shark, for example, the skin is like an emery.
          1. Berkut24 22 November 2019 10: 27 New
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            I think that our cat would also prefer emery, otherwise everyone would squeeze it and make amends.
            1. venik 22 November 2019 13: 04 New
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              Quote: Berkut24
              I think that our cat would also prefer emery, otherwise everyone would squeeze it and make amends.

              ========
              Yah??? And our hate brushes and combs, he - shaggy like a hippie (aerodynamic drag - hoo hoo!!) .... And the apartment rushes with "speed of sound"!!! belay
              Probably aerodynamics have calculated something wrong ....... request
          2. rhino 22 November 2019 10: 39 New
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            The levels of the creator of the shark and the airplane are generally not comparable.
            1. Alex_59 22 November 2019 14: 48 New
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              Quote: Nashorn
              The levels of the creator of the shark and the airplane are generally not comparable.

              Right. Shark is a much more perfect creature. smile At least the planes themselves do not breed until now.
              1. rhino 22 November 2019 21: 53 New
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                If the one who created the shark creates an airplane, then they will also multiply.
                1. Alexey LK 25 November 2019 14: 26 New
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                  Quote: Nashorn
                  If the one who created the shark creates a plane, then they will also multiply

                  Already. Long. But you won’t make them fight, just hunt.
          3. Svarog51 22 November 2019 11: 54 New
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            a shark such as an emery skin

            Well, the shark will do, it doesn’t often especially accelerate. But the dolphin is very smooth. But in this case, the skin of mackerel is most suitable. While alive - smooth, but smoked just becomes similar to the skin of a Boeing. yes
            1. venik 22 November 2019 13: 08 New
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              Quote: Svarog51
              But in this case, the skin of mackerel is most suitable. While alive - smooth, but smoked just becomes similar to the skin of a Boeing.

              =======
              The conclusion follows: "DO NOT NEED Boeing" SMOKE!!!! " laughing In the "smoked" form - it looks "not marketable" !!! wassat
            2. Sasha_5 17 February 2020 17: 46 New
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              Yes, I would not say that dolphins are smooth. It feels like if not like emery is zero, then at least some kind of rough tarpaulin or something. But you can’t call it smooth
          4. venik 22 November 2019 13: 00 New
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            Quote: Aerodrome
            but maybe the opposite? in a shark, for example, the skin is like an emery.

            ========
            Can you imagine what speed a shark would develop if its skin was smooth "like a mirror" ???? belay
        2. Nick 22 November 2019 10: 09 New
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          Quote: andrewkor
          It seems to me that wrinkles eat up the economic efficiency of the aircraft, and this is very important for passenger sides. I think so.

          Yes, if the wavy sheathing increases the resistance of the air, then the consumption of aviation fuel, which is now very expensive, is increasing.
        3. APES 22 November 2019 11: 15 New
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          Is it worth the worry?

          Worry about the quality training of the flight personnel, especially in civil
        4. venik 22 November 2019 12: 59 New
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          Quote: andrewkor
          It seems to me that wrinkles eat up the economic efficiency of the aircraft, and this is very important for passenger sides. I think so.

          =========
          Folk wisdom says: "when it" seems "- you need to be baptized!" .... Andrei, you - there is no need to "be baptized!" All right! good "Wrinkles" - lead to an increase in aerodynamic drag = decrease in maximum and cruising speed + increase in fuel consumption + increased vibration (especially at low altitudes and high speeds)!
          drinks
      2. venik 22 November 2019 12: 53 New
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        Quote: Uncle Lee
        Whatever wrinkles were visible, the airplanes were made corrugated.

        ==========
        If this is a joke, then good drinks , well, if seriously - negative fool
      3. Alex_59 22 November 2019 14: 50 New
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        Quote: Uncle Lee
        Whatever wrinkles were visible, the airplanes were made corrugated.

        But not for long. Because as soon as speeds increased, it became impossible to put up with the growth of the "wetted surface" of corrugated airplanes. Too great resistance to such a skin.
    2. The leader of the Redskins 22 November 2019 07: 36 New
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      I suggest to smear these places with a cream with collagen! Well, they recommend women, but we can’t ?! laughing
      1. Ross xnumx 22 November 2019 08: 17 New
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        Quote: Leader of the Redskins
        I propose to smear these places with a cream with collagen! And what, women are recommended,

        Women use collagen (fibrillar protein, which forms the basis of the connective tissue of the body and provides its strength and elasticity, the main component of connective tissue) ...
        I’m afraid that you are proposing to use (collagen) only a stinking smell may appear, and women probably do not use it. lol
    3. smart ass 22 November 2019 10: 53 New
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      Especially AvtoVAZ
  2. Wedmak 22 November 2019 06: 47 New
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    Well, if we compare the wrinkles of the B-52N and our airplanes, then the American no longer even has wrinkles, there are already some failures. It was as if someone had typed in there with decent strength. It can hardly be said that such problems with the skin do not affect aerodynamics.
    1. Ross xnumx 22 November 2019 08: 22 New
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      Quote: Wedmak
      Well, if we compare the wrinkles of the B-52N and our planes, the American no longer even has wrinkles, there are already some failures.

      good
      That's right, why compare freckles with smallpox. The Chinese are sewing such jackets on us, in waves:
  3. bubalik 22 November 2019 09: 37 New
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    It should be noted that this is not the only photo of the B-52 with similar deformations.


    Known for numerous shots of other aircraft





    1. Alien From 22 November 2019 15: 06 New
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      And I wrote last time, they are inflatable))))
  4. Servisinzhener 22 November 2019 12: 13 New
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    A few days ago, in the Yandex news feed, there was news that they would upgrade the Tu-22M3 that was in storage.
    So in the comments, as soon as we were not exhausted on the topic of the fact that this "old" 40 years ago is not capable of anything. Such aircraft are only suitable for scrap. How American pilots will laugh at our people flying on such a "junk".
    Maybe they will laugh. But only flying on B-52 whose production ended in the year 65, the F-15 and F-16 made their first flight in the year 72 and 74, respectively. It does not fit into the brains of our Internet opposition that military equipment is at least ours, at least foreign. It does not cease to be the most modern and relevant for many years. Unlike smartphones that are "updated" every six months.
    1. okko077 25 November 2019 12: 22 New
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      There is also a small winged wing with a rotary assembly, it collapses! And the fuselage is not bearing! Old junk discord .. Like that !!!
  5. Operator 22 November 2019 13: 00 New
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    Close-up

  6. Undecim 22 November 2019 14: 31 New
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    Airplanes with wrinkles. Is it worth the worry? Not worth it. This phenomenon has long been known and its mechanism has been well studied.

    Hawker “Typhoon”
    1. Undecim 22 November 2019 14: 33 New
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      B-29 Superfast.
      1. Undecim 22 November 2019 14: 35 New
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        British Spitfire
        1. Undecim 22 November 2019 14: 47 New
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          I wonder what the body that put the minus meant? Or is it because of universal dislike for the neighbor who knows more?
          Here, some particularly zealous minusers were reset recently, by the way.
          1. Alien From 22 November 2019 15: 12 New
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            Is it possible to learn more about minusers? And then I have a whole circle of such comrades ....))
        2. mmaxx 30 November 2019 17: 11 New
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          The riveting of thin skin is very difficult. Even skilled workers make a blanket. There was no automatic riveting then ((((.
      2. Filxnumx 23 November 2019 22: 59 New
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        and you, hour, do not confuse "wrinkles" with riveted seams?
  7. Rwmos 22 November 2019 20: 28 New
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    Not an aviator ... I heard this:
    There it was originally done / conceived / succeeded - at a high altitude (for which he was calculated) and speed "the old lady smoothes her wrinkles"

    As far as I remember, BlackBerds also flowed forever, and they had a working mode - when they were already dispersed in the stratosphere - the fuselage lengthened, and nothing was flowing, and that’s not wrinkles for you
  8. mvmptzna 22 November 2019 21: 26 New
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    About the "wrinkles" on the hull most sailors know. It is easy to find photos of Russian warships with wrinkles. Doesn’t bother anyone.
    At airplane speeds, wrinkles probably worsen aerodynamics.
    1. 7,62h54 23 November 2019 09: 57 New
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      Wrinkles are smoothed out at speeds
  9. Evil 55 23 November 2019 05: 59 New
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    Senile wrinkles, age pigmentation and age-related dementia are still possible .. I hope it is also present on their planes ..
  10. 7,62h54 23 November 2019 09: 56 New
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    So that’s why NATO so close to our strategists, wrinkles are trying to make out.
  11. The comment was deleted.
  12. Prisoner 23 November 2019 17: 27 New
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    What about sparks? laughing Don't worry too? Although us something? Let the pins worry.
  13. mmaxx 30 November 2019 17: 07 New
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    The plane flies 50 years. Should I pay attention to any wrinkles?