J-20 gun armament
Background:
The Chengdu Aircraft Company (CAC) J-20 5th generation stealth fighter made its first flight on 11th of January, 2011. Since then, the aircraft had come under immense scrutiny by Chinese military watchers, general military watchers, defence media, and general media. The existence or non-existence of a gun has been one of the aircraft’s many characteristics which have come into question.
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Emergence of the J-20 has prompted a great deal of discussion among defence commentators and military watchers in recent years[/caption]
As an air to air fighter, the J-20 would be expected to carry an onboard gun for last ditch self defence, and of the many types of fighter aircraft in the world, the vast majority carry an internal gun. Exceptions of the rule do exist, such as dedicated electronic warfare aircraft like the EA-18G which lacks an internal gun, and the F-35B and F-35C variants of the Joint Strike Fighter which both also lack an internal gun but have the provision to carry an external gun pod.
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EA-18G Growler, an electronic warfare variant of the F/A-18F Super Hornet. Many minor differences exist between the two, with one of the more significant ones being the removal of the F/A-18F’s internal gun on the EA-18G[/caption]
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The F-35 Joint Strike Fighter family. Of the three variants, only the conventional take off and landing F-35A variant is equipped with an internal gun[/caption]
However, virtually no air to air fighters today and in the recent past exist without an internal gun, and even among general fighter aircraft it is a rare exception for an aircraft to lack an internal gun.
Reasons for doubt:
Some of the controversy surrounding the J-20’s gun armament status could be boiled down to two reasons.
-Lack of visual identification of a gunport on J-20
-Lack of any “official” confirmation or acknowledgement of a gun on J-20
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Initial pictures of J-20 were not conducive to searching for the presence of a gun, partly because very few high quality pictures of the dorsal side of the aircraft could be taken by photographers, and partly because the matte black paint of initial prototypes made identification of panel lines immensely difficult which was further compounded by a lack of very high quality pictures[/caption]
Needless to say, the lack of an “official” acknowledgement of a gun on J-20 by Chinese military or government sources is not unexpected, given the overall state of Chinese military operational security. Therefore it may be unreasonable to use the lack of “official” acknowledgement of a gun as a basis for questioning its presence, because so much more about the aircraft is also unknown. At this stage even the official length of the aircraft is not known, let alone its armament, or sensor suite or anything else.
Virtually all of the conclusions about J-20’s subsystems and characteristics have emerged from eagle eyed Chinese military watchers using open source pictures and information to reach conclusions. Fortunately, recent pictures taken of J-20 have been of higher quality and have also shown a greater variety of the aircraft’s surfaces, allowing for more thorough examination of potential gunports.
Possible positions:
Prior to considering the exact location of J-20’s gun, one must first consider whether it is located on the dorsal or ventral side of the aircraft. Aircraft like the Su-27, Mig-29, F-22, and F-16 feature gunports on the dorsal side, while other aircraft such as the Gripen, J-10, JH-7, place a gunport on the ventral side. Some aircraft such as the F-15 and Eurofighter Typhoon also equip their gunport at the wing root, and the F-18 family equips its gunport well inside the nose.
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F-16 gun exposed, on the dorsal side close to its wing root[/caption]
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Su-35 gun exposed, also on the dorsal side near its wing root. Other aircraft of the Su-27 family feature a gunport in the same position[/caption]
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J-10 is equipped with a gun on its ventral side, in a visible and distinctive fairing[/caption]
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F-15E gun, directly in line with its wing root[/caption]
In the case of J-20, it becomes immediately obvious that it would be difficult for a gunport to be located on the ventral side of the aircraft, given the virtually completely smooth nature of the ventral fuselage, and the necessary presence of the main weapons bay which would obstruct the line of fire of any gunport.
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The smooth ventral side of the J-20 makes ventral positioning of a gun like J-10 impossible to exist without clear observation. The lack of any distinctive gunport and the near completely smooth ventral side makes it virtually certain that J-20 would not field a gun on its ventral side[/caption]
It is equally unlikely for J-20 to fit a gunport in its nose, due to the likely lack of space in the nose due to the fitting out of extensive avionics equipment.
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The geometry of the nose, combined with the likelihood of significant volume of avionics occupying real estate in the nose, makes it unlikely for the nose to hold a gunport[/caption]
It would similarly be impossible for J-20 to locate a gunport in or near its wing root, as such a position would have its line of fire obstructed by the action of the forward canards, and bullets fired a wing root position may pass dangerously close to the canards, if not outright damage the aircraft itself. Needless to say, such a configuration would have been imbecilic and likely not even considered by the aircraft’s designers.
Likely position:
Therefore, any gunport position would likely have to be on the dorsal side of the J-20, and it should also sit in a position where its line of fire is safe from any obstruction by the canards or any other part of the aircraft itself.
In other words, the location of a gunport would likely be quite similar in position to that of the F-22, or Su-27, Mig-29 or F-16. However, the lack of sufficiently detailed photos of the J-20’s dorsal side have not allowed for serious inspection of this possibility until recently.
The fact that J-20 is a stealth aircraft means its gunport may be very difficult to observe compared to non-stealthy aircraft. The F-35A and the current prototypes of the Russian T-50 both feature somewhat obvious, “bulging” gunports, however the F-22’s gunport is enclosed within a door which only opens to expose the gun during firing, and is all but smooth and indistinguishable compared to the aircraft’s dorsal fuselage when the door is closed. Given the careful attention paid by the CAC to the rest of the J-20’s geometry for preserving stealth, it would not be unlikely for the aircraft to have a very difficult to distinguish gunport as well.
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F-22’s gunport is located on its starboard, dorsal/”shoulder” position. To allow readers to appreciate the difficulty of identifying a stealth fighter’s potential gunport, the F-22’s has not been highlighted in this picture. The panels of F-22’s gunport are smooth and blended with the rest of its fuselage, and if J-20’s gunport is of a similar nature then it would be equally difficult to identify. The lack of clear pictures of J-20’s dorsal side (until recently), meant observers could not conduct a fair search of a potential gunport. Therefore, assumptions by skeptics that J-20 does not have a gunport are at best premature[/caption]
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F-35A gunport, visible on its port, dorsal, shoulder position. However, different to the F-22 and the suspected gunport of J-20, the F-35A gunport bulges out significantly[/caption]
Fortunately, higher quality pictures depicting J-20’s dorsal side emerged in mid 2015, and to the great joy of Chinese military watchers who have been following the J-20 gun saga, some of the pictures depicted a very distinctive set of panels on J-20’s port (left) and dorsal side, a few meters immediately posterior to the port air intake.
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This clear picture of prototype s/n 2013 provided the first indication of the gunport of J-20, on the port, dorsal, shoulder location[/caption]
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The gunport panel outlined for clarity. Note there appears to be two sections to the gunport, a rear rectangular panel and a forward square panel, which join together to form the overall gunport. The rear rectangular panel is likely removable for maintaining the gun and its support equipment, while the forward square panel opens during the actual firing process[/caption]
The position of those panels appeared perfect for a gunport to be located, as such a position would provide a clear line of fire well safe by the J-20’s canards, as well as provide sufficient volume for a gun and its supporting equipment (power source, ammunition canister) to be located despite being barely visible externally. Furthermore, the location of the panels on J-20 is also similar to the location of the F-22’s gun and gunport, only that it is located on the port side rather than the starboard side.
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The view of the gunport is virtually impossible to distinguish from forward angles, similar to that of the F-22. However, careful analysis of its position indicates the gunport would have a clear line of sight forwards[/caption]
The geometry of the panels is also consistent with the size and configuration that would be expected for accommodating a gun. The larger, more posterior panel is rectangular in overall shape and aligned lengthwise with the axis of the aircraft, which would be consistent with the standard arrangement of a gun and supporting systems aboard a fighter aircraft. The smaller, more anterior panel is generally square in shape, and is consistent in relative position and size (compared to the rectangular panel to what would be expected for the door mechanism to expose the gun’s barrel during firing.
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Dark contrast of the image of prototype 2013 reveals further details of the panels of the suspected gunport[/caption]
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The same above image, with red outline over the entire gunport. The thinner red line delineates the rear rectangular panel from the front square panel[/caption]
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Detail of the F-22 gunport. Note the presence of two separate panels joined together: a larger rear panel which houses the gun and its supporting systems and can be opened for ease of maintenance and reloading, and the more forward smaller panel which is a door that opens to reveal the gun barrel during the firing process. From the above pictures, it is a sensible conclusion that J-20 fields a similar arrangement of its gunport panels[/caption]
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Another clear image of the dorsal/port side of J-20, displaying the suspected gunport panels from a different angle[/caption]
The lack of a similar set of panels on the starboard side of the aircraft further supports the notion that the panels on the port side are for a gunport, because virtually all modern fighters only have one single gunport alone, mounted in one position.
However, the suspected gunport does not provide any details as to just what type of gun the J-20 may field. Currently, two major guns equip the Chinese Air Force fighter fleet: the domestically produced version of the Russian, dual barrel 23mm GSh-23, or the domestically produced version of the Russian, single barrel 30mm GSh-30. Either gun could be suitable for J-20, or an entirely new design could grace the aircraft instead.
Conclusion:
At present, the logical rationale supporting J-20 having a gunport, together with recent photographic evidence which likely depicts J-20’s gunport on the port/dorsal side of the fuselage, help to make a strong case for J-20 to have a gunport.
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F-22 gunport visible by the opening of its gun door during the firing process. It will likely be many years until an equivalent image of J-20 is released by the Chinese Air Force. For skeptics, it is likely that only such an image or video would truly satisfy their requirements for confirming the existence of a gun on J-20[/caption]
However, skeptics may remain unconvinced until pictures or video clearly display J-20’s gunport exposed and open, revealing the gun itself. Unfortunately, such resources may not be released by the Chinese Air Force for many years, and until then, skeptics will likely remain vocal in asserting the J-20’s lack of gun armament.
