- Yes
- No (Explain why)
Suggestion No.66
G’day lads. I want to suggest a very unknown J-7 variant, specifically a J-7II variant, which features stealth coating (yes, you heard it right) and other changes to lower it’s RCS, all of which is found on the J-7IIS, with the aircraft number 950137!
Description:
Spoiler
The J-7IIS was a stealth technology verification aircraft developed by Chengdu Aircraft Company during the late stages of China’s Eighth Five-Year Plan. Based on the J-7II airframe, it was designed as a low-cost experiment to explore radar cross-section (RCS) reduction techniques without altering the aircraft’s fundamental shape, due to limited resources. Main areas of focus included the cockpit, air inlet, and radar, identified as the strongest sources of radar reflections. Modifications included the use of radar-absorbing materials and paints, structural changes to reduce cavity reflection, and innovations such as a band-pass filter radome and frequency-selective surfaces. The canopy was coated with a metallic film to minimize radar reflection, and the windshield frame was redesigned for stealth optimization. These efforts led to a significant reduction in the radar signature, achieving partial stealth performance.
History:
Spoiler
The development of the J-7IIS stealth technology demonstrator began during the introduction of the world’s first (production) stealth aircraft, the F-117 in the early 1980s. The F-117, alongside the B-2 stealth bomber, proved the value of stealth technology in warfare. As beyond-visual-range combat became a reality, nations with advanced aviation industries prioritized the development of low-observable technologies, particularly those aimed at reducing radar cross-section (RCS).
China’s effort trying to get stealth technology and failing during this period was influenced by domestic economic and technical constraints. Instead of designing a new stealth aircraft, Chengdu Aircraft Industry Corporation proposed modifications to the J-7, a short-range fighter, to develop a stealth technology demonstrator. The goal was to enhance radar stealth capabilities without altering the basic airframe design.
The J-7IIS, based on the J-7II prototype (Aircraft No. 137), was developed to validate three key stealth technologies: cockpit stealth, radome stealth, and air intake stealth. Beijing University of Aeronautics and Astronautics conducted RCS calculations and analysis of the cockpit, exploring the use of radar-absorbing materials and jagged-edge designs to reduce reflections. In radome stealth, the team tested band-pass filter radomes and frequency-selective surfaces to minimize radar wave reflections while ensuring transmission performance. For the air intake, Chengdu engineers conducted flow field calculations and vibration tests, applying radar-absorbing materials to key areas to reduce RCS.
The J-7IIS underwent extensive ground tests, technical studies, and stealth comparison flight tests at the China Flight Test Research Institute. These tests demonstrated significant reductions in radar reflectivity, confirming that stealth modifications to existing aircraft could achieve measurable results. The cockpit, radome, and air intake areas met design goals, reducing the radar detection probability of the aircraft.
While the J-7IIS was limited in its stealth capabilities compared to entirely new stealth designs, it still massively helped China with their stealth knowledge.
Armaments:
Spoiler
The IIS should still have the weapons of the J-7II, like PL-2 (which can be seen on the first image) or PL-5. I would recommend having this aircraft with PL-5 (earlier ones) as it would make the aircraft more unique instead of just being a J-7II with way lower RCS.
Due to it being having the same weapon load as a J-7II, it can carry the following weapons:
2 30mm Type-30-1 cannons
PL-5 (A?) AAM
PL-2/A/B AAM
500kg dumb bombs
57mm unguided rockets
Fuel tank
These are also J-7II images. The IIS wasn’t seen carrying them, but should still have the capability to do so.
Specifications:
Spoiler
The J-7IIS, being a stealth technology demonstrator based on the J-7II, likely retained similar dimensions, weight, and engine specifications to its base model. The aircraft had a length of approximately 14.85m, a wingspan of about 7.15m, and a height of roughly 4.10m, with a wing area of 23 square meters. In terms of weight, it had an empty weight of approximately 5292 kg and a maximum takeoff weight of around 9100kg. The J-7IIS was powered by a single WP-7B turbojet engine, which produced a thrust of about 6600kg-force with afterburner. While these specifications represent the baseline of the J-7II, it is worth noting that the stealth modifications introduced in the J-7IIS might have led to slight variations. Modifications for stealth technology testing, such as radar-absorbing materials or changes in the air intake and canopy design, could have marginally influenced these parameters without drastically altering the core specifications of the aircraft. The modifications brought the RCS down to approximately 8 square meters in the nose direction, within a range of 0 to 30 degrees, achieving a reduction of about 8dB ± 2dB. One source says it has an RCS of around 0.1 square meters, most likely from the front from a very long distance, but please do take this with a grain of salt.
Sources:
Spoiler
成飞隐身技术前传——谈谈成飞歼-7IIS隐身技术验证机_进气道 (Archived version)
中国X系列战机：歼7II隐身技术验证飞机(组图)-搜狐新闻中心 (Archived version)
https://mil.sina.cn/sd/2018-06-20/detail-ihefphqk2678769.d.html (Archived version)
Thanks a lot for reading! If you have any extra information, as this vehicle is quite obscure, then feel free to share them in the replies! As always, have a good day :)
