One of the most advanced fighter jets in the U.S. Air Force’s arsenal faces an engineering problem which an ancient Chinese silk-weaving tactic may solve.
The Lockheed Martin F-22 Raptor remains the world’s most capable air superiority fighter in service today.
This is especially true because the F-22 was developed in the 1980s, when few Americans rarely visited the “world-wide web” and mobile phones were the size of a brick. For the beginning of the digital age, this bird was highly advanced technology.
Technology has advanced considerably and continues to do so, leading to U.S. Air Force (USAF) officials expressing concerns that any sixth-generation fighter could be part of the system of systems of the Next Generation Air Dominance (NGAD) program. Aircraft designers need to consider how any future fighter will employ artificial intelligence, data fusion, cyber warfare, autonomous functionality, variable cycle engines, directed-energy weapons (DEW) and advances in human-machine interface.
However, when it comes to addressing an ongoing problem with the F-22’s radar-absorbent coating, which helps provide the Raptor with its low radar signature and stealth capabilities, the United States may be wise to follow the lead of Chinese engineers, who have looked to the past—the distant past, as it turns out.
The F-22’s Long-Standing Coating Problem
Images circulated in 2019 that showed serious delamination of the radar absorbent material (RAM) on the U.S. Air Force’s Raptor.
According to a report from TheWarZone at the time, the material of the aircraft “silver skin remains a tightly guarded secret,” and added that it “takes a lot of work to maintain [as] many of these applications start degrading shortly after they are applied, with friction from high-speed flight, crushing G forces, and the elements accelerating that process.”
While the layered coatings on the F-22 and the F-35 Lightning II deflect radar, they can degrade under stress; even minor abrasions can be a serious problem. Thus, the fifth-generation stealth fighters need to have the RAM reapplied after just a few weeks, and the process can be costly, as much as $60,000 per flight hour.
“In regions like Florida, humidity exacerbates bonding issues, while corrosion near coastal bases further compromises performance,” The South China Morning Post explained.
The paper added that the delamination of the RAM has been “likened to moulting cicada wings,” and Chinese researchers may have developed a unique stealth coating that could address delaminating issues by looking to a resilient “3,000-year-old textile innovation: the art of silk jacquard weaving.”
The Ancient Chinese Silk Weaving Solution
The technique is believed to have been developed in China around the second century BC and could solve the delamination problem.
A study on weaving was published in the Chinese peer-reviewed journal Knitting Industries last month. It suggested that “a dual-layer composite fabric inspired by Han dynasty jacquard looms” could be used in the stealth coating.
“Those Han looms weren’t just for luxury,” an unnamed Beijing-based science historian told the Chinese paper of record. “They were like early binary computers, storing weaving codes in physical memory. Today’s military engineers seem to have revived that wisdom.”
The modern technique doesn’t use silk; instead, it has integrated conductive yarns that have been proven to absorb 90.6 percent of radar waves in the 8-26GHz spectrum.
“[It is a] marriage of ancient patterning and modern electromagnetism,” added Professor Jiang Quian, who is overseeing the team effort, and who noted the process has outperformed conventional coatings. Whereas in the past the silk threads were used artistically to create images, modern conductive threads utilize equally-complex patterns that are meant to guide and trap signals.
In addition to the radar-absorbing capabilities, the composite material is significantly stronger than traditional coatings, reportedly able to withstand a tensile stress of 93.5 megapascals in the longitudinal direction.
That is noteworthy as even routine flight operations regularly put stress on the airfare, and this technique could help ensure that pushing the aircraft to its limits won’t impact the structural integrity of the RAM coating.
While it is unclear if this silk weaving technique is already being employed on any of the People’s Liberation Army Air Force (PLAAF) aircraft, or even if it will in the future, the recent study serves as a reminder that sometimes the best way forward to solve a problem is to look to the past.
About The Author: Peter Suciu
Peter Suciu is a Michigan-based writer. He has contributed to more than four dozen magazines, newspapers, and websites with over 3,200 published pieces over a twenty-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, politics, and international affairs. Peter is also a Contributing Writer for Forbes and Clearance Jobs. You can follow him on Twitter: @PeterSuciu. You can email the author: [email protected].
Image: Shutterstock/Joris van Boven.
