Hard to say.Some of this has been asked and answered before. But for the new crowd...
Some in the land of unicorns and model airplane glue think that the aircraft only has radar absorbent skin. That the low-observable effects are "baked into the skin". That it doesn't need radar absorbent material (RAM)
But that is not true:
"The process of coating the F-35 is one of great finesse and refinement. It consists of several stages: sanding, priming, spraying precise layers of paint, meticulous touch-ups and final stenciling.
In today’s world of increased automation, the use of robots for these tasks is commonplace. However, even on the world’s most technologically advanced aircraft, the role of the robots is far overshadowed by the human element. According to Kelly, approximately 85 percent of the work in AFF is done by hand. The rest of the work is completed by robots that are operated by her team.
“The robot is one of our milestones and one of our finishers. But from the time that very first panel is put on, we are building fit panels, filling seams, doing hot dots and applying boots. All of this is done by hand—there’s no automation in that,” Darren said."
You can read here all the manhours involved in the F-22 ...real...world.
"It can be very stressful at times, but when I'm out on the jet, I go into my zone. It is very meditative," said Airman 1st Class Freddie Newman, 325th MXS Low Observable apprentice.
Since these entities maintain the F-22s skin, they are involved in most aircraft maintenance on base.
"No one touches the aircraft and gets into the systems without LO having a part in that job," Senior Master Sgt. Angela Stovall, 325th MXS Fabrication flight chief, said. "LO is the first one to touch the aircraft because they have to remove the coatings so [maintainers] can take panels and parts off. LO is the last one to touch the aircraft because they restore the coatings."
"Each week, LO does outer mold line inspections. This involves checking each jet's signature, which is makes an aircraft appear on detection devices. A very high signature equals a very low stealth capability leaving the jet exposed to radar.
"It is extremely essential. Being invisible is priceless in combat situations," said Scott Christian, DS2 Aircraft Maintenance supervisor.
The OML helps determine where the jets sit in margin, the range of stealth capability that the aircraft need to be, and allows LO to identify the damages to the coating. When an aircraft is selected for a major signature reduction, it is in need of around 150 necessary repairs on about 30 different panels. These repairs can take up to three weeks to complete.
"We do everything from major three week repairs to what we call spike maintenance, which is just over a weekend," Sergeant Stovall said.
Safety is a high priority during the entire process. The maintainer's personal protective equipment is designed to repel the harmful chemicals and debris that they might be exposed to while working with the coatings. Their PPE includes: a Tyvek protective over suit, a pair of gloves and a respirator.
"The first step is always going to be to mask the aircraft, to ensure sanding debris is contained," said Staff Sgt. Armando Castellon, 325th MXS Low Observable Signatures coordinator.
This step keeps from spreading the contamination of hazardous chemicals associated with working with the LO coatings.
Next, the maintainers remove the damaged areas by sanding and then thoroughly cleaning those sanded areas to ensure a proper bonding of the coatings.
Once that is complete, LO reapplies the coatings starting with the boot layer, which is the radar absorbent material that allows for stealth capabilities. The additional top coats of paint follow. The jet is then removed from the system to avoid confusion.
One of the biggest obstacles the group face while applying the coatings is the Florida weather. Lighting within five miles of the base halts all flight line activities, including LO restorations taking place there, and the humidity and temperature levels makes it difficult to get a proper bond with the coatings, Sergeant Castellon said.
"When working with low observable material, everything deals with chemicals, and a lot of chemicals are required to stay within a certain temperature and humidity range to get the best bond," said Sergeant Stovall. "Here in Florida, we have a tremendous level of humidity. If we have one of those high humidity days when these guys are doing repairs, it is very possible there will be a disbond in the material just because environmental controls aren't where they need to be."
The F-35 has to do better than the F-22 on stealth maintenance. The F-22 was built where only 5 percent of scheduled maintenance actions require paint/patch up of the low observable material. The F-35 was 1 percent, then later (after observing operational F-22 squadrons?) 2 percent. Part of this makes sense when you see where the F-35 has strong low resistance...and where it does not.
F-35 maintenance practices have to beat F-22 maintenance practices. The big challenge is that the F-22, with all of its troubles, brings combat capability.
Here is a wider view of how F-22 aircraft maintenance works around low-observable conditions.
"Then, his crew of five Airmen goes to work.
First, they strip off the low observable paint that coats the panels over the components in need of repair.
"The whole aircraft is painted," Rose said. "You have to remove that paint layer to gain access to the fasteners."
After the components are exposed, the crew repairs each DD, which, individually, could take from three days to a week. The jet's doctor visit lasts three weeks on average."
And that inconvenient reminder from the F-35 sales-force.
*** H/T- To Joe for finding this read.
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