LO: how the F-22 gets its stealth
By Airman 1st Class Alex Echols, 325th Fighter Wing Public Affairs
/ Published August 08, 2013
TYNDALL AIR FORCE BASE, Fla. -- When painting a house each coat is applied evenly ensuring consistent color and protection from the elements. Though the idea is similar, applying the coatings that will make up the stealth skin of the F-22 Raptor is very different. These coatings prevent the jet from being located on enemy radar. Luckily, if a spot of paint is missed on a house, it is highly unlikely it will get blown up.
The 325th Maintenance Squadron's Low Observable team and their contractor counterparts, Defense Support Systems, work to make sure the F-22s at Tyndall maintain their stealth capabilities by restoring and maintaining the low observable coatings on the jets.
"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."
To counter these conditions, LO has two climate controlled bays that are the ideal location for restorations, but due to constant need of LO restoration, these bays are never empty.
During a week, the team continually work on six jets, which increases to eight to 10 during weekends. This does not include the flight line dispatch work they do.
DS2 contributes 76 personnel in support of the LO mission.
"Our work force is extremely honored to serve the 325th Fighter Wing and the Air Force, which is evident in the quality work, pride and professionalism they perform each day," Mr. Christian said.
The Low Observable team works closely with the Aeronautics Health of the Fleet program. Click here to read more about their cooperation.