OFFUTT AIR FORCE BASE, Neb. -- The tread is worn, you run over glass or your tire simply just blows because of issues with pressure. Easy fix, right? Not always, especially when it comes to the 150-pound versions of wheels and tires found on the aircraft fleet here. 

The process of putting together a new wheel and tire for one of the many variants of C-135s or the E-4B aircraft assigned here is much more extensive, according to Ron Newton, 55th Maintenance Squadron Isochronal Phase Inspection aircraft mechanic work leader. 

"Once flight line maintainers change out a tire and deliver it to our wheel and tire shop as unserviceable, it takes 24 hours on average to get another skin on that wheel assembly and tag it as serviceable again," Mr. Newton said. 

The responsibility of keeping Offutt's stock of main and nose wheels at the level necessary rests in large part on the shoulders of about 40 maintainers in the Bennie Davis Maintenance Facility's ISO dock since the wheel and tire back shop isn't regularly manned. 

"All of us in ISO have the additional responsibility of working in the wheel and tire shop when necessary," said Bobby Nelson, 55th MXS aircraft technician, "and we all know getting called in to work there is just part of the job." 

Maintainers get the call to go to wheel and tire about 400 times a year to mainly process replacement tires, although the ISO workers also overhaul nose wheels for the 135s here, Mr. Newton explained. Variants of the 135 have 10 tires each including nose gear tires and the E-4 aircraft have 16 each. 

Similar to a car owner monitoring his or her vehicle, Offutt flight line maintainers monitor things like depth of tread and splits on the aircraft tires, Mr. Nelson said. They also abide by strict technical orders on due dates for wheel and tire change outs. 

Tires on a 135 aircraft have a five-year cycle while the main tires on an E-4 are on a one-year cycle, according to Mr. Newton. It is possible for a tire to last through a cycle but things like sidewall or tread damage are causes for a wheel assembly to be pulled of an aircraft by flight line maintainers, he added. 

No matter what the reason, wheels and tires deemed unserviceable are delivered to the wheel and tire shop to begin the process to go from unserviceable to receiving a serviceable tag. 

"When we receive a tire and repair or replace paperwork from the flight line, the first thing we do is document it in our Integrated Maintenance Data System," Mr. Nelson explained. 

If the system shows the wheel and tire as outdated, maintainers send it to depot maintenance in Utah. If the removal date is good, maintainers "break the bead," or seal, and separate the tire from the wheel. 

Tires are put on a rack in the shop to be turned in as unserviceable. 

With the wheel assembly, maintainers clean it before sending it to the non destructive inspection section for inspection. 

"In NDI, they'll make sure there are no cracks, gouges or scratches that would prohibit the wheel assembly from being later returned as serviceable," Mr. Nelson said. "If everything is good, they'll send it back to us. We look at it again to see if it needs to be sent to corrosion control to be repainted." 

If everything looks good, maintainers working wheel and tire put a new skin, or tire, on it and put it back together. With the wheel paired with a new tire, the complete assembly then has to pass two strict tests. 

"First, we put it on a three-hour stretch test to allow tires to settle," Mr. Newton said. "If it passes that, we follow up with a 12-hour leak check where it's allowed to leak so much PSI within that 12-hour test." 

If it's within established parameters, it's ready for a serviceable tag and put back in the supply system. For 135 tires it means they go to the supply section. Tires for the E-4 go on a rack in the shop. 

Although the wheel and tire mission isn't a constant one for ISO maintainers, they don't lose sight of its role in overall mission success. 

"If you're short of wheels and tires or in case of an emergency - say you blow a lot of tires on landing - if we don't have enough (wheels) ready to go, we could lose a sortie and probably one that's very important to the overall mission," said Mr. Nelson. "Or, perhaps there's an aircraft out there that runs over a foreign object on the runway that damages a tire and it was taxing out to an important mission, if we don't have a serviceable tire ready to put on that aircraft, now you're looking at delaying or scrubbing that mission. In my opinion, what we do in here is pretty important out there on the flight line." 

Mr. Newton referred to the wheel and tire mission "as pretty cut and dry," but added, "like any maintenance back shop, we much needed. 

"Aircraft aren't going to fly without parts ... everything depends on quality parts."