JOINT BASE SAN ANTONIO-RANDOLPH, Texas –
Student fighter and instructor pilots fly dozens of sorties each day from Joint Base San Antonio-Randolph, spending nearly all of that time in the air.
However, their aircraft also touch ground during takeoff and landing, and it is during those moments that they rely on a small team of professionals who work each day to ensure their aircraft’s wheels and tires are able to withstand the rigors of the runway.
The 12th Maintenance Group Aircraft Wheel and Tire Shop comprises two full-time technicians along with supplemental help provided by 12th MXG Aerospace Ground Equipment personnel.
“Without the Aircraft Wheel and Tire Shop, you can’t go too far,” said technician Royzell Spencer, who has served the JBSA-Randolph shop for more than 20 years, most of those as a civilian. “We keep everybody rolling.”
Spencer, who was an aircraft mechanic for most of his 21 years on active duty, said he and Michael Riddle, a technician with five years’ experience, build, inspect and tear down all the wheels from JBSA-Randolph’s trainer aircraft fleet of T-1As, T-6As and T-38Cs.
“We’re one of the few shops here that deal with all three aircraft,” he said.
Aircraft tires do not last long, Spencer said.
“Tires are changed as needed, based on a wear limit,” he said. “The typical lifespan is two weeks for T-38 tires and four weeks for the T-1 and T-6, but they may be retired earlier depending on damage.”
Conditions on the runway – when the surface is hot or it’s wet from rainfall – are the primary reasons for tire failure, Spencer said.
“We have more blown tires when the runway’s wet,” he said. “It can cause the brakes to lock and that can lead to a blowout.”
Technicians replace about 10-15 tires each day, Spencer said.
“We replaced 432 last month,” he said. “That’s a typical month.”
Wheels are replaced far less frequently, but they undergo rigorous inspection.
Technicians receive wheels from the flightline each day and follow a procedure of cleaning, inspection and reassembly or replacement. Cleaning is a prerequisite for inspection since wheels are covered with brake dust and other debris when they arrive from the flightline.
“Each wheel has an inspection cycle,” Spencer said. “It’s once a year for the T-38, every tire change for the T-1 and every 10 tire changes for the T-6. They’re also inspected each time a tire is damaged.”
The 12th MXG’s corrosion control, nondestructive inspection and machine shops also play roles in the process. For example, the NDI shop uses specialized equipment to scan wheels for any cracks that can compromise a wheel’s integrity and lead to an event that endangers the pilot and damages the aircraft.
The worst damage Spencer has seen was a wheel on a T-38 that was ground in half when the brake locked up.
“When something like that happens, pieces from the wheel – bolts, nuts and washers – can scatter all over the place and even end up in an engine or the flight control area,” he said.
The tire shop technicians rely on an array of equipment to help them carry out their duties, notably a tire cage, called the “big red box,” used for inflating tires; machines that wash wheels and parts; and a bead breaker that does what the name indicates – breaks the beads on a tire.
Spencer said tires have improved over the years.
“They do last longer,” he said. “Another thing that helps is the nitrogen we use to inflate tires; the pressure is steady, more so than the air we used in the past.”