12th FTW mechanics solve T-38 engine problems

  • Published
  • By Robert Goetz
  • 502nd Air Base Wing OL-B Public Affairs
RANDOLPH AIR FORCE BASE, Texas --  The roar of the T-38C Talon's J-85 engine is heard throughout the day at Randolph, but sometimes that sound is far removed from the base community.

It is contained within a detached structure near the north end of the west flightline, distinguishable only to the veteran mechanics of the 12th Flying Training Wing's propulsion shop who spend part of their time in that facility, home of the J-85 engine test cell.

The mechanics' job is to evaluate each J-85 engine brought to them from the flight line or another Air Force base and fix or replace external parts and systems as needed or send them to a facility at Laughlin Air Force Base, Texas, for internal repairs. Part of their evaluation involves running the engine, which produces more than 30,000 pounds of thrust.

"We make sure the engines are safe to run," said Richard Jones, 12th Flying Training Wing aircraft engine mechanic with more than 40 years' experience on active duty and as a civilian. "We install them in the test cell and do a hands-on evaluation. We also run the engines to see what is wrong."

Mechanics inside the test cell wear double hearing protection -- earplugs and a specially designed helmet -- when the engine is running, while soundproofing protects those at a cockpit-like console in an adjoining room from the deafening noise. The console houses a variety of digital and analog gauges that measure everything from oil pressure and fuel flow to thrust and exhaust gas temperature.

An engine's journey to the test cell typically begins with the pilot, who reports a discrepancy with an aircraft to an expediter from the sortie generation section. Expeditors perform pre- and post-flight inspections, launch and recovery, and servicing of aircraft.

"The expediter is responsible for relaying information from the pilots to the maintenance operations center and the appropriate maintenance personnel," said Randy Schul, 12th FTW propulsion shop supervisor. "They are also involved in the debrief process."

He said a debriefer works for sortie generation and takes the information from the pilot, expediter and mechanics and enters it into the Core Automated Maintenance System, the data collection system used by the Air Force to record all aircraft maintenance actions, and the aircraft 781 forms.

Mechanics from the maintenance support unit, who are involved in the troubleshooting process, may perform repairs themselves, but if the engine is taken out of the aircraft for further evaluation, it is taken to the test cell.

"If the engine comes out, we're going to get it," Mr. Jones said. "We can repair anything external, but anything internal (such as bearing or compressor failure) goes to ERRC (the Engine Regional Repair Center at Laughlin) for repairs."

Engines that are repaired or overhauled at Laughlin AFB also come back to the propulsion shop mechanics for reverification at the test cell, he said.

Mr. Schul said the evaluation of each engine that comes to the test cell is rigorous.

"The mechanics go through a trouble-shooting guide," he said, referring to the manufacturer's technical order. "They have a procedure to follow. Every engine gets a complete check, no matter what the problem might be."

"We run the whole engine and check everything," Mr. Jones said. "It's like taking the car to a mechanic. We just go down the line until we hit the problem."

Mr. Schul, whose mechanics evaluate some 35 to 40 engines per month, said an inventory of spare engines is available, so when one is removed from an aircraft, it can immediately be replaced.

"We're always rotating engines," he said. "We usually have 14 to 16 spares available."

Mr. Schul said the test cell operators at Randolph average more than 37 years of military and civil service experience in aircraft and engine maintenance. He also said most of them performed complete disassembly, inspection and buildup of J-85 engines when the base had an engine overhaul facility.

"This vast knowledge of the engine, understanding of the interrelationship of the components and operational experience working on the flight line provides them with superb test cell troubleshooting skills," he said. "The experience and skills they possess are invaluable to an engine mechanic whose sole job is to produce reliable engines in support of the T-38 pilot training mission here at Randolph."