NDI helps keep older aircraft in the air Published July 23, 2010 By John Ingle 82nd Training Wing Public Affairs SHEPPARD AIR FORCE BASE, Texas -- Even the smallest crack on an aircraft can cause a catastrophic event that could result in the loss of an aircraft, or even worse, the loss of a pilot. Maintainers at the 80th Flying Training Wing Non-destructive Inspection shop work to find defects in aircraft to ensure the pilot, and the aircraft, return to Sheppard AFB after a successful training mission. Don Gough, 80th FTW NDI maintainer lead at the shop, said what his crews accomplish is an important step in the overall maintenance mission keeping aircraft in the sky and helping the Euro-NATO Joint Jet Pilot Training Program continue to produce combat pilots. "We're really a big part of the aging aircraft inspection procedure," he said. "As the T-38C aircraft get older, NDI is an integral part of keeping them safe to fly. We inspect the parts without harming the serviceability of the part." Click here to see the video about the NDI Shop of Sheppard's YouTube channel. The 80th FTW and other organizations in the Air Force continue to use the T-38C Talon, which rolled off the production line in the late 1950s. Production of the aircraft stopped in 1972. More than 1,100 T-38s were delivered to the Air Force. Mr. Gough said his crews inspect about 10 Talons per month, and other parts that are removed from the aircraft. NDI also inspects the T-6A Texan II, ENJJPT's introductory aircraft for undergraduate pilot trainees. Mr. Gough said since the Texan II is relatively new, his team inspects two aircraft per week. Chris Reed, an NDI specialist, said he feels his job is important to the overall mission of ENJJPT. "It's very important. It's preventative maintenance," he said. "We can prevent (an incident) before it happens. We can catch (a defect) when it's small (and doesn't) cause catastrophic damage to the aircraft." NDI uses five methods to search for defects in parts and the aircraft: fluorescent penetrate, magnetic particle, ultrasound, eddy current and X-ray. The fluorescent penetrate method allows technicians to take small parts from an aircraft, take it through a series of dips in solutions, rinsing, drying and inspections to locate defects. In the magnetic particle method, technicians magnetize steel parts after running them under a metal particle and fluorescent solution. When the piece is magnetized, the solution will be drawn to the surface of the part to indicate a defect. During the ultrasound method, sound waves are sent through an aircraft by the use of two probes. The sound waves bounce off the other side of the part and return. The readings on the ultrasound screen will indicate whether or not there is a defect. By using the eddy current method, technicians can send an eddy current, created by a magnetic field, through a part to look for surface defects. Finally, the X-ray method uses X-ray equipment to capture images of aircraft such as the wings to locate cracks as well as any build up of moisture. "We look for defects that you can't see with your naked eye," Mr. Gough said. "Also parts of the aircraft you don't have access to. A lot of the wing structure you don't have access to or get into." The crews are required to complete at least two types of inspections on aircraft, according to technical orders. Mr. Gough said a major inspection is completed every 900 flying hours, whereas a minor inspection is every 450 flying hours. He added they also inspect aircraft following hard landings or when an aircraft is "over G'd," meaning, in simple terms, the gravitational pull during a maneuver was more than the aircraft was supposed to surpass. Mr. Gough said his crews are highly trained and that they all can work in the various stations of the shop.