OCR Text |
Show I r Mm HILLTOP TIMES Friday, May 17. 1985 i - U.S. Air Force Photos by Bob New technique George - v.O...y. A II the 2952nd Combat Logistics Support SquadTSgt. Jackie R. Cooper, an aircraft hot-asoldering. ron, desolders a ''wafer" before attaching new wires in preparation for electrician in ir AAainieneance personnel By Jean Williamson Ogden ALC Public Affairs To meet the Air Force need for personnel trained in high-tecsoldering, Hill AFB instructors are presently teaching classes on the latest h state-of-the-a- rt technique, "hot-air- " soldering. Max Aubele, an aerospace instruc- tor in the Directorate of Maintenance's Training Branch, who teaches the "hot-air- " soldering classes, says expert soldering is almost a dying art. He attributes that to circuit units being assembled as a whole which eliminates the need for soldering. "That makes it difficult to find personnel experienced in soldering," Mr. Aubele said. "But, the sophisticated avionics in today's aircraft require more flexible solders to withstand the extreme temperature fluctuations." He cited the 6 which may take off from hot runways where temperatures F-1- sometimes exceed 100 degrees Fahrenheit and drop to minus 60 degrees Fahrenheit as the aircraft climbs to high altitudes. "These sudden temperature changes expand and contract metal circuits causing stress teach and vibrations to soldering connections," he explains. "This makes the soldered older, more rigid pencil-typ- e blobs snap." Mr. Aubele says heat is also generated in the compact areas enclosing aircraft. "In these circuits in high-tec- h e small areas, circuits are more and need higher soldering " melting points," he said. "To alleviate are behigh temperatures when an blows air outside intake ing tested, air into the aircraft to cool it down and prevent circuits from melting." Frank Rehling, an aerospace instructor who teaches the basic soldering classes noted that these classes begin with a strong foundation of proper soldering techniques and the pitfalls to avoid. Students are also taught to clean connections with alcohol to keep corrosion down. After mastering the basic concepts, students are taught advanced techniques which include the "hot-air- " method. The difference between this method and the older, pencil-typ- e technique is in the type and precise application of the connections. Flat, ribbon connections are used in "hot-air- " soldering because they take less space. Compo heat-sensitiv- F-1- 6s met hds high-tec- h nents are premeasured rather than applied at the solder point to give a more flexible connection. The new method involves covering the solder area with a high altitude, collapsible emersion sleeve over the solder area. Simultaneously, as the heat gun shrinks the sleeve, premeasured solder flows down and makes the connection. Mr. Aubele says the main technique students must learn is proper heat application with the heat gun. He says this type soldering is relatively new. Only the multinational TAC wings countries flying the Thunderbird aircraft, and with the new commercial planes use it. Air Force personnel are trained at Hill AFB, the only Air Force installation presently teaching this concept. The students' soldering work is inspected by Wendell Mann, an inspector in the Maintenance chemical lab who ensures the soldering techniques are performed correctly, . Both soldering methods were recently demonstrated at Utah Technical College in Salt Lake City. Mr. Aubele says the purpose of these demonstrations is to show students F-16- F-16- s, s, the techniques of modern soldering that are acceptable to the Air Force "what's required, what we do and why we do it," he said. "Students who've learned these techniques can better apply this today's state-of-the-a- soldering in rt sophisticated aircraft avionics. Mr. Rehling says both types of soldering techniques are taught on base, two or three times each month. "The method still standard soldering-iro- n has a wjde range of applications and is presently used in several base functions such as the electrical shop, here machine shop, automotive general solder repairs still suffice." shop-anyw- . i)w"mifff?4 '4 4i.a I-- I - i mmmsm lf Jig .jt J 'nSssW,:&yj'ssy.--f...-- ' ' c- -- - -- A student in the Directorate 0I i:.:l'ir-i?anvoiitional:oldeHntt- 4 - - r0 .... n .... .',Ju- - - ''''" '"-- ' ' vv f-y':-" soldering class practices the A student practices the new, high-tec- h, mm hot-a- ir - soldering method |