<div class="htmlview paragraph">THE production problems associated with turbojet engines are not more complex than those encountered with reciprocating engines, according to the author, but they are of a surprisingly different nature.</div> <div class="htmlview paragraph">For instance, he points out that, whereas reciprocating engine parts are made chiefly from forgings, castings, and bar stock, the major portion of the turbojet engine is welded sheet metal structure.</div> <div class="htmlview paragraph">Then, the so-called hot parts - the combustion chamber, nozzle diaphragm, turbine, and tail cone - also present entirely new problems. The control of heat distortion caused by the high temperatures and the high temperature differentials in these parts requires closer coordination with metallurgists, steel mills, forge shops, welders, and parts fabricators than is required with reciprocating engines.</div>