Downloaded from https://www.everyspec.com ADS-43A-HDBK targeting, and proper spray pattern. A complete dimensional inspection is also required. j. Deviations from drawing dimensions and tolerances, considered critical characteristics, will not be permitted for FSP. In some cases, final dimensions are affected by heat treating, plating, or other processes. Therefore, the vendor must make allowances to arrive at the correct dimension. Master tooling requirements are specified on the drawings for compressor blades and vanes, turbine blade and vane, airfoils, castings, forging, spiral bevel gears, and some compound curvature parts.
This master tooling must be traceable to the original master in order to provide part interchangeability. Machining practices must be of the highest quality to insure proper form, fit, and function. Grinding, honing, or polishing procedures must also be of the highest quality. Checks for abusive grinding must be conducted on each part to prevent the possibility of surface cracking, leading to failure. Finish requirements must be equal to, or better than those specified on the drawings. k . All high speed rotating components require balancing. In some cases, shafts rotate at speeds above the first critical speed and sometimes above the third critical speed.
Usually damping is required while transversing critical speed points and any steady state operating speed, including idle, must be removed from any critical speed by at least 20%. Bladed disks require careful blade weighing and selection such that blades on opposite sides of the disc are within prescribed weight tolerances. Balance must be within blueprint requirements. The type of balancing machine selected by a prospective vendor must be approved by USAATCOM engineering. High speed gears must also be dynamically balanced. Any response frequency within 20% of any gear steady state operating speed, or multiple thereof, can indicate a potential hazardous condition leading to gear failure. 1.
In order to provide concentricity for mating parts, surfaces called centering journals are machined on each part. These diameters are closely controlled such that fits, when mated, are snug to very tight. Both male and female parts require close adherence to tolerances for runout, diameter and concentricity such that, when mated, the assembly is in perfect alignment for proper engine function. m. All digital engine controls will be subjected to full electromagnetic environmental effects testing to verify that the controls, and ultimately the engine, will operate to specifications in the Army’s worldwide electromagnetic environment.
All electronic controls will also be subjected to full environmental qualification testing per the Engine Model Specification or MIL-STD-8 1 OC, software validation and verification testing per the engine model or component specification, MIL-STD-498C or RTCA-DO 178, and system operational and endurance testing per the engine or component model specification or AV-E-8593D. Input and output signals will be checked for each digital control before mating to the engine. The dimensions, 1 6