ADS-27A-SP, AERONAUTICAL DESIGN STANDARD STANDARD PRACTICE: REQUIREMENTS FOR ROTORCRAFT VIBRATION SPECIFICATIONS, MODELING, AND TESTING (02 MAY 2006)

ADS-27A-SP, AERONAUTICAL DESIGN STANDARD STANDARD PRACTICE: REQUIREMENTS FOR ROTORCRAFT VIBRATION SPECIFICATIONS, MODELING, AND TESTING (02 MAY 2006). This standard practice presents the vibration related requirements for the development and qualification of rotorcraft, rotor craft subsystems, and equipment to be installed on rotorcraft, including external stores. Gunfire induced vibration qualification, when appropriate, should be in accordance with the vibration tests of MIL-STD-810. The development process follows the engineering System Specification (system procurement) or Production Specification (item procurement). Prior to a Request for Proposal (REP) release, the Government defines its engineering specification based on MIL-STD-961. Competing contractors base their proposed engineering specification on the Government specification, their interpretation of the specification and the peculiarities of their proposed hardware. The contractual engineering specification is negotiated based on cost, technology, and specification considerations between contractors and Government prior to contract award. The companion document to the engineering specification is the Airworthiness Qualification Specification (AQS) which describes the analysis and testing required at each step of the development process to show that the contractor's design will be able to meet the intent of the engineering systems specification. The AQS is negotiated in concert with the engineering specification and should reflect state-of-the-art design, analysis, and testing techniques. Equipment to be developed and qualified requires different development and qualification strategies depending on the complexity of the system or item and trade-offs between development costs, production costs, rotorcraft weight penalties associated with over-design and performance and reliability penalties associated with under-design.