AC 120-42B ETOPS and Polar Ops - Code7700

AC 120-42B 6/13/08b. In order to achieve and maintain the required engine reliability standards, the certificateholder operating a two-engine airplane in ETOPS should assess the proposed maintenance andreliability program’s ability to maintain a satisfactory level of airplane systems reliability for theparticular airplane-engine combination. All certificate holders should design the flight operationsand, if applicable, the maintenance programs for ETOPS with an objective to preclude diversionsand, if a diversion does occur, to protect that diversion. Required ETOPS maintenance practicesalso must minimize the potential for procedural and human errors that could be detrimental to thesafety of the operation. Fuel planning must account for the possibility of a depressurizationand/or failure of an engine with considerations for in-flight icing conditions (§ 121.646).c. The type design requirements for ETOPS certification consider the probability ofoccurrence of conditions that would reduce the capability of the airplane or the ability of theflight crewmember to cope with an adverse operating condition. System failures or malfunctionsoccurring during extended range operations could affect flight crewmember workload andprocedures. Although the demands on the flight crewmember may increase, a manufacturerapplying for ETOPS type design approval must consider crew workload, operationalimplications, and the crew's and passengers' physiological needs during continued operation withfailure effects for the longest diversion time for which it seeks approval. The manufacturer mustalso conduct flight tests to validate the adequacy of the airplane's flying qualities andperformance, and the flightcrew's ability to safely conduct an ETOPS diversion with expectedsystem failures and malfunctions. An ETOPS operator should carefully consider the possibleadverse effects that changes in airplane equipment or operating procedures may have on theoriginal evaluations conducted when the airplane was approved for ETOPS before implementingsuch changes.d. Following a determination that the airframe systems and propulsion systems are ETOPStype design approved as per part 25, an in-depth review of the applicant’s required ETOPSprograms will be accomplished to show the ability to achieve and maintain an acceptable level ofsystems reliability, and to safely conduct these operations.Page 12 Par 208