Abstract: This invention relates to a hard landing indication system that will provide a quantitative assessment that a hard landing did or did not occur at the last landing of an airplane. A hard landing can cause structural damage to an airplane. An airplane that has been declared to have a hard landing must be grounded until an inspection of the structure has been made to determine if repairs are required.

Abstract: This invention relates to a hard landing indication system that will provide a quantitative assessment that a hard landing did or did not occur at the last landing of an airplane. A hard landing can cause structural damage to an airplane. An airplane that has been declared to have a hard landing must be grounded until an inspection of the structure has been made to determine if repairs are required.

Abstract: A gas turbine engine combustion noise suppressor for a jet engine combustor assembly of the annular, cannular, or canannular variety includes a resonant cavity-type or bulk absorber-type noise suppressor. The inner wall of the combustor assembly is configured to couple combustion noise, generated within the burner cavity formed by the inner combustor wall, into the airflow duct formed between the inner and outer walls of the combustor assembly. The outer wall is perforated to, in turn, couple the combustion noise from the airflow duct into the resonant cavity-type or bulk absorber-type noise suppressor that is mounted on the portion of the outer wall that is adjacent the burner cavity. The inner combustor wall can include a large number of small acoustic openings and/or a smaller number of larger openings that include airflow barriers to couple the combustion noise into the combustor airflow duct while simultaneously minimizing air flow into the burner cavity from the combustor airflow duct.