Resulting Safety Initiatives

Engine Bird Ingestion

The NTSB issued Safety Recommendation A-76-64, related to the bird ingestion threat to engines, and updated the bird ingestion standards for large turbofan engines.

A-76-64 stated:

"Amend 14 CFR, part 33.77 to increase the maximum number of birds in the various size categories required to be ingested into large turbine engines. These increased numbers and sizes should be consistent with the birds ingested during service experience of these engines."

The engine bird ingestion regulatory standards were first incorporated into 14 CFR part 33.77 at Amendment 6, effective in 1974. Based on the above recommendation, the amendment removed section 33.13 and introduced a new section 33.77 on foreign object ingestion that included requirements for ingestion of birds and other foreign objects. The FAA again revised section 33.77 in 1984 at Amendment 10.

The above safety recommendation also led the FAA to sponsor an industry-wide study of the types, sizes, and quantities of birds that had been ingested into engines of all sizes and the resulting effects on engine performance. Subsequently, the FAA requested that the Aerospace Industries Association (AIA) analyze the data and report back to the FAA.

Based on the AIA analysis, the FAA concluded that the bird ingestion standards should be modified to increase the severity of the bird ingestion testing standards for large, high-bypass ratio engines, and that the design and testing requirements for all engine sizes should be updated to reflect the actual numbers and bird sizes being ingested. That effort was adopted as a 14 CFR part 33 and Joint Aviation Regulation engine (JAR-E) harmonization project and selected as an Aviation Rulemaking Advisory Committee (ARAC) project. The revised engine bird ingestion standards were defined in a new 33.76 section and became effective on December 13, 2000 at Amendment 20 to 14 CFR section 33. The FAA also issued AC-33.76 that provides guidance and acceptable methods of compliance with the engine bird ingestion requirements of section 33.76.

The following table highlights the evolution of the turbine engine bird ingestion standards:

Turbine Engine Bird Ingestion Standards
Turbine Engine Bird Ingestion Standards
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Airplane Tires, Wheels, and Brakes

A series of accidents and incidents involving large commercial jet airplanes, particularly wide body types in the mid 1970's, involved failures of tires, wheels, brakes, and antiskid devices. The NTSB issued safety recommendations and advisory actions in this time period that addressed the standards, testing, quality control, and operational limits of aircraft tires. The FAA intensified its surveillance efforts with respect to aircraft tires and began an analysis of the failures and potential corrective actions. This led to joint FAA-Industry meetings in 1976 and 1977 that resulted in a proposed set of revised and updated standards and regulations to reflect the latest technology and to meet operating conditions.

Tires/Wheels/Brakes standards and regulations: Amendments 25-49 and 37-46 were issued on November 29, 1979 and improved the Technical Standard Order (TSO) applicable to landing gear main and nose wheel tires and added more comprehensive certification requirements covering tire loads and speed ratings. Amendments 25-48 and 37-45 were issued on November 29, 1979 and revised the TSO standards for aircraft wheels and wheel brake assemblies and related certification requirements for airplane brakes.

Wildlife Management Programs

Several recommendations from the NTSB highlighting the problems and deficiencies related to airport bird control and the potential hazards of aircraft bird strikes. Currently, CFR Part 139 addresses the operational rules for airport. Airports must comply with 14 CFR part139.201 and have an airport certificate manual in order to operate. The manual must include a description of operating procedures, facilities and equipment, responsibility assignments, and any other information needed by personnel concerned with operating the airport. The airport certificate manual must also include information on the airports wildlife hazardous management programs. 14 CFR part139.337 addresses the information required in the Wildlife Hazardous Management Plan which is meant to alleviate immediate wildlife hazards whenever they are detected. The FAA also issued various Advisory Circulars that provides guidance and acceptable methods of compliance for the airport operating rules mentioned above. The AC are the following:

AC 150/5210-22 Airport Certification Manual

AC 150/5200-33B Hazardous Wildlife Attractants On or Near Airports

AC 150/5200-36 Qualification for Wildlife Biologist Conducting Wildlife Hazards Assessment and Training Curriculum for Airport Personnel Involved in Controlling Wildlife Hazards on Airports

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