A new final rule revising FAR Part 33 bird ingestion certification test requirements ensures that modern-day turbofan engines can ingest the largest medium flocking bird (MFB) into the engine core during climb or approach conditions without an engine failure. The rule traces its roots back to the “Miracle on the Hudson.”
On Jan. 15, 2009, a US Airways Airbus A320 struck a flock of Canada geese at 2,800 feet during climb-out from New York LaGuardia Airport. Both of the airplane’s engines ingested at least two birds, substantially damaging both engine cores and causing total thrust loss. The captain, Chesley “Sully” Sullenberger, was able to glide the aircraft to a safe ditching in the Hudson River, with all 155 aboard rescued.
As a result of the accident, the FAA established an aviation rulemaking advisory committee (ARAC) to review and update bird ingestion standards. In its 2015 report, the ARAC concluded that modern engine fan blades have relatively wider chords than those in service when the FAA implemented the MFB ingestion test in September 2000. The report also noted that tests are currently conducted with the engine operating at 100 percent takeoff power—ideal for testing the fan blades but not representative of the lower fan speeds used during climbs and approaches.
In July 2018, the FAA proposed rulemaking to revise the tests to reflect the recommendations from the ARAC as well as those in the NTSB’s final investigation report of the A320 accident. The new requirements were adopted on April 4 and take effect on June 5.