Recommendations for new engine certification procedures, emergency checklists, aircraft equipage and pilot training are included in 34 safety recommendations the US National Transportation Safety Board has issued to certification authorities in the wake of the investigation into the US Airways Airbus A320 ditching in the Hudson river.
All 155 passengers and crew survived the 15 January 2009 Flight 1549 ditching after the CFM International CFM56-powered twinjet struck a flock of Canada geese less than 2min after departure from New York's LaGuardia airport. The NTSB attributed the survival to decision-making and crew resource management skills of the crew and availability of forward slide rafts on the aircraft.
Despite the success of ditching an aircraft that could not remain aloft because of severe core damage in both engines from ingesting a 3.6kg (8lb) bird in each powerplant, the NTSB believes the Federal Aviation Administration's ditching certification lacks guidance for pilots to determine "ditching parameters without engine thrust".
The board says that lack of information, coupled with no industry standard for flightcrew training and guidance on ditching techniques contributed to rear fuselage damage that prevented use of rear slides/rafts on the Airbus narrowbody.
Passengers evacuated into the forward rafts and the wing surfaces until help arrived.
The NTSB says that if passengers had been forced into the water there would likely to have been "serious injuries and/or fatalities" as a result of the low temperature.
US Airways was not required to use an aircraft with rafts for the route, a turn of events the NTSB called "fortuitous". As such, the NTSB is recommending that the FAA require all airline and air taxi operators to provide flotation seat cushions and life vests for all occupants, regardless of route.
For engine certification, the NTSB, among other actions, is requesting a change to engine speed from 100% fan speed to the lowest expected fan speed for the small and medium flocking bird ingestion certification test, a change that will expose the engine to a larger amount of bird material.
The NTSB is also asking the FAA to re-evaluate whether only engines with an inlet size of 2.5m² (27ft²) or greater, an inlet size larger than the CFM56 inlet, should be required to undergo certification testing for large birds. The FAA will have to require airframers to develop checklists and procedures for dual engine failures at low altitudes, an aid not now available.
In addition to working with NASA to develop "technology capable of informing pilots about the continuing operational status of an engine" and requiring the installation of the resultant products on all transport aircraft equipped with full authority digital engine control systems, the NTSB wants the FAA to work with the US Department of Agriculture (USDA) to "develop and implement innovative technologies that can be installed on aircraft that would reduce the likelihood of a bird strike".
The USDA has been investigating whether the effects of pulsating lights, lasers and other methods that could be used to repel birds.
Source: Flight International
