BRENDAN SOBIE / HAMPTON, VIRGINIA
NASA is stepping up its involvement in the investigation of last November's American Airlines Airbus A300-600R crash (AA587) as its composites experts prepare for an advanced structural analysis of data from new simulations.
A team of 12 NASA scientists has been aiding the National Transportation Safety Board (NTSB) since December with the non-destructive evaluation of the A300's broken tail fin. NASA Langley Research Center director for structures and materials Mark Shuart expects this team will at least double in size as the NTSB tries to determine whether the loads on the fin exceeded design limits or its composite structure failed to meet design standards.
NTSB chairwoman Marion Blakey says the team is now ready to perform "more intrusive examinations". These include inspecting every layer of the composite laminate for pre-existing damage and testing, possibly to destruction, a used A300-600 rudder.
NASA and the NTSB will use Airbus's A300-600 finite element model to replicate the loads experienced by the AA587 aircraft. Blakey says the NTSB is considering using a vertical motion simulator at NASA Ames Research Center to see how easy it was to manipulate the controls. "Right now the number one goal is to recreate the environment the pilots were in as best we can and infer from there," says NTSB's head of safety John Clark.
Blakey says the NTSB has "a pretty good sense" of what the rudder inputs and lateral loads on the fin were, but investigators still do not know what caused the rudder movements. Clark says the lateral loads were different and stronger than seen in any other US accident.
Source: Flight International
