Safety board slams system of oversight after structural problems on crashed 1947 Mallard were 'not addressed'
Oversight of ageing aircraft by the US Federal Aviation Administration must be boosted, the National Transportation Safety Board has insisted at a public hearing on the 19 December 2005 fatal accident to a Grumman G-73T Turbo Mallard that killed all 20 people on board.
The probable cause of the accident to the 1947-built Chalk's Ocean Airways Mallard (N2969) was the "failure and separation of the right wing, which resulted from the airline's failure to identify and properly repair fatigue cracks in the wing, and the failure of the FAA to detect and correct deficiencies in the company's maintenance programme", the NTSB says.
"This accident tragically illustrates a gap in the safety net with regard to older airplanes," says NTSB chairman Mark Rosenker. "The signs of structural problems were there - but not addressed." Investigators found the Turbo Mallard had a history of recurring fuel leaks near the area where the right wing separated and that there were "indicators" present of the internal structural damage.
The NTSB adds: "Although some repairs were attempted, many were ineffective in that they did not properly restore the load-carrying capability of the wing structure." Once the failure had taken place "there was nothing the crew could have done to regain control".
In July 2006 the NTSB recommended that the FAA eliminate an exemption that allows aircraft with fewer than 30 seats type-certificated before 1 January 1958 to forgo certain supplemental inspections that would reveal fatigue faults. It calls on the FAA to "verify that airline maintenance programmes include stringent criteria to address recurring or systemic problems, if necessary through comprehensive engineering evaluations and, to modify procedures for oversight of maintenance programmes of carriers like Chalk's to ensure the continued airworthiness of the fleet".
Source: Flight International
