This condition, if not addressed, could result in undetected damaged or missing rivet heads on the sloping pressure deck web, which could result in loss of sloping pressure deck panels, causing decompression and pressure loss, and loss of the hydraulic systems in the area for wheel brakes (both normal and alternate) and steering—potentially leading to runway departure and adversely affecting the structural integrity of the airplane. The agency believes the cost to repair each affected 777 could be as much as $33,000 per aircraft. The airworthiness directive could potentially affect nearly 225 individual aircraft. For more information, interested parties should contact Luis Cortez, aerospace engineer, Airframe Section, Seattle ACO Branch, 2200 South 216th Avenue, Des Moines, Washington, 98198. Email contact is Luis.A.Cortez-Muniz@faa.gov.