going to incorporate Glare into its Irkut MS-21 narrowbody airliner, refers to its version of Glare as SIAL. The name is a translation from the Russian acronym for fiberglass and aluminum/plastic (С.И.А.Л.). It defines the grades SIAL-1 through SIAL-4, which usually contain the second-generation Russian aluminum-lithium alloy 1441 and range in density from . SIAL is used in the wing covering of the Beriev Be-103 amphibious seaplane. Airbus bases their material designations on the underlying aluminum alloy, using prefixes such as 2024-FML, 7475-FML, and 1441-FML instead of Glare and HSS Glare. Airbus parts production Glare contributes of material to each A380 plane. This material constitutes three percent by weight of the A380 structure, which has an operating empty weight (OEW) of . Because of the ten-percent lower density of Glare compared to a typical standalone aluminum alloy, Glare's usage on the A380 results in an estimated direct (volume-based) savings of , which doesn't include the follow-on weight savings in the entire aircraft structure that result from the lower material weight. For example, a 1996 internal Airbus study calculated that the weight savings from Glare in the upper fuselage would be from just the lighter material, but it would total due to the "snowball effects" of smaller engines, smaller landing gear, and other positive changes. (However, this is much smaller than an Airbus vice president's early claim that Glare would result in of savings, presumably if it were used throughout most of the aircraft.) To take advantage of Glare's higher tensile strength, is used on the upper fuselage of the front and rear sections. Glare was removed from the center upper fuselage in 2000 as shear strength precaution (although the Glare supplier felt it could have handled that area), and the fuselage underside is made of other materials with higher Young's modulus (stiffness) values to resist buckling. In the fuselage, Glare2A is applied to stringers, Glare2B to butt straps, and Glare3 and Glare4B to the fuselage skins. Late in the A380 development process, the plane was found to be heavier than the original specifications, so Airbus replaced conventional aluminum with Glare5 as a weight-saving measure for the leading edges of the horizontal stabilizer and the vertical stabilizer, though at great expense. The A380 Glare fuselage skin panels have a minimum thickness of but can be much thicker, as some areas of the shells may need up to 30 layers of aluminum