Rationale: The use of cellular phones while on board airplanes is dangerous. Cellular phones emit electro-magneti c frequencies which interfere, alter or jam computer programmed precision instruments. They also are known to jam communication instruments. In fact, the manufacturers of cellular phones themselves have inidcated in the manual that comes with every purchase of a cellular phone that such device is not to be used in certain conditions because of the inherent dangers it poses. However,not all consumers of this product read and follow such safety tips included in the manual which leads to accidents or disasters.