This is an example of how flight data was stored on flight data recorders from about the 1960s through the 1980s. Magnetic tape has since been replaced by all solid-stated storage devices.
Gift of Loral Data Systems.
Country of Origin: United States of America
3-D Test: 11.4 x 11.4 x 1.3cm (4 1/2 x 4 1/2 x 1/2 in.)
Typical tape reel from flight data of voice stored on magnetic tape.