This is an unflown example of a recording medium (foil) that was used on the earliest flight data recorders. It recorded a few basic parameters of a flight as scratches on a piece of foil. This medium is obsolete and has been replaced by magnetic or solid-state recorders, although a few aircraft still in service may continue to use foil.
Gift of Loral Data Systems.
Stainless steel spool with a roll of Inconel metal foil.