Logikirja

Logikirja, or logbook in English, is a written or digital record used to document noteworthy events, measurements, and times over a period. It serves as an auditable history for operations, safety, and compliance. It is used across professions, from ships and aircraft to laboratories and engineering projects.

In maritime settings, the ship's log records position, course, speed, weather, navigational events, cargo, crew on watch, and maintenance or incidents. It has historically been used to prove voyage details and substantiate claims in disputes. Entries are typically dated, signed, and preserved for the voyage.

In aviation, the flight log documents flight hours, routes, aircraft used, pilot endorsements, medical certificates, and training progress. For pilots, the logbook is essential for currency and certification, and for operators as part of the airworthiness record.

In science and industry, lab notebooks and maintenance logs capture experiments, methods, data, equipment status, and service history. With digital logbooks, data can be timestamped, backed up, and exported; however, concerns about integrity and tampering are managed with digital signatures and controlled access.

Etymology and history: The term logbook derives from nautical practice of recording a ship’s speed with a log and line; over time the practice expanded to record many voyage aspects. Today logbooks exist in paper and electronic forms across fields.