Warning - long reply ahead - bring a snack!
Quick answer - both paper (hardcopy) and electronic recording (softcopy) of flight hours and cycle data are common in modern air carrier operations.
Longer answer - due to record keeping requirements of the FAA and EASA, and established maintenance procedures, there are multiple sources for flight cycle data, both in hardcopy and electronic form. To name the most common as related to the airframe:
Line Maintenance Log: often updated every cycle.
**Maintenance Log: updated by LM Log and at every inspection/repair procedure.
**Engine Maintenance Logs: updated by LM Log and at every inspection/repair procedure (1 per engine).
ACARS: If installed - automated recording of WOW (weight on wheels) data.
Dispatch Log: updated every time the aircraft is dispatched (added to this is the load sheet signed by the PIC)
*Flight Attendant Cabin Log: updated every flight - (not required)
*Flight Crew Logbooks: Each pilot records time/date/hours/type.
*ATC Logs: Every aircraft movement is recorded.
FOQA via QAR: Voluntary - data added to aircraft maintenance log book
*Typically not cross-checked against maintenance logbooks.
**Periodically signed off and cross-checked by regulator.
In addition to routine maintenance logbook entries, there are flight hour and flight cycle life limited parts that must be inspected at regular intervals. These inspections are integrated into the aircraft maintenance logbook, but are subject to periodic certification by regulators. All maintenance and dispatch log entries are signed off at entry. Electronic cycle and flight hour data is becoming more common with a transfer of the DFDR/QAR data being uploaded after each flight. In addition to the human-generated log data, there are many independent electronic sources of cycle and flight hour data located in various LRU's installed on the aircraft - valid as long as the LRU remains aboard the aircraft in question.
Some areas where historical data can slip through the cracks: Through incompetence or deliberate action, failure to enter or falsification of an entry. Transfer of ownership can lead to missing data, particularly when the transfer crosses international borders. The corruption and lack of accurate maintenance record keeping is not limited to third world operations - there have been many instances of top tier airline maintenance personnel mucking up the record books - via both incompetence and deliberate action. Modern health monitoring computerized systems often share data with the carrier and the manufacturer and limit the possibilities of both incompetence or outright fraud.
Signposts and milestones: AD/AC compliance, SB compliance, maintenance deferrals, manufacturer/regulator required maintenance checks (A,B,C,D), periodic engine inspection, and manufacturer/regulator imposed life-limited part documentation, and unscheduled maintenance operations and incidents are all procedures that serve to document accumulated flight hours and flight cycles on a specific date and time.
Last edited by vapilot2004; 11th May 2015 at 04:35.