Aeroplane Equipment and Instruments — Page 82, Lesson 125

I want to walk you through the regulatory requirements for Flight Data Recorders — what they are, which aircraft must carry them, and how long they must record. This is a key piece of aeroplane equipment, and the rules are phased by the date the aircraft was first issued with its individual Certificate of Airworthiness, or CofA. Let’s start with the most recent rule, which the book labels Flight Data Recorders - 1. An operator cannot operate an aeroplane first issued with an individual CofA on or after 1 April 1998 unless it meets certain conditions. The aircraft must be equipped with a flight data recorder that uses a digital method of recording and storing data, and there must be a method of readily retrieving that data from the storage medium. So we are talking about a digital recorder, not an older analogue tape system, and the data has to be easily accessible for analysis. Which aircraft fall under this rule? Two categories. First, any multi-engine turbine powered aeroplane with a maximum approved passenger seating configuration of more than 9. Second, any aeroplane with a maximum certificated take-off mass over 5700 kg. If either condition applies, the recorder is mandatory. Now, how long must it keep the data? The flight data recorder must be capable of retaining the data recorded during at least the last 25 hours of its operation. However, there is an exception: for those aeroplanes with a maximum certificated take-off mass of 5700 kg or less, this period may be reduced to 10 hours. So a smaller turbine aircraft with more than 9 passenger seats can get away with a 10-hour recording capability instead of 25. Next, we have Flight Data Recorders - 2, which covers an earlier period. This applies to any aeroplane first issued with an individual CofA on or after 1 June 1990 up to 31 March 1998, with a maximum certificated take-off mass over 5700 kg. For those aircraft, the same requirement applies: a digital flight data recorder with a method of readily retrieving the data. The retention period here is at least the last 25 hours — no reduction to 10 hours is mentioned for this group. Then we have Flight Data Recorders - 3, for the oldest aircraft. This applies to any turbine-engined aeroplane first issued with an individual CofA before 1 June 1990, which has a maximum certificated take-off mass over 5700 kg. Again, it must be equipped with a digital flight data recorder with retrievable data, and it must retain at least the last 25 hours of operation. The book provides a Summary that ties these three cases together chronologically. Let me walk through it. The earliest requirement — Case 3 — covered turbine-powered aeroplanes with a maximum take-off mass, or MTOM, over 5700 kg. Then, after 1 June 1990, the rule was expanded to include all aeroplanes over 5700 kg MTOM, not just turbine-powered ones — that is Case 2. Finally, after 1 April 1998, the rule was further extended to include turbine-powered aeroplanes with an MTOM less than 5700 kg, but only if they have more than 9 passenger seats. And on those smaller turbine aircraft, the recording time can be reduced to 10 hours. So the key takeaway: the regulations have progressively widened the net over time, bringing in more aircraft types, and the retention period is generally 25 hours, with a 10-hour allowance only for the lighter turbine aircraft with more than 9 seats that fall under the most recent rule.