Flight Data Recording Questions and Answers

Answer: A

The programme exists to find systemic issues, and a rate four times the network average points at the procedure or the airport rather than at individuals. Using it punitively would end the crew agreement the data depends on.

Answer: B

Correct answer: A recommendation to add the parameter to future requirements

The aircraft complied with the list in force when it was built, so there is no non-compliance to find - and that is precisely the point. The mandatory list has grown steadily because investigations keep discovering what it lacks.

The normal outcome is a safety recommendation to the regulator to add the parameter for future aircraft, and sometimes retrospectively. Neither operator negligence nor certificate withdrawal follows from meeting the applicable requirement.

Answer: C

Correct answer: Power can destroy surviving data

Salt water is conductive and corrosive. Applying power to a wet module can short tracks, and current through an electrolyte drives corrosion far faster than immersion alone - destroying cells that would have been readable after proper cleaning and drying.

There is only one attempt at a unique record, which is why the sequence is fixed: assess, clean, dry, then read, with the memory chips removed and read directly if the interface is damaged. The data is not erased by immersion, which is what makes the haste so costly.

Answer: D

That frequency propagates well through sea water and is picked up by a hydrophone. The radio frequencies used by emergency locator transmitters do not travel through water at all, which is why a separate acoustic device is fitted.

Answer: A

Correct answer: bright orange

The casing is painted bright orange, often with reflective strips, so that it can be found in wreckage, in vegetation or floating. "Black box" is a colloquialism with no basis in the hardware.

The name is usually traced to wartime usage for any sealed instrument whose workings were not the operator's concern, and it stuck. Visibility is a genuine design requirement rather than a convention, which is why the colour is specified along with the survivability standards.

Answer: B

Correct answer: loop

The recorder writes continuously into a fixed memory and returns to the beginning on reaching the end, so it always holds the most recent interval and overwrites what precedes it.

Recording therefore never stops for want of space, but evidence is lost if the unit keeps running after the event - which is why the circuit breaker is pulled promptly after a serious incident. A write-once or single-pass medium would fill and stop; the loop trades permanence for continuity.

Answer: C

Correct answer: acquisition

The flight data acquisition unit gathers parameters from sensors and system buses, converts them to the required resolution, and assembles them into the frames and subframes the recorder writes.

It is where the data frame layout lives, which is why a readout is meaningless without the layout document for that aircraft - the same word position carries different parameters on different installations. The recorder itself simply stores what the acquisition unit hands it and protects it.

Answer: D

Correct answer: quick access

The quick access recorder holds the same data stream in an ordinary enclosure that is easy to reach and download, and it exists for routine flight data monitoring rather than accident investigation.

That is why it is not crash protected: the crash-protected recorder is deliberately hard to access, and downloading it after every flight would be impractical. The QAR is not mandated by regulation but is fitted almost universally, since a monitoring programme depends on getting the data off the aircraft easily.

Answer: A

Correct answer: The beacon operating period

Read the table for the row where the requirement changed in response to search experience. The beacon's period is the one that grew from 30 days to 90 on some installations.

The reason is direct: deep-water accidents have taken longer than 30 days to locate, and once the battery expires the acoustic search ends. Data recorder duration is unchanged, and the voice recorder's extension was driven by investigations wanting more of the flight rather than by the difficulty of finding the unit.

Answer: B

Correct answer: Rate is matched to how fast the parameter can meaningfully change

Read the reason column: it runs from "changes very rapidly" down to "changes slowly", and the rates fall with it from 8 Hz to 0.25.

Frame capacity is finite, so bandwidth is spent where information exists. Vertical acceleration carries turbulence and hard landings within a fraction of a second; fuel quantity cannot change meaningfully between one four-second frame and the next. Sampling everything at 8 Hz would exhaust the frame without adding anything.