Flight Data Recording Questions and Answers

Answer: C

Correct answer: All four sectors and the turnarounds

Add the elapsed time:

\[ 4 \times 3 + 3 \times 1 = 12 + 3 = 15\ \mathrm{hours} \]

which is comfortably within the 25 hours retained, so nothing has been overwritten. Note that the turnarounds count: the recorder runs whenever the aircraft has power, so ground time consumes retention exactly as flight time does. That is why the requirement is expressed in hours of recording rather than in sectors.

Answer: D

Correct answer: 33 000 m/s squared

Convert the g figure using \( g = 9.81 \) m/s\(^2\):

\[ 3400 \times 9.81 = 33\,354\ \mathrm{m/s^2} \]

The distractor 3400 m/s\(^2\) omits the conversion entirely. The magnitude is what the test represents: a deceleration of that order for 6.5 milliseconds is the crash impact the memory module must survive, and it is applied along with crush, penetration, fire and immersion in a defined sequence.

Answer: A

Correct answer: 3.0 per cent

The rate is events over flights:

\[ \frac{120}{4000} \times 100 = 3.0\% \]

Such a figure is meaningful only in comparison - against the fleet, against last quarter, against a particular airport or approach. That is the purpose of flight data monitoring: single events say little, while a rate that moves points to a procedure or a location worth examining, and the same measurement afterwards shows whether the change worked.

Answer: B

Correct answer: 80

Apply the conversion in order, multiplying before subtracting:

\[ 400 \times 0.25 - 20 = 100 - 20 = 80 \]

The distractor 100 stops before the offset and 380 subtracts before multiplying. Every recorded parameter carries such a scaling, and it is specific to the aircraft and the installation - which is why a readout is meaningless without the correct data frame layout document, and why an investigation validates the converted values against independently known events.

Answer: C

Correct answer: Both Statement I and Statement II are correct

Both are true and the second is the reason for the first. The recorder writes on a loop, so every minute it continues running overwrites a minute of the oldest material.

Where the relevant events lie near the start of the retained period, leaving it powered destroys the evidence. Pulling the breaker stops the loop, and the requirement is written into operators' procedures. It is also why voice retention has grown from 30 minutes to two hours and to 25 on new types.

Answer: D

Correct answer: Both Statement I and Statement II are correct

Both are true and the second explains the first. Sea water conducts, and the radio frequencies used by emergency locator transmitters are attenuated within a very short distance of the surface - a 406 MHz signal does not escape from depth at all.

Sound does propagate, and well, so the underwater beacon emits an acoustic pulse at 37.5 kHz that a hydrophone can detect at a range of a mile or two. The physics of the medium dictates the choice.

Answer: A

Correct answer: Both Statement I and Statement II are correct

Both are true and the second is the reason for the first. Recording bandwidth is finite, so it is allocated where it does most good.

Control positions and accelerations change within a fraction of a second and need several samples per second to be reconstructed; fuel quantity and configuration discretes change over minutes and one sample every few seconds captures them fully. Sampling everything at the highest rate would exhaust the frame without adding information, which is what the layered subframe format exists to avoid.

Answer: B

Correct answer: Both Statement I and Statement II are correct

Both are true and the second gives the reasons. Solid-state memory has no moving parts, so there is no transport mechanism to jam, no tape to stretch or snap, and no head to misalign.

It survives impact and fire far better, and it is easier to protect because the whole memory sits in one small armoured module rather than on a length of tape. Capacity ceased to be a constraint at the same time, which is why parameter lists grew so markedly once the change was made.

Answer: C

The second statement is broadly true but the first is not, because a quick access recorder is not armoured and would not survive an accident. It exists for routine downloads rather than for post-accident investigation.

Answer: D

Correct answer: Both Statement I and Statement II are correct

Both are true and the second is why the first is done. A flight data monitoring programme depends on crews accepting that the data will not be used against them individually.

Where it is perceived as punitive, crews avoid the behaviours that generate events rather than the hazards that cause them, and the programme stops measuring anything real. De-identification, with a gatekeeper able to re-identify only under an agreed protocol, is what keeps the data honest - a matter of programme design rather than of privacy law alone.