Your Answer : (Not Answered)

Correct Answer : A

Nothing transmits until the controller commands it, which makes the traffic entirely deterministic. The cost is that the controller becomes critical, so a backup controller is normally provided. Central control has a price.

Your Answer : (Not Answered)

Correct Answer : D

A null state between every bit makes the clock recoverable and removes any direct current component from the line. The three states are a positive pulse, a negative pulse and the null between them. The null carries the clock.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: The glide path is paired with it automatically

Each localiser frequency in the 108 to 112 MHz band is paired by international agreement with a glide path frequency in the 329 to 335 MHz band. Selecting the localiser therefore tunes the glide path as well, and only one frequency need be published or set.

The arrangement removes an opportunity for error at a busy moment. It also explains why a localiser can exist without a glide path - giving a non-precision localiser-only approach - while a glide path is never provided without its paired localiser.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: Corrections must shrink as the runway nears

Every figure in the table falls as the distance falls, because the guidance is angular and the beams converge on their transmitters. Full scale localiser deflection is 2650 feet at ten miles but only 265 at one - a tenfold reduction for the same needle position.

The consequence for handling is direct: a correction that is right at ten miles is ten times too large at one. A pilot who continues to correct as vigorously as at range will oscillate about the centreline, and the oscillation grows worse precisely as the margin for it disappears.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Distance measuring equipment interrogator in the aircraft

The interrogator is airborne equipment carried by the aircraft, not part of the ground installation. It transmits to a ground transponder and times the reply to derive slant range.

The instrument landing system installation proper consists of the localiser transmitter at the far end of the runway, the glide path transmitter beside the touchdown zone, and the marker beacons on the approach path - together with the monitoring that shuts the system down if it drifts out of tolerance. The distinction between ground and airborne elements is worth holding clearly.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: 1200 feet

The pressure altimeter on QNH reads height above mean sea level, and the radio altimeter reads height above the ground directly beneath. The terrain elevation is the difference:

\[ 1250 - 50 = 1200\ \mathrm{ft} \]

The two instruments answer different questions, which is why both are carried. On an approach the pressure altimeter is used against the published procedure altitudes, while the radio altimeter provides the decision height and the automatic callouts in the final stages, where what matters is the ground rather than the datum.

Your Answer : (Not Answered)

Correct Answer : C

Both hold and the second gives both halves of the argument. The cost is an output that depends on a difference, so cold junction compensation must be applied before the reading is absolute. That single requirement shapes the whole installation.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: It is an incremental encoder needing a homing sequence

Two clues fix it. The indication is random at power up, so no absolute position is being read; and cycling the flaps once corrects it, which is a homing sequence finding its reference mark.

That is exactly incremental encoder behaviour: the device counts increments, the count is lost with power, and position is meaningless until a reference is passed. An absolute encoder would report correctly at power up, and a worn potentiometer or broken synchro winding would give a fault that cycling could not clear.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: Has a large non-linear change

A thermistor is a semiconductor, and its resistance changes far more steeply with temperature than a metal's - typically several per cent per degree against 0.4 for platinum - but the relation is strongly non-linear, roughly exponential.

The trade is sensitivity against linearity and range. A thermistor gives a large signal over a narrow band, which suits monitoring around a set point; an RTD gives a smaller but linear signal over hundreds of degrees. Both are passive and both need excitation.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: magenta

Magenta marks the active flight plan leg - the segment being flown towards the active waypoint. The convention runs across the flight deck: magenta also marks the selected target values and the flight director cues, so it consistently means "what the aircraft is doing or aiming at now".

It carries no alerting sense. Red and amber alone signify warnings and cautions, green a normal or engaged condition, and cyan information or reference data. Reserving the alerting colours strictly for alerts is what makes their appearance meaningful.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Both Statement I and Statement II are correct

Both statements are correct and the second is the reason for the first. Standby instruments run from their own sensors, their own power - typically including a dedicated battery - and their own display, sharing nothing with the main system.

Without that independence, a single failure of the symbol generators, the display power supply or a main electrical bus could remove every attitude reference at once, leaving the crew with no means of keeping the aircraft upright in cloud. The standby is the last line of defence, so its value lies entirely in what it does not share.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: A terrain and obstacle database

A synthetic vision system draws a computer-generated view of the terrain and obstacles ahead from a stored database, positioned and oriented by the aircraft's own navigation solution. The result is a clear, uncluttered picture of the world in any weather and at night.

Its limitation follows directly from its source: it can only show what the database holds and what the navigation system believes the position to be. Nothing transient - another aircraft, a vehicle, an unmapped obstruction - appears at all, which is why it complements rather than replaces an enhanced vision system.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Only three

The first three are right. The underwater locator beacon transmits at 37.5 kHz, the older emergency locator transmitter frequency is 121.5 MHz, and 406 MHz is the satellite-detected distress frequency.

The fourth is wrong: 8.33 kHz is the channel spacing used in VHF air-band radio, a matter of how the aeronautical spectrum is divided, and has nothing to do with underwater acoustics. Note the three orders of magnitude separating the acoustic frequency from the radio ones.

Your Answer : (Not Answered)

Correct 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.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: absolute

An absolute pressure gauge is referenced to vacuum, so it reads the true pressure of the charge rather than its excess over ambient. With the engine stopped the manifold is open to atmosphere through the induction system, so the gauge indicates ambient pressure.

That gives a useful pre-start check - the reading should agree with the local altimeter setting. A gauge measuring differential or gauge pressure would read zero instead, and would also lose its meaning as altitude changed, since the same manifold pressure at sea level and at height represents the same charge density either way only on an absolute scale.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: 11500 rpm

The percentage indication is referred to the datum speed:

\[ N = 0.92 \times 12\,500 = 11\,500\ \mathrm{rpm} \]

The distractor 13587 divides by 0.92 instead of multiplying, giving a speed above the datum for an indication below 100 per cent - an impossibility worth spotting before any arithmetic is done. Percentage display is used because it lets one scale and one set of limits serve engines whose absolute speeds differ widely, low-pressure and high-pressure spools included.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: A-1, B-2, C-3, D-4

The four terms cover the property, the response, the failure and the correction. Rigidity is the axis staying fixed absent a torque; precession is the motion at 90 degrees when a torque is applied.

Toppling is the axis tumbling when the gimbal limits are exceeded, after which the reference is lost. Erection is the system that torques the axis gently back towards the vertical, correcting drift - and it is the source of the acceleration and turn errors, since it finds the vertical pendulously.

Your Answer : (Not Answered)

Correct Answer : A

The other three all depend on a spinning rotor for their indication. The ball is a purely mechanical device responding to the resultant of gravity and centrifugal force, and it merely shares a case with the turn instrument.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason explains the first exactly. The instrument displays the rate at which static pressure is changing, so if the port is blocked the trapped pressure stops changing and the indication falls to zero regardless of what the aircraft is doing. A zero vertical speed during an evident climb is therefore a direct pointer to a static blockage.

Your Answer : (Not Answered)

Correct Answer : C

The pitot line vents through the drain to static pressure, so the differential across the capsule collapses. If the drain is blocked as well, the trapped pressure instead makes the instrument behave like a crude altimeter.