Cockpit Display Systems Questions and Answers

Answer: C

The crew or the system reassigns the important content to a working screen, so a display failure degrades the presentation rather than removing the information. Compacting two pictures onto one screen is the cost of doing so.

Answer: D

Correct answer: Give an independent attitude reference

Standby instruments exist to survive whatever takes the main displays away. They run from their own sensors, their own power supply - typically including a battery - and their own display, sharing nothing with the glass system, so a failure of the symbol generators, the display units or the main electrical busses leaves them working.

What they must provide above all is attitude, together with airspeed and altitude, since attitude is what keeps the aircraft under control. They are not there for engine data, and they cannot substitute for a navigation display.

Answer: A

Correct answer: Collimated in the forward field of view

A head-up display projects symbology onto a transparent combiner in the pilot's forward field of view, collimated so that the image appears focused at infinity. The pilot therefore sees the symbols superimposed on the outside world without refocusing between the two, and without looking down into the cockpit.

That is the whole benefit: eyes-out flying with the flight information present. A screen below the glareshield or projected onto the panel would be head-down, and a handheld device is neither collimated nor fixed in the field of view.

Answer: B

Correct answer: Overlay the real world features they represent

Conformal symbology is drawn so that it aligns with the real world seen through the combiner. The artificial horizon lies along the true horizon, the runway outline overlays the actual runway, and the flight path vector sits at the point on the ground the aircraft is actually going to.

This requires the display to know the aircraft's attitude and position accurately and to update fast enough that the symbols do not lag the scene. Non-conformal elements such as airspeed and altitude readouts are placed clear of the centre so as not to obscure the view.

Answer: C

Correct answer: Sensors imaging the real scene

An enhanced vision system images the actual scene in front of the aircraft using sensors that see through conditions the eye cannot - infrared, millimetre wave radar, or low-light cameras - and presents that image on a head-up or head-down display.

Because it shows what is really there, it can reveal an unlit obstruction or an aircraft on the runway. That is the essential contrast with a synthetic vision system, which draws a clean picture from a stored terrain database and therefore shows only what the database contains.

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.

Answer: A

Depth, weight and heat all fall dramatically, which matters in a panel with no spare volume. Sunlight readability was the other decisive advantage, since a flight deck is one of the brightest working environments there is.

Answer: B

Correct answer: Excess information slows extraction

Clutter is a human factors problem, not an engineering one. Beyond a certain density each additional symbol makes every other symbol harder to find, so the time to extract a needed value rises and the chance of missing something important rises with it - exactly when workload is highest and the margin least.

The remedies are decluttering options that remove layers on demand, automatic suppression of irrelevant data by flight phase, and disciplined use of colour and brightness so that important items stand out. Weight, power and display life are unaffected.

Answer: C

The aircraft then does something correct for its actual mode and unexpected to the crew. Clear annunciation of the active mode is the primary defence, which is why mode annunciators sit at the top of the primary flight display.

Answer: D

The most demanding requirement concerns displaying misleading information, which is treated as more hazardous than displaying nothing at all. A blank screen tells the crew to look elsewhere while a plausible wrong value does not.