Flight Instrument Flashcards

How should a pilot determine the direction of bank from an attitude indicator such as the one illustrated?

Answer: By the relationship of the miniature airplane (C) to the deflected horizon bar (B).

The attitude indicator displays the aircraft's attitude relative to the natural horizon. The miniature airplane (C) remains fixed relative to the pilot, while the horizon bar (B) moves to represent the actual horizon. Therefore, the direction of bank is determined by observing how the miniature airplane's wings relate to the deflected horizon bar.

Deviation in a magnetic compass is caused by the

Answer: magnetic fields within the aircraft distorting the lines of magnetic force.

Deviation is a compass error caused by localized magnetic fields within the aircraft itself. These fields originate from electrical currents, ferrous metals, and other magnetic sources in the cockpit and airframe. They distort the Earth's natural magnetic lines of force, causing the compass needle to point slightly away from magnetic north.

In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the west if

Answer: a right turn is entered from a north heading.

This is an example of Northerly Turning Error (UNOS - Undershoot North, Overshoot South). When turning right from a north heading in the Northern Hemisphere, the magnetic compass's dip errors cause it to initially lag behind the actual turn. This lag makes it appear as if the aircraft is turning towards the west, even though it's turning right (east).

In the Northern Hemisphere, a magnetic compass will normally indicate initially a turn toward the east if

Answer: a left turn is entered from a north heading.

This is another instance of Northerly Turning Error (UNOS). When entering a left turn from a north heading in the Northern Hemisphere, the magnetic compass's dip errors cause it to initially lag behind the actual turn. This lag makes it appear as if the aircraft is turning towards the east, even though it's turning left (west).

In the Northern Hemisphere, a magnetic compass will normally indicate a turn toward the north if

Answer: an aircraft is accelerated while on an east or west heading.

This describes Acceleration Error (ANDS - Accelerate North, Decelerate South). When accelerating on an east or west heading in the Northern Hemisphere, the compass card tilts due to inertia and magnetic dip, causing the compass to indicate a turn towards the north. This error is most pronounced on east and west headings.

In the Northern Hemisphere, the magnetic compass will normally indicate a turn toward the south when

Answer: the aircraft is decelerated while on a west heading.

This is an example of Acceleration Error (ANDS - Accelerate North, Decelerate South). When decelerating on an east or west heading in the Northern Hemisphere, the compass card tilts due to inertia and magnetic dip, causing the compass to indicate a turn towards the south. This error is most pronounced on east and west headings.

In the Northern Hemisphere, if an aircraft is accelerated or decelerated, the magnetic compass will normally indicate

Answer: correctly when on a north or south heading.

Acceleration and deceleration errors (ANDS) primarily affect the magnetic compass when the aircraft is on an east or west heading. When flying directly north or south, the magnetic lines of force are aligned with the compass's axis of rotation, minimizing the effect of inertia and magnetic dip on the compass card. Therefore, the compass will indicate correctly during acceleration or deceleration on these headings.

During flight, when are the indications of a magnetic compass accurate?

Answer: Only in straight-and-level unaccelerated flight.

A magnetic compass is subject to several errors, including variation, deviation, magnetic dip, and acceleration/deceleration errors. These errors are minimized or absent only when the aircraft is in stable, straight-and-level flight without any acceleration or deceleration. Any change in attitude, speed, or direction will introduce inaccuracies.

If a pilot changes the altimeter setting from 30.11 to 29.96, what is the approximate change in indication?

Answer: Altimeter will indicate 150 feet lower.

The altimeter setting is decreasing from 30.11 to 29.96, a difference of 0.15 inches of mercury. Since 1 inch of mercury typically equates to 1,000 feet of altitude, 0.15 inches Hg corresponds to 150 feet (0.15 x 1000 = 150). When the altimeter setting is decreased, the altimeter will indicate a lower altitude.

If a flight is made from an area of low pressure into an area of high pressure without the altimeter setting being adjusted, the altimeter will indicate

Answer: lower than the actual altitude above sea level.

When flying from an area of low pressure into an area of high pressure without adjusting the altimeter, the instrument will 'think' it's in lower pressure than it actually is. This causes the altimeter to indicate a lower altitude than the aircraft's actual height above sea level. This is often remembered by the phrase 'High to Low, Look Out Below'.

If a flight is made from an area of high pressure into an area of lower pressure without the altimeter setting being adjusted, the altimeter will indicate

Answer: higher than the actual altitude above sea level.

When flying from an area of high pressure into an area of lower pressure without adjusting the altimeter, the instrument will 'think' it's in higher pressure than it actually is. This causes the altimeter to indicate a higher altitude than the aircraft's actual height above sea level. This is a critical safety consideration, often remembered by 'High to Low, Look Out Below', as it can lead to flying lower than intended.

Under what condition will true altitude be lower than indicated altitude?

Answer: In colder than standard air temperature.

Altimeters are calibrated for standard atmospheric conditions. In colder than standard air temperatures, the air is denser and contracts, meaning that a given pressure level will be physically lower than it would be in standard conditions. If the altimeter is set to the correct pressure, it will indicate a higher altitude than the aircraft's true altitude above sea level, a concept often summarized as 'Cold to High, Look Out Below'.

Which condition would cause the altimeter to indicate a lower altitude than true altitude?

Answer: Air temperature warmer than standard.

Altimeters are calibrated for standard atmospheric conditions. In warmer than standard air temperatures, the air is less dense and expands, meaning that a given pressure level will be physically higher than it would be in standard conditions. If the altimeter is set to the correct pressure, it will indicate a lower altitude than the aircraft's true altitude above sea level, a concept often summarized as 'Warm to Low, No Go'.

What should be the indication on the magnetic compass as you roll into a standard rate turn to the right from a south heading in the Northern Hemisphere?

Answer: The compass will indicate a turn to the right, but at a faster rate than is actually occurring.

This is an example of Southerly Turning Error (UNOS - Undershoot North, Overshoot South). When turning right (west) from a south heading in the Northern Hemisphere, the magnetic compass's dip errors cause it to lead the actual turn. This means the compass will initially indicate a turn to the right at a faster rate than the aircraft is actually turning.

Deviation error of the magnetic compass is caused by

Answer: certain metals and electrical systems within the aircraft.

Deviation error is caused by localized magnetic fields within the aircraft itself. These fields are generated by electrical currents flowing through wiring, as well as the presence of ferrous metals (like steel) in the aircraft structure or engine components. These internal magnetic influences distort the Earth's magnetic field, causing the compass to 'deviate' from magnetic north.

What is an advantage of an attitude indicator that is displayed digitally?

Answer: The horizon line extends all the way to the edges of the PFD.

A significant advantage of a digitally displayed attitude indicator (on a Primary Flight Display or PFD) is the ability to extend the horizon line across the entire width of the screen. This provides a much larger and clearer visual reference for the pilot, enhancing situational awareness of the aircraft's pitch and bank attitude, especially during unusual attitudes or instrument flight.

The Air Data Computer or ADC

Answer: combines data from the pitot-static sensors and temperature sensors.

The Air Data Computer (ADC) is a crucial component in modern aircraft avionics. It receives raw pressure data from the pitot tube (for dynamic pressure) and static port (for static pressure), along with outside air temperature information. The ADC then processes this data to calculate and output critical flight parameters such as airspeed, altitude, vertical speed, and outside air temperature to other systems and displays.

Glass cockpit aircraft refer to

Answer: aircraft with both digital and limited number of analog instruments.

While 'glass cockpit' implies a heavy reliance on digital displays (like PFDs and MFDs), most modern glass cockpit aircraft still retain a limited number of traditional analog instruments. These analog instruments often serve as standby or backup instruments for critical flight parameters (e.g., airspeed, altitude, attitude) in case of a primary digital system failure, providing redundancy and ensuring safety.

What antidotal phrase can help reverse the hazardous attitude of impulsivity?

Answer: Not so fast, think first.

Impulsivity is a hazardous attitude characterized by acting quickly without thinking through the consequences. The antidotal phrase 'Not so fast, think first' directly addresses this tendency by encouraging a pause for reflection and analysis before taking action. This helps pilots make more deliberate and safer decisions.