IFR Written Test – Flight Instruments [항공사 기출문제]

In straight-and-level flight, when reducing airspeed from high to low cruise, the primary instrument for pitch is the altimeter; the primary instrument for bank is the heading indicator; and the primary instrument for power is the manifold pressure gauge or tachometer.

During a straight, stabilized climb at a constant rate, the heading indicator is the primary instrument for bank. The supporting bank instruments are the turn coordinator and the attitude indicator.

When you are establishing a level standard-rate turn, the attitude indicator is the primary bank instrument and is used to establish the approximate angle of bank. The turn coordinator is the supporting bank instrument as you check for the standard-rate turn indication.

The primary instrument for bank control in straight-and-level flight is the heading indicator.

The pitch control instruments are the attitude indicator, altimeter, vertical speed indicator, and airspeed indicator.

The primary pitch instrument for straight-and-level flight is the altimeter.

To maintain level flight at constant thrust, the attitude indicator is the least appropriate for determining the need for pitch change. Until you have established and identified the level flight attitude for that airspeed, you have no way of knowing whether level flight as indicated on the attitude indicator is resulting in level flight as shown on the altimeter, vertical speed indicator, and airspeed indicator.

With the gyroscopic heading indicator inoperative, the primary bank instrument in unaccelerated straight-and-level flight is the magnetic compass. Since any banking results in a turn and change in heading, the magnetic compass is the only other instrument that indicates direction.

When you are entering a constant airspeed climb, the attitude indicator is the primary pitch instrument, the heading indicator is the primary bank instrument, and the tachometer or manifold pressure gauge is the primary power instrument.

After a standard-rate turn is established, the turn coordinator is the primary bank instrument.

After a standard-rate turn is established, the turn coordinator or turn and slip indicator is the primary bank instrument.

The primary pitch instrument in level flight, either straight or turns, is the altimeter.

The initial primary bank instrument when establishing a level standard-rate turn is the attitude indicator.

The initial primary bank instrument when establishing a level standard-rate of turn is the attitude indicator.

When entering a constant-airspeed climb from straight-and-level flight, the primary bank instrument is the heading indicator. Supporting bank instruments are the turn coordinator and the attitude indicator.

In a climbing left turn at a constant airspeed, the airspeed indicator is the primary instrument for pitch once the climb is established.

The supporting instruments for pitch during a change of airspeed in a level turn are the attitude indicator and the vertical speed indicator. The primary instrument is the altimeter.

The airspeed indicator is the primary power instrument as the airspeed reaches the desired value during a change of airspeed in a level turn.

The quality (coordination) of a turn relates to whether the horizontal component of lift
balances the centrifugal force. It is indicated by the ball of the turn coordinator or the ball in a turn-and-slip indicator. The airplane is neither slipping nor skidding when the ball is centered, indicating the desired quality of a turn.

As the power is increased to enter a constant-rate climb in straight flight, the primary pitch instrument is the attitude indicator until the vertical speed indicator stabilizes at the desired rate of climb (then the vertical speed indicator becomes primary). The primary bank instrument is the heading indicator. The primary power instrument is the manifold pressure gauge or tachometer.

In Fig. 145, a nose-low attitude is indicated by a negative vertical speed indicator, high airspeed (i.e., near VNE), and the airplane below the horizon on the attitude indicator. For nose-low unusual attitudes, the correct sequence for recovery is to reduce power to prevent excessive airspeed and loss of altitude; level the wings with coordinated aileron and rudder pressure to straight flight by referring to the turn coordinator; and raise the nose to level flight attitude by smooth back elevator pressure.

As the rate of movement of the altimeter and airspeed indicator needles decreases, the attitude is approaching level flight. When the needles stop and reverse direction, the aircraft is passing through level flight.

In Fig. 147, a nose-high attitude is indicated by the increasing altitude, the rate-of-climb indication on the vertical speed indicator, and the decreasing airspeed. The correct sequence for recovery is to add power, apply forward elevator pressure to lower the nose and prevent a stall, level the wings with coordinated aileron and rudder pressure to straight flight, and return to original altitude and heading.

If the attitude indicator is inoperative, a nose-low or nose-high attitude can be determined by the airspeed and altimeter. In a nose-high attitude, airspeed is decreasing and altimeter is increasing, and vice versa for nose-low attitudes.

For nose-low unusual attitudes, one should reduce the power, level the wings, and then increase the pitch to raise the nose to a level attitude.

In unusual attitudes, you can determine the attainment of level flight (not vertical movement) when the altimeter and airspeed needles stop prior to reversing their direction of movement.

In Fig. 146, the airplane is in a right turn as indicated by the attitude indicator, the heading indicator, and the turn coordinator; thus the vacuum and electrical instruments are consistent with each other. Since the attitude indicator indicates a climb, which is consistent with the altimeter and the VSI, the airspeed should not be increasing. Thus, the pitot tube ram air and drain holes are blocked, causing the airspeed indicator to react like an altimeter. To return the airplane to straight-and-level flight, you should lower the nose and level the wings to level-flight attitude by use of the attitude indicator.

Fig. 148 illustrates a climbing turn to the right. Note that the attitude indicator shows a climbing turn to the right, the heading indicator shows a turn to the right, and both the altimeter and vertical speed indicator indicate a climb. The turn coordinator shows no turn and is malfunctioning.

In Fig. 149, the vertical speed indicator, altimeter, and turn coordinator all indicate straight-and-level flight. The heading indicator indicates a turn to the south from west, which is a turn to the left. The attitude indicator indicates a turn to the right; i.e., the attitude indicator and heading indicator are in conflict. Thus, the vacuum system must be malfunctioning, and the airplane must be in straight-and-level flight.

In Fig. 150, the airplane is in a climb as evidenced by the vertical speed indicator, altimeter, and airspeed indicator. The heading indicator indicates a turn from west to north, which is a turn to the right. The turn coordinator also indicates a turn to the right. Thus, the airplane is in a climbing turn to the right. The attitude indicator is the instrument that is malfunctioning since it indicates a level turn to the left.

The vertical speed indicator, altimeter, and attitude indicator indicate level flight. The turn coordinator, attitude indicator, and heading indicator indicate a turn to the right. Accordingly, there is a level turn to the right, and the airspeed should not be near the stall speed. Thus, the ram air inlet and the drain hole of the pitot tube are clogged. The airspeed indicator will react the same way as an altimeter, if the static port is open, by showing a decrease in airspeed as altitude decreases and an increase in speed as altitude increases.

In severe turbulence, you should attempt to maintain a level flight attitude. You will not be able to maintain a constant altitude and/or airspeed, but you should fly at or below design maneuvering speed (V A) and attempt to maintain a level flight attitude.

Flight at or below the design maneuvering speed (VA) means that the airplane will stall before excess loads can be imposed on the wings.

When climbing through an inversion or wind-shear zone, the danger is a sudden change in airspeed. If the airplane were to move abruptly from a headwind to a tailwind, the airspeed would slow dramatically, and a stall or rapid descent could be induced.