Exercise 6 - Straight and Level Flight

Question 1

Definitions - Heading

Answer 1

• Direction the aircraft nose is pointed
• Measured in degrees form magnetic north

Question 2

Definitions - KIAS

Answer 2

• Knots Indicated Airspeed
• Read off airspeed indicator

Question 3

Straight and Level Flight

Answer 3

• Straight Flight means constant heading
• Level Flight means constant altitude
• Straight and Level is both, can only be cruise attitude

Question 4

Airspeed Changes

Answer 4

• Straight and Level can be at various airspeeds
• 100 RPM change correlates to 5 KIAS change
• If we change power but keep attitude the same, the aircraft with climb or descend
• We must change our altitude slightly
• 5 KIAS correlates to 1 degree nose up/down to maintain attitude
• Attitude + Power = Performance

Question 5

Pitch Trim - What the Tail is Doing

Answer 5

• Lift acts behind centre of gravity in conventional aircraft, nose naturally wants to pitch down
• Elevator is used to hold nose up, amount of deflection depends on speed
• Trim balances the forces on the elevator to hold it in place

Question 6

Pitch Trim - How Trim Works

Answer 6

• Trim tab attached to elevator, can be adjusted up or down
• Airflow over the tab forces the elevator in the opposite direction
• Trim maintains speed, but also allows us to maintain altitude without working very hard
• Trim tab moves in the opposite direction of the elevator

Question 7

Procedure - Establish Straight and Level Flight

Answer 7

• Look Out
• Level the Wings with ailerons
• Adjust attitude to maintain altitude
• Trim to relieve control pressure

Question 8

Procedure - Changing Speed in Straight and Level Flight

Answer 8

• Look Out
• Adjust Power
• Slowly adjust attitude to maintain altitude as speed changes
• Trim to relieve control pressure

Question 9

Factors affecting Straight and Level - Yaw

Answer 9

• Changing power will change adverse yaw forces
• Remember to check ball and adjust accordingly

Question 10

Factors affecting Straight and Level - Trim

Answer 10

• Aircraft will fly at the trimmed speed even if we change power settings
• Remember to trim following speed changes

Question 11

Factors affecting Straight and Level - Compass Errors

Answer 11

• Compass works by aligning with earth’s magnetic field lines
• field lines are not parallel to surface of earth, so the compass has freedom to tilt
• this is known as magnetic dip, and makes the compass react to acceleration forces by turning
• more pronounced towards the poles
• Solution is to know when they occur, set heading when compass is reliable
• Heading indicator used for reference when turning or accelerating

Question 12

Factors affecting Straight and Level - Acceleration Errors

Answer 12

• Compass turns while accelerating, even though no heading change is occurring
• Most apparent on east and west headings
• No error on north and south headings
• ANDS, Accelerate, North, Decelerate, South

Question 13

Factors affecting Straight and Level - Turning Errors

Answer 13

• Compass lags or leads during turns, depending on heading
• Most apparent on north and south headings
• No error on east or west headings
• NAGS and SEADS
• NAGS is North lAGS
• SEADS is South lEADS

Question 14

Factors affecting Straight and Level - Heading Indicator

Answer 14

• Direction Gyro is stable reference, no magnetic dip
• Set against compass, then use as main heading reference
• Errors include gyroscopic precession due to internal friction, and also apparent precession
• Reset every 15 minutes

Question 15

Straight and Level Flight - Lookout

Answer 15

• Keep and eye out for traffic, particularly at lower speeds (higher nose up attitude reduces visibility)