Instrument Flight: Principles of Flight (instrument flying)
What the exam tests
Principles of Flight for instrument flying tests attitude instrument flying, stability, control, trim, load factor, turn coordination and unusual attitude recovery. It is about flying accurately without outside reference.
Core rules
- Attitude plus power equals performance; use pitch and power together to control altitude and speed.
- Trim relieves control pressure; it does not change stability.
- In a level turn, load factor increases with bank; stall speed rises.
- Adverse yaw: use rudder and keep the slip or skid ball centred.
- Instrument scan: attitude, ASI, altimeter, VSI, heading and turn coordinator; avoid fixation.
- Unusual attitude: recover with the attitude indicator, reduce power if nose-high, level the wings, then recover pitch.
Worked example
In a 45 degree bank level turn, load factor is about 1.41 g; stall speed increases by about 19%. If you pull to hold altitude without adding power, speed decays and the aircraft may stall. The fix is to lower the nose or reduce bank, then add power.
Traps
- Using trim as a primary control.
- Overbanking in a steep turn and pulling into a spiral.
- Fixating on one instrument.
- Recovering from a nose-low unusual attitude by pulling hard before levelling the wings.