What is straight and level flight?
Straight and level flight is a fundamental flying skill that involves maintaining a constant altitude, heading and airspeed. It is used to fly cross-country between two points.
When done correctly the airspeed will remain constant, the attitude indicator will be level, the altimeter will not move, the turn coordinator will read wings level with the ball in the centre, the heading indicator will not move and the vertical speed indicator will indicate no climb or descent.
All forces are equal during unaccelerated flight.
Pitch control
Pitch Angle or Pitch Attitude – This angle is the difference between the pitch and the horizon. Think of it as the angle between the airplane’s current nose up or down attitude and the flat horizon.
Altimeter
The altimeter is the primary pitch instrument.
Attitude indicator
The attitude indicator is a supporting pitch instrument, giving a direct indication of pitch.
Vertical speed indicator
The VSI is a supporting pitch instrument, giving an indirect indication of trend and rate.
Lag must be considered.
Airspeed indicator
The airspeed indicator gives an indirect indication of pitch.
Constant pitch will result in constant airspeed, when stable.
Bank control
Bank angle is the angle at which the airplane is tilted sideways during a turn. It is the angle between the wings and the horizontal plane.
Heading indicator
The heading indicator is the primary bank instrument.
Attitude indicator
Directly and instantly shows changes in bank, but is considered a supporting bank instrument.
Turn coordinator
The turn coordinator gives an indirect indication of bank, and is a supporting bank instrument.
- Ball centred = straight and level
- Ball right = right wing low, in a right turn
- Ball left = left wing low, in a left turn
Ball indicators display the quality of a turn (coordination).
Wings level with any deflection is a skid.
Power control
Thrust is created to overcome the forces of gravity and drag.
Altitude and airspeed determine changes of pitch or power.
Power settings
The airspeed indicator is the primary power instrument, which will be thrown out of balance in under/over power conditions.
Tachometers are primary instruments to set power, but secondary once stable.
Straight and level flight procedure:
- Perform clearing turns.
- Pick a reference point, the farther away the better. Be sure to be sitting ‘normally’ when choosing a point. This point should not move in your ‘picture’.
- Maintain pitch attitude. Set the pitch so that your reference point is motionless. Note the ‘picture’ (horizon relative to the top of the dash).
- Glance at the instruments to see if the airplane is flying level. Corrections should be made with the elevator using a light grip. Adjust the pitch slowly, making small changes each time.
- Adjust the trim.
- Cross-check the instruments.
- Maintain straight flight. Check each wingtip with the horizon. They should be equidistant with the horizon.
- Glance at the heading indicator to verify straight flight. Corrections should be made with the ailerons. Check aircraft coordination with the turn coordinator.
Instrument reference
For any manoeuvre, the pitch, bank, and power control requirements are most clearly indicated by certain key instruments.
Those instruments which provide the most pertinent and essential information are referred to as primary instruments.
Supporting instruments back up and supplement the information shown on the primary instruments.
| Pitch | Bank | Power | |
| Primary | Altimeter | Heading indicator | Airspeed indicator |
| Supporting | Attitude / VSI | Attitude / Turn coordinator | Tachomer RPM |