Exercise 6 – Straight and Level
1. STRAIGHT & LEVEL, BALANCED FLIGHT (CRUISE)
- Pitch Attitude (Datum)/Constant Altitude, Wings Level, Straight (Visual Reference/DI),
- Ball: Inherent Stability
- Pitch to level attitude
- Check level (Altimeter)
- Adjust attitude
- Level wings (Horizon ahead)
- Check Wingtips
- Prevent yaw with rudder (PYR)
- (Reference feature)Trim
Achieving Straight and Level
- Level wings (Horizon ahead)
- Pitch to level attitude
- Check wingtips
- PYR (Reference feature)
- Check level (Altimeter) /Adjust attitude
Scan pattern and technique, integration of
- LOOKOUT, ATTITUDE; INSTRUMENTS
- Looks & feels wrong, inefficient, ball
- Looks & feels OK, still inefficient, ball
- Centre ball (rudder) / Keep straight with aileron
Maintaining S&L, Balanced Flight on Datums
- Lookout (Keep wings level/aircraft straight with aileron)
- Instruments (Altimeter, DI, ball) (LAI mnemonic)
- Adjust pitch attitude to regain datum level
- Small bank angles to regain visual reference or heading
2. STRAIGHT AND LEVEL FLIGHT WHEN DECELERATING OR ACCELERATING
Changing Power at Constant Attitude
Reduce RPM (by ± 300 RPM)
- Lower IAS, descent
Increase RPM (by ± 300 RPM)
- Higher IAS, climb
Deceleration & Acceleration
- Set Power
- Attitude (maintain initially) then Progressively Adjust Attitude (use of LAI ( Lookout, Attitude, Instruments) to maintain balanced S&L during deceleration / acceleration)
- Trim (once IAS stabilized) (PAAT mnemonic)
- Note attitude and IAS corresponding to different RPM
3. STRAIGHT AND LEVEL AT SPECIFIED AIRSPEEDS
- Assess and set power required
- P A A T
- Check IAS once stabilized
- Adjust power, if required
Full Power Acceleration
- Set full power, Progressively adjust attitude, trim.
- Anticipate IAS (5 kts), set power required
4. STRAIGHT AND LEVEL FLIGHT WITH FLAP
Effect of Extending/Retracting Flap
- At 70 kts – Constant attitude = Climb
Extending/Retracting Flap – Maintaining
- STRESS: LIMITATION, OPERATION, INDICATION
Straight And Level
- Coordination of attitude change with flap selection
- Adjust power to maintain IAS
STRAIGHT AND LEVEL FLIGHT: AMPLIFYING NOTES
- Accurate straight and level flight is frequently required for most types of operation; therefore you must teach this exercise particularly thoroughly so that your student uses correct techniques and can attain a high standard.
- Forces acting on an aircraft in flight
- Control of attitude in all planes
- Balanced flight
- Effect of power
- Threat and error management
Stress again the importance of a good lookout. Introduce the clock code to report other aircraft and ask the student to report their position using this system.
Point out local landmarks and their position relative to base.
STRAIGHT AND LEVEL FLIGHT AT CRUISING POWER
- Although in practice the wings are levelled first and then the correct pitch attitude is selected, for teaching purposes it is more efficient to teach the student to master selection of the correct pitch attitude before progressing to maintaining the direction and balance.
- Because you used the level flight (cruise) attitude as the “Datum Attitude” in Exercise 4, your student will already be familiar with it, so his task in selecting and maintaining it will be eased. (This is an example of the “Building Block” approach, used throughout the syllabus).
- Teach the student how to choose a reference point on which to keep straight and how to bring the aircraft back to the point should the direction alter.
- Teach the “Lookout, Attitude, Instruments (LAI)” work-cycle, and how to carry out an effective all-round lookout.
- Once the student has become proficient at achieving the straight and level attitude, introduce small errors and allow him ample opportunity to practice making the small corrections necessary to maintain datums accurately
- Demonstrate the inherent stability of the aircraft in straight and level by trimming the aircraft accurately and then releasing the controls.
- Demonstrate unbalanced flight by applying considerable rudder and banking the aircraft in the opposite direction to maintain direction. Ensure that you maintain both straight and level for this demo and point out the feeling of slipping, the “wrong” picture and loss of airspeed. Teach recovery by levelling the wings and stopping yaw with rudder, using outside references. Point out that reliance upon poor external references may result in slight residual imbalance and that, in these circumstances, the slip indicator must be used to obtain completely balanced flight – by centering the ball with rudder and using aileron to keep straight.
- Teach trimming:
Select and hold the pitch attitude. Sense the stick/yoke force (pushing or pulling to hold attitude?), trim wheel in the natural sense to take out stick force. Use of coarse trim A/R to relieve high control loads, then fine trim Stress – if attitude changes while trimming, stop, reselect attitude, then resume. Never use trim to change attitude.
Ensure wings are level, stop any yaw, use rudder trim in natural sense to take out rudder force. Stress keeping head up and maintaining lookout during trimming.
STRAIGHT AND LEVEL FLIGHT AT VARIOUS POWER SETTINGS
- Confirm that your student can correct for pitch and yaw tendencies that occur during power changes (as taught in Exercise 4) before continuing with the lesson.
- Demonstrate that when settled in straight and level flight, increasing power at constant attitude causes the aircraft to accelerate and climb and reducing power causes it to decelerate and descend. To maintain level flight, the correct technique is therefore to adjust the attitude progressively while the airspeed is changing. Teach: “Progressively Adjust the Attitude and Trim (PAAT)”.
- Teach also how to compensate for changing rudder effectiveness and slipstream as speed changes.
- Teach your student to associate airspeeds with power settings during this exercise to provide a basis for interpolation when flying at selected airspeeds.
- Ensure that the student trims both elevator and rudder after making power/ speed changes.
STRAIGHT AND LEVEL FLIGHT AT SELECTED AIRSPEED
- This is simply an extension of the previous part of the lesson. Nominate a speed and ask the student to assess the power required, to set it and use PAAT to maintain straight and level flight.
- Use power changes of ± 300 RPM initially. Eventually, student should learn
to fly at any airspeed within the range of the aircraft.
- As the student gains experience, teach him to use full throttle for large speed increases, reducing power as the required speed is approached (anticipate by 5 kts).
STRAIGHT AND LEVEL FLIGHT WITH FLAP
- Stress: Limitation, Operation, Indication (LOI). Never allow your student to select a flap without calling out a speed check. If he tries to, take control, remind him of the proper procedure and have him try again.
- Demonstrate that, at constant attitude, the aeroplane climbs when the flap is extended and descends (sinks) when the flap is retracted. Stress that this is instantaneous.
- Teach extending and retracting flap, whilst maintaining attitude. A lower pitch attitude is required with flap than when clean. Stress that, unlike IAS changes (when lift change is gradual), it is instantaneous when new flap selection is made manually. (With electric flaps, the change is more gradual). So co-ordinate attitude changes with flap selection. Teach initially at 70 kts as the required attitude at flap 20 is the same as 90 kts, clean.
- Show IAS reduction when flap is extended and increase with flap retraction. Teach making small power changes to maintain IAS.
- Difficulties encountered in eliminating yaw are usually due to the following causes:
- Aircraft are not laterally level (wings level).
- As speed changes, no compensation is made for changing rudder effectiveness.
- Despite careful instruction and warnings to the contrary, some students tend to develop the habit of using the trimmer to change the attitude. Nip any such tendency in the bud, if necessary by keeping your hand on the trim wheel until it’s the right time for the student to trim.