Climbing and Descending The Flight Training Manual - Sections 7 and 8 Add References

Objectives To enter the climb or the descent from straight and level flight. To maintain a climb or a descent at a: - constant speed; - constant rate; - in a constant direction; and, - in balance. To level off at specific altitudes.

Principles of Flight Forces in a Climb Climb Performance Climb Configurations Forces in a Glide/Descent Descent Performance Descent Configurations

Forces in a Climb The aeroplane is in EQUILIBRIUM Thrust is GREATER than Drag Lift (W1) is LESS than Weight Thrust is EQUAL to Drag plus RCW R2 Lift Relative Airflow Drag Thrust W1 RCW Weight R1

Forces in a Climb Which Force Controls the Climb? Thrust A small aeroplane doesn’t have very much power, so use FULL Power R2 Lift Relative Airflow Drag Thrust W1 RCW Weight R1

Climb Performance – ROC (VY) Power vs Airspeed Power is the rate of doing work (climbing) (Thrust x TAS) The Best Rate of Climb (ROC) VY will be achieved at the speed at which the maximum excess of power is available. Rapid Climb to gain altitude in a short time.

Climb Performance – AOC (VX) Thrust vs Airspeed The Best Angle of Climb (AOC) VX will be achieved at the speed at which the maximum excess of thrust is available. Steep Climb to gain altitude in a short distance (e.g. to clear obstacles).

Climb Performance – Density Altitude Engine Performance (Power) decreases with increasing density altitude, therefore there is a limit to how high the aeroplane can climb

Climb Performance – Density Altitude Hot, High and Humid Increased Temperature Decreased Pressure Increased Humidity Reduces Air Density (Higher Density Altitude) L = CL½ρV2S ρ = Rho (the density of the air) V = True Airspeed (TAS) ½ρV2 equates to IAS Reduced ρ requires increased V to obtain same IAS

Climb Performance – Mass Mass (Weight) The greater the Mass, the greater the RCW, Therefore less excess Thrust/Power. VY for a heavy aeroplane may be higher than for lighter aeroplane. An increase in Mass reduces Rate of Climb and Angle of Climb.

Climb Performance – Flap Flap increases Lift and Drag. Since Drag opposes Thrust, any increase will reduce the Rate of Climb and Angle of Climb

Climb Performance – Wind Affects only the climb angle, i.e. distance travelled over the ground to reach a specific altitude.

Climb Configuration Performance = Power + Attitude C152 PA38 Best Angle of Climb (VX) Full Power/No Flap 55kt 60kt Best Rate of Climb (VY) Full Power/No Flap 65kt 70kt Climb in the circuit Full Power/No Flap 70kt 70kt Cruise Climb Full Power/No Flap 80kt 80kt

Forces in a Glide Descent The aeroplane is in EQUILIBRIUM To maintain flying speed after removing power “Lower the Nose.” FCW Balances Drag R Lift Drag Relative Airflow W1 FCW Weight

Descent Performance – Power When Power is applied, the resulting Thrust plus the FCW will exceed Drag. To maintain IAS – Raise the nose. Cruise Descent and Approach Power controls: Rate of Descent (ROD) Descent Angle Distanced Travelled Glide Add Power

Descent Performance – Lift/Drag Ratio Maximum Gliding Range The maximum gliding range is achieved at the speed for: Best Lift/Drag Ratio

Descent Performance – Lift/Drag Ratio Lift/Drag (L/D) Ratio is a measure of the efficiency of the wing Steepness of the glide depends on the L/D Ratio The HIGHER L/D, the GREATER the gliding range C152 L/D Ratio = 9:1 (1.5NM per 1000ft) at 60kt PA38 L/D Ratio = 8:1 (1.3NM per 1000ft) at 70kt

Descent Performance – Mass An increased Mass (Weight) will increase the FCW. To fly at the Best L/D Ratio requires an increase in Lift to balance the FCW. How is the increased Lift produced? Increased speed An increased ROD (NOT increased descent angle) Arrives at the same point but sooner L  AOA x IAS +Lift Lift Glide Path The variation in weight of training aircraft is not enough to significantly affect the glide speed FCW +FCW Weight +Weight

Descent Performance – Flap Flaps 0° Flaps Down Flap increases Drag, which decreases the L/D ratio. An increased FCW required to overcome the Drag to maintain speed (lower the nose). Results in a steeper Descent Angle, and an increased Rate of Descent.

Descent Performance – Wind Affects the Descent Angle and the Range from an Altitude Tailwind – Extends the Gliding Range Headwind – Reduces the Gliding Range

Descent Configurations Performance = Power + Attitude C152 PA38 Best Glide Idle / No Flap 60kt 70kt Approach 1500 RPM / Flap – A/R 70kt 70kt Cruise 2300 RPM / No Flap 100kt 100kt Glide: Engine Failure Range – Best L/D Ratio Powered: Approach. Maintains control over the descent and keeps the engine warm. Cruise: Initial descent to the Circuit. Maintain cruising speed while descending to circuit altitude.

Situational Awareness Airmanship Situational Awareness Knowing what is going on around you, and being able to predict what could happen. (Street Smarts) Level 1: Perception of the current environment; Level 2: Interpretation of the immediate situation; and Level 3: Anticipation of the future environment. Traffic Radio Maintain listening watch Location Vicinity of airfield, training area, etc. Terrain Location and Elevation

Threat and Error Management Airmanship Threat and Error Management Threats are defined as external events or errors that: occur outside the influence of the pilot(s); increase the operational complexity of the flight; and require pilot attention and management if safety margins are to be maintained. Errors are defined as pilot actions or inactions that: lead to a deviation from pilot or organisational intentions or expectations; reduce safety margins; and increase the probability of adverse operational events on the ground and during flight.

Airmanship VFR Met Minima

Lower level of Controlled Airspace? Airmanship – Levels QNH – Subscale set correctly Maximum Altitudes Lower level of Controlled Airspace? Minimum Heights Terrain Minimum Safe Altitude (MSA) Unpopulated areas 500ft AGL Built-up areas 1000ft AGL, but not less than required to Glide clear of the area

Airmanship LOOKOUT Check the area ahead every 500ft “S-Turns” or Lower the Nose (cooling) Door & Window Pillars, Instructor

Airmanship – Personal Checklist I’M S.A.F.E Illness Medication Stress Alcohol (or Drugs) Fatigue Eating

Aeroplane Management Throttle Mixture RICH Smooth throttle movements (Idle to Full Power ~ 2 sec) Climb: Full Power Prolonged Glide: Plug Fouling Excessive Cylinder Head Cooling Engine warms or Powered Descent? Mixture RICH Climb: Aids engine cooling and prevents detonation Descent: Common practice for training. Mixture will become progressively more lean as aircraft descends An excessively lean mixture can lead to detonation

Aeroplane Management Carburettor Heat Temperatures and Pressures Climb: Not used. Reduces engine performance and therefore climb performance. Descent: Select Carb Heat HOT prior to reducing power. Difficult to detect Carb Icing at low power settings, and with a closed throttle means a greater chance of it occurring. Power may not be available when needed to level out Temperatures and Pressures Climb Descent Oil Temperature Increases Decreases Oil Pressure Increase CHT Decrease Gauges in Normal Range (GREEN) Lower Nose for Cooling Engine Warm 500ft – 1000ft Powered Descent

Human Factors Trapped Gases Diving Empty sky Noise Gases in the Middle Ear, Sinus (toothache), Stomach Valsalva Manoeuvre Diving Mixed with flying can be dangerous – increase pressure change Empty sky With nothing to focus on, a short distance resting focal length (a few metres). Ensure the windscreen is clean and clear. Noise Increased noise at high power – added distraction Protection against damage to hearing.

Air Exercise – Climbing Entry: P A T Power Attitude Trim Lookout, Reference Point (DI), Reference Altitude Mixture Rich, Full Power, Balance, Keep Straight Climb Attitude, Wings Level, in Balance Remove control forces Airspeed 70kt Rate of Climb 600-800ft/min Check - Power, Attitude, Trim

Air Exercise – Climbing Airspeed Controlled by Attitude

Air Exercise – Climbing Maintaining: LAI Lookout Left to Right Attitude Correct Instruments Right to Left Confirm Change – Hold – Trim – Check

Air Exercise – Climbing Exit: A P T Attitude Power Trim Anticipate (10% ROC), Reference Pt, Reference Alt Select and hold S & L, Adjust as speed ↑, Balance Through 80kt reduce power to 2200 RPM, Balance Remove control forces Check - Power, Attitude, Trim

Air Exercise – Descending Entry: P A T Power Attitude Trim Lookout, Reference Point, Reference Altitude Mixture Rich, Carb Heat Hot, Close Throttle, Keep Straight Hold S & L, until nearly 70kt, Descent Attitude, Wings Level, Balance Remove control forces Airspeed 70kt Rate of Descent 700ft/min Check - Power, Attitude, Trim

Air Exercise – Descending Airspeed Controlled by Attitude

Air Exercise – Descending Maintaining: LAI Lookout Left to Right Attitude Correct Instruments Right to Left Confirm Change – Hold – Trim – Check

Air Exercise – Descending Exit: P A T Power Attitude Trim Anticipate (10% ROD), Reference Pt, Reference Alt 100ft to go Carb Heat Cold, 50ft to go increase power to 2200RPM, Keep Straight Select and hold S & L, Adjust as speed ↑, Balance Remove control forces Check - Power, Attitude, Trim