Climbs and climbing turns are basic flight maneuvers in
which the pitch attitude and power result in a gain in altitude. A straight
climb is one in which the airplane gains altitude while traveling straight
ahead. Climbing turns are those in which the airplane gains altitude while
|As used in this chapter, a normal climb is one made at
a pitch attitude and airspeed which, when constantly maintained, will give
the best altitude gain with the engine controls set to the climb power
recommended by the manufacturer.
As with the other maneuvers, climbs should be performed by using both flight instruments and outside visual references (Fig. 6-8). The normal climb speed recommended by the airplane manufacturer should be used. This is usually very close to the airplane's best rate of climb airspeed, but may be slightly higher to provide better engine cooling or increased flight visibility.
As a climb is started, the airspeed will gradually diminish. This reduction in airspeed is gradual, rather than immediate, because of the initial momentum of the airplane. The thrust required to maintain straight and level flight at a given airspeed is not sufficient to maintain the same airspeed in a climb; climbing flight takes more power than straight and level flight. Consequently, the engine power controls must be advanced to a higher power setting.
The effects of torque at the climb power setting are a primary factor in climbs. Since the climb airspeed is lower than cruising speed, the airplane's angle of attack is relatively high. With these conditions, torque and asymmetrical loading of the propeller will cause the airplane to have a tendency to roll and yaw to the left. To counteract this, right rudder pressure must be used. During the early practice of climbs and climbing turns, this may make coordination of the controls feel awkward, but after a little practice the correction for torque effects will become instinctive.
Trim is also a very important consideration during a climb. After the climbing attitude, power setting, and airspeed have been established, the airplane should be trimmed to relieve all pressures from the controls. If further adjustments are made in the pitch attitude, power, or airspeed, the airplane must be retrimmed.
As the airplane gains altitude during a climb, the manifold pressure gauge (if the airplane is so equipped) will indicate a loss in pressure (power), because the same volume of air going into the engine's induction system gradually decreases in density as altitude increases. Thus, the total pressure in the manifold (and consequently power) decreases. This will occur at the rate of approximately 1" of manifold pressure for each 1,000 foot gain in altitude. During prolonged climbs, then, the throttle must be continually advanced if a constant power is to be maintained.
When performing a climb, the power should be advanced to the climb power settings recommended by the airplane manufacturer. If the airplane is appropriately equipped, this will include engine RPM and manifold pressure. Normally, the flaps and landing gear (if retractable) should be in the up position to reduce drag, although practice may also be accomplished with the gear down to simulate a climb immediately after takeoff.
To enter the climb, simultaneously advance the throttle and apply back pressure on the elevator. As the power is increased to the climb setting, the airplane's nose will tend to rise toward the climbing attitude. While the pitch attitude increases and as the airspeed decreases, progressively more right rudder pressure must be used to compensate for torque effects and to maintain direction. Usually right rudder trim will be required to relieve this pressure.
When the climb is established, back elevator pressure must be maintained to keep the pitch attitude constant. It will be noted that as the airspeed decreases, the elevators will try to return to their neutral or streamlined position and the airplane's nose will tend to lower. Nose up elevator trim should be used to compensate for this so that the pitch attitude can be maintained without holding back pressure on the elevator control. Throughout the climb, since the power is fixed at the climb power setting, the airspeed must be controlled by the use of elevator.
The pilot should cross check the airspeed indicator and the position of the airplane's nose in relation to the horizon, as well as the pitch attitude shown on the attitude indicator, to determine if the pitch attitude is correct. At the same time a constant heading should be held with the wings level if a straight climb is being performed, or a constant angle of bank if in a climbing turn.
To return to straight and level flight from a climbing attitude, it is necessary to start the level off approximately 50 feet below the desired altitude. While approaching that altitude, the wings should be leveled and the nose lowered to the level flight attitude. The nose must be lowered gradually, however, because a loss of altitude will result if the pitch attitude is decreased to the cruising level flight position without allowing the airspeed to increase proportionately. As the nose is lowered and the wings leveled, the airplane should be retrimmed (Fig. 6-9).
After the airplane is in a level attitude, climb power should be retained temporarily so that the airplane will accelerate to desired cruise speed. When the airspeed reaches the desired cruise speed, the throttle setting and the propeller control (if so equipped) should then be reduced to appropriate cruise power settings, the mixture control adjusted to a lean position, and the airplane trimmed for "hands off" flight.
In developing skills in the performance of climbing turns, the following factors should be considered:
1. With a constant power setting, the
same pitch attitude and airspeed cannot be maintained in a bank as in a
straight climb due to the decrease in effective lift and airspeed during
2. The degree of bank should be neither too steep nor too shallow. Too steep a bank intensifies the effect mentioned in 1 above. If too shallow, the angle of bank may be difficult to maintain because of the inherent stability of the airplane.
3. A constant airspeed, a constant rate of turn, and a constant angle of bank must be stressed. The coordination of all controls is likewise a primary factor to be stressed and developed.
4. The airplane will have a greater tendency towards nose heaviness than in a normal straight climb, due to the decrease in effective lift as is the case in all turns.
5. As in all maneuvers, attention should be diverted from the airplane's nose and divided among all references equally.
6. Proficiency in turns to the right as well as to the left should be developed.
All of the factors that affect the airplane during level (constant altitude) turns will affect it during climbing turns or any other turning maneuver. It will be noted that because of the low airspeed, aileron drag (adverse yaw) will have a more prominent effect than it did in straight and level flight and more rudder pressure will have to be blended with aileron pressure to keep the airplane in coordinated flight during changes in bank angle. Additional elevator back pressure and trim will also have to be used to compensate for centrifugal force, for loss of vertical lift, and to keep the pitch attitude constant.
During climbing turns the loss of vertical lift becomes
greater as the angle of bank is increased, so shallow turns must be used
to maintain an efficient rate of climb. If a medium or steep banked turn
is used, the airplane will not climb so rapidly.
There are two ways to establish a climbing turn. Either establish a straight climb and then turn or establish the pitch and bank attitudes simultaneously from straight and level flight. The second method is usually preferred because the pilot can more effectively check the area for other aircraft while the climb is being established.