Straight-and-level flight is a fundamental airplane flight maneuver in which the pilot maintains a constant heading and altitude. Mastering this skill requires proper use of flight controls, visual reference points, and flight instruments to recognize and correct deviations. These techniques provide the foundation for learning other basic flight maneuvers.
Other basic flight maneuvers are variations of straight-and-level flight, so developing proper and effective straight-and-level flying skills is essential. The ability to perform this maneuver accurately comes through repetition and practice. A high level of skill develops when the pilot observes outside visual references, briefly cross-checks the flight instruments, and makes timely, proportional corrections to prevent small deviations in heading, altitude, and flightpath.
Straight-and-level flight involves maintaining the relationship between a selected reference point on the airplane and the natural horizon. [Figure 1]
These reference points should be established on the ground because they depend on the pilot’s seating position, height, and posture. The pilot should sit in a normal position with the seat adjusted to provide an adequate view over the instrument panel while allowing full operation of the rudder pedals without straining or reaching.
A flight instructor may use a dry-erase marker or removable tape to mark reference lines on the windshield or cowling to help a student pilot establish visual reference points. Vertical reference lines are best established on the ground, such as when the airplane is positioned on a marked centerline with the student pilot seated correctly.
Horizontal reference lines are best established in flight, such as during slow flight and cruise configurations. The horizon reference remains the natural horizon, although its apparent position relative to the airplane depends on the airplane’s attitude and the pilot’s viewing position. Different pitch attitudes may require different horizontal reference points. These teaching aids are generally needed only until the student pilot understands where and when to look while maneuvering the airplane.
Straight Flight
Maintaining a constant direction or heading requires visually checking the relationship between the airplane’s wingtips and the natural horizon. Depending on the airplane’s design and the pilot’s seating position, the wingtips may appear level with the horizon or at different apparent heights. The pilot should learn the normal visual references for the particular airplane and recognize deviations from the desired bank attitude. Any necessary bank corrections should be made using coordinated aileron and rudder inputs. [Figure 2]
The pilot should understand that when an airplane is banked, it normally begins turning. The objective of straight flight is to detect and correct small deviations with minor, coordinated control inputs. Bank attitude can also be checked by briefly scanning the attitude indicator, which shows the airplane’s bank and pitch attitude relative to the instrument’s reference, and the heading indicator, which helps determine whether the airplane is maintaining the desired heading.
Although an airplane can be made to change direction by applying aileron or rudder pressure independently, using these controls independently as a routine method of correcting bank or maintaining straight flight is inappropriate. Coordinated use of the ailerons and rudder helps produce smooth, accurate control. In smooth air, a properly trimmed airplane may require very little control pressure to maintain straight-and-level flight. Therefore, pilots should avoid unnecessary control movements. They should learn to recognize when corrections are needed and respond with measured, smooth, and accurate control inputs.
Pilots may tend to look continually toward one side, often to the left because of their seating position. This restricts the field of view and may lead to unconscious control inputs. Pilots should avoid fixating in one direction and should scan the area outside the airplane continuously. This helps them monitor the airplane’s attitude, detect other traffic, assess terrain and weather conditions, and maintain overall situational awareness. Observing both wingtips also helps the pilot recognize deviations from the desired bank attitude.
Straight flight involves maintaining a desired direction along a ground track. When suitable visual references are available, the pilot can select a point on the horizon and align it with another reference point ahead. Maintaining this alignment can help the pilot maintain the desired heading, provided the airplane’s nose and heading remain aligned with the selected references. However, wind may cause the airplane’s ground track to differ from its heading.
When flying under visual flight rules (VFR), pilots should use suitable outside references and periodically cross-check the heading indicator or other appropriate instruments. Over water, snow-covered terrain, or other areas with few distinct visual references, outside references may be unreliable or unavailable. In these conditions, pilots should use appropriate flight instruments and navigation information to maintain orientation and the intended course.
Level Flight
When learning to maintain level flight, pilots should use a light touch on the flight controls, applying pressure with the fingers rather than gripping the controls tightly with the palm. Only enough pressure to produce the desired response should be applied. Pilots should learn to associate the apparent movement of visual references with the control pressures that change the airplane’s attitude. With practice, they can develop the ability to make small attitude adjustments without repeatedly looking at the instruments or outside references after every minor correction.
The pitch attitude for level flight is initially established by sitting in the correct position, selecting a reference point toward the airplane’s nose, and maintaining that point in the appropriate position relative to the natural horizon. [Figure 3]
The principles of attitude flying require the pilot to cross-check the selected visual reference against the flight instruments to determine whether the airplane is maintaining the desired flight condition.
If the instruments indicate a developing deviation from the desired altitude, the pilot should assess the airplane’s pitch attitude and make an appropriate correction using outside visual references and flight instruments as applicable. The pilot should then cross-check the instruments to determine whether the correction is producing the desired result.
In level-flight instruction, the terms “increase back pressure” or “increase pitch attitude” generally mean raising the airplane’s nose relative to the natural horizon. The terms “decrease pitch attitude” or “lower the nose” mean reducing the nose-up attitude relative to the horizon. The natural horizon is an important visual reference, while the flight instruments help the pilot verify the airplane’s attitude and performance.
In steady, straight-and-level flight, airspeed can remain approximately constant when power, configuration, and flight conditions remain unchanged. Intentional airspeed changes made by increasing or decreasing engine power help pilots develop proficiency in maintaining the desired heading and altitude as airspeed changes. Extending or retracting flaps, landing gear, and other drag-producing devices, such as spoilers, can also produce pitching moments and affect airplane performance. The effects of these configuration changes should be covered during the appropriate airplane checkout.
Common Errors
A common error made by student pilots is attempting to maintain level wings by observing only the airplane’s nose. The nose may provide a useful pitch reference, but relying on it alone can allow small bank deviations to go unnoticed. Observing the wingtips in relation to the natural horizon provides additional information about bank attitude and helps the pilot recognize when the wings are not level.
This technique also helps prevent the habit of flying with one wing low while using opposite rudder pressure to compensate for directional deviations. A pilot who habitually flies with one wing low or uses rudder instead of coordinated control inputs may have difficulty mastering other flight maneuvers.
Common errors include:
- Using incorrect or inconsistent pitch and bank reference points.
- Forgetting the location of previously selected visual reference points on subsequent flights.
- Attempting to establish or correct airplane attitude using flight instruments alone rather than primarily using outside visual references when appropriate for visual flight.
- Chasing instrument indications instead of applying the principles of attitude flying.
- Pushing or pulling mechanically on the flight controls rather than applying smooth, precise pressure.
- Failing to scan outside the airplane for other traffic and to assess terrain and weather conditions.
- Gripping the flight controls too tightly, reducing sensitivity to small control pressures.
- Overcontrolling the airplane.
- Habitually flying with one wing low or attempting to maintain directional control using only the rudder.
- Failing to make timely, measured control inputs when deviations from straight-and-level flight occur.
- Failing to develop an awareness of the airplane’s sensory cues and to use consistent visual reference points when establishing and maintaining attitude.