Private Pilot Ground Course Lesson 10: Load Factor Basics Explained

Load factor is one of those aviation concepts that sounds more complicated than it really is. Once you understand what the airplane is being asked to do, the numbers begin to make sense.

In Lesson 10 of the Red Yeti Aviation Private Pilot Ground Course, we break down load factor, g-forces, and the relationship between aircraft speed and the loads placed on the airplane. These are important concepts for the FAA knowledge test, but more importantly, they help explain why seemingly normal control inputs can become a problem when an airplane is moving fast or maneuvering aggressively.

What Is Load Factor?

Load factor is the ratio between the aerodynamic load supported by the wings and the airplane's weight. Pilots normally describe it in terms of G. In straight-and-level, unaccelerated flight, an airplane is generally operating at about 1 G. The wings are producing enough lift to support the airplane's weight.

When the airplane turns, pulls up, encounters turbulence, or otherwise changes its flight path, the required aerodynamic load can increase. The pilot may feel heavier in the seat because both the airplane and its occupants are experiencing a higher load factor.

Bank Angle and G-Forces

A level turn requires more total lift than straight-and-level flight because part of the lift vector is being used to turn the airplane. As bank angle increases, the amount of lift required to maintain altitude also increases. That means load factor increases as well.

This is why steep turns require more attention to pitch and airspeed. The airplane may still be well within its normal operating envelope, but it is working harder aerodynamically than it was in level flight.

Load Factor and Stall Speed

One of the most important practical lessons is that an airplane can stall at a higher indicated airspeed when the load factor increases. This is an accelerated stall.

A stall is still caused by exceeding the wing's critical angle of attack. The difference is that, under increased load, the wing must produce more lift. That higher demand can bring the wing to its critical angle of attack at an airspeed above the airplane's familiar 1-G stall speed.

For a student pilot, this is especially important when thinking about steep turns, abrupt pull-ups, turbulence, and aggressive maneuvering. A published stall speed should never be treated as the only speed at which the airplane can stall.

Speed Matters When Applying Loads

The faster an airplane is moving, the greater the aerodynamic forces that can be produced by a sudden or excessive control input. At higher speeds, a rapid control movement can place substantial loads on the aircraft before the wing reaches a stall.

This is one reason pilots need to understand the airplane's operating limitations and maneuvering speed. Maneuvering speed is not permission to make unnecessarily abrupt control movements, and it changes with aircraft weight. Always use the limitations and procedures published for the specific airplane you are flying.

Why Load Limits Matter

Aircraft are designed and certificated to operate within defined structural limits. Exceeding those limits can damage the airframe, even when the damage is not immediately obvious from the cockpit.

Good flying technique is therefore not simply about keeping the airspeed indicator out of the red. Pilots also need to consider how speed, turbulence, bank angle, aircraft weight, and control inputs combine to create loads on the airplane.

What to Remember for the FAA Written Exam

For your FAA knowledge test, remember the basic relationships: increased load factor increases stall speed; steeper level turns increase load factor; and high airspeed combined with abrupt control inputs can create excessive structural loads. Understanding the reason behind those relationships is much more useful than memorizing isolated answers.

Watch Private Pilot Ground Course Lesson 10

Watch the complete lesson here: Load Factor BASICS Explained (EASY to Understand).

This lesson follows the aeronautical knowledge areas used in private-pilot training and is designed to help you prepare for both the FAA knowledge test and practical flight training.

Continue Your Private Pilot Ground Training

If you want the complete structured course, FAA written-exam preparation, and endorsement path, enroll in the Red Yeti Aviation Affordable Online Private Pilot Ground School | FAA Written Exam Prep & Endorsement. The complete course is currently $50.

Training note: Always use the FAA-approved limitations, placards, and Pilot's Operating Handbook or Airplane Flight Manual for the specific aircraft you fly. This article is supplemental ground-training material and does not replace aircraft-specific instruction.