The Four Fundamentals

 From FAA's "Helicopter Flying Handbook"   FAA-H-8083-21A           www.faa.gov

There are four fundamentals of flight upon which all maneuvers are based: straight-and-level flight, turns, climbs, and descents. All controlled flight maneuvers consist of one or more of the four fundamentals of flight. If a student pilot is able to perform these maneuvers well, and the student’s proficiency is based on accurate “feel” and control analysis rather than mechanical movements, the ability to perform any assigned maneuver is only a matter of obtaining a clear visual and mental conception of it. The flight instructor must impart a good knowledge of these basic elements to the student, and must combine them and plan their practice so that perfect performance of each is instinctive without conscious effort. The importance of this to the success of flight training cannot be overemphasized. As the student progresses to more complex maneuvers, discounting any difficulties in visualizing the maneuvers, most student difficulties are caused by a lack of training, practice, or understanding of the principles of one or more of these fundamentals to more complex maneuvers, discounting any difficulties in visualizing the maneuvers, most student difficulties are caused by a lack of training, practice, or understanding of the principles of one or more of these fundamentals.      

Guidelines

Good practices to follow during maneuvering flight include:

1. Move the cyclic only as fast as trim, torque, and rotor can be maintained. When entering a maneuver and the trim, rotor, or torque reacts quicker than anticipated, pilot limitations have been exceeded. If continued, an aircraft limitation will be exceeded. Perform the maneuver with less intensity until all aspects of the machine can be controlled. The pilot must be aware of the sensitivity of the flight controls due to the high speed of the main rotor.

2. Anticipate changes in aircraft performance due to loading or environmental condition. The normal collective increase to check rotor speed at sea level standard (SLS) may not be sufficient at 4,000 feet pressure altitude (PA) and 95 °F.

3. Anticipate the following characteristics during aggressive maneuvering flight, and adjust or lead with collective as necessary to maintain trim and torque:

• Left turns, torque increases (more anti-torque). This applies to most helicopters, but not all.• Right turns, torque decreases (less anti-torque). This applies to most helicopters, but not all.

• Application of aft cyclic, torque decreases and rotor speed increases.

• Application of forward cyclic (especially when immediately following aft cyclic application), torque increases and rotor speed decreases.

• Always leave a way out.

• Know where the winds are.

• Engine failures occur during power changes and cruise flight.

• Crew coordination is critical. Everyone needs to be fully aware of what is going on, and each crew member has a specific duty.

• In steep turns, the nose drops. In most cases, energy (airspeed) must be traded to maintain altitude as the required excess engine power may not be available (to maintain airspeed in a 2G/60° turn, rotor thrust/engine power must increase by 100 percent). Failure to anticipate this at low altitude endangers the crew and passengers. The rate of pitch change is proportional to gross weight and density altitude.

• Many over-torques during flight occur as the aircraft unloads from high G maneuvers. This is due to insufficient collective reduction following the increase to maintain consistent torque and rotor rpm as G-loading increased (dive recovery or recovery from high G-turn to the right).

• Normal helicopter landings usually require high power settings, with terminations to a hover requiring the highest power setting.

• The cyclic position relative to the horizon determines the helicopter’s travel and attitude.