Helicopter and Instructional Hazards

Helicopter Hazards

During the entire training program, CFIs should emphasize safe operation of the aircraft. The student must be introduced to and completely understand the flight characteristics of the type helicopter being flown. Loss of tail rotor effectiveness (LTE), dynamic rollover (DRO), and the meaning of and how to interpret the height velocity diagram are three topics of discussion for continuous review. By virtue of its many moving parts, the helicopter presents numerous hazards. [Figure 1] It is the responsibility of the CFI to teach safe operating practices in and around the aircraft.

Helicopter Hazards
Figure 1. Safe operating procedures in and around the helicopter

A CFI should draw to the attention of the student the hazards that include, but are not limited to the following:
  • For single rotor helicopters, students should be taught from the beginning that it is preferred to approach and exit the helicopter from the sides but that the forward quarter is acceptable. If approaching or exiting a helicopter that is on a slope, always exit on the downward side to avoid contact with the rotor blades. Limited access to the near aft portion of the fuselage is acceptable for some helicopters, such as the BO-105 and BK-117, in which the tail rotor has been elevated and loading is in the rear of the fuselage. CFIs should advise students to always consult with the pilot or trained personnel before going aft of the cockpit doors. This instills in the students the preferred direction to enter and exit the rotor disk area so the pilot can maintain eye contact with personnel around the aircraft. During preflight, the CFI should teach students to do a proper walk-around before moving any control surfaces to ensure that nothing is in the way of the main or tail rotor blades.

  • Always avoid the tail rotor by approaching from the sides. The rotor disk should be tipped so the students understand just how low the main rotor blades may dip in winds and as a result of exaggerated control movements.
  • Hands and fingers can be pinched by rotor hubs and hinges during preflight and postflight inspections.
  • Main and tail rotor blades pose significant hazards for those unaccustomed to being around helicopters during ground operations.
  • Any moving blade is dangerous and can cause injury or damage while under power or during the start up and coast down periods after engine power has been removed.
  • Wind or a control input can easily cause slow moving blades to droop or flex, reducing clearance for people standing underneath the rotor disk.
  • If the helicopter must be moved from the hangar, students should be cautioned on the hazards of having a piece of machinery raised off the surface and the correct methods of raising and lowering the aircraft. Since helicopters may be taller than an equal size airplane; the student should be taught to ensure plenty of vertical clearance for the aircraft as it is moved. Trip hazards, such as ground wires, should be explained as to requirements, storage, and attachment at end of flights.
  • The movement of the helicopter for flight should include preplanning to prevent the hangar from filling with grass, dirt, and excessive wind in the facility. The direction of the wind and airflow around the building should be considered before selecting a takeoff point for the helicopter.
  • Jewelry, especially rings, should be removed before preflight and postflight to ensure that they will not be caught on any fasteners or sharp objects. Loose clothing should be secured, and objects in pockets should be removed if the pockets cannot be fastened.

In hover flight, the CFI should emphasize the hazards that rotor wash presents to persons or light aircraft nearby. Dust and debris cause eye injuries and vortices damage light aircraft. A tail rotor is another source of significant hazard because it is out of sight of the pilot. Instructors should ensure the student is aware of the requirement to keep the tail rotor area cleared. Hazards such as those listed above are but a few of the hazards unique to the helicopter. The observant CFI identifies potential hazards during the lesson, corrects the deficiency immediately with an explanation, and develops them as teaching points.

Instructional Hazards

Flying a helicopter offers a different set of physical and mental challenges for a student. The stress of learning how to fly is coupled with the physical demands of flying the helicopter. The constant vibration of the aircraft, as well as the continually need to make control inputs to “fly” the aircraft, make helicopter flight a more physically and mentally strenuous type of flying. The vibration, noise, and stress can lead to fatigue, which can have a detrimental effect upon the ability of the student not only to fly a helicopter but to absorb instruction. To combat this hazard, limit the length of the lesson to less than an hour until the student becomes accustomed to the demands of this type of flying. For further discussion of medical factors associated with flying, refer to the Aeronautical Knowledge section.

As shown in Figure 2, the CFI must remain vigilant when the student has control of the helicopter because the student’s knee may get in the way of the cyclic movement. The student’s size cannot be changed, but it is the CFI’s responsibility to teach the student to be aware of how their size may affect the flight controls input.

Helicopter Instructional Hazards
Figure 2. Robinson Helicopter R-22

The instructor should always ensure that all of the flight controls are unencumbered. Students are so focused on the task at hand when learning to fly and often times will unknowingly obstruct the flight controls. For example, water bottles, clothing and cameras can get stuck under the collective levers preventing movement, or anti-torque pedals can get blocked from movement by the students boot or shoe.

Another potential instructional hazard stems from the ability of helicopter rotor blades to strike the terrain or objects in a 360° arc. This unique capability of the helicopter must be stressed when teaching a student who is transitioning from fixed-wing aircraft. A fixed-wing pilot is accustomed only to the idea that one wing will hit if the aircraft is banked too far. If teaching someone who is transitioning from airplanes, the CFI needs to stress to the student the speed of the rotor and its close proximity to the ground.

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