FH.XI.F.K3
KnowledgeVarious frequency vibrations and the possible components that may be affected.
From the FAA library
- Chapter 11: Helicopter Emergencies and Hazards › System Malfunctions › Low-Frequency Vibrations
Abnormal Vibration With the many rotating parts found in helicopters, some vibration is inherent. A pilot needs to understand the cause and effect of helicopter vibrations because abnormal vibrations cause premature component wear and may even result in structural failure ... With experience, a pilot learns what vibrations are normal and those that are abnormal and can then decide whether continued flight is safe or not. Helicopter vibrations are categorized into low, medium, or high frequency. Low-Frequency Vibrations Low-frequency…
- Chapter 4: Helicopter Components, Sections, and Systems › Electrical Systems
exceeding the output of the alternator or generator, and the battery is helping to supply electrical power. This may mean the alternator or generator is malfunctioning, or the electrical load is excessive. An ammeter displays the load placed ... alternator or generator causes the load meter to indicate zero. Electrical switches are used to select electrical components. Power may be supplied directly to the component or to a relay, which in turn provides power to the component. Relays…
- Chapter 11: Helicopter Emergencies and Hazards › System Malfunctions › Medium- and High-Frequency Vibrations
Medium-frequency vibrations are felt through the entire airframe, and prolonged exposure to the vibrations will result in greater pilot fatigue. Most tail rotor vibrations fall into the high-frequency range (2,100 cycles per minute or higher ... felt through the tail rotor pedals as long as there are no hydraulic actuators to dampen out the vibration. This vibration is felt by the pilot through his or her feet, which are usually “put to sleep” by the vibration…
- Chapter 3: Helicopter Flight Controls › Antitorque Pedals › Heading Control
chapter also correlates the use of flight controls and aerodynamics and how the two work together to make flight possible. Chapter 4: Helicopter Components, Sections, and Systems This chapter discusses the components, sections, and systems found on most modern helicopters ... Helicopters come in a variety of sizes and shapes, but most share the same major components. The chapter introduces the major components/ sections of the helicopter and the systems that correlate with each. Knowing how the components and systems work…
- Chapter 4. Air Traffic Control › Section 3. Airport Operations › 4-3-14. Communications
takeoff when they reach the runway or warm-up block unless advised otherwise. c. The majority of ground control frequencies are in the 121.6-121.9 MHz bandwidth. Ground control frequencies are provided to eliminate frequency congestion on the tower (local ... control) frequency and are limited to communications between the tower and aircraft on the ground and between the tower and utility vehicles on the airport, provide a clear VHF channel for arriving and departing aircraft. They are used for issuance…