INTRODUCTION
Helicopters are quite reliable for flight. But it is
always important to know and understand
emergency proced...
AUTOROTATION
“In a helicopter, an autorotative descent is a
power-off maneuver in which the engine is
disengaged from the ...
AUTOROTATION
Is the action taken when engine failure occurs or the
initiated action of a complete tail rotor failure (refe...
AUTOROTATION
Once an engine failure happens the pilot
must lower the collective pitch which lift
and drag will be reduced....
AUTOROTATION
Kinetic energy and Potential energy are used by the
rotor blades to arrest the descent rate and ensure a
soft...
RETREATING BLADE STALL
“In forward flight, the relative airflow through the main
rotor disk is different on the advancing ...
GROUND RESONANCE
“Helicopters with articulating rotors (usually designs
with three or more main rotor blades) are subject ...
DYNAMIC ROLLOVER
Dynamic rollover is when a helicopter is
susceptible to a lateral rolling tendency.
Caused when the helic...
LOW-G CONDITIONS AND MAST BUMPING
Low-G conditions is the imbalance of force, not the
loss of thrust. Such as excessive fo...
LOW ROTOR RPM AND BLADE STALL
During an autorotation with low rotor rpm can result in
a less successful maneuver but if ro...
RECOVERY FROM LOW ROTOR RPM
Simultaneously applying additional throttle (if
available) when low rotor rpm is detected and
...
ADDITIONAL INFORMATION
For additional information and more in depth
explanations please ask your instructor, visit the
Fed...
Helicopter emergency procedures
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Helicopter emergency procedures

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Helicopter emergency procedures

  1. 1. INTRODUCTION Helicopters are quite reliable for flight. But it is always important to know and understand emergency procedures. Discussing and practicing these procedures is important. Helicopter Flying Handbook 2012
  2. 2. AUTOROTATION “In a helicopter, an autorotative descent is a power-off maneuver in which the engine is disengaged from the main rotor system and the rotor blades are driven solely by the upward flow of air through the rotor.” Helicopter Flying Handbook 2012
  3. 3. AUTOROTATION Is the action taken when engine failure occurs or the initiated action of a complete tail rotor failure (refer to the individual helicopters RFM) The freewheeling unit automatically disengages the engine from the main rotor This allows the main rotor to rotate freely When revolutions per minute are less than the rotor rpm, the freewheeling unit will disengage Helicopter Flying Handbook 2012
  4. 4. AUTOROTATION Once an engine failure happens the pilot must lower the collective pitch which lift and drag will be reduced. This will cause the helicopter to descend to produce an upward flow of air. Having upward flow of air will allow for enough air to provide thrust to maintain rotor rpm during descent. The antitorque pedals need to maintain heading control like in normal flight. Helicopter Flying Handbook 2012
  5. 5. AUTOROTATION Kinetic energy and Potential energy are used by the rotor blades to arrest the descent rate and ensure a soft landing, when landing from an autorotation. “Autorotative descents at very low or very high airspeeds are more critical than those performed at the minimum rate of descent airspeed.” For particular helicopter specific autorotation airspeeds, refer to the Federal Aviation Administration (FAA) and the approved rotorcraft flight manual (RFM). Helicopter Flying Handbook 2012
  6. 6. RETREATING BLADE STALL “In forward flight, the relative airflow through the main rotor disk is different on the advancing and retreating blades.” “Retreating blade stall is a major factor in limiting a helicopter’s never-exceed speed (Vne) and its development can be felt by a low frequency vibration, pitching up of the nose, and a roll in the direction of the retreating blade.” Helicopter Flying Handbook 2012
  7. 7. GROUND RESONANCE “Helicopters with articulating rotors (usually designs with three or more main rotor blades) are subject to ground resonance, a destructive vibration phenomenon that occurs at certain rotor speeds when the helicopter is on the ground.” A rotor that is out-of-balance can be intensified when a mechanical design issue from the helicopter’s airframe having natural frequency is ground resonance. Increase in vibrations can cause the helicopter to self- destruct in a matter of seconds. Helicopter Flying Handbook 2012
  8. 8. DYNAMIC ROLLOVER Dynamic rollover is when a helicopter is susceptible to a lateral rolling tendency. Caused when the helicopter pivots or rolls around a skid or landing gear wheel until the rollover angle is reached. Beyond a certain point of roll over recovery is impossible. To stop a dynamic rollover, quickly reduce collective pitch. (this is the most effective way) Helicopter Flying Handbook 2012
  9. 9. LOW-G CONDITIONS AND MAST BUMPING Low-G conditions is the imbalance of force, not the loss of thrust. Such as excessive forward cyclic pitching causing a feeling of weightlessness in your body. Mast bumping is when the rotor blade exceeds flapping limits which then the rotor hub bumps into the rotor mast. Helicopter Flying Handbook 2012
  10. 10. LOW ROTOR RPM AND BLADE STALL During an autorotation with low rotor rpm can result in a less successful maneuver but if rotor rpm decays and all rotor blades stall, the results are fatal.  Decrease in rotor rpm= blades produce less lift making it necessary to increase collective pitch.  Pitch increased + drag increases= more power to keep the blades turning at the proper rpm.  When power is not available to maintain rpm= helicopter will begin to descend which changes the relative wind causing the blades to stall unless rpm is restored. Helicopter Flying Handbook 2012
  11. 11. RECOVERY FROM LOW ROTOR RPM Simultaneously applying additional throttle (if available) when low rotor rpm is detected and lower the collective based on altitude. “Rotor rpm is life!” Helicopter Flying Handbook 2012
  12. 12. ADDITIONAL INFORMATION For additional information and more in depth explanations please ask your instructor, visit the Federal Aviation Administration (FAA) documents, manuals and books and the approved rotorcraft flight manual (RFM).

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