Land as soon as Practicable
The landing site and duration of flight are at the discretion of the pilot. Extended flight beyond the nearest approved landing area where appropriate assistance can be expected is not recommended.
Land as soon as Possible
Land without delay at the nearest adequate site (i.e. open field) at which a safe approach and landing can be made.
LAND IMMEDIATLEY
The urgency of landing is paramount. Primary consideration is to ensure survival of the occupants. Landing in water, trees, or other unsafe areas should be considered as a last resort.
Dynamic Rollover
A helicopter is susceptible to a lateral rolling tendency.
3 Conditions needed for Dynamic rollover
1) Pivot Point
2)Rolling motion
3)Exceeding Critical angle
Human Factors of Dynamic Rollover
F-Failure to make timely corrective action
L-Loss of Visual Reference
I-Innattention
I-Inexperience
I-Innappropriate control input
Hypoxia
Results when the body lacks oxygen. It generally is associated with high altitude flights. However, other factors such as alcohol abuse, heavy smoking,and various medications can interfere with blood's ability to carry and absorb oxygen, reducing the body
4 Types of Hypoxia
1) Hypoxic Hypoxia (High altitude)
2) Hypemic Hypoxia (Blood Loss)
3)Stagnant Hypoxia (High G-Forces)
4) Histotoxic Hypoxia (Alcohol/Drugs)
Stages of Hypoxia
1) Indifferent (98-90% O2), 0-10,000 ft, Decreased Night Vision
2) Compensatory (89-80% O2), 10,000-15,000, Drowsiness, poor judgement, impaired coordination & efficiency
3) Disturbance (79-70% O2), 15,000-20,000, Impaired flight control, handwriting, spe
Spacial Disorientation
An individuals inability to determine his/her position, altitude, and motion relative to the earth's surface.
Spacial Disorientation (Type I) Unrecognized
Aviator does not perceive any indication of SD or think anything is wrong.
Spacial Disorientation (Type II) Recognized
The pilot perceives a problem resulting from SD but might not recognize it as SD
-Might feel as though a control is malfunctioning or perceive an instrument failure but will not make corrections because his/her vestibular indications are so strong.
Spacial Disorientation (Type III) Incapacitating
The Pilot experiences such an overwhelming sensation of movement that he/she cannot orient using visual cues or instruments
-Not Fatal if pilot can gain control of the aircraft
Vestibular System
Located within the inner ear, which contains the sense organs that detect motion & gravity (semicircular canals and vestibule (otolith)
Alcohol Consumption
12 hours after the last drink with no residual physiological effects present
Total Aerodynamic Force (Resultant Force)`
As air flows around an airfoil, a pressure differential develops between the upper and lower surfaces. The differential, combined with air resistance to passage of the airfoil, creates a force on the airfoil.
2 Components Lift and Drag
Drag
force opposing the motion of an airfoil through the air
3 Types of Drag
1) Parasite
2) Profile
3) Induced
Parasitic Drag
incurred from the nonlifting portions of the aircraft. It includes form drag, skin friction, and interference drag associated with the fuselage, engine cowlings, mast and hub, landing gear, wing stores, external load, and rough finish paint. Parasite drag
Profile Drag
incurred from frictional resistance of the blades passing through the air. It does not change significantly with AOA of the airfoil section but increases moderately at high airspeeds. At high airspeeds, profile drag increases rapidly with onset of blade s
Induced Drag
a result of production of lift. Higher angles of attack, which produce more lift, also generate downward velocities and vortices that increase induced drag. In rotary-wing aircraft, induced drag decreases with increased aircraft airspeed
Translating Tendency
the counterclockwise rotating, single-rotor helicopter has a tendency to drift laterally to the right. The translating tendency (figure 1-52, page 1-36) results from right lateral tail-rotor thrust exerted to compensate for main rotor torque (main rotor t
Dissymmetry of Lift
the differential (unequal) lift between advancing and retreating halves of the rotor disk caused by the different wind flow velocity across each half.
Translational Lift
improved rotor efficiency resulting from directional flight is translational lift
Traverse Flow effect
air passing through the rear portion of the rotor disk has a greater downwash angle than air passing through the forward portion. Gyroscopic Procession causes a right rolling motion
Effective Translational Lift
occurs with the helicopter at about 16 to 24 knots, when the rotor�depending on size, blade area, and RPM of the rotor system�completely outruns the recirculation of old vortexes and begins to work in relatively undisturbed air. The rotor no longer pumps
Lift
component of the airfoil's TAF perpendicular to the resultant relative wind