Aeromed & Aerodynamics Flashcards
Self-imposed stressors
DEATH: Drugs Exhaustion Alcohol Tobacco Hypoglicemia (diet)
4 types of Hypoxia
Hypoxic
Hypemic
Stagnant
Histotoxic
Define Hypoxic hypoxia
Insufficient pressure of O2 in the air; e.g. flying at altitude
Four stages of hypoxia
Indifferent
Compensatory
Disturbance
Critical
Define Histotoxic hypoxia
Interference with the use of O2 by the body tissues; e.g. cyanide poisoning
Define Hypemic hypoxia
Reduction in O2 carrying capability of red blood cells; e.g. carbon monoxide
Define Stagnant hypoxia
Reduction in blood flow; e.g. positive G maneuvers
Treatment for Spatial disorientation
Develop and maintain cross-check
Delay intuitive reactions
Refer to instruments
Transfer controls
Somatogravic illusions
The leans
Graveyard spin
Coriolis
Most deadly and most unrecoverable Somatogravic illusion
Coriolis illusion
Measures to prevent SD include:
- Never fly without visual reference points
- Maintain SA
- Never try to fly both IFR and VRF at the same time
- Avoid self-imposed stressors (DEATH)
- Trust your instruments
- Cockpit management
- Education/training
- Instrument proficency
- Aircraft design
Define Spatial disorientation
The inability to determine ones position, attitude and motion relative to the earth or significant objects.
The 3 types of Spatial disorientation
Type 1. - Unrecognized
Type 2. - Recognized
Type 3. - Incapacitating
Most dangerous type of SD
Type 1. - unrecognized
Which of the 5 senses is the most important to maintain equilibrium and orientation?
Vision
Semicircular canals sense changes in _______ acceleration and react to any changes in ______, ________ and ______ attitude
Angular
Yaw
Roll
Pitch
A smoker at sea level is actually at altitude:
5000 ft.
At 18.000 ft., the usefull time of consciousness is:
20-30 mins
Define Fatigue
The state of feeling tired, weary, or sleepy that results from periods of anxiety, exposure, to harsh environment, or loss of sleep.
The 3 types of fatigue
- Acute
- Chronic
- Burnout
Describe chronic fatigue
Being mantally and physically tiered over a long period of time.
The 3 characteristics associated with chronic fatigue
Depressed mood
Irritability
poor judgement
The only significant effect of hypxia in the indifferent stage is ______ and_______ and it occurs at what altitude?
Acuity
Color perception
SL-10.000 ft.
Which type of hypoxia does smoking cause?
Hypoxic hypoxia
Prevention methods for hypoxic hypoxia
- Limit time at altitude
- Pressurzed cabin
- minimize self-imposed stressors
- 100% O2
Define hypoxia
State of oxygen deficiency in the blood cells and tissues sufficient to cause impairment of function.
Define tranlating tendency
The tendency of a single rotor helicopter with a counterclockwise rotating rotor system to drift laterally to the right while at a hover
What causes Translating tendency
Thrust produced by the tail rotor to compensate for main rotor torque.
Translating tendency compensation
- Rigging of the flight control system
- Tilting of the mast
- Stabilization augmentation systems
- Left cyclic input by the pilot
Define Dissymmetry of lift
Unequal lift between advancing and retreating halves of the rotor disk caused by the different wind flow velocity across each half
Relative wind velocity of advancing blade is blade speed ____ airspeed
Plus
Relative wind velocity of retreating blade is blade speed ____ airspeed
Minus
Main rotor method to overcome dissymmetry of lift
Flapping
When blade flapping has compensated for dissymmetry of lift, the rotor disk is tilted to the rear is called?
Blowback
What can the pilot do to compensate for dissymmetry of lift?
Cyclic feathering
Effective tranlational lift (ETL) definition
The Rotor dick outruns the recirculation of old vortices and begins to work in relatively undisturbed air
Airspeed for ETL
16-24 kts
ETL causes relative wind to become more horizontal, resulting in:
- More vertical lift component
- Less induced drag
- Increased angle of attack
Define Settling with power
A condition of powered flight in which the helicopter settles in it’s own downwash
What conditions must exist simultaneously for sttling with power to occur
- Vertical or near vertical descent rate of at least 300 ft/min depenting upon:
- Gross weight
- Rotor RPM
- Density altitude - 20% - 100% of available engine power with insufficient power remaining to arrest the descent
- Sow forward airspeed, less than ETL
Settling with power recovery
Increase airspeed with forward cyclic
Reduce collective pitch as altitude permits
Define Dynamic rollover
A helicopters susceptibility to a lateral rolling tendency
Dynamic rollover conditions
Pivot point
Rolling motion
Exceed critical angle
Physical factors for dynamic rollover
- Main rotor thrust
- CG
- Tail rotor thrust
- Crosswind component
- Ground surface
- Sloped landing area
- Low fuel condition
Human factors
- Inattention
- Inexperience
- Inappropriate control input
- Failure to take timely corrective action
- Loss of visual reference
Recovery of dynamic rollover
A smooth moderate collective reduction
Primary factor for retreating blade stall
Excessive airspeed
Contributing factors for retreating blade stall
- High gross weight
- High DA
- High “G” maneuvers
- Low rotor RPM
- Turbulence
Symptoms of retreating blade stall
- Abnormal vibrations
- Pitch-up of nose
- Tendency to roll toward the stalled (left) side
- Loss of control (if corrective action is not applied)
Corrective actions for retreating blade stall
- Reduce collective pitch
- Regain aircraft control
- Reduce airspeed
- Increase rotor RPM to normal operating range
- Minimize maneuvering
- Descent to a lower altitude.
Explain why hovering OGE requires more power than hovering IGE
Induced flow velocity is increased, causing a decrease in AOA. A higher blade pitch angle is required to maintain the same AOA as in IGE hover. The increased pitch angle also creates more drag. More power to hover OGE than IGE is required by this increased pitch angle and drag
