Daily Questions Flashcards
WARNING
An operating procedure, practice, etc., which, if not correctly followed, could result in personal injury or loss of life.
CAUTION
An operating procedure, practice, etc., which if not strictly observed, could result in damage to or destruction of equipment.
NOTE
An operating procedure, condition, etc., which is essential to highlight.
Autorotation - steady state
Rotor RPM is within limits.
The aircraft is at the correct airspeed.
The aircraft is descending at a normal rate.
The aircraft is in a position to terminate in the intended landing area.
Single Engine Failure - call out
Rotor within limits
N1 stabilized
Aircraft in trim
Mayday, mayday, mayday
Shoulder harness lock
Transponder to emergency
TYPES OF HYPOXIA
hypoxic, hypemic, stagnant, and histotoxic
Definition of Hypoxia
Hypoxia results when the body lacks oxygen.
HYPOXIC
Hypoxic hypoxia occurs when there is not enough oxygen in the air or when decreasing atmospheric pressure prevents diffusion of oxygen from the lungs to the bloodstream.
HYPEMIC
Hypemic, or anemic, hypoxia is caused by a reduction in blood’s oxygen-carrying capacity.
STAGNANT
With stagnant hypoxia, blood’s oxygen-carrying capacity is adequate but circulation is inadequate
HISTOTOXIC
Histotoxic hypoxia results from an interference with the use of oxygen by body tissues.
Less than 5% TQ differential
Ensure that adequate room exists for takeoff with minimum or existing PWR. The destination must allow a normal or shallower-than-normal approach to landing areas with a surface, which will permit a descent to the ground if necessary.
Five to 9% TQ differential
Normal approaches and takeoffs may be performed.
Ten to 14% TQ differential
Steep approaches, instrument takeoffs and confined area operations may be performed.
15% or more TQ differential
Takeoff and landing restrictions do not apply.
SPATIAL DISORIENTATION
*SD is a pilot’s erroneous perception of position, attitude, or motion in relation to the gravitational vertical and the Earth’s surface.
An individual’s inability to determine his or her position, attitude, and motion relative to the Earth’s surface.
When SD occurs, pilots are unable to see, believe, interpret, or prove information derived from their flight instruments. They instead rely on false information provided by their senses.
TYPES OF SPATIAL DISORIENTATION
TYPE I (UNRECOGNIZED)
TYPE II (RECOGNIZED)
TYPE III (INCAPACITATING)
Spatial D. Type 1
an aviator does not perceive any indication of SD or think anything is wrong.
Spatial D. Type 2
the pilot perceives a problem resulting from SD but might not recognize it as SD.
Spatial D. Type 3
the pilot experiences such an overwhelming sensation of movement that he or she cannot orient using visual cues or the aircraft instruments.
DYNAMIC ROLLOVER definition
PRE & RRLLC
Defined as the susceptibility of a helicopter to a lateral-rolling tendecy. Three condition must be present:
Pivet point
Rolling motion
Exceeding the dynamic/critical rollover angle
Certain factors influence dynamic rollover:
Right skid down High Roll rates Left pedal input Lateral loading Crosswind
DYNAMIC ROLLOVER
3 main rollover types
rolling over on level ground (takeoff) rolling downslope (takeoff or landing) rolling upslope (takeoff)
DYNAMIC ROLLOVER
Physical factors
MASS TC
Main rotor thrust Aicraft CG/Low fuel Sloped landing area Ground Surface Tail rotor thrust Crosswind component
DYNAMIC ROLLOVER
Human factors
IIIFL
(I failed)
Inattention Inexperiance Inappropiate control inputs Failure to make timely corrective action Loss of visual referance
RETREATING BLADE STALL
The retreating blade of a helicopter will eventually stall in forward flight. As the stall of an airplane wing limits the low speed of a FW aircraft, the stall of a rotor blade limits the high speed of a rotary-wing aircraft.
CONDITIONS PRODUCING RETREATING BLADE STALL
In operations at high forward speeds, the following conditions are most likely to produce blade stall in either single- or tandem-rotor helicopters-
High blade loading (high gross weight).
Low rotor RPM.
High- density altitude.
High G-maneuvers.
Turbulent air.
RECOVERING FROM RETREATING BLADE STALL
The following steps enable the aviator to recover from retreating blade stall—
Reduce collective.
Reduce airspeed.
Descend to a lower altitude (if possible).
Increase rotor RPM to normal limits.
Reduce the severity of the maneuver.
SETTLING WITH POWER
Settling with power is a condition of powered flight in which the helicopter settles in its own downwash. This condition may also be referred to as vortex ring state.
Settling with power
vortex ring state
roughness and loss of control occur due to turbulent rotational flow on the blades and unsteady shifting of the flow along the blade span.
Conditions for settling with power
The following conditions must exist simultaneously for settling with power to occur:
A vertical or near-vertical descent of at least 300 feet per minute (FPM).
Slow forward airspeed (less than ETL).
Rotor system must be using 20 to 100 percent of the available engine power.
Flight conditions conducive to settling with power
Steep approach at a high rate of descent.
Downwind approach.
Formation flight approach (where settling with power could be caused by turbulence of preceding aircraft).
Hovering above the maximum hover ceiling.
Not maintaining constant altitude control during an OGE hover.
During masking/unmasking.
Recovery from settling with power may be affected by one, or a combination, of the following ways:
During the initial stage (when a large amount of excess power is available), a large application of collective pitch may arrest rapid descent. If done carelessly or too late, collective increase can aggravate the situation resulting in more turbulence and an increased rate of descent.
In single-rotor helicopters, aviators can accomplish recovery by applying cyclic to gain airspeed and arrest upward induced flow of air and/or by lowering the collective (altitude permitting). Normally, gaining airspeed is the preferred method as less altitude is lost.
Several conclusions can be drawn from the last chart on SWP
The vortex ring state can be completely avoided by descending on flight paths shallower than about 30 degrees (at any speed).
For steeper approaches, the vortex ring state can be avoided by using rates of descent versus horizontal velocity either faster or slower than those passing through the area of severe turbulence and thrust variation.
At very shallow angles of descent, the vortex ring wake is dispersed behind the helicopter. Forward airspeed coupled with induced-flow velocity prevents the upflow from materializing on the rotor system.
At steep angles, the vortex ring wake is below the helicopter at slow rates of descent and above the helicopter at high rates of descent. Low rates of descent prevent the upflow from exceeding the induced flow velocities. High rates of descent result in autorotation or the windmill brake state.
VESTIBULAR ILLUSIONS
SOMATOGYRAL and SOMATOGRAVIC
SOMATOGYRAL ILLUSIONS
Somatogyral illusions occur when angular acceleration and deceleration stimulates the semicircular canals. Some types of somatogyral illusions that might be encountered in flight are the leans, graveyard spin, and Coriolis illusion.
Leans
the most common form of SD. This illusion occurs when a pilot fails to perceive angular motion.
Graveyard Spin
if a pilot enters a spin and remains in it for several seconds, the semicircular canals will reach equilibrium and no motion will be perceived. Upon recovering from the spin, the pilot will undergo deceleration, which is sensed by the semicircular canals. He or she will have a strong sensation of being in a spin in the opposite direction even if the flight instruments contradict that perception.
Coriolis illusion
Regardless of aircraft type, Coriolis illusions are the most dangerous of all vestibular illusions and cause overwhelming disorientation.
POST-ROLL (GILLINGHAM) ILLUSION
This illusion can manifest after a roll maneuver, usually in the absence of a visible horizon and ambient visual cues.
SOMATOGRAVIC ILLUSIONS
Somatogravic illusions are caused when changes in gravity or linear acceleration and deceleration stimulate the otolith organ. The two types of somatogravic illusions encountered in flight are G-Excess and elevator.
OCULOARGRAVIC ILLUSION
The illusions occur due to the misperception of movement of a fixed object (such as, instrument panel) relative to the pilot during change of direction of gravitoinertial force. This is likely due to reflexive desire to maintain visual fixation. Consider the example of an approach without useful visual frame of reference or visible horizon whereby a pilot may misinterpret the resulting gravitoinertial vector in a slowing helicopter in increasing pitch up attitude as a stable level, descending approach attempting to keep the landing target in the same position on the windscreen.
Elevator Illusion
Elevator illusions occur during upward or downward acceleration. False pitch up or pitch down of the nose
Dissymmetry of lift. (Main rotor and Tail rotor)
Definition : Differential lift between the advancing and retreating halves of the rotor disk caused by different wind velocities across each half. On the advancing half, add rotational velocity to rotational relative wind On the retreating half, subtract rotational velocity from rotational relative wind
Indications: Pitch up (blow back) during takeoff
Corrective Action: Blade flapping (aerodynamic) Upflap - increases induced flow/drag, less lift. Downflap - decreases induced flow/drag, increases lift. Cyclic feathering (mechanical) FWD cyclic applied when blades are right and left, manifested forward and backward.
No Lift Areas produced from Dissymmetry of Lift (from the hub to tip)
- Reverse Flow
- Negative Stall
- Negative Lift
*Tail rotor also experiences dissymmetry of lift in forward flight, but is compensated by automatic blade flapping by a Delta Hinge.
Transverse flow effect
Definition: Differences in lift, drag and induced flow between the fore and aft portions of the rotor disk, occurring from 10-20 knots In forward flight, air passing through the forward portion of the rotor disk is more horizontal (increased AOA and more lift) and air passing through the rear portion of the rotor disk is more vertical (reduced AOA and less lift) The greater the distance the air flows over the rotor disk, the longer the disk has to work on it and the greater the deflection.
Indications: Vibrations - This causes unequal drag and results in vibration, noticeable during takeoff and during deceleration for landing. Right rolling motion - Gyroscopic precession causes the effects to be manifested 90 degrees in the direction of rotation
Corrective Action: Cyclic Feathering - Apply left cyclic until after 10-20 knots, then move cyclic back to center.
Effective translational lift (ETL)
Definition: Effective translational lift (ETL) is when the rotor completely outruns the recirculation of old vortexes and begins to work in relatively undisturbed air and occurs at about 16 to 24 knots, Efficiency continues with increased airspeed until the best climb airspeed is reached, when total drag is at its’ lowest point. Greater airspeeds result in lower efficiency due to increased parasite drag.
Indications: As translational lift becomes more effective, the combined effects of gyroscopic precession, dissymmetry of lift, and transverse flow effect cause both the nose to pitch up (blowback) and the aircraft to roll to the right.
Corrective action: Aviators must correct with additional forward and left lateral cyclic input to maintain a constant rotor-disk attitude. *Four types of drag are induced drag, profile drag, parasite drag, and total drag.
Airflow during a hover (IGE/OGE)
Definition:
- Hover occurs when lift produced by downward airflow from the rotor system equals total weight of the helicopter.
- Two types of airflow at a hover: Induced Flow, Wing Tip Vortices
- Ground effect - increased efficiency of the rotor system caused by interference of the airflow when near the ground.
In-Ground-Effect (IGE) ground surface to one rotor diameter height
Out-of-Ground-Effect (OGE) one rotor diameter height and above
IGE – airflow is smaller due to ground interference pushing air out for recirculation, less induced flow and drag, less power.
OGE – airflow is larger, due to no ground interference providing the recirculation, more induced flow and drage, more power. Angle of attack will remain the same, but Angle of Incidence larger for OGE.
FATIGUE
Fatigue is the state of feeling tired, weary, or sleepy that results from prolonged mental or physical work, extended periods of anxiety, exposure to harsh environments, or loss of sleep. Boring or monotonous tasks can increase fatigue.
types of fatigue
acute, chronic, and motivational exhaustion (burnout)
ACUTE FATIGUE
Acute fatigue is associated with physical or mental activity between two regular sleep periods. Loss of coordination and lack of error awareness are the first signs of fatigue to develop. Crewmembers might experience these symptoms, for example, at night after being awake for 12 to 15 hours. With adequate rest or sleep, typically after one regular sleep period, crewmembers will overcome this fatigue. These and other mental deficits (listed below) are apparent to others before the individual notices any physical signs of fatigue. Acute fatigue is characterized by—
Inattention.
Distractibility.
Errors in timing.
Neglect of secondary tasks.
Loss of accuracy and control.
Lack of awareness of error accumulation.
Irritability.
CHRONIC FATIGUE
This type of fatigue is much more serious than acute fatigue, occurs over a longer period, and is typically the result of inadequate recovery from successive periods of acute fatigue. Mental tiredness develops in addition to physical tiredness. It might take several weeks of rest to eliminate chronic fatigue. There also might be underlying social causes, such as family or financial difficulties, that must be addressed before any amount of rest will help the individual recover. The crewmember or unit commander must identify chronic fatigue early and initiate a referral to the flight surgeon for evaluation and treatment. Chronic fatigue is characterized by some or all of the following characteristics:
Insomnia.
Depressed mood.
Irritability.
Weight loss.
Poor judgment.
Loss of appetite.
Slowed reaction time.
Poor motivation and performance on the job.
MOTIVATIONAL EXHAUSTION (BURNOUT)
If chronic fatigue remains untreated for too long, the individual will eventually “shut down” and cease functioning occupationally and socially. Motivational exhaustion is also known as burnout.
Fatigue (quick notes)
Defintion (TWS,WASHB) The state of feeling tired, weary, or sleepy that results from prolonged mental or physical work, extended periods of anxiety, loss of sleep or exposure to harsh environments. Boring or monotonous tasks can increase fatigue.
Types of Fatigue
- Acute Fatigue (fatigue associated with activity between 2 sleep cycles)(irritability, inattention, distractability)
- Chronic Fatigue (inadequate recovery from several acute fatigue periods)(insomnia, depression, loss of weight)
- Motivational Exhaustion (when chronic fatigue remains untreated for too long)(also known as burnout, body shuts down)
Physiological / Self-Imposed Stressors (DEATH)
- Drugs
- Exhaustion
- Alcohol
- Tobacco
- Hypoglycemia
Breakdown of Drug Use (self-imposed stressors)(SOAPS-C)
- Self-Medication can lead to:
- Overdose Problems
- Allergic Reaction
- Predictable Side-Effects
- Synergistic Effects
- Caffeine (if not moderate, delays drowsiness and fatigue)
Weight and balance requirements (PC responsibility per AR 95-1).
AR 95-1, 5-2, h. Weight and balance. The PC will ensure—
(1) That a completed DD Form 365–4 is aboard the aircraft to verify that the weight and center-of-gravity will remain within allowable limits for the entire flight.
(2) The accuracy of computations on the DD Form 365–4 (Weight and Balance Clearance Form F)
(3) That the aircrafts loading configuration is well within the extremes of the preprinted forms, if preprinted forms are used.
Fuel requirements per 95-1
At takeoff, aircraft must have enough fuel to reach the destination and alternate airport (if required) and have a planned fuel reserve of—
(1) Rotary wing.
(a) VFR, 20 minutes at cruise.
(b) IFR, 30 minutes at cruise.
