POH R-22 / Aircraft Flashcards
Special Flight Permits
Issued for an aircraft that may not currently meet applicable airworthiness requirements but is still capable of safe flight
- flying to base where repairs, alterations, or maintenance are to be performed
- delivering or exporting the aircraft
- production flight testing, new aircraft, demo flights
- Evacuating aircraft from areas of impending danger
- authorize the operation of an aircraft at a weight in excess of its max certificated take off weight
Master Minimum Equipment List
MMEL
- Categorized list of on-board systems, instruments, and equipment that may be inoperative during flight
- Defined by aircraft manufacturer on a per aircraft model basis
- FAA approved
Minimum Equipment List
MEL
- A list of equipment that must be installed and operable for the aircraft to be considered airworthy
- It is aircraft-specific and spells out which pieces of equipment may be inoperable while maintaining airworthiness
- Prepared by operator of specific aircraft
- FAA approved
Authority and Responsibility Inflight Emergency
- PIC has responsibility and final authority for operation of aircraft
- Can deviate from any rule or regulation in an emergency situation to meet the emergency
- Send a written report upon request of the administration when rule is deviated
Documents For PIC
- Pilot Certificate
- Photo ID
- Medical certificate
Eligibility and Requirements For Private Pilot
- 17 years of age
- Speak, read, write, English
- 3rd class medical
- M eet experience requirements
- P ass written/oral and practical test
- G round and flight endorsements
SMILE
Documents on person:
- Student pilot certificate
- Medical
- ID
- Logbook
- Endorsements
AROW
Documents for airworthiness:
- Airworthiness certificate
- Registration
- Operators handbook
- Weight and balance
FADWAR
Pre-flight action 91.103:
- Fuel
- Alternates
- Delays
- Weather
- Aircraft
- Runway
NAILS or FLAPS
Required equipment VFR night 91.205:
-Navigation lights -Fuses
-Anti-collision lights -Landing lights
-Instrument lights -Anti-collision lights
-Landing lights -Position lights
-Source of power -Source of power
add CG/LG = Celestial or ground illumination for R22
CAMAFOOTS
Required equipment for day VFR 91.205:
- Compass
- Altimeter
- Manifold pressure
- Airspeed
- Fuel gauge
- Oil temp
- Oil pressure
- Tachometer (engine)
- Seat belts
CROCWAAG
Required equipment POH:
- Cylinder head temp
- Rotor tach
- Outside are temp
- Warning lights
- Carb heat
- Alternator
- Amp
- Governor
Heli-FACTFOID
Immediate report to NTSB 830:
- Heli = rotor blades or tail strikes ground
- Fire in flight
- Accident
- Collision in air
- Turbine failure not out the exhaust
- Flight control loss
- Overdue
- Inability of a crew member
- Damage to property of 25k or greater
100 PASTVALT
Required inspections
- 100 hour inspection
- Pitot/Static system
- Airworthy directives
- Service Bulletins
- Transponder
- VOR
- Annual
- Life limited parts
- Time before overhaul
IMSAFE
Pilot self assessment:
- Illness = any symptoms
- Medical = prescriptions or OTC drugs
- Stress = psychological, physiological, personal problems
- Alcohol = drinking within the last 8hrs 24hrs
- Fatigue = tired or not adequately rested
- Emotions = angry, depressed, or anxious
PAVE
Personal minimum checklist for pilots:
- Personal = hrs sleep, hrs flight, experience, meds
- Aircraft = airworthy, inspections, fuel, w/b, performance
- enVironment = weather, pireps, notams, airspace, terrain
- External = stressed or anxious, pressure to perform, plan b, difficult passengers, unhealthy safety culture, abilities
R22 Operation Limitation Day/Night
VFR day approved
VFR Night - orientation must be maintained by visual reference to ground objects illuminated solely by lights on the ground or celestial illumination
FLAPS C/G or NAILS C/G
R22 VFR Equipment
CAMAFOOTS Compass Altimeter Manifold pressure Airspeed Fuel gauge Oil temp Oil pressure Tachometer(engine) Seat belts
R22 Night VFR Equipment
FLAPS C/G NAILS C/G
Angle Of Attack
Angle between the chord line(CL) and the resultant relative wind(RW)
H/V Diagram
- Height to velocity chart
- Safe/unsafe flight operations
CHT Overheats
Cylinder Head Temperature
-blown head gasket may occur causing serious damage and engine failure
Engine Oil Overheats
Could cause serious damage and lead to engine failure
Danger Of Exceeding Manifold Pressure
- could damage engine as well as blade failure
- Robinson safety notice SN-37 + SN-39
Danger If You Overspeed Engine
Could result in damage to the engine which could result in the engine seizing causing the pilot to perform an autorotation
Danger Of Flying Over Gross Weight
- Illegal per FAR 91.9(a)
- Put extra stress on parts of the helicopter not designed for over gross weight operations
Danger If You Overspeed Main Rotor
Cause severe damage to the main rotor mast and may cause separation of the main rotor mass
Torque
something that produces or tends to produce torsion or rotation; a moment of a force or system of forces tending to cause rotation
Stall
Low Rotor RPM Stall - Blade Stall:
- Rotor stall is a complete loss of lift from RPM decay
- Recovery not possible if stalled completely
Blade Stalls at 80% RPM @ sea level:
- Critical angle of attack is exceeded to RW coming from below
- Increases in drag, insufficient centrifugal force for blade rigidity
- 80% + 1% per 100ft altitude
Causes:
- Not reacting to RPM decay quick enough
- Reacting to low rotor RPM the wrong way
Basic Empty Weight
Starting point of weight and balance computations:
- Weight of standard helicopter
- Optimal Equipment
- Unusable fuel
- Full operating fluids(including engine oil)
Moment
Product of the weight of an object multiplied bu it’s arm and expressed in pound-inches
Weight x Arm = Moment
Pilot Restrictions
Drugs + Alcohol
- 8 hour bottle to throttle
- Not be over .04 blood alcohol level
- Cannot use drugs that effect pilots faculties
- Cannot fly under the influence
Intoxicated Persons?
Portable Electronic Devices?
Objects Be Dropped?
- No intoxicated persons on aircraft unless they are a patient
- No devices that can interfere with radio signals
- Yes, if reasonable precautions are taken to protect persons and property
Dangers Of Using Low Octane Fuel
- Poor air/fuel mixture in carburetor engines
- Excess fuel left in cylinders causing pre-ignition and engine knock
- Can eventually lead to engine damage
Redline On MAP Gauge
Do not exceed this number
Clutch Actuator
-Electrical system located between the two drive sheaves
-Raises upper sheave when the clutch is engaged
=Actuator senses belt tension and switches off when the V-belts are tensioned to a prescribed value
Cabin Heat
- Fresh air vent is heated by an exhaust shroud and is directed into the cabin
- Fresh air is mixed with the heated air thru a plunger control
Acrobatic Flight Is Not Permitted Where?
No Acrobatic Flight In R22 Allowed!
FAR 91.303
- Over a congested city or town
- Over an open air assembly of people
- Within lateral boundaries of Class B,C,D, or E airspace designed for airports
- Below altitudes of 1,500ft
- When flight visual is less than 3 miles
Solo In The Left Seat?
No - Not permitted by Robinson
- Possibility of running out of cyclic authority due to center of gravity
- Controls/radio on left for easier access
Center Of Gravity
Point a which an aircraft will balance
Total Moment / Total Weight = CG(inches aft of datum)
Datum
Fixed starting point of a scale
Empty Weight
Airframe, engine, fixed equipment and unusable fuel and oil
Useful Load
Pilots, passengers, baggage, oil and fuel
Sympathetic Resonance
- Occurs in the R22 between 60-70% RPM. This type of vibration occurs when the main rotor frequencies interact with the tail rotor frequencies
- Can cause the drive shaft in the tail boom to start vibrating and oscillating causing damage
- Keep rotor RPM out of 60-70%, hence yellow band
Drag
- Force opposing thrust and is the retarding force created by the development of lift + movement
- An aerodynamic force on a body acting parallel and opposite to relative wind
Lift
- Vertical forced created by the affect of airflow as it passes around and airfoil
- Lift counteracts weight
Chord Line(CL)
Imaginary straight line between the blades leading edge and the tailing edge of an airfoil section
Pitch Angle
Angle between the chord line and the plane of rotation
Relative Wind
Resultant Relative:
resultant airflow velocity as a result of blade rotation, induced flow, blade flap, along with airspeed and wind velocities
Rotational Relative:
Airflow velocity over the blades as a result of blade rotation
Airfoil
Any surface that provides aerodynamic forces when moving through a stream of air
Aircraft Speeds
- Indicated: read off instrument
- Calibrated: IAS corrected for instrument and position error
- Equivalent: CAS corrected adiabatic compressible flow and altitude
- True: CAS corrected for non-standard temp and pressure
- Ground: TAS corrected for wind
Airspeed Indicator
Measures difference of pressure from pitot tube and the static source
Limitations:
Getting poor flow to pitot tube
Errors:
- Position: static port sensing erroneous atmosphere pressure
- Density: changes in altitude and pressure
- Compressibility: packing air in pitot tube at hi speed
Altimeter
Aneroid wafers expand and contract as atmosphere pressure changes, shaft and gear linkage rotate pointers and dials
Limitation:
- Hi-temp or pressure: altimeter indicates lower than actual altitude(low to high, nothing but sky)
- Low-temp or pressure: altimeter indicates higher than actual altitude(high to low, look out below)
AP WOTFEEL
off airport
A ltitude P ower W ind O bstacles T errain F orced landing zone E ntry E xit L anding zone
High and low reconnaissance
Preventive Maintenance
Oil changes, hydraulic fluids, operating fluids, wheel bearing lube, bulbs, air filter, shoes on skids, battery, chip detectors, gascolator, cotter pins/safety wires
Logbook entry required:
- Date of work
- Description of work
- Total hours on aircraft
- Pilot Certificate number
- Signature of Pilot
Recommended Airspeeds
Takeoff and climb: 60KIAS Max rate of climb(Vy): 53KIAS Max range: 83KIAS Landing approach: 60KIAS Autorotation: 65KIAS
Elements Of Aircraft Performance
- Rate of climb
- Ceiling
- Payload
- Range
- Speed
- Fuel economy
Takeoffs and Landings:
- Density Altitude
- Wind direction
- Wind speed
- Weight
Factors That Effect Performance
- Density Altitude, weight, wind
- Humidity effects performance because air is less dense
Aircraft Certificates and Documents
AROW
R22 Emergency Water Landing Power On
- Descend to hover above water
- Unlatch doors
- Passenger exits aircraft
- Fly to safe distance from passenger to avoid possible injury from rotors
- Switch battery and alternator OFF
- Roll throttle off into over travel spring
- Keep aircraft level and apply full collective as aircraft contacts water
- Apply later cyclic to stop rotors
- Release seat bealt and quickly clear aircraft after rotors stop
R22 Emergency Water Landing Power Off
- Follow same procedures as far as power failure over land until contacting water. If time permits unlatch doors
- Apply lateral cyclic when aircraft contacts the water to stop rotors
- Release seat belt and quickly clear aircraft when rotors stop
R22 Engine De-rated, why?
- Achieves acceptable high-altitude performance
- Saves weight
- Increased engine life
RPM Of Main Rotor
Why different with power off then power on?
Main rotor can safely handle the RPM’s at those given RPM’s, where as the engine cannot
Power On Power Off
Max: 104% Max: 110%
Min: 101% 0-360 Min: 90%
Min: 97% 0-320
R22 Tachometer/Governor Failure
Tach:
if rotor/engine tach malfunctions in flight, use remaining tach to monitor RPM. If not clear or both fail, allow governor to control RPM and land as soon as practical
Governor:
Engine RPM governor malfunctions, grip throttle firmly to override governor, then switch governor off. Complete flight using manual throttle control
R22 Electrical Fire In Flight
- Master battery switch -OFF
- Alternator switch - OFF
- Land immediately
- Extinguish fire and inspect for damage
R22 Loss Of Tail Rotor Thrust
Hover
- Failure is usually indicated by nose right yaw which cannot be stopped by applying left pedal
- Immediately roll throttle off into over travel spring and allow aircraft to settle
- Raise collective just before touchdown to cushion landing
R22 Fire In Flight
- Enter autorotation
- Master battery switch OFF(if time permits)
- Cabin heat OFF(if time permits)
- Cabin vent - ON(if time permits)
- If engine is running, perform normal landing and immediately shut off fuel valve
- If engine stops running, shut off fuel valve and execute autorotation landing
R22 Loss Of Tail Rotor Thrust
Forward Flight
- Failure indicated by nose right yaw which cannot be corrected by applying left pedal
- Immediately enter autorotation
- Maintain at least a 70KIAS airpseed if practical
- Select landing spot, roll throttle off into over travel spring and perform autorotation landing
When suitable landing site is not available, vertical fin may permit limited control at very low power settings and 70KIAS
Full Throttle Line
MAP Chart
Achieving this altitude is theoretical and most likely unattainable at the current temperature
R22 Power Failure
Above 500ft AGL
1.Lower collective immediately to maintain rotor RPM
2.Steady glide at 65KIAS
3.Adjust collective to keep RPM between 97-110%
Apply full down if light weight prevents 97%
4.Select landing spot, if altitude permits land into wind
5.Restart attempt at pilots discretion
6.No restart, turn off unnecessary switches and fuel valve
7.About 40ft AGL, begin cyclic flare to reduce rate of descent/speed
8.About 8ft AGL, apply forward cyclic to level, pull collective to cushion
R22 Max/Min Gross Weight
Max gross: Standard + HP = 1300lbs Max Gross: Alpha, Beta, Beta II =1370lbs Min Gross: 920lbs Max Per Seat: 240lbs(including baggage compartment) Max either baggage compartment: 50lbs
R22 V(ne)
102 KIAS
up to 3000ft
R22 Power Failure
8ft - 500ft AGL
- Lower collective immediately to maintain rotor RPM
- Adjust collective to keep RPM between 97-110% or full down if light weight prevents reaching 97%
- Maintain airspeed until ground is approached, then begin cyclic flare to reduce rate of descent and speed
- About 8ft AGL, apply forward cyclic to level ship and raise collective just before touchdown to cushion landing
R22 Power Failure
Below 8ft
- Apply right pedal as required to prevent yawing
- Allow aircraft to settle
- Raise collective just before touchdown to cushion landing
R22 Max Glide Distance
- Airspeed appx 75KIAS
- Rotor RPM appx 90%
- Best glide ratio is about 4:1 or one nautical mile per 1500ft
R22 Air-restart Procedure
- Mixture - full rich
- Primer(if installed) - down and locked
- Throttle - closed, then cracked slightly
- Actuate starter with left hand
Rigid Rotor System
- Made up of three or more blades
- Feathers on hinges
- Blades absorb the operating loads of flapping and lead/lag through bending rather than hinges
- They are mechanically more simple but more expensive due to the structural complexity of the blades
Advantages:
- no mast bumping
- reliable and easy to maintain
Disadvantages:
- expensive
- more vibration
Semi-rigid Rotor System
- consists of two or more blades
- able to feather independently and teeter/flap as a unit
- type of rotor system on the R22
- R22 different than others because of coning hinges
Advantages:
- cheap and easy to maintain
- small storage space
- light
Disadvantages:
-low-g mast bumping
Fully Articulated Rotor System
- made up of three or more blades
- able to feather, flap, and lead and lag independent of each other
Advantages:
- smooth flight conditions
- no mast bumping
Disadvantages:
- ground resonance
- high maintenance
- heavy
Blade Flapping
-the way the rotor system compensates for the dissymmetry of lift and creates equal amount of lift across the rotor system
- more lift on the advancing blade causes the blade to flap up, decreasing the AoA(CL)
- less lift on the retreating blade side causes the blade to flap down, increasing the AoA(CL)
Retreating Blade Stall
- potentially hazardous condition caused by excessive forward speed which causes an excessive angle of attack on the retreating blade
- stall begins at the tips of the retreating blades due to high AoA
Cause: Indications:
Exceeding Vne -vibrations
high weight -pitching up of the nose(gyro pro)
low rotor RPM -rolling motion(twrd rtring blade)
high DA
steep abrupt turns
Recovery:
Lower collective to decrease the AoA, ensure RPM 104%, gentle aft cyclic
Settling With Power
- helicopter settles into its own downwash and vortices
- state of powered flight where the heli descends rapidly even with power
3 requirements:
- Vertical descent of 300ft/min or greater
- must have power applied (20% or more)
- A/S is less than ETL
Indications:
- increased vibrations
- uncommanded pitch, roll and yawing
- little cyclic authority
- OGE hover with descent rate
- Tail wind approach
- steep approach with high descent rate
Recovery(eliminate one of 3 req.):
- forward cyclic for airspeed
- ASI and trim come alive, climb profile, pitch for power
Loss Of Tail Rotor Effectiveness
LTE
-tail rotor is unable to provide adequate thrust to maintain directional control; not a tail rotor failure
3 types of wind induced LTE:
-main rotor interference = wind from NW into heli
-weather cock = wind from behind
tail rotor cortex ring state = wind from rotor side of heli
Autorotation
-state of flight in which the rotor blades are driven solely by the aerodynamic forces resulting from the rate of descent and an upward flow of air through the rotor disc
-sprag clutch:
allows for an autorotation by automatically disengaging the rotor system from the engine
direction of airflow:
airflow is from below the disc no longer being pulled down from above by the rotors
Mast Bumping
- when the rotor hub teeters/flaps so great that it contacts the rotor mast
- can occur in an unloaded rotor system by applying lateral cyclic during the rolling movement of the fuselage
- severe damage likely, even potentially chopping off the rotor hub
Causes:
- incorrect inputs or no inputs during low-g conditions
- excessive blade teetering/flapping
- gust, wind, turbulence
- abrupt cyclic inputs
Correction:
- light aft cyclic
- left cyclic for roll
AvGas Colors
91/96 Purple (all engines)
100LL Blue (all engines)
100/130 Green (320-b2c + 360 j2a)
Weighs 6lbs a gallon
Ground Resonance
- vibration of large amplitude resulting from a deliberate or unintentional oscillation of the helicopter from the ground contact or when resting on the ground
- on set recognizable by slow rocking of the fuselage
- initiate lift off if power and rotor RPM permit
- not able, shut down and immediately apply rotor brake
ARM
-horizontal distance measured in inches from the datum line to a point on the aircraft
+ Positive if move aft
- Negative if moved forward
Electrical System
Battery:
12volt 25 amp
-starts engine
-store energy = 20 minutes worth if power failure
Alternator:
14volt 60amp
-primary source for power to electrical system, charge battery
Circuit Breakers:
-protects against over voltage, push to reset
Magnetos(x2)
Fuel System
Two Tanks:
- main(19.8/19.2)
- aux(10.9/10.5)
- gravity fed
- shut off valve behind left seat
- gascolator = sediment bowl or fuel strainer
- tank air vent = prevents vacuum from developing in tanks, in main mast
Ignition System
Magnetos:
small electrical generators driven by crankshaft rotation to provide voltage for spark plugs
Why two?
- Redundancy: two if aircraft loses one magneto, still has another to run off
- Performance: two sparks allow more complete combustion
Oil System
Two types:
- Mineral oil: for engine break in purposes, no additions
- Ashless dispersant: mineral oil with additives, multi viscosity, suspends contamination
Quantity:
4-6 quarts
Weight:
7.5lbs per gallon
Carb Ice + Indications
- moisture in air freezes in the carburetor due to the low pressure/low temp
- indicated by RPM drop
- RPM will go back up if the carb heat is applied
- warm/cool air, high moisture content
Engine Fire On Ground
- Continue to start engine
- If it starts, run at 50-60% then shut off
- If it doesn’t, turn off fuel and battery
- Put out fire
- Inspect for damage
Instruments On Pitot/Static System
- Altimeter
- Vertical airspeed
- Airspeed indicator
Landing Gear On R22
Spring and Yield
- will absorb most landings
- hard landings will hinge up and outward
Flight Review R22
-energy management
-mast bumping
-low rotor RPM
-low-g hazards
rotor RPM decay
Limitations Not On Airspeed Indicator
V(A):design maneuvering speed V(LO):landing gear operating speed V(LE):landing gear extended speed V(X):best angle of climb speed V(y):best rate of climb V(ySE):single engine best rate of climb V(MC):minimum control speed
R22 MAP Limitation
Standard:
yellow - 23.2-25.9
red - 25.9
HP+Alpha(o-320-b2c):
yellow - 21.0 -24.1
red - 24.1
Beta(0-320-b2c)
yellow - 21.0 - 25.2
red - 25.2
Beta II(0-360-j2a)
yellow - 19.6-24.1
red - 24.1
R22 Temperature Limitations
Oil temp:
green 75-245°
red 245°F
CHT:
green 200-500°
red 500°F
Carb Temp:
yellow arc: -15°-5°sC
Lift Equation
Lift = CL 1/2p V2 S
CL= coefficent of lift 1/2p = half rho(rho relates to air density) V2 = velocity squared (velocity is a vector quantity made up of speed and direction) s = surface area of wing
Define:
Category
Class
Type
Category: airplane, rotorcraft, glider Class: helicopter, gyroplane Type: specific model
Center Of Pressure
-imaginary point on the chord line where the resultants of all aerodynamic forces are supposed to be concentrated
Magnus Effect
-cylinder rotating in an airstream in the same direction of airflow, local velocity is high on top and low on the bottom
high velocity = low pressure
low velocity = high pressure
Air always moves to areas of low pressure
Bernouilli’s Principle
- as air velocity increases the pressure decreases
- air traveling over the upper surface of the airfoil moves faster
- creates a lower pressure on the upper surface than the lower surface, thus creating lift
Dissymmetry Of Lift
- difference in lift between the advancing and retreating halves of the rotor disc due to different velocities of relative wind
- counterclockwise rotating rotor systems advance on the right and retreat on the left
Advancing side:
-Res. RW = tip speed + relative wind(forward airspeed and/or wind)
Retreating side:
Res. RW = tip speed - relative wind(forward airsseed and/or wind)
Effective Translational Lift
The increase in rotor system efficiency due to an increase in horizontal relative wind across the entire rotor disc
- occurs with relative winds of about 16-24KIAS
- horizontal RW allows both the MR and TR to outrun vortices
- Rotor system is more efficient due to smaller vertical IF, increases AoA for the same collective pitch
- efficiency continues to increase until the L/D max 53KIAS where the total drag is at its lowest point
- recognized by a left yaw and nose pitch up, heli tries to climb
- correct by giving right pedal and forward/left cyclic inputs
Transverse Flow Effect
TFE
- the difference in lift between the fore and aft portions of the disc
- acceleration in forward A/S causes vertical IF to drop significantly in the fore portion of the rotor disc and remain the same in aft
- due to gyroscopic tendency, max lift is felt 90° in direction of rotation causing the tendency for the heli to roll slightly to the right as it accelerates through 20KIAS
- recognized bu increased vibrations at airspeeds just less than ETL
- as A/S increases, heli responds with a right roll and pitch up of the nose
- correct by giving forward/left cyclic inputs to push thru into ETL
Translational Lift
-additional lift gained due to horizontal movement of the aircraft or surface winds
-any movement or wind creates a more horizontal airflow across both the MR and TR systems
-vertical induced flow decreases as airflow becomes more horizontal, creating a greater AoA for the same collective pitch
MR system vortices begin to recede in the forward portion of the disc
Gyroscopic Procession
- when force is applied to a rotating body, the deflection will manifest 90° later in the direction of rotation
- pitch angle change applied at the 3 o’clock position will manifest at the 12 o’clock position in a rotor system rotating counter clockwise
Ground Effect
- any increase in rotor efficiency due to the proximity of the ground
- occurs when the aircraft is within 1 rotor diameter of the ground due to the change in induced flow
Out of ground effect(OGE):
-greater than 1 rotor diameter from ground, allows full vortex
In ground effect(IGE):
-less than 1 rotor diameter above the ground over a hard smooth surface 2 diameters wider
-increases AoA for the same pitch angle
Coriolis Effect
- tendency of a rotor blade to change its rotational velocity(RPM) in its plane of rotation when the Center of Mass(CM) moves closer or further from the Axis of Rotation(AoR)
- blade flaps center of mass moves closer to the AoR causing an increase in RPM (ice skater)
Blade Coning
- an upward sweep of the rotor blades as a result of lift and centrifugal force
- angle determined by the resultant force of lift and centrifugal force
- allowed through blade bending, the flapping hinge, the coning hinge, or a combo of both
- accentuated by - low RPM, high GW +load factor
Translating Tendency
-tendency for a helicopter to drift in the direction of the tail rotor thrust during hovering flight
Compensated by:
- manual inputs
- main rotor mast rigging
- flight controls rigging
- tail rotor location
Light Gun Signals
Steady Green:
G = cleared for takeoff
A = Cleared to land
Flashing Green:
G = cleared to taxi
A = return for landing
Steady Red:
G = stop
A = give way to other aircraft
Flashing Red:
G = taxi clear of runway
A = airport is unsafe / do not land
Flashing White:
G = return to starting point
Alternating Green/Red:
A = exercise extreme caution
