Ground School (private) Notes

-3+ blades
-Each blade can flap, feather, lead or lag independently
-Done through various hinges (allows movement) and dampers (controls amount of movement)
--ADV: smooth ride, and lots of lift (because of independent blade movement)
--DISADV: high maintenance cost, storage (more blades), and ground resonance (to be cont’d…)

-2 blades
-Flap as a unit through a teetering hinge (one goes up other goes down)
-Feather through a feathering hinge
<<-Lead and lag forces minimized because blades are underslung
--ADV: low maintenance cost, storage space
--DISADV: Low G/ mast bumping, less lift, bumpy ride in turbulence

-3+ blades
-Blades can feather through a hinge, but flapping/lead and lad absorbed through blade flexing
--ADV: low maintenance cost (compared to full articulated), very maneuverable e.g Red Bull heli
--DISADV: requires hydraulics/computer, bumpy, expensive blades-made of carbon fiber

spring and yield skid type

FOR STUDENT

Min age - 16
Medical - 3rd
Carry Pax - No
Fly for hire - No
Cert expires - 24 months, over 40; 60 months, under 40
Privileges and Limitations - Part 61, subpart C

for PRIVATE

Min age - 17
Medical - 3rd
Carry Pax - Yes
Fly for hire - No (must pay pro rata share)
Cert. expires - No, remain current
Privileges and Limitations - E

For COMMERCIAL

Min. age - 18
Medical - 2nd
Carry Pax - Yes
Fly for hire - Yes – info 61, 91, 119 regulations
Cert. expires - No, remain current
Privileges and Limitations - F

Airworthiness Certificate
Registration
Radio License
Operating Limits
Weight and Balance

must be complied with before the next flight

must be complied with by a specific date or # of hours

issued by manufacturer, compliance generally voluntary

-Annual: 12 months inspection carried out by IA tech
-100 hour: inspection required if used for hire
-Life limited parts: R22 overhaul 2200
-A.D.’s and S.B.’s: complied with and in date
-Transponder: 24 months: test and inspection
-ELT (Emergency Location Transmitter): 12 month inspection, replace battery after 50% shelf life or one hour cumulative use

-As the velocity of the fluid (air) increases, pressure decreases
-The decrease in pressure is created on top of the airfoil
-The higher pressure below tries to get to the lower pressure

every action…equal and opposite reaction, e.g. hand out the window (changing angle)

created by all parts of the helicopter not creating lift, parasite drag increases with the square of the airspeed…

from frictional resistance of rotor blades, increases moderately with airspeed
-includes form drag and skin friction.

downwash or tip vortices are created when lift is created, as a by-product, this develops induced flow

--> Induced flow, acts vertically and makes the relative wind more vertical

-induced drag is created whenever lift is created

-induced drag decreases with an increase in airspeed

-air density
-blade size
-angle of attack
-velocity of airflow

-Longitudinal (nose to tail)
Movement about this axis is roll

-Lateral (side to side)
Movement about this axis is pitch

-Normal or Vertical (top to bottom)
Movement about this axis is Yaw

• Uncommanded Yaw that does not subside of its own accord

1- Main rotor disc interference {Fig 11-10}
-occurs with 10-30 kt winds
-from 285⁰-315⁰ (relative to the nose)
-most likely to get dangerous in a right pedal turn (b/c thrust already reduced)

2- Weathercock Stability (AKA weathervane instability)
-occurs with tail winds 120-240⁰ {Fig 11-11}

3- Tail Rotor Vortex Ring State
-occurs with winds from 210-330⁰

Higher altitudes – apply full left pedal, lower collective and apply forward cyclic

Lower altitudes- as above is obstacle clearance is guaranteed, if not, perform a hover autorotation

-Cause by normal vibrations from engine, tail rotor, main rotor combining
-together the vibrate at a certain frequency, this can damage tail section in R22
-avoid prolonged operation in the yellow arc, 60-70%
-not all helicopters have this problem

o A direct-drive, squirrel cage blower
o Blows air around the engine, alternator and gearbox (MR) using ducts

o
o Lubricates, cools, removes debris and inhibit corrosion
o Types used:
- First 50 hours: (new/rebuilt engine) – use mineral oil SAE 50 (@ QH)
- After 50 hours: we use an ashless dispersant (AD) 100+

*independent of electrical system*
o Creates electrical energy using magnetos
o Magnetos are engine-driven, self-contained, permanent magnetos that rotate within a wire coil
o R22 uses dual magnetos: each on provides power to 1 spark plug per cylinder
-Improves performance and reliability
o Mag drop less that 7% in 2 seconds

80/87 – dyed red – do not use in BII
91/96 – purple – can be used
100LL – blue – low lead - preferred
10130 – green – can be used

fuel explodes instead of burning (lower than recommended fuel grades)

when fuel/air mixture ignites before it’s supposed to
-Caused by hot spots (carbon deposits)

o 100LL weighs about 6 lbs per gallon
o R22 burns ~10 gallons per hour

AND temperature / dew point spread is < 11⁰C

...And before take off and descent (Because of carb heat assist)

12 volts / used to start engine and run avionics if alternator fails (about 30 mins)
o Master switch

electric motor turns engine to start it
*start motor it turns off

engine driven power supply (like a generator)
o Light comes on when alt off or system fails
o Magnetos separate – engine still runs
o Will lose avionics including governor, not tach
o 14 V, 16 amps

o A “-“ indicates a discharging batter – using it, as in starting
o A “+” indicates a charging (from alt)

-Clutch Assembly
-Clutch Actuator
-Drive Belts

o Consists of upper sheave and sprag clutch (need for autorotation)
*NO LEAKS*

o Electrically driven motor, pushes upper sheave 
o Flex couplings allow that movement

2 double V belts

11:47 reductions (slows MR)

3:2 increase (speeds up TR)

o Variation --- difference between true and magnetic north
-Use isogenic lines to correct for the difference
-“East is Least, West is Best”
o Deviation --- errors due to magnetic field in aircraft
-Use deviation card to correct (in aircraft)
o Magnetic Dip --- compass points down to magnetic pole / field
-Weight on needle compensates
o Oscillation --- turbulence causes needle to swing making it hard to read
o Northerly Turning Errors
-UNOS – Undershoot North, Overshoot South
-No correction for east/west
-When turning, due to weight
o Acceleration/Deceleration Errors
-ANDS – Accelerate North, Decelerate South (fixed wing)
-Caused by weight

(Compass error)

Accelerate North, Decelerate South (fixed wing)

Undershoot North, Overshoot South

Balloon has right of way over…
Glider has right of way over…
Aircraft towing or refueling has right of way over…
An airship has right of way over…
Powered parachute, weight shift control, & airplane, rotorcraft

engine-driven, self-contained, permanent magnetos that rotate within a wire coil