• Fuel flow varies directly with the power output of the engine (power availiable)
• Minimum fuel flow will be found on the power required curve

(there is no direct relationship btwn thrust and fuel flow because thrust provided by a propeller is not produced directly by the engine)

• maximum endurance - the maximum amount of time that an airplane can remain airborne on a given amount of fuel.
• maximum range - the maximum distance traveled over ground for a given amount of fuel.

• Max Endurance - decreases with an increase in weight(& AS increases), increases with an increase in altitude(& AS increases), decreases with a configuration change(AS decreases for lowering flaps but remains the same for lowering gear). winds have no effect on max endurance
• Max Range - decreases with changes in weight(b/c higher fuel flow=higher velocity to produce more thrust, & AS increases), increases with increase in altitude(AS increases), decreases with configuration change(lowering flaps/landing gear...AS decreases with flaps but stays same with gear)headwinds will decrease max range/tailwinds increase max range

• Max angle of climb - comparison of altitude gained to distance traveled.  Objective is to gain sufficient altitude to clear obstacles with the least horizontal distance traveled.
• Max rate of climb - Comparison of altitude gain relative to time needed to reach an altitude.  Objective is to gain the greatest vertical distance in the shortest time possible.

Max AOC/ROC performance will decrease with an increase in eight, altitude, or change in config (max Te/Pe decreases)

• wind does not affect ROC performance
• a headwind will increaes max AOC b/c it reaches the same altitude as before with a smaller distance covered over the ground.  A tailwind has the opposite effect.

absolute ceiling - max ROC = 0 fpm

service ceiling - max ROC = 100 fpm

cruise ceiling - max ROC = 300 fpm

combat ceiling - max ROC = 500 fpm

max operating ceiling - max altitude that an aircraft can be operated at

• max glide range - gliding as far as possible when an engine fails (the max distance that can be traveled in a glide as a function of altitude, wind, and lift to drag ratio).
• max glide endurance - maximize time aloft. Used if you lose an engine wihtin easy reach of a safe runway, while the runway is being cleared (the masimum time an airplane ca nstay airborne in a glide as a function of weight, altitude and AOA.

• at L/Dmax
• V_best (max glide range velocity) is 100 KIAS for the T-34

Max glide range - increasing weight does not effect max glide range;increasing altitude increases max glide range;configuration(lowering flaps/gear)decreases max glide range;headwind decreases max glide range & tailwind increases max glide range;feathering the prop increases max glide range.

Max Glide Endurance - decreases with increase in weight;increases with increase in altitude;wind has no effect on max glide endurance;decreases with configuration change(lowering flaps/gear);feathering the prop increases max glide endurance

• normal command - velocities above max endurance AOA; characterized by airspeed stability
• reverse command - velocities below max endurance AOA; characterized by airspeed instability

• normal command - velocities and throttle settings are directly related
• reverse command - velocities and throttle settings are inversely related; the slower you fly, the more thrust/power you need

T-34 uses control surfaces to cerate airplane motions, such as yaw, pitch and roll.

The T-34 uses conventional controls

• Elevator - moving the stick forward causes the elevator to move down, forcing the tail on the airplane up and pitching the nose down.
• ailerons - ailerons move in unison in opposite directions; if stick is moved left, the left aileron rises, right aileron loers and the plane rolls left.
• spoilers - disrupt the airflow over the top of the wing in order to decrease lift on the wing and cause the wing to roll downward.
• Rudder - stepping on the right rudder pedal moves the rudder to the right, pushing the tail left and yawing the nose to the right.

trimming reduces the forces required to hold control surface in a position necessary to maintain a desired flight attitude

• trim tabs must always be moved in the opposite direction as the control surface

• aileron trim - adjusted after takeoff and seldom requires further adjustment during flight.  only the left aileron trimtab moves.  the right aileron trim tab is preset by maintenance
• right rudder trim - required for power increases and slower airspeeds
• left rudder trim - required for power reductions and faster airspeeds
• elevator trim - adjusted up at slower airspeeds and down at higher speeds

• aerodynamic balance - used to keep control pressures(associated with higher velocities) within resonable limits
• as trailing edge of the control sfc is deflected in one direction, the leading edge deflects into the airstream forward of the hingeline.
• the force on the leading edge creates a moment that reduces the force required to deflect the control surface, so the pilot may control the airplane more easily.

• to gain a balance between control response and stability, the T-34 control CG's are located on the hingeline
• technique used to locate the CG onthe hingeline, weights are placed inside the control sfc in the area forward of the hingeline (shielded horn and overhang)

• aerodynamic balancing - shielded horns on the elevator and rudder and an overhang on the ailerons
• mass balancing - to locate the CG on the hingeline, weights are placed inside the control surface in the area forward of the hingeline (shielded horn and overhang)

• servo trim tabs - (ailerons) provide artificial feel by moving in opposite direction as the aileron, thus helping the pilot deflect the aileron and making the airplane easier to maneuver
• anti-servo trim tab - (rudder) provides artificial feel by moving in the same direction at a faster rate. Thus, the more that a rudder pedal is pressed, the greater the resistance that the pilot will feel.
• Neutral Trim Tab - (elevator) maintains a constant angle to the elevator when the control surface is deflected.

• bobweights - increases the force required to pull the stick aft during maneuvering flight
• downspring - increases the force required to pull the stick aft at low airspeeds when required control pressures are extremely light

• servo trim tabs (ailerons)
• anti-servo trim tab (rudder)
• neutral trim tab (elevator)

• static stability - the initial tendency of an object to move toward or away from its original equilibrium position
• the position with respect to time, or motion of an object after a disturbance

• maneuverability and stability are opposites
• a stable airplane tends to stay in equilibrium and it is difficult for the pilot to move out of equilibrium
• a maneuverable plane departs from equilibrium easily and is less likely to return to equilibrium

• give an airplane weak stability which allows the airplane to move quickly from its trimmed equilibrium attitude
• give an airplane larger control surfaces which would generate large moments by producing greater aerodynamic forces

• longitudinal stability - stability of the longitudinal axis around the lateral axis (pitch)
• neutral point - the location of the center of gravity, along the longitudinal axis that would provide neutral longitudinal static stability.  Can be thought of as the aerodynamic center for the entire airplane.

Static Stability

• positive static stability - object has an initial tendency toward its original equilibrium position after a disturbance
• negative static stability - initial tendency to continue moving away from equilibrium following a disturbance
• neutral static stability - initial tendency to accept the displacement position as a new equilibrium.

Dynamic Stability

• positive dynamic stability - if a ball was released in a bowl, we naturally expect it to roll back to the bottom and up the other side.  It would roll back and forth, oscillating less and less about the equilibrium position until it finally stops......Damped Oscillation
• neutral dynamic stability - if the ball oscillates about the equilibrium position and the oscillations never dampen out......Undamped Oscillation
• negative dynamic stability - if the ball did not slow down and continued to climb to a higher and higher position with each oscillation.....Divergent Oscillation

• straight wings - negative contributor
• wing sweep - sweeping wings back is a positive contributor
• fuselage - a negative contributor
• horizontal stabilizer - the greatest positive contributor
• if the neutral point is behind the airplane's CG the component will be a positive contributor & if the neutral point is in front of the airplan's CG the component will be a negative contributor

• straight wings has a small positive effect
• swept wings are positive contributors
• the fuselage is a negative contributor
• the vertical stabilizer is the biggest positive contributor to directional static stability

• dihedral wings are the greatest positive contributors to lateral static stability
• anhedral wings are greatest negative contributors
• a high mounted wing is a positive contributor/a low mounted wing is a negative contributor
• swept wings are laterally stabilizing/pos contributors
• vertical stabilizer can help right the plane when in a lateral sideslip

condition of flight in which the reaction to a small initial sideslip results in an increase in sideslip angle.

directional divergence is caused by negative directional static stability

• Directional divergence is caused by negative directional static stability
• spiral divergence is caused by strong directional stability and weak lateral stability
• dutch roll is caused by strong lateral stability and weak directional stability
• phugoid motion is caused by being struck by an upward gust.

• proverse roll is the tendency of an airplane to roll in the same direction as it is yawing
• adverse yaw is the tendency of an airplane to yaw away from the direction of aileron input
• pilot induced oscillations (PIO) are short period oscillations of pitch attitude and AOA

• yawing moment caused by one prop blade creating more thrust than the other
• if the relative wind is above the thrust line, the up going propeller blade on the left side creates more thrust since it has a larger AOA with the relative wind.  This yaws the nose to the right
• if the relative wind is below the thrust line, such as imn flight near the stall speed, the down going blade on the right side will create more thrust and will yaw the nose to the left.

it is a reactive force based on newton's third law of motion

a force must be applied to the propeller to cause it to rotate clockwise.  a force of equal magnitude but opposite direction is produced which tends to roll the airplane's fuselage counter clockwise.

spin is an aggravated stall that results in autorotation

autorotation is a combination of roll and yaw that propagates itself and progressively gets worse due to asymmetrically stalled wings

• weight - weight away from the center of gravity creates a large moment of inertia for a spin to overcome
• pitch attitude - will have direct impact on the speed the aircraft stalls; the higher the pitch attitude, the greater the vertical component of thrust and the lower the stall speed;slower stall speeds make spin entry slower and with less oscillations;at lower pitch attitudes the acft stalls at a higher AS and entries are faster and more oscillatory
• gyroscopic effect - in a right spin, the nose will tend to pitch down due to the clockwise rotating propeller

in a left rolling stall:

• left/down-going wing has higher AOA & is stalled more than right wing
• down-going wing has higher C_D due to inceased AOA, greater drag=continued yawing motion in direction of roll
• the right/up-going wing has lower AOA & is less stalled
• up-going wing has a greater C_Ldue to smaller AOA and has greater total lift which results in continued rolling motion

• erect (normal) spin - results from positive G stall entries; altimeter will rapidly decrease, AS will be stable, AOA will be 30 units pegged, turn needle will be pegged in direction of spin, VSI pegged and attitude gyro may be tumbling
• inverted spin - results from negative G stall entries;altimeter will rapidly decrease, AS will be zero;AOA 2-3 units, turn needle pegged in direction of spin, VSI pegged, attitude gyro may be tumbling and accelerometer will show 1 negative G

• the rudder is the principle control for stopping autorotation
• opposite rudder (anti-spin rudder) creates drag that can be divided in a horizontal and vertical component.  Opposite rudder maximizes both components.
• The horizontal component creates a force that opposes the yawing of the airplane
• the vertical component creates a force that pulls the tail up and pitches the nose down.

• progressive spin - if proper spin recovery procedures are not followed, you can reverse spin direction;you will get into a progressive spin if, upon recovery, you put in full opposite rudder but inadvertently maintain full aft stick
• aggravated spin - results from pushing the stick forward while maintaining rudder in the direction of spin; characterized by a steep nose down pitch and an increase in spin rate.

step 1:  landing gear/flaps check up

step 2:  verify spin indications by checking AOA/AS/turn needle (if recovery does not occur in 2 spins verify cockpit indications & confirm proper spin recovery controls are applied

step 3:  apply full rudder opposite turn needle

step 4:  position stick forward of neutral (ailerons neutral)

(1) erect spin-expect a push force of 40 lbs to keep stick forward

(2) inverted spin-expect a pull force of approximately 30 lbs to place stick in neutral position

step 5:  neutralize controls as rotation stops/reduce power to idle

step 6:  recover from the ensuing unusual attitude (slowly apply back-stick pressure until nose on horizon/wings level

• The T-34 use a dorsal fin, strakes and ventral fins to decrease the severity of spin characteristics
• dorsal fin - is attached to the front of the vertical stabilizer to increase its surface area.  this decreases the spin rate and aids in stopping autorotation
• ventral fins - located beneath the empennage decreases the spin rate and aid in maintaining a nose down attitude
• strakes - the T-34 has strakes located in front of the horizontal stabilizer. they increase the SA of the horizontal stabilizer in order to keep the nose pitched down and prevent a flat spin

• during a turn the lift vector is divided into 2 components, a horzontal component and a vertical compnent
• the horizontal component is called centripetal force, and accelerates the airplane towards the inside of the turn
• in straight and level flight total lift is equal to weight but in a turn only the vertical component of the lift vector opposes weight

The ratio of total lift to the airplane's weight.  Called G's:

n - (L/W) or L = W n

• in level flight Lift=Weight, therefore Load Factor (n)=1
• In order to maintain level flight in a bank, total lift must be increased and therefore the load factor increases.

• maneuvering will significantly affect stall speed
• stall speed increases when we induce a load factor greater than one on an airplane

is the greatest oad factor an airplane can sustain withoutany risk of permanent deformation.

T-34 limit load factor is +4.5 G's and -2.3 G's

condition of possible permanent deformation or damage that results from exceeding the limit load factor

• will reduce the service life of the airplane because it weakens the airplane's basic structure

the maximum load that may be applied to a component without permanent deformation

• limit load factor is designed to be less than the elastic limit of individual components

• the maximum load factor that the airplane can withstand without structural failure
• there will be some permanent deformation at the ultimate load factor, but no actual failure of the major load carrying components should occur.
• if exceeded, something will break
• ultimate limit load factor is 150% of the limit load factor

• the V-n/V-g diagram is a graph that summarizes an airplane's structural and aerodynamic limitations
• horizontal axis is indicated airspeed, vertical axis is load factor/G
• accelerated stall lines/lines of maximum lift are the curving lines on the left side.  They represent the maximum load factor that an airplane can produce based on airspeed.  They are determined by C_LmaxAOA
• limit/ultimate load factor lines are horizontal and represent structural limitations.  Any G load above the ultimate load factor will likely cause structural failure.
• The point where the accelerated stall line and the limit load factor line intersect is the maneuver point.  The IAS at the nameuver point is called the maneuvering speed (V_a) or cornering speed. It is the lowest airspeed at which the limit load factor can be reached.
• redline airspeed (V_NE) (never exceed speed) is the vertical line on the right side.  it is the highest airspeed that your airplane is allowed to fly
• safe flight envelope is the portion of the V-n diagram that is bounded by the accelerated stall lines, the limit load factors and redline airspeed

V_NE is determined by:

M_Crit

airframe temperature

excessive structural loads

controllability limits

• limit load factors: +4.5 G's, -2.3 G's
• maneuvering speed: 135 KIAS at max gross weight
• Redline airspeed:  280 KIAS

• If weight decreases the limit load factor will increase which increases the safe flight envelope
• if altitude increases the indicated redline airspeed must decrease in order to keep a subsonic airplane below M_crit TAS
• Configuration - when landing gear and high lift devices are extended, the safe flight envelope substantially reduces in size

• asymetric loading: the uneven production of lift on the wings of an airplane; it may be caused by a rolling pullout, trapped fuel, or hung ordnance
• limitations: the limit load factor due to pilot induced loads should be reduced to approximately 2/3 of the normal limit load factor

• turn radius (r) - measure of the radius of the circle the flight path scribes

r = (V²/gtanφ)

• turn rate (ω) - rate of heading change, measure in degrees per second

ω = (gtanφ)/V

• if velocity increases (at a given angle of bank) turn rate decreases and trun radius increases
• if angle of bank increases for a given velocity, turn rate increases and turn radius decreases
• both turn rate and turn radius are independent of weight
• in a skid turn radius decreases, turn rate increases
• in a slip turn radius increases, turn rate decreases

• a rough estimate used to determine standard rate turns in the T-34 is angle of bank equal to 15-20% of airspeed
• standard rate turn is equal to 2 needle widths deflection on the turn needle in the T-34

• Weight(W), density(ρ), and wing area(S), (the same factors that affect stall speed)
• high lift devices are often used to decrease takeoff/landing speeds
• indicated airspeed for takeoff/landing will not be affected by changes in air density

• increase in weight will require an increase in IAS and TAS
• indicated airspeed remains constant, reguardless of density.  TAS will increase with a decrease in density
• high lift devices decrease both IAS & TAS.  Since TAS decreases the ground speed during takeoff will decrease
• a headwind will decrease takeoff distance by reducing ground speed assoc with takeoff velocity. tailwind will increase takeoff groundspeed

• Rolling Friction(effects of friction btwn lndg gear & runway) {coefficient of friction is dependant on rw sfc & condition, tire type and degree of brake application}
• Net Accelerating Force: thrust - drag - rolling friction
• Net decelerating force:  drag + rolling friction - thrust

• weight is the greatest factor in determining takeoff distance
• 4-H club: high, hot, heavy, humid.  2 or even 1 of these factors may causelonger takeoff/landing distances
• using high lift devices will decrease takeoff distance
• a headwind reduces landing distance(GS decreases)/tailwind increases landing distance(GS increases)

• increase in weight = increased landing distance
• increase in elevation/temp/humidity = increased landing distance(reduced density results in a higher landing velocity)
• high lift devices decrease landing distance(b/c they reduce ground spd)
• a headwind reduces landing distance (b/c it reduces ground spd) a tailwind increases landing distances (b/c GS increases)

• rudder is primary means of directional control
• ailerons must be placed into wind to overcome lateral stability that is trying to roll the airplane away fromthe crosswind

• entering ground effect (during landing) increases effective lift and decreases induced drag by preventing the aft inclination of the lift vector
• as an airplane takes off and leaves ground effect, induced drag increases and lift decreases, which could cause an altitude loss, possibly resulting in an unintentional gear up landing

• avoid use of frictional brakes, since they may cause loss of directional control
• beta settings should be used (T-34)

• during formation flight/in-flight refueling, airplanes close to one another produce a mutual interference(especially when the trailing airplane is slightly aft and below the lead)
• the lead airplane experiences an effect similar to ground effect b/c of a reduction in downwash and induced drag
• for the 2nd airplane, the mutual interference can instantaneously alter the direction of the relative wind
• flying through the lead's flight path will place you in his wake turbulence which could cause an over g or flameout

• structural damage, over-g
• changing direction of relative wind causing one or both eings to stall or disrupt airflow in the engine inlet unducing a compressor stall/flameout
• most common hazard: rolling moments can exceed roll control capability of airplane(it is more difficult for airplanes with short wingspans to counter impsed roll)[relative wingspan btwn the 2 airplanes]

• stay at or above a large airplane's final approach path & land beyond its TD point
• ensure interval of 2 minutes before takeoff behind large acft OR takeoff beyond the acft's TD point
• ensure your landing/takeoff rotation is complete prior to larger plane's point of rotation
• small airplanes should avoid operating within 3 rotor diameters of any hovering helicopter

jet streams

land/sea breezes

fronts

inversions

thunderstorms

• Takeoff - headwind increases IAS=increases lift and causes initial increase in performance.  a decreasing wind shear will decrease performance
• Landing - tailwind to a headwind on approach = increase in performance;  headwind to decreasing headwind = decreases IAS; headwind to tailwind (worst type) = a strong decreasing performance