Aero Ii Ch.11

Front 1

Describe how the forces acting on an airplane produce a level coordinated turn.

Back 1

During a turn, the lift vector is divided into 2 components, a horizontal
component (LH) and a vertical component (LV).
• LH called centripetal force, accelerates the airplane toward 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.

Front 2

Define load factor.

Back 2

Load Factor (n)
o Is the ratio of total lift to the airplane’s weight. Called G’s
n = (L/W) or L = W·n

Front 3

Describe the relationship between load factor and angle of bank for level flight.

Back 3

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.

Front 4

State the effect of maneuvering on stall speed.

Back 4

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

Front 5

Define load, strength, static strength, static failure, fatigue strength, fatigue
failure, service life, creep, limit load factor, elastic limit, overstress/over-G, and
ultimate load factor.

Back 5

Load
o Stress producing force that is imposed upon an airplane or component.
• Strength
o Measure of a materials resistance to load. 2 types: Static and Fatigue
Strength.
Static Strength
o Measure of a material’s resistance to a single application of a steadily
increasing load or force.
• Static Failure
o The breaking (or serious permanent deformation) of a material due to a
single application of a steadily increasing load or force.
• Fatigue Strength
o Measure of a material’s ability to withstand a cyclic application of load or
force, ie, numerous small applications of a small force over a long period
of time.
• Fatigue Failure
o The breaking (or serious permanent deformation) of a material due to a
cyclic application of a steadily increasing load or force.
• Service Life
o Number of applications of load or force that a component can withstand
before it has the probability of failing.
Creep
o When a metal is subjected to high stress and temperature it tends to stretch
or elongate. This is called plastic deformation or creep.
• Limit Load Factor
o Is the greatest load factor an airplane can sustain without any risk of
permanent deformation.

Front 6

State the relationship between the elastic limit and the limit load factor.

Back 6

To ensure that the airplane may operate at its limit load factor without permanent
deformation, the limit load factor is designed to be less than the elastic limit of
individual components.

Front 7

Describe and identify the parts of the V-n/V-g diagram, including the major axes,
limit load factor, ultimate load factor, maneuvering speed/cornering velocity,
redline airspeed, accelerated stall lines, and the safe flight envelope.

Back 7

The V-n/B-g diagram is a graph that summarizes an airplane’s structural and
aerodynamic limitations.
• Horizontal axis is indicated airspeed. The Vertical Axis is the load factor, or G.
• Accelerated stall lines or 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 CLmax AOA.
• Limit/Ultimate load factor lines are horizontal and represent structural
limitations. Any G load above the limit load factor will overstress the airplane.
Any G load abut 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 maneuver point is called the maneuvering
speed (Va) or cornering speed. It is the lowest airspeed at which the limit load
factor can be reached.
The point where the accelerated stall line and the limit load factor line intersect is
the maneuver point. The IAS at the maneuver point is called the maneuvering
speed (Va) or cornering speed. It is the lowest airspeed at which the limit load
factor can be reached.
• Redline airspeed, or VNE (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.

Front 8

List and describe the phenomena that are used to determine redline airspeed.

Back 8

VNE is determined by: MCRIT, airframe temperature, excessive structural loads, or
controllability limits.

Front 9

State the limit load factors, maneuvering speed, and redline airspeed for the
T-34C.

Back 9

T-34
o Limit load factors- +4.5 G’s and -2.3 G’s
o Maneuvering speed – 135 KIAS at max gross weight.
o Redline airspeed – 280 KIAS.

Front 10

Describe the effects of weight, altitude, and configuration on the safe flight envelope.

Back 10

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

Front 11

Define asymmetric loading and state the limitations.

Back 11

Asymmetric Loading
o The uneven production of lift on the wings of an airplane.
o It may be caused by a rolling pullout, trapped fuel, or hung ordnance.
o Limitations
• The limit load factor due to pilot induced loads should be reduced
to approximately 2/3 of the normal limit load factor.

Front 12

Define gust loading.

Back 12

Gust Loading: The increase in G loads due to vertical wind gusts

Front 13

State what should be done not to exceed the limit load factor in moderate
turbulence.

Back 13

NATOPS states that the maximum airspeed for the T-34C in moderate turbulence
is 195 KIAS

Front 14

Define turn radius and turn rate.

Back 14

Turn Radius (r)
o Measure of the radius of the circle the flight path scribes
r = (V2/g·tan

Front 15

State the effect of velocity, angle of bank, weight, slipping, and skidding on turn rate and turn radius.

Back 15

If velocity is increased for a given angle of bank, turn rate will decrease, and turn
radius will increase.
• If angle of bank is increased for a given velocity, turn rate will increase, and turn
radius decreases.
• Turn rate and turn radius are independent of weight.
• In a skid, turn radius will decrease and turn rate will increase.
• In a slip, turn radius will increase and turn rate will decrease.

Front 16

Define standard rate turn.

Back 16

3° of turn per second.

Front 17

State the approximate angle of bank for a standard rate turn in the T-34C.

Back 17

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